id int64 0 190k | prompt stringlengths 21 13.4M | docstring stringlengths 1 12k ⌀ |
|---|---|---|
173,480 | from __future__ import annotations
from contextlib import contextmanager
from csv import (
QUOTE_NONE,
QUOTE_NONNUMERIC,
)
from decimal import Decimal
from functools import partial
from io import StringIO
import math
import re
from shutil import get_terminal_size
from typing import (
IO,
TYPE_CHECKING,
Any,
Callable,
Final,
Generator,
Hashable,
Iterable,
List,
Mapping,
Sequence,
cast,
)
from unicodedata import east_asian_width
import numpy as np
from pandas._config.config import (
get_option,
set_option,
)
from pandas._libs import lib
from pandas._libs.missing import NA
from pandas._libs.tslibs import (
NaT,
Timedelta,
Timestamp,
get_unit_from_dtype,
iNaT,
periods_per_day,
)
from pandas._libs.tslibs.nattype import NaTType
from pandas._typing import (
ArrayLike,
Axes,
ColspaceArgType,
ColspaceType,
CompressionOptions,
FilePath,
FloatFormatType,
FormattersType,
IndexLabel,
StorageOptions,
WriteBuffer,
)
from pandas.core.dtypes.common import (
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_extension_array_dtype,
is_float,
is_float_dtype,
is_integer,
is_integer_dtype,
is_list_like,
is_numeric_dtype,
is_scalar,
is_timedelta64_dtype,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import (
isna,
notna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
TimedeltaArray,
)
from pandas.core.arrays.string_ import StringDtype
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.construction import extract_array
from pandas.core.indexes.api import (
Index,
MultiIndex,
PeriodIndex,
ensure_index,
)
from pandas.core.indexes.datetimes import DatetimeIndex
from pandas.core.indexes.timedeltas import TimedeltaIndex
from pandas.core.reshape.concat import concat
from pandas.io.common import (
check_parent_directory,
stringify_path,
)
from pandas.io.formats import printing
Any = object()
The provided code snippet includes necessary dependencies for implementing the `get_level_lengths` function. Write a Python function `def get_level_lengths( levels: Any, sentinel: bool | object | str = "" ) -> list[dict[int, int]]` to solve the following problem:
For each index in each level the function returns lengths of indexes. Parameters ---------- levels : list of lists List of values on for level. sentinel : string, optional Value which states that no new index starts on there. Returns ------- Returns list of maps. For each level returns map of indexes (key is index in row and value is length of index).
Here is the function:
def get_level_lengths(
levels: Any, sentinel: bool | object | str = ""
) -> list[dict[int, int]]:
"""
For each index in each level the function returns lengths of indexes.
Parameters
----------
levels : list of lists
List of values on for level.
sentinel : string, optional
Value which states that no new index starts on there.
Returns
-------
Returns list of maps. For each level returns map of indexes (key is index
in row and value is length of index).
"""
if len(levels) == 0:
return []
control = [True] * len(levels[0])
result = []
for level in levels:
last_index = 0
lengths = {}
for i, key in enumerate(level):
if control[i] and key == sentinel:
pass
else:
control[i] = False
lengths[last_index] = i - last_index
last_index = i
lengths[last_index] = len(level) - last_index
result.append(lengths)
return result | For each index in each level the function returns lengths of indexes. Parameters ---------- levels : list of lists List of values on for level. sentinel : string, optional Value which states that no new index starts on there. Returns ------- Returns list of maps. For each level returns map of indexes (key is index in row and value is length of index). |
173,481 | from __future__ import annotations
from contextlib import contextmanager
from csv import (
QUOTE_NONE,
QUOTE_NONNUMERIC,
)
from decimal import Decimal
from functools import partial
from io import StringIO
import math
import re
from shutil import get_terminal_size
from typing import (
IO,
TYPE_CHECKING,
Any,
Callable,
Final,
Generator,
Hashable,
Iterable,
List,
Mapping,
Sequence,
cast,
)
from unicodedata import east_asian_width
import numpy as np
from pandas._config.config import (
get_option,
set_option,
)
from pandas._libs import lib
from pandas._libs.missing import NA
from pandas._libs.tslibs import (
NaT,
Timedelta,
Timestamp,
get_unit_from_dtype,
iNaT,
periods_per_day,
)
from pandas._libs.tslibs.nattype import NaTType
from pandas._typing import (
ArrayLike,
Axes,
ColspaceArgType,
ColspaceType,
CompressionOptions,
FilePath,
FloatFormatType,
FormattersType,
IndexLabel,
StorageOptions,
WriteBuffer,
)
from pandas.core.dtypes.common import (
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_extension_array_dtype,
is_float,
is_float_dtype,
is_integer,
is_integer_dtype,
is_list_like,
is_numeric_dtype,
is_scalar,
is_timedelta64_dtype,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import (
isna,
notna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
TimedeltaArray,
)
from pandas.core.arrays.string_ import StringDtype
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.construction import extract_array
from pandas.core.indexes.api import (
Index,
MultiIndex,
PeriodIndex,
ensure_index,
)
from pandas.core.indexes.datetimes import DatetimeIndex
from pandas.core.indexes.timedeltas import TimedeltaIndex
from pandas.core.reshape.concat import concat
from pandas.io.common import (
check_parent_directory,
stringify_path,
)
from pandas.io.formats import printing
class WriteBuffer(BaseBuffer, Protocol[AnyStr_contra]):
def write(self, __b: AnyStr_contra) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
def flush(self) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
The provided code snippet includes necessary dependencies for implementing the `buffer_put_lines` function. Write a Python function `def buffer_put_lines(buf: WriteBuffer[str], lines: list[str]) -> None` to solve the following problem:
Appends lines to a buffer. Parameters ---------- buf The buffer to write to lines The lines to append.
Here is the function:
def buffer_put_lines(buf: WriteBuffer[str], lines: list[str]) -> None:
"""
Appends lines to a buffer.
Parameters
----------
buf
The buffer to write to
lines
The lines to append.
"""
if any(isinstance(x, str) for x in lines):
lines = [str(x) for x in lines]
buf.write("\n".join(lines)) | Appends lines to a buffer. Parameters ---------- buf The buffer to write to lines The lines to append. |
173,482 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def _parse_date_columns(data_frame, parse_dates):
"""
Force non-datetime columns to be read as such.
Supports both string formatted and integer timestamp columns.
"""
parse_dates = _process_parse_dates_argument(parse_dates)
# we want to coerce datetime64_tz dtypes for now to UTC
# we could in theory do a 'nice' conversion from a FixedOffset tz
# GH11216
for col_name, df_col in data_frame.items():
if is_datetime64tz_dtype(df_col.dtype) or col_name in parse_dates:
try:
fmt = parse_dates[col_name]
except TypeError:
fmt = None
data_frame[col_name] = _handle_date_column(df_col, format=fmt)
return data_frame
def _convert_arrays_to_dataframe(
data,
columns,
coerce_float: bool = True,
dtype_backend: DtypeBackend | Literal["numpy"] = "numpy",
) -> DataFrame:
content = lib.to_object_array_tuples(data)
arrays = convert_object_array(
list(content.T),
dtype=None,
coerce_float=coerce_float,
dtype_backend=dtype_backend,
)
if dtype_backend == "pyarrow":
pa = import_optional_dependency("pyarrow")
arrays = [
ArrowExtensionArray(pa.array(arr, from_pandas=True)) for arr in arrays
]
if arrays:
return DataFrame(dict(zip(columns, arrays)))
else:
return DataFrame(columns=columns)
Literal: _SpecialForm = ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
The provided code snippet includes necessary dependencies for implementing the `_wrap_result` function. Write a Python function `def _wrap_result( data, columns, index_col=None, coerce_float: bool = True, parse_dates=None, dtype: DtypeArg | None = None, dtype_backend: DtypeBackend | Literal["numpy"] = "numpy", )` to solve the following problem:
Wrap result set of query in a DataFrame.
Here is the function:
def _wrap_result(
data,
columns,
index_col=None,
coerce_float: bool = True,
parse_dates=None,
dtype: DtypeArg | None = None,
dtype_backend: DtypeBackend | Literal["numpy"] = "numpy",
):
"""Wrap result set of query in a DataFrame."""
frame = _convert_arrays_to_dataframe(data, columns, coerce_float, dtype_backend)
if dtype:
frame = frame.astype(dtype)
frame = _parse_date_columns(frame, parse_dates)
if index_col is not None:
frame = frame.set_index(index_col)
return frame | Wrap result set of query in a DataFrame. |
173,483 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def pandasSQL_builder(
con,
schema: str | None = None,
need_transaction: bool = False,
) -> PandasSQL:
"""
Convenience function to return the correct PandasSQL subclass based on the
provided parameters. Also creates a sqlalchemy connection and transaction
if necessary.
"""
import sqlite3
if isinstance(con, sqlite3.Connection) or con is None:
return SQLiteDatabase(con)
sqlalchemy = import_optional_dependency("sqlalchemy", errors="ignore")
if isinstance(con, str) and sqlalchemy is None:
raise ImportError("Using URI string without sqlalchemy installed.")
if sqlalchemy is not None and isinstance(con, (str, sqlalchemy.engine.Connectable)):
return SQLDatabase(con, schema, need_transaction)
warnings.warn(
"pandas only supports SQLAlchemy connectable (engine/connection) or "
"database string URI or sqlite3 DBAPI2 connection. Other DBAPI2 "
"objects are not tested. Please consider using SQLAlchemy.",
UserWarning,
stacklevel=find_stack_level(),
)
return SQLiteDatabase(con)
def import_optional_dependency(
name: str,
extra: str = "",
errors: str = "raise",
min_version: str | None = None,
):
"""
Import an optional dependency.
By default, if a dependency is missing an ImportError with a nice
message will be raised. If a dependency is present, but too old,
we raise.
Parameters
----------
name : str
The module name.
extra : str
Additional text to include in the ImportError message.
errors : str {'raise', 'warn', 'ignore'}
What to do when a dependency is not found or its version is too old.
* raise : Raise an ImportError
* warn : Only applicable when a module's version is to old.
Warns that the version is too old and returns None
* ignore: If the module is not installed, return None, otherwise,
return the module, even if the version is too old.
It's expected that users validate the version locally when
using ``errors="ignore"`` (see. ``io/html.py``)
min_version : str, default None
Specify a minimum version that is different from the global pandas
minimum version required.
Returns
-------
maybe_module : Optional[ModuleType]
The imported module, when found and the version is correct.
None is returned when the package is not found and `errors`
is False, or when the package's version is too old and `errors`
is ``'warn'``.
"""
assert errors in {"warn", "raise", "ignore"}
package_name = INSTALL_MAPPING.get(name)
install_name = package_name if package_name is not None else name
msg = (
f"Missing optional dependency '{install_name}'. {extra} "
f"Use pip or conda to install {install_name}."
)
try:
module = importlib.import_module(name)
except ImportError:
if errors == "raise":
raise ImportError(msg)
return None
# Handle submodules: if we have submodule, grab parent module from sys.modules
parent = name.split(".")[0]
if parent != name:
install_name = parent
module_to_get = sys.modules[install_name]
else:
module_to_get = module
minimum_version = min_version if min_version is not None else VERSIONS.get(parent)
if minimum_version:
version = get_version(module_to_get)
if version and Version(version) < Version(minimum_version):
msg = (
f"Pandas requires version '{minimum_version}' or newer of '{parent}' "
f"(version '{version}' currently installed)."
)
if errors == "warn":
warnings.warn(
msg,
UserWarning,
stacklevel=find_stack_level(),
)
return None
elif errors == "raise":
raise ImportError(msg)
return module
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
The provided code snippet includes necessary dependencies for implementing the `execute` function. Write a Python function `def execute(sql, con, params=None)` to solve the following problem:
Execute the given SQL query using the provided connection object. Parameters ---------- sql : string SQL query to be executed. con : SQLAlchemy connection or sqlite3 connection If a DBAPI2 object, only sqlite3 is supported. params : list or tuple, optional, default: None List of parameters to pass to execute method. Returns ------- Results Iterable
Here is the function:
def execute(sql, con, params=None):
"""
Execute the given SQL query using the provided connection object.
Parameters
----------
sql : string
SQL query to be executed.
con : SQLAlchemy connection or sqlite3 connection
If a DBAPI2 object, only sqlite3 is supported.
params : list or tuple, optional, default: None
List of parameters to pass to execute method.
Returns
-------
Results Iterable
"""
warnings.warn(
"`pandas.io.sql.execute` is deprecated and "
"will be removed in the future version.",
FutureWarning,
stacklevel=find_stack_level(),
) # GH50185
sqlalchemy = import_optional_dependency("sqlalchemy", errors="ignore")
if sqlalchemy is not None and isinstance(con, (str, sqlalchemy.engine.Engine)):
raise TypeError("pandas.io.sql.execute requires a connection") # GH50185
with pandasSQL_builder(con, need_transaction=True) as pandas_sql:
return pandas_sql.execute(sql, params) | Execute the given SQL query using the provided connection object. Parameters ---------- sql : string SQL query to be executed. con : SQLAlchemy connection or sqlite3 connection If a DBAPI2 object, only sqlite3 is supported. params : list or tuple, optional, default: None List of parameters to pass to execute method. Returns ------- Results Iterable |
173,484 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_sql_table(
table_name,
con,
schema=...,
index_col: str | list[str] | None = ...,
coerce_float=...,
parse_dates: list[str] | dict[str, str] | None = ...,
columns: list[str] | None = ...,
chunksize: None = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
) -> DataFrame:
... | null |
173,485 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
class Iterator(Iterable[_T_co], Protocol[_T_co]):
def __next__(self) -> _T_co:
def __iter__(self) -> Iterator[_T_co]:
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_sql_table(
table_name,
con,
schema=...,
index_col: str | list[str] | None = ...,
coerce_float=...,
parse_dates: list[str] | dict[str, str] | None = ...,
columns: list[str] | None = ...,
chunksize: int = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
) -> Iterator[DataFrame]:
... | null |
173,486 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def has_table(table_name: str, con, schema: str | None = None) -> bool:
"""
Check if DataBase has named table.
Parameters
----------
table_name: string
Name of SQL table.
con: SQLAlchemy connectable(engine/connection) or sqlite3 DBAPI2 connection
Using SQLAlchemy makes it possible to use any DB supported by that
library.
If a DBAPI2 object, only sqlite3 is supported.
schema : string, default None
Name of SQL schema in database to write to (if database flavor supports
this). If None, use default schema (default).
Returns
-------
boolean
"""
with pandasSQL_builder(con, schema=schema) as pandas_sql:
return pandas_sql.has_table(table_name)
def pandasSQL_builder(
con,
schema: str | None = None,
need_transaction: bool = False,
) -> PandasSQL:
"""
Convenience function to return the correct PandasSQL subclass based on the
provided parameters. Also creates a sqlalchemy connection and transaction
if necessary.
"""
import sqlite3
if isinstance(con, sqlite3.Connection) or con is None:
return SQLiteDatabase(con)
sqlalchemy = import_optional_dependency("sqlalchemy", errors="ignore")
if isinstance(con, str) and sqlalchemy is None:
raise ImportError("Using URI string without sqlalchemy installed.")
if sqlalchemy is not None and isinstance(con, (str, sqlalchemy.engine.Connectable)):
return SQLDatabase(con, schema, need_transaction)
warnings.warn(
"pandas only supports SQLAlchemy connectable (engine/connection) or "
"database string URI or sqlite3 DBAPI2 connection. Other DBAPI2 "
"objects are not tested. Please consider using SQLAlchemy.",
UserWarning,
stacklevel=find_stack_level(),
)
return SQLiteDatabase(con)
class Iterator(Iterable[_T_co], Protocol[_T_co]):
def __next__(self) -> _T_co: ...
def __iter__(self) -> Iterator[_T_co]: ...
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
The provided code snippet includes necessary dependencies for implementing the `read_sql_table` function. Write a Python function `def read_sql_table( table_name: str, con, schema: str | None = None, index_col: str | list[str] | None = None, coerce_float: bool = True, parse_dates: list[str] | dict[str, str] | None = None, columns: list[str] | None = None, chunksize: int | None = None, dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, ) -> DataFrame | Iterator[DataFrame]` to solve the following problem:
Read SQL database table into a DataFrame. Given a table name and a SQLAlchemy connectable, returns a DataFrame. This function does not support DBAPI connections. Parameters ---------- table_name : str Name of SQL table in database. con : SQLAlchemy connectable or str A database URI could be provided as str. SQLite DBAPI connection mode not supported. schema : str, default None Name of SQL schema in database to query (if database flavor supports this). Uses default schema if None (default). index_col : str or list of str, optional, default: None Column(s) to set as index(MultiIndex). coerce_float : bool, default True Attempts to convert values of non-string, non-numeric objects (like decimal.Decimal) to floating point. Can result in loss of Precision. parse_dates : list or dict, default None - List of column names to parse as dates. - Dict of ``{column_name: format string}`` where format string is strftime compatible in case of parsing string times or is one of (D, s, ns, ms, us) in case of parsing integer timestamps. - Dict of ``{column_name: arg dict}``, where the arg dict corresponds to the keyword arguments of :func:`pandas.to_datetime` Especially useful with databases without native Datetime support, such as SQLite. columns : list, default None List of column names to select from SQL table. chunksize : int, default None If specified, returns an iterator where `chunksize` is the number of rows to include in each chunk. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 Returns ------- DataFrame or Iterator[DataFrame] A SQL table is returned as two-dimensional data structure with labeled axes. See Also -------- read_sql_query : Read SQL query into a DataFrame. read_sql : Read SQL query or database table into a DataFrame. Notes ----- Any datetime values with time zone information will be converted to UTC. Examples -------- >>> pd.read_sql_table('table_name', 'postgres:///db_name') # doctest:+SKIP
Here is the function:
def read_sql_table(
table_name: str,
con,
schema: str | None = None,
index_col: str | list[str] | None = None,
coerce_float: bool = True,
parse_dates: list[str] | dict[str, str] | None = None,
columns: list[str] | None = None,
chunksize: int | None = None,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
) -> DataFrame | Iterator[DataFrame]:
"""
Read SQL database table into a DataFrame.
Given a table name and a SQLAlchemy connectable, returns a DataFrame.
This function does not support DBAPI connections.
Parameters
----------
table_name : str
Name of SQL table in database.
con : SQLAlchemy connectable or str
A database URI could be provided as str.
SQLite DBAPI connection mode not supported.
schema : str, default None
Name of SQL schema in database to query (if database flavor
supports this). Uses default schema if None (default).
index_col : str or list of str, optional, default: None
Column(s) to set as index(MultiIndex).
coerce_float : bool, default True
Attempts to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point. Can result in loss of Precision.
parse_dates : list or dict, default None
- List of column names to parse as dates.
- Dict of ``{column_name: format string}`` where format string is
strftime compatible in case of parsing string times or is one of
(D, s, ns, ms, us) in case of parsing integer timestamps.
- Dict of ``{column_name: arg dict}``, where the arg dict corresponds
to the keyword arguments of :func:`pandas.to_datetime`
Especially useful with databases without native Datetime support,
such as SQLite.
columns : list, default None
List of column names to select from SQL table.
chunksize : int, default None
If specified, returns an iterator where `chunksize` is the number of
rows to include in each chunk.
dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames
Which dtype_backend to use, e.g. whether a DataFrame should have NumPy
arrays, nullable dtypes are used for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
Returns
-------
DataFrame or Iterator[DataFrame]
A SQL table is returned as two-dimensional data structure with labeled
axes.
See Also
--------
read_sql_query : Read SQL query into a DataFrame.
read_sql : Read SQL query or database table into a DataFrame.
Notes
-----
Any datetime values with time zone information will be converted to UTC.
Examples
--------
>>> pd.read_sql_table('table_name', 'postgres:///db_name') # doctest:+SKIP
"""
check_dtype_backend(dtype_backend)
if dtype_backend is lib.no_default:
dtype_backend = "numpy" # type: ignore[assignment]
with pandasSQL_builder(con, schema=schema, need_transaction=True) as pandas_sql:
if not pandas_sql.has_table(table_name):
raise ValueError(f"Table {table_name} not found")
table = pandas_sql.read_table(
table_name,
index_col=index_col,
coerce_float=coerce_float,
parse_dates=parse_dates,
columns=columns,
chunksize=chunksize,
dtype_backend=dtype_backend,
)
if table is not None:
return table
else:
raise ValueError(f"Table {table_name} not found", con) | Read SQL database table into a DataFrame. Given a table name and a SQLAlchemy connectable, returns a DataFrame. This function does not support DBAPI connections. Parameters ---------- table_name : str Name of SQL table in database. con : SQLAlchemy connectable or str A database URI could be provided as str. SQLite DBAPI connection mode not supported. schema : str, default None Name of SQL schema in database to query (if database flavor supports this). Uses default schema if None (default). index_col : str or list of str, optional, default: None Column(s) to set as index(MultiIndex). coerce_float : bool, default True Attempts to convert values of non-string, non-numeric objects (like decimal.Decimal) to floating point. Can result in loss of Precision. parse_dates : list or dict, default None - List of column names to parse as dates. - Dict of ``{column_name: format string}`` where format string is strftime compatible in case of parsing string times or is one of (D, s, ns, ms, us) in case of parsing integer timestamps. - Dict of ``{column_name: arg dict}``, where the arg dict corresponds to the keyword arguments of :func:`pandas.to_datetime` Especially useful with databases without native Datetime support, such as SQLite. columns : list, default None List of column names to select from SQL table. chunksize : int, default None If specified, returns an iterator where `chunksize` is the number of rows to include in each chunk. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 Returns ------- DataFrame or Iterator[DataFrame] A SQL table is returned as two-dimensional data structure with labeled axes. See Also -------- read_sql_query : Read SQL query into a DataFrame. read_sql : Read SQL query or database table into a DataFrame. Notes ----- Any datetime values with time zone information will be converted to UTC. Examples -------- >>> pd.read_sql_table('table_name', 'postgres:///db_name') # doctest:+SKIP |
173,487 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_sql_query(
sql,
con,
index_col: str | list[str] | None = ...,
coerce_float=...,
params: list[str] | dict[str, str] | None = ...,
parse_dates: list[str] | dict[str, str] | None = ...,
chunksize: None = ...,
dtype: DtypeArg | None = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
) -> DataFrame:
... | null |
173,488 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
class Iterator(Iterable[_T_co], Protocol[_T_co]):
def __next__(self) -> _T_co: ...
def __iter__(self) -> Iterator[_T_co]: ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_sql_query(
sql,
con,
index_col: str | list[str] | None = ...,
coerce_float=...,
params: list[str] | dict[str, str] | None = ...,
parse_dates: list[str] | dict[str, str] | None = ...,
chunksize: int = ...,
dtype: DtypeArg | None = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
) -> Iterator[DataFrame]:
... | null |
173,489 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def pandasSQL_builder(
con,
schema: str | None = None,
need_transaction: bool = False,
) -> PandasSQL:
"""
Convenience function to return the correct PandasSQL subclass based on the
provided parameters. Also creates a sqlalchemy connection and transaction
if necessary.
"""
import sqlite3
if isinstance(con, sqlite3.Connection) or con is None:
return SQLiteDatabase(con)
sqlalchemy = import_optional_dependency("sqlalchemy", errors="ignore")
if isinstance(con, str) and sqlalchemy is None:
raise ImportError("Using URI string without sqlalchemy installed.")
if sqlalchemy is not None and isinstance(con, (str, sqlalchemy.engine.Connectable)):
return SQLDatabase(con, schema, need_transaction)
warnings.warn(
"pandas only supports SQLAlchemy connectable (engine/connection) or "
"database string URI or sqlite3 DBAPI2 connection. Other DBAPI2 "
"objects are not tested. Please consider using SQLAlchemy.",
UserWarning,
stacklevel=find_stack_level(),
)
return SQLiteDatabase(con)
class Iterator(Iterable[_T_co], Protocol[_T_co]):
def __next__(self) -> _T_co: ...
def __iter__(self) -> Iterator[_T_co]: ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
The provided code snippet includes necessary dependencies for implementing the `read_sql_query` function. Write a Python function `def read_sql_query( sql, con, index_col: str | list[str] | None = None, coerce_float: bool = True, params: list[str] | dict[str, str] | None = None, parse_dates: list[str] | dict[str, str] | None = None, chunksize: int | None = None, dtype: DtypeArg | None = None, dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, ) -> DataFrame | Iterator[DataFrame]` to solve the following problem:
Read SQL query into a DataFrame. Returns a DataFrame corresponding to the result set of the query string. Optionally provide an `index_col` parameter to use one of the columns as the index, otherwise default integer index will be used. Parameters ---------- sql : str SQL query or SQLAlchemy Selectable (select or text object) SQL query to be executed. con : SQLAlchemy connectable, str, or sqlite3 connection Using SQLAlchemy makes it possible to use any DB supported by that library. If a DBAPI2 object, only sqlite3 is supported. index_col : str or list of str, optional, default: None Column(s) to set as index(MultiIndex). coerce_float : bool, default True Attempts to convert values of non-string, non-numeric objects (like decimal.Decimal) to floating point. Useful for SQL result sets. params : list, tuple or dict, optional, default: None List of parameters to pass to execute method. The syntax used to pass parameters is database driver dependent. Check your database driver documentation for which of the five syntax styles, described in PEP 249's paramstyle, is supported. Eg. for psycopg2, uses %(name)s so use params={'name' : 'value'}. parse_dates : list or dict, default: None - List of column names to parse as dates. - Dict of ``{column_name: format string}`` where format string is strftime compatible in case of parsing string times, or is one of (D, s, ns, ms, us) in case of parsing integer timestamps. - Dict of ``{column_name: arg dict}``, where the arg dict corresponds to the keyword arguments of :func:`pandas.to_datetime` Especially useful with databases without native Datetime support, such as SQLite. chunksize : int, default None If specified, return an iterator where `chunksize` is the number of rows to include in each chunk. dtype : Type name or dict of columns Data type for data or columns. E.g. np.float64 or {‘a’: np.float64, ‘b’: np.int32, ‘c’: ‘Int64’}. .. versionadded:: 1.3.0 dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 Returns ------- DataFrame or Iterator[DataFrame] See Also -------- read_sql_table : Read SQL database table into a DataFrame. read_sql : Read SQL query or database table into a DataFrame. Notes ----- Any datetime values with time zone information parsed via the `parse_dates` parameter will be converted to UTC.
Here is the function:
def read_sql_query(
sql,
con,
index_col: str | list[str] | None = None,
coerce_float: bool = True,
params: list[str] | dict[str, str] | None = None,
parse_dates: list[str] | dict[str, str] | None = None,
chunksize: int | None = None,
dtype: DtypeArg | None = None,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
) -> DataFrame | Iterator[DataFrame]:
"""
Read SQL query into a DataFrame.
Returns a DataFrame corresponding to the result set of the query
string. Optionally provide an `index_col` parameter to use one of the
columns as the index, otherwise default integer index will be used.
Parameters
----------
sql : str SQL query or SQLAlchemy Selectable (select or text object)
SQL query to be executed.
con : SQLAlchemy connectable, str, or sqlite3 connection
Using SQLAlchemy makes it possible to use any DB supported by that
library. If a DBAPI2 object, only sqlite3 is supported.
index_col : str or list of str, optional, default: None
Column(s) to set as index(MultiIndex).
coerce_float : bool, default True
Attempts to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point. Useful for SQL result sets.
params : list, tuple or dict, optional, default: None
List of parameters to pass to execute method. The syntax used
to pass parameters is database driver dependent. Check your
database driver documentation for which of the five syntax styles,
described in PEP 249's paramstyle, is supported.
Eg. for psycopg2, uses %(name)s so use params={'name' : 'value'}.
parse_dates : list or dict, default: None
- List of column names to parse as dates.
- Dict of ``{column_name: format string}`` where format string is
strftime compatible in case of parsing string times, or is one of
(D, s, ns, ms, us) in case of parsing integer timestamps.
- Dict of ``{column_name: arg dict}``, where the arg dict corresponds
to the keyword arguments of :func:`pandas.to_datetime`
Especially useful with databases without native Datetime support,
such as SQLite.
chunksize : int, default None
If specified, return an iterator where `chunksize` is the number of
rows to include in each chunk.
dtype : Type name or dict of columns
Data type for data or columns. E.g. np.float64 or
{‘a’: np.float64, ‘b’: np.int32, ‘c’: ‘Int64’}.
.. versionadded:: 1.3.0
dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames
Which dtype_backend to use, e.g. whether a DataFrame should have NumPy
arrays, nullable dtypes are used for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
Returns
-------
DataFrame or Iterator[DataFrame]
See Also
--------
read_sql_table : Read SQL database table into a DataFrame.
read_sql : Read SQL query or database table into a DataFrame.
Notes
-----
Any datetime values with time zone information parsed via the `parse_dates`
parameter will be converted to UTC.
"""
check_dtype_backend(dtype_backend)
if dtype_backend is lib.no_default:
dtype_backend = "numpy" # type: ignore[assignment]
with pandasSQL_builder(con) as pandas_sql:
return pandas_sql.read_query(
sql,
index_col=index_col,
params=params,
coerce_float=coerce_float,
parse_dates=parse_dates,
chunksize=chunksize,
dtype=dtype,
dtype_backend=dtype_backend,
) | Read SQL query into a DataFrame. Returns a DataFrame corresponding to the result set of the query string. Optionally provide an `index_col` parameter to use one of the columns as the index, otherwise default integer index will be used. Parameters ---------- sql : str SQL query or SQLAlchemy Selectable (select or text object) SQL query to be executed. con : SQLAlchemy connectable, str, or sqlite3 connection Using SQLAlchemy makes it possible to use any DB supported by that library. If a DBAPI2 object, only sqlite3 is supported. index_col : str or list of str, optional, default: None Column(s) to set as index(MultiIndex). coerce_float : bool, default True Attempts to convert values of non-string, non-numeric objects (like decimal.Decimal) to floating point. Useful for SQL result sets. params : list, tuple or dict, optional, default: None List of parameters to pass to execute method. The syntax used to pass parameters is database driver dependent. Check your database driver documentation for which of the five syntax styles, described in PEP 249's paramstyle, is supported. Eg. for psycopg2, uses %(name)s so use params={'name' : 'value'}. parse_dates : list or dict, default: None - List of column names to parse as dates. - Dict of ``{column_name: format string}`` where format string is strftime compatible in case of parsing string times, or is one of (D, s, ns, ms, us) in case of parsing integer timestamps. - Dict of ``{column_name: arg dict}``, where the arg dict corresponds to the keyword arguments of :func:`pandas.to_datetime` Especially useful with databases without native Datetime support, such as SQLite. chunksize : int, default None If specified, return an iterator where `chunksize` is the number of rows to include in each chunk. dtype : Type name or dict of columns Data type for data or columns. E.g. np.float64 or {‘a’: np.float64, ‘b’: np.int32, ‘c’: ‘Int64’}. .. versionadded:: 1.3.0 dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 Returns ------- DataFrame or Iterator[DataFrame] See Also -------- read_sql_table : Read SQL database table into a DataFrame. read_sql : Read SQL query or database table into a DataFrame. Notes ----- Any datetime values with time zone information parsed via the `parse_dates` parameter will be converted to UTC. |
173,490 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_sql(
sql,
con,
index_col: str | list[str] | None = ...,
coerce_float=...,
params=...,
parse_dates=...,
columns: list[str] = ...,
chunksize: None = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
dtype: DtypeArg | None = None,
) -> DataFrame:
... | null |
173,491 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
class Iterator(Iterable[_T_co], Protocol[_T_co]):
def __next__(self) -> _T_co: ...
def __iter__(self) -> Iterator[_T_co]: ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_sql(
sql,
con,
index_col: str | list[str] | None = ...,
coerce_float=...,
params=...,
parse_dates=...,
columns: list[str] = ...,
chunksize: int = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
dtype: DtypeArg | None = None,
) -> Iterator[DataFrame]:
... | null |
173,492 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def has_table(table_name: str, con, schema: str | None = None) -> bool:
"""
Check if DataBase has named table.
Parameters
----------
table_name: string
Name of SQL table.
con: SQLAlchemy connectable(engine/connection) or sqlite3 DBAPI2 connection
Using SQLAlchemy makes it possible to use any DB supported by that
library.
If a DBAPI2 object, only sqlite3 is supported.
schema : string, default None
Name of SQL schema in database to write to (if database flavor supports
this). If None, use default schema (default).
Returns
-------
boolean
"""
with pandasSQL_builder(con, schema=schema) as pandas_sql:
return pandas_sql.has_table(table_name)
def pandasSQL_builder(
con,
schema: str | None = None,
need_transaction: bool = False,
) -> PandasSQL:
"""
Convenience function to return the correct PandasSQL subclass based on the
provided parameters. Also creates a sqlalchemy connection and transaction
if necessary.
"""
import sqlite3
if isinstance(con, sqlite3.Connection) or con is None:
return SQLiteDatabase(con)
sqlalchemy = import_optional_dependency("sqlalchemy", errors="ignore")
if isinstance(con, str) and sqlalchemy is None:
raise ImportError("Using URI string without sqlalchemy installed.")
if sqlalchemy is not None and isinstance(con, (str, sqlalchemy.engine.Connectable)):
return SQLDatabase(con, schema, need_transaction)
warnings.warn(
"pandas only supports SQLAlchemy connectable (engine/connection) or "
"database string URI or sqlite3 DBAPI2 connection. Other DBAPI2 "
"objects are not tested. Please consider using SQLAlchemy.",
UserWarning,
stacklevel=find_stack_level(),
)
return SQLiteDatabase(con)
class SQLiteDatabase(PandasSQL):
"""
Version of SQLDatabase to support SQLite connections (fallback without
SQLAlchemy). This should only be used internally.
Parameters
----------
con : sqlite connection object
"""
def __init__(self, con) -> None:
self.con = con
def run_transaction(self):
cur = self.con.cursor()
try:
yield cur
self.con.commit()
except Exception:
self.con.rollback()
raise
finally:
cur.close()
def execute(self, sql: str | Select | TextClause, params=None):
if not isinstance(sql, str):
raise TypeError("Query must be a string unless using sqlalchemy.")
args = [] if params is None else [params]
cur = self.con.cursor()
try:
cur.execute(sql, *args)
return cur
except Exception as exc:
try:
self.con.rollback()
except Exception as inner_exc: # pragma: no cover
ex = DatabaseError(
f"Execution failed on sql: {sql}\n{exc}\nunable to rollback"
)
raise ex from inner_exc
ex = DatabaseError(f"Execution failed on sql '{sql}': {exc}")
raise ex from exc
def _query_iterator(
cursor,
chunksize: int,
columns,
index_col=None,
coerce_float: bool = True,
parse_dates=None,
dtype: DtypeArg | None = None,
dtype_backend: DtypeBackend | Literal["numpy"] = "numpy",
):
"""Return generator through chunked result set"""
has_read_data = False
while True:
data = cursor.fetchmany(chunksize)
if type(data) == tuple:
data = list(data)
if not data:
cursor.close()
if not has_read_data:
result = DataFrame.from_records(
[], columns=columns, coerce_float=coerce_float
)
if dtype:
result = result.astype(dtype)
yield result
break
has_read_data = True
yield _wrap_result(
data,
columns,
index_col=index_col,
coerce_float=coerce_float,
parse_dates=parse_dates,
dtype=dtype,
dtype_backend=dtype_backend,
)
def read_query(
self,
sql,
index_col=None,
coerce_float: bool = True,
parse_dates=None,
params=None,
chunksize: int | None = None,
dtype: DtypeArg | None = None,
dtype_backend: DtypeBackend | Literal["numpy"] = "numpy",
) -> DataFrame | Iterator[DataFrame]:
cursor = self.execute(sql, params)
columns = [col_desc[0] for col_desc in cursor.description]
if chunksize is not None:
return self._query_iterator(
cursor,
chunksize,
columns,
index_col=index_col,
coerce_float=coerce_float,
parse_dates=parse_dates,
dtype=dtype,
dtype_backend=dtype_backend,
)
else:
data = self._fetchall_as_list(cursor)
cursor.close()
frame = _wrap_result(
data,
columns,
index_col=index_col,
coerce_float=coerce_float,
parse_dates=parse_dates,
dtype=dtype,
dtype_backend=dtype_backend,
)
return frame
def _fetchall_as_list(self, cur):
result = cur.fetchall()
if not isinstance(result, list):
result = list(result)
return result
def to_sql(
self,
frame,
name,
if_exists: str = "fail",
index: bool = True,
index_label=None,
schema=None,
chunksize=None,
dtype: DtypeArg | None = None,
method=None,
engine: str = "auto",
**engine_kwargs,
) -> int | None:
"""
Write records stored in a DataFrame to a SQL database.
Parameters
----------
frame: DataFrame
name: string
Name of SQL table.
if_exists: {'fail', 'replace', 'append'}, default 'fail'
fail: If table exists, do nothing.
replace: If table exists, drop it, recreate it, and insert data.
append: If table exists, insert data. Create if it does not exist.
index : bool, default True
Write DataFrame index as a column
index_label : string or sequence, default None
Column label for index column(s). If None is given (default) and
`index` is True, then the index names are used.
A sequence should be given if the DataFrame uses MultiIndex.
schema : string, default None
Ignored parameter included for compatibility with SQLAlchemy
version of ``to_sql``.
chunksize : int, default None
If not None, then rows will be written in batches of this
size at a time. If None, all rows will be written at once.
dtype : single type or dict of column name to SQL type, default None
Optional specifying the datatype for columns. The SQL type should
be a string. If all columns are of the same type, one single value
can be used.
method : {None, 'multi', callable}, default None
Controls the SQL insertion clause used:
* None : Uses standard SQL ``INSERT`` clause (one per row).
* 'multi': Pass multiple values in a single ``INSERT`` clause.
* callable with signature ``(pd_table, conn, keys, data_iter)``.
Details and a sample callable implementation can be found in the
section :ref:`insert method <io.sql.method>`.
"""
if dtype:
if not is_dict_like(dtype):
# error: Value expression in dictionary comprehension has incompatible
# type "Union[ExtensionDtype, str, dtype[Any], Type[object],
# Dict[Hashable, Union[ExtensionDtype, Union[str, dtype[Any]],
# Type[str], Type[float], Type[int], Type[complex], Type[bool],
# Type[object]]]]"; expected type "Union[ExtensionDtype, str,
# dtype[Any], Type[object]]"
dtype = {col_name: dtype for col_name in frame} # type: ignore[misc]
else:
dtype = cast(dict, dtype)
for col, my_type in dtype.items():
if not isinstance(my_type, str):
raise ValueError(f"{col} ({my_type}) not a string")
table = SQLiteTable(
name,
self,
frame=frame,
index=index,
if_exists=if_exists,
index_label=index_label,
dtype=dtype,
)
table.create()
return table.insert(chunksize, method)
def has_table(self, name: str, schema: str | None = None) -> bool:
wld = "?"
query = f"SELECT name FROM sqlite_master WHERE type='table' AND name={wld};"
return len(self.execute(query, [name]).fetchall()) > 0
def get_table(self, table_name: str, schema: str | None = None) -> None:
return None # not supported in fallback mode
def drop_table(self, name: str, schema: str | None = None) -> None:
drop_sql = f"DROP TABLE {_get_valid_sqlite_name(name)}"
self.execute(drop_sql)
def _create_sql_schema(
self,
frame,
table_name: str,
keys=None,
dtype: DtypeArg | None = None,
schema: str | None = None,
):
table = SQLiteTable(
table_name,
self,
frame=frame,
index=False,
keys=keys,
dtype=dtype,
schema=schema,
)
return str(table.sql_schema())
class Iterator(Iterable[_T_co], Protocol[_T_co]):
def __next__(self) -> _T_co: ...
def __iter__(self) -> Iterator[_T_co]: ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
The provided code snippet includes necessary dependencies for implementing the `read_sql` function. Write a Python function `def read_sql( sql, con, index_col: str | list[str] | None = None, coerce_float: bool = True, params=None, parse_dates=None, columns: list[str] | None = None, chunksize: int | None = None, dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, dtype: DtypeArg | None = None, ) -> DataFrame | Iterator[DataFrame]` to solve the following problem:
Read SQL query or database table into a DataFrame. This function is a convenience wrapper around ``read_sql_table`` and ``read_sql_query`` (for backward compatibility). It will delegate to the specific function depending on the provided input. A SQL query will be routed to ``read_sql_query``, while a database table name will be routed to ``read_sql_table``. Note that the delegated function might have more specific notes about their functionality not listed here. Parameters ---------- sql : str or SQLAlchemy Selectable (select or text object) SQL query to be executed or a table name. con : SQLAlchemy connectable, str, or sqlite3 connection Using SQLAlchemy makes it possible to use any DB supported by that library. If a DBAPI2 object, only sqlite3 is supported. The user is responsible for engine disposal and connection closure for the SQLAlchemy connectable; str connections are closed automatically. See `here <https://docs.sqlalchemy.org/en/13/core/connections.html>`_. index_col : str or list of str, optional, default: None Column(s) to set as index(MultiIndex). coerce_float : bool, default True Attempts to convert values of non-string, non-numeric objects (like decimal.Decimal) to floating point, useful for SQL result sets. params : list, tuple or dict, optional, default: None List of parameters to pass to execute method. The syntax used to pass parameters is database driver dependent. Check your database driver documentation for which of the five syntax styles, described in PEP 249's paramstyle, is supported. Eg. for psycopg2, uses %(name)s so use params={'name' : 'value'}. parse_dates : list or dict, default: None - List of column names to parse as dates. - Dict of ``{column_name: format string}`` where format string is strftime compatible in case of parsing string times, or is one of (D, s, ns, ms, us) in case of parsing integer timestamps. - Dict of ``{column_name: arg dict}``, where the arg dict corresponds to the keyword arguments of :func:`pandas.to_datetime` Especially useful with databases without native Datetime support, such as SQLite. columns : list, default: None List of column names to select from SQL table (only used when reading a table). chunksize : int, default None If specified, return an iterator where `chunksize` is the number of rows to include in each chunk. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 dtype : Type name or dict of columns Data type for data or columns. E.g. np.float64 or {‘a’: np.float64, ‘b’: np.int32, ‘c’: ‘Int64’}. The argument is ignored if a table is passed instead of a query. .. versionadded:: 2.0.0 Returns ------- DataFrame or Iterator[DataFrame] See Also -------- read_sql_table : Read SQL database table into a DataFrame. read_sql_query : Read SQL query into a DataFrame. Examples -------- Read data from SQL via either a SQL query or a SQL tablename. When using a SQLite database only SQL queries are accepted, providing only the SQL tablename will result in an error. >>> from sqlite3 import connect >>> conn = connect(':memory:') >>> df = pd.DataFrame(data=[[0, '10/11/12'], [1, '12/11/10']], ... columns=['int_column', 'date_column']) >>> df.to_sql('test_data', conn) 2 >>> pd.read_sql('SELECT int_column, date_column FROM test_data', conn) int_column date_column 0 0 10/11/12 1 1 12/11/10 >>> pd.read_sql('test_data', 'postgres:///db_name') # doctest:+SKIP Apply date parsing to columns through the ``parse_dates`` argument The ``parse_dates`` argument calls ``pd.to_datetime`` on the provided columns. Custom argument values for applying ``pd.to_datetime`` on a column are specified via a dictionary format: >>> pd.read_sql('SELECT int_column, date_column FROM test_data', ... conn, ... parse_dates={"date_column": {"format": "%d/%m/%y"}}) int_column date_column 0 0 2012-11-10 1 1 2010-11-12
Here is the function:
def read_sql(
sql,
con,
index_col: str | list[str] | None = None,
coerce_float: bool = True,
params=None,
parse_dates=None,
columns: list[str] | None = None,
chunksize: int | None = None,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
dtype: DtypeArg | None = None,
) -> DataFrame | Iterator[DataFrame]:
"""
Read SQL query or database table into a DataFrame.
This function is a convenience wrapper around ``read_sql_table`` and
``read_sql_query`` (for backward compatibility). It will delegate
to the specific function depending on the provided input. A SQL query
will be routed to ``read_sql_query``, while a database table name will
be routed to ``read_sql_table``. Note that the delegated function might
have more specific notes about their functionality not listed here.
Parameters
----------
sql : str or SQLAlchemy Selectable (select or text object)
SQL query to be executed or a table name.
con : SQLAlchemy connectable, str, or sqlite3 connection
Using SQLAlchemy makes it possible to use any DB supported by that
library. If a DBAPI2 object, only sqlite3 is supported. The user is responsible
for engine disposal and connection closure for the SQLAlchemy connectable; str
connections are closed automatically. See
`here <https://docs.sqlalchemy.org/en/13/core/connections.html>`_.
index_col : str or list of str, optional, default: None
Column(s) to set as index(MultiIndex).
coerce_float : bool, default True
Attempts to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
params : list, tuple or dict, optional, default: None
List of parameters to pass to execute method. The syntax used
to pass parameters is database driver dependent. Check your
database driver documentation for which of the five syntax styles,
described in PEP 249's paramstyle, is supported.
Eg. for psycopg2, uses %(name)s so use params={'name' : 'value'}.
parse_dates : list or dict, default: None
- List of column names to parse as dates.
- Dict of ``{column_name: format string}`` where format string is
strftime compatible in case of parsing string times, or is one of
(D, s, ns, ms, us) in case of parsing integer timestamps.
- Dict of ``{column_name: arg dict}``, where the arg dict corresponds
to the keyword arguments of :func:`pandas.to_datetime`
Especially useful with databases without native Datetime support,
such as SQLite.
columns : list, default: None
List of column names to select from SQL table (only used when reading
a table).
chunksize : int, default None
If specified, return an iterator where `chunksize` is the
number of rows to include in each chunk.
dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames
Which dtype_backend to use, e.g. whether a DataFrame should have NumPy
arrays, nullable dtypes are used for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
dtype : Type name or dict of columns
Data type for data or columns. E.g. np.float64 or
{‘a’: np.float64, ‘b’: np.int32, ‘c’: ‘Int64’}.
The argument is ignored if a table is passed instead of a query.
.. versionadded:: 2.0.0
Returns
-------
DataFrame or Iterator[DataFrame]
See Also
--------
read_sql_table : Read SQL database table into a DataFrame.
read_sql_query : Read SQL query into a DataFrame.
Examples
--------
Read data from SQL via either a SQL query or a SQL tablename.
When using a SQLite database only SQL queries are accepted,
providing only the SQL tablename will result in an error.
>>> from sqlite3 import connect
>>> conn = connect(':memory:')
>>> df = pd.DataFrame(data=[[0, '10/11/12'], [1, '12/11/10']],
... columns=['int_column', 'date_column'])
>>> df.to_sql('test_data', conn)
2
>>> pd.read_sql('SELECT int_column, date_column FROM test_data', conn)
int_column date_column
0 0 10/11/12
1 1 12/11/10
>>> pd.read_sql('test_data', 'postgres:///db_name') # doctest:+SKIP
Apply date parsing to columns through the ``parse_dates`` argument
The ``parse_dates`` argument calls ``pd.to_datetime`` on the provided columns.
Custom argument values for applying ``pd.to_datetime`` on a column are specified
via a dictionary format:
>>> pd.read_sql('SELECT int_column, date_column FROM test_data',
... conn,
... parse_dates={"date_column": {"format": "%d/%m/%y"}})
int_column date_column
0 0 2012-11-10
1 1 2010-11-12
"""
check_dtype_backend(dtype_backend)
if dtype_backend is lib.no_default:
dtype_backend = "numpy" # type: ignore[assignment]
with pandasSQL_builder(con) as pandas_sql:
if isinstance(pandas_sql, SQLiteDatabase):
return pandas_sql.read_query(
sql,
index_col=index_col,
params=params,
coerce_float=coerce_float,
parse_dates=parse_dates,
chunksize=chunksize,
dtype_backend=dtype_backend, # type: ignore[arg-type]
dtype=dtype,
)
try:
_is_table_name = pandas_sql.has_table(sql)
except Exception:
# using generic exception to catch errors from sql drivers (GH24988)
_is_table_name = False
if _is_table_name:
return pandas_sql.read_table(
sql,
index_col=index_col,
coerce_float=coerce_float,
parse_dates=parse_dates,
columns=columns,
chunksize=chunksize,
dtype_backend=dtype_backend,
)
else:
return pandas_sql.read_query(
sql,
index_col=index_col,
params=params,
coerce_float=coerce_float,
parse_dates=parse_dates,
chunksize=chunksize,
dtype_backend=dtype_backend,
dtype=dtype,
) | Read SQL query or database table into a DataFrame. This function is a convenience wrapper around ``read_sql_table`` and ``read_sql_query`` (for backward compatibility). It will delegate to the specific function depending on the provided input. A SQL query will be routed to ``read_sql_query``, while a database table name will be routed to ``read_sql_table``. Note that the delegated function might have more specific notes about their functionality not listed here. Parameters ---------- sql : str or SQLAlchemy Selectable (select or text object) SQL query to be executed or a table name. con : SQLAlchemy connectable, str, or sqlite3 connection Using SQLAlchemy makes it possible to use any DB supported by that library. If a DBAPI2 object, only sqlite3 is supported. The user is responsible for engine disposal and connection closure for the SQLAlchemy connectable; str connections are closed automatically. See `here <https://docs.sqlalchemy.org/en/13/core/connections.html>`_. index_col : str or list of str, optional, default: None Column(s) to set as index(MultiIndex). coerce_float : bool, default True Attempts to convert values of non-string, non-numeric objects (like decimal.Decimal) to floating point, useful for SQL result sets. params : list, tuple or dict, optional, default: None List of parameters to pass to execute method. The syntax used to pass parameters is database driver dependent. Check your database driver documentation for which of the five syntax styles, described in PEP 249's paramstyle, is supported. Eg. for psycopg2, uses %(name)s so use params={'name' : 'value'}. parse_dates : list or dict, default: None - List of column names to parse as dates. - Dict of ``{column_name: format string}`` where format string is strftime compatible in case of parsing string times, or is one of (D, s, ns, ms, us) in case of parsing integer timestamps. - Dict of ``{column_name: arg dict}``, where the arg dict corresponds to the keyword arguments of :func:`pandas.to_datetime` Especially useful with databases without native Datetime support, such as SQLite. columns : list, default: None List of column names to select from SQL table (only used when reading a table). chunksize : int, default None If specified, return an iterator where `chunksize` is the number of rows to include in each chunk. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 dtype : Type name or dict of columns Data type for data or columns. E.g. np.float64 or {‘a’: np.float64, ‘b’: np.int32, ‘c’: ‘Int64’}. The argument is ignored if a table is passed instead of a query. .. versionadded:: 2.0.0 Returns ------- DataFrame or Iterator[DataFrame] See Also -------- read_sql_table : Read SQL database table into a DataFrame. read_sql_query : Read SQL query into a DataFrame. Examples -------- Read data from SQL via either a SQL query or a SQL tablename. When using a SQLite database only SQL queries are accepted, providing only the SQL tablename will result in an error. >>> from sqlite3 import connect >>> conn = connect(':memory:') >>> df = pd.DataFrame(data=[[0, '10/11/12'], [1, '12/11/10']], ... columns=['int_column', 'date_column']) >>> df.to_sql('test_data', conn) 2 >>> pd.read_sql('SELECT int_column, date_column FROM test_data', conn) int_column date_column 0 0 10/11/12 1 1 12/11/10 >>> pd.read_sql('test_data', 'postgres:///db_name') # doctest:+SKIP Apply date parsing to columns through the ``parse_dates`` argument The ``parse_dates`` argument calls ``pd.to_datetime`` on the provided columns. Custom argument values for applying ``pd.to_datetime`` on a column are specified via a dictionary format: >>> pd.read_sql('SELECT int_column, date_column FROM test_data', ... conn, ... parse_dates={"date_column": {"format": "%d/%m/%y"}}) int_column date_column 0 0 2012-11-10 1 1 2010-11-12 |
173,493 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def pandasSQL_builder(
con,
schema: str | None = None,
need_transaction: bool = False,
) -> PandasSQL:
"""
Convenience function to return the correct PandasSQL subclass based on the
provided parameters. Also creates a sqlalchemy connection and transaction
if necessary.
"""
import sqlite3
if isinstance(con, sqlite3.Connection) or con is None:
return SQLiteDatabase(con)
sqlalchemy = import_optional_dependency("sqlalchemy", errors="ignore")
if isinstance(con, str) and sqlalchemy is None:
raise ImportError("Using URI string without sqlalchemy installed.")
if sqlalchemy is not None and isinstance(con, (str, sqlalchemy.engine.Connectable)):
return SQLDatabase(con, schema, need_transaction)
warnings.warn(
"pandas only supports SQLAlchemy connectable (engine/connection) or "
"database string URI or sqlite3 DBAPI2 connection. Other DBAPI2 "
"objects are not tested. Please consider using SQLAlchemy.",
UserWarning,
stacklevel=find_stack_level(),
)
return SQLiteDatabase(con)
Literal: _SpecialForm = ...
IndexLabel = Union[Hashable, Sequence[Hashable]]
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
The provided code snippet includes necessary dependencies for implementing the `to_sql` function. Write a Python function `def to_sql( frame, name: str, con, schema: str | None = None, if_exists: Literal["fail", "replace", "append"] = "fail", index: bool = True, index_label: IndexLabel = None, chunksize: int | None = None, dtype: DtypeArg | None = None, method: str | None = None, engine: str = "auto", **engine_kwargs, ) -> int | None` to solve the following problem:
Write records stored in a DataFrame to a SQL database. Parameters ---------- frame : DataFrame, Series name : str Name of SQL table. con : SQLAlchemy connectable(engine/connection) or database string URI or sqlite3 DBAPI2 connection Using SQLAlchemy makes it possible to use any DB supported by that library. If a DBAPI2 object, only sqlite3 is supported. schema : str, optional Name of SQL schema in database to write to (if database flavor supports this). If None, use default schema (default). if_exists : {'fail', 'replace', 'append'}, default 'fail' - fail: If table exists, do nothing. - replace: If table exists, drop it, recreate it, and insert data. - append: If table exists, insert data. Create if does not exist. index : bool, default True Write DataFrame index as a column. index_label : str or sequence, optional Column label for index column(s). If None is given (default) and `index` is True, then the index names are used. A sequence should be given if the DataFrame uses MultiIndex. chunksize : int, optional Specify the number of rows in each batch to be written at a time. By default, all rows will be written at once. dtype : dict or scalar, optional Specifying the datatype for columns. If a dictionary is used, the keys should be the column names and the values should be the SQLAlchemy types or strings for the sqlite3 fallback mode. If a scalar is provided, it will be applied to all columns. method : {None, 'multi', callable}, optional Controls the SQL insertion clause used: - None : Uses standard SQL ``INSERT`` clause (one per row). - ``'multi'``: Pass multiple values in a single ``INSERT`` clause. - callable with signature ``(pd_table, conn, keys, data_iter) -> int | None``. Details and a sample callable implementation can be found in the section :ref:`insert method <io.sql.method>`. engine : {'auto', 'sqlalchemy'}, default 'auto' SQL engine library to use. If 'auto', then the option ``io.sql.engine`` is used. The default ``io.sql.engine`` behavior is 'sqlalchemy' .. versionadded:: 1.3.0 **engine_kwargs Any additional kwargs are passed to the engine. Returns ------- None or int Number of rows affected by to_sql. None is returned if the callable passed into ``method`` does not return an integer number of rows. .. versionadded:: 1.4.0 Notes ----- The returned rows affected is the sum of the ``rowcount`` attribute of ``sqlite3.Cursor`` or SQLAlchemy connectable. The returned value may not reflect the exact number of written rows as stipulated in the `sqlite3 <https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.rowcount>`__ or `SQLAlchemy <https://docs.sqlalchemy.org/en/14/core/connections.html#sqlalchemy.engine.BaseCursorResult.rowcount>`__
Here is the function:
def to_sql(
frame,
name: str,
con,
schema: str | None = None,
if_exists: Literal["fail", "replace", "append"] = "fail",
index: bool = True,
index_label: IndexLabel = None,
chunksize: int | None = None,
dtype: DtypeArg | None = None,
method: str | None = None,
engine: str = "auto",
**engine_kwargs,
) -> int | None:
"""
Write records stored in a DataFrame to a SQL database.
Parameters
----------
frame : DataFrame, Series
name : str
Name of SQL table.
con : SQLAlchemy connectable(engine/connection) or database string URI
or sqlite3 DBAPI2 connection
Using SQLAlchemy makes it possible to use any DB supported by that
library.
If a DBAPI2 object, only sqlite3 is supported.
schema : str, optional
Name of SQL schema in database to write to (if database flavor
supports this). If None, use default schema (default).
if_exists : {'fail', 'replace', 'append'}, default 'fail'
- fail: If table exists, do nothing.
- replace: If table exists, drop it, recreate it, and insert data.
- append: If table exists, insert data. Create if does not exist.
index : bool, default True
Write DataFrame index as a column.
index_label : str or sequence, optional
Column label for index column(s). If None is given (default) and
`index` is True, then the index names are used.
A sequence should be given if the DataFrame uses MultiIndex.
chunksize : int, optional
Specify the number of rows in each batch to be written at a time.
By default, all rows will be written at once.
dtype : dict or scalar, optional
Specifying the datatype for columns. If a dictionary is used, the
keys should be the column names and the values should be the
SQLAlchemy types or strings for the sqlite3 fallback mode. If a
scalar is provided, it will be applied to all columns.
method : {None, 'multi', callable}, optional
Controls the SQL insertion clause used:
- None : Uses standard SQL ``INSERT`` clause (one per row).
- ``'multi'``: Pass multiple values in a single ``INSERT`` clause.
- callable with signature ``(pd_table, conn, keys, data_iter) -> int | None``.
Details and a sample callable implementation can be found in the
section :ref:`insert method <io.sql.method>`.
engine : {'auto', 'sqlalchemy'}, default 'auto'
SQL engine library to use. If 'auto', then the option
``io.sql.engine`` is used. The default ``io.sql.engine``
behavior is 'sqlalchemy'
.. versionadded:: 1.3.0
**engine_kwargs
Any additional kwargs are passed to the engine.
Returns
-------
None or int
Number of rows affected by to_sql. None is returned if the callable
passed into ``method`` does not return an integer number of rows.
.. versionadded:: 1.4.0
Notes
-----
The returned rows affected is the sum of the ``rowcount`` attribute of ``sqlite3.Cursor``
or SQLAlchemy connectable. The returned value may not reflect the exact number of written
rows as stipulated in the
`sqlite3 <https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.rowcount>`__ or
`SQLAlchemy <https://docs.sqlalchemy.org/en/14/core/connections.html#sqlalchemy.engine.BaseCursorResult.rowcount>`__
""" # noqa:E501
if if_exists not in ("fail", "replace", "append"):
raise ValueError(f"'{if_exists}' is not valid for if_exists")
if isinstance(frame, Series):
frame = frame.to_frame()
elif not isinstance(frame, DataFrame):
raise NotImplementedError(
"'frame' argument should be either a Series or a DataFrame"
)
with pandasSQL_builder(con, schema=schema, need_transaction=True) as pandas_sql:
return pandas_sql.to_sql(
frame,
name,
if_exists=if_exists,
index=index,
index_label=index_label,
schema=schema,
chunksize=chunksize,
dtype=dtype,
method=method,
engine=engine,
**engine_kwargs,
) | Write records stored in a DataFrame to a SQL database. Parameters ---------- frame : DataFrame, Series name : str Name of SQL table. con : SQLAlchemy connectable(engine/connection) or database string URI or sqlite3 DBAPI2 connection Using SQLAlchemy makes it possible to use any DB supported by that library. If a DBAPI2 object, only sqlite3 is supported. schema : str, optional Name of SQL schema in database to write to (if database flavor supports this). If None, use default schema (default). if_exists : {'fail', 'replace', 'append'}, default 'fail' - fail: If table exists, do nothing. - replace: If table exists, drop it, recreate it, and insert data. - append: If table exists, insert data. Create if does not exist. index : bool, default True Write DataFrame index as a column. index_label : str or sequence, optional Column label for index column(s). If None is given (default) and `index` is True, then the index names are used. A sequence should be given if the DataFrame uses MultiIndex. chunksize : int, optional Specify the number of rows in each batch to be written at a time. By default, all rows will be written at once. dtype : dict or scalar, optional Specifying the datatype for columns. If a dictionary is used, the keys should be the column names and the values should be the SQLAlchemy types or strings for the sqlite3 fallback mode. If a scalar is provided, it will be applied to all columns. method : {None, 'multi', callable}, optional Controls the SQL insertion clause used: - None : Uses standard SQL ``INSERT`` clause (one per row). - ``'multi'``: Pass multiple values in a single ``INSERT`` clause. - callable with signature ``(pd_table, conn, keys, data_iter) -> int | None``. Details and a sample callable implementation can be found in the section :ref:`insert method <io.sql.method>`. engine : {'auto', 'sqlalchemy'}, default 'auto' SQL engine library to use. If 'auto', then the option ``io.sql.engine`` is used. The default ``io.sql.engine`` behavior is 'sqlalchemy' .. versionadded:: 1.3.0 **engine_kwargs Any additional kwargs are passed to the engine. Returns ------- None or int Number of rows affected by to_sql. None is returned if the callable passed into ``method`` does not return an integer number of rows. .. versionadded:: 1.4.0 Notes ----- The returned rows affected is the sum of the ``rowcount`` attribute of ``sqlite3.Cursor`` or SQLAlchemy connectable. The returned value may not reflect the exact number of written rows as stipulated in the `sqlite3 <https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.rowcount>`__ or `SQLAlchemy <https://docs.sqlalchemy.org/en/14/core/connections.html#sqlalchemy.engine.BaseCursorResult.rowcount>`__ |
173,494 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
class BaseEngine:
def insert_records(
self,
table: SQLTable,
con,
frame,
name,
index: bool | str | list[str] | None = True,
schema=None,
chunksize=None,
method=None,
**engine_kwargs,
) -> int | None:
"""
Inserts data into already-prepared table
"""
raise AbstractMethodError(self)
class SQLAlchemyEngine(BaseEngine):
def __init__(self) -> None:
import_optional_dependency(
"sqlalchemy", extra="sqlalchemy is required for SQL support."
)
def insert_records(
self,
table: SQLTable,
con,
frame,
name,
index: bool | str | list[str] | None = True,
schema=None,
chunksize=None,
method=None,
**engine_kwargs,
) -> int | None:
from sqlalchemy import exc
try:
return table.insert(chunksize=chunksize, method=method)
except exc.StatementError as err:
# GH34431
# https://stackoverflow.com/a/67358288/6067848
msg = r"""(\(1054, "Unknown column 'inf(e0)?' in 'field list'"\))(?#
)|inf can not be used with MySQL"""
err_text = str(err.orig)
if re.search(msg, err_text):
raise ValueError("inf cannot be used with MySQL") from err
raise err
The provided code snippet includes necessary dependencies for implementing the `get_engine` function. Write a Python function `def get_engine(engine: str) -> BaseEngine` to solve the following problem:
return our implementation
Here is the function:
def get_engine(engine: str) -> BaseEngine:
"""return our implementation"""
if engine == "auto":
engine = get_option("io.sql.engine")
if engine == "auto":
# try engines in this order
engine_classes = [SQLAlchemyEngine]
error_msgs = ""
for engine_class in engine_classes:
try:
return engine_class()
except ImportError as err:
error_msgs += "\n - " + str(err)
raise ImportError(
"Unable to find a usable engine; "
"tried using: 'sqlalchemy'.\n"
"A suitable version of "
"sqlalchemy is required for sql I/O "
"support.\n"
"Trying to import the above resulted in these errors:"
f"{error_msgs}"
)
if engine == "sqlalchemy":
return SQLAlchemyEngine()
raise ValueError("engine must be one of 'auto', 'sqlalchemy'") | return our implementation |
173,495 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def _get_unicode_name(name):
try:
uname = str(name).encode("utf-8", "strict").decode("utf-8")
except UnicodeError as err:
raise ValueError(f"Cannot convert identifier to UTF-8: '{name}'") from err
return uname
def _get_valid_sqlite_name(name):
# See https://stackoverflow.com/questions/6514274/how-do-you-escape-strings\
# -for-sqlite-table-column-names-in-python
# Ensure the string can be encoded as UTF-8.
# Ensure the string does not include any NUL characters.
# Replace all " with "".
# Wrap the entire thing in double quotes.
uname = _get_unicode_name(name)
if not len(uname):
raise ValueError("Empty table or column name specified")
nul_index = uname.find("\x00")
if nul_index >= 0:
raise ValueError("SQLite identifier cannot contain NULs")
return '"' + uname.replace('"', '""') + '"' | null |
173,496 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from contextlib import (
ExitStack,
contextmanager,
)
from datetime import (
date,
datetime,
time,
)
from functools import partial
import re
from typing import (
TYPE_CHECKING,
Any,
Iterator,
Literal,
cast,
overload,
)
import warnings
import numpy as np
from pandas._libs import lib
from pandas._typing import (
DateTimeErrorChoices,
DtypeArg,
DtypeBackend,
IndexLabel,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import (
AbstractMethodError,
DatabaseError,
)
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_datetime64tz_dtype,
is_dict_like,
is_integer,
is_list_like,
)
from pandas.core.dtypes.dtypes import DatetimeTZDtype
from pandas.core.dtypes.missing import isna
from pandas import get_option
from pandas.core.api import (
DataFrame,
Series,
)
from pandas.core.arrays import ArrowExtensionArray
from pandas.core.base import PandasObject
import pandas.core.common as com
from pandas.core.internals.construction import convert_object_array
from pandas.core.tools.datetimes import to_datetime
def pandasSQL_builder(
con,
schema: str | None = None,
need_transaction: bool = False,
) -> PandasSQL:
"""
Convenience function to return the correct PandasSQL subclass based on the
provided parameters. Also creates a sqlalchemy connection and transaction
if necessary.
"""
import sqlite3
if isinstance(con, sqlite3.Connection) or con is None:
return SQLiteDatabase(con)
sqlalchemy = import_optional_dependency("sqlalchemy", errors="ignore")
if isinstance(con, str) and sqlalchemy is None:
raise ImportError("Using URI string without sqlalchemy installed.")
if sqlalchemy is not None and isinstance(con, (str, sqlalchemy.engine.Connectable)):
return SQLDatabase(con, schema, need_transaction)
warnings.warn(
"pandas only supports SQLAlchemy connectable (engine/connection) or "
"database string URI or sqlite3 DBAPI2 connection. Other DBAPI2 "
"objects are not tested. Please consider using SQLAlchemy.",
UserWarning,
stacklevel=find_stack_level(),
)
return SQLiteDatabase(con)
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
The provided code snippet includes necessary dependencies for implementing the `get_schema` function. Write a Python function `def get_schema( frame, name: str, keys=None, con=None, dtype: DtypeArg | None = None, schema: str | None = None, ) -> str` to solve the following problem:
Get the SQL db table schema for the given frame. Parameters ---------- frame : DataFrame name : str name of SQL table keys : string or sequence, default: None columns to use a primary key con: an open SQL database connection object or a SQLAlchemy connectable Using SQLAlchemy makes it possible to use any DB supported by that library, default: None If a DBAPI2 object, only sqlite3 is supported. dtype : dict of column name to SQL type, default None Optional specifying the datatype for columns. The SQL type should be a SQLAlchemy type, or a string for sqlite3 fallback connection. schema: str, default: None Optional specifying the schema to be used in creating the table. .. versionadded:: 1.2.0
Here is the function:
def get_schema(
frame,
name: str,
keys=None,
con=None,
dtype: DtypeArg | None = None,
schema: str | None = None,
) -> str:
"""
Get the SQL db table schema for the given frame.
Parameters
----------
frame : DataFrame
name : str
name of SQL table
keys : string or sequence, default: None
columns to use a primary key
con: an open SQL database connection object or a SQLAlchemy connectable
Using SQLAlchemy makes it possible to use any DB supported by that
library, default: None
If a DBAPI2 object, only sqlite3 is supported.
dtype : dict of column name to SQL type, default None
Optional specifying the datatype for columns. The SQL type should
be a SQLAlchemy type, or a string for sqlite3 fallback connection.
schema: str, default: None
Optional specifying the schema to be used in creating the table.
.. versionadded:: 1.2.0
"""
with pandasSQL_builder(con=con) as pandas_sql:
return pandas_sql._create_sql_schema(
frame, name, keys=keys, dtype=dtype, schema=schema
) | Get the SQL db table schema for the given frame. Parameters ---------- frame : DataFrame name : str name of SQL table keys : string or sequence, default: None columns to use a primary key con: an open SQL database connection object or a SQLAlchemy connectable Using SQLAlchemy makes it possible to use any DB supported by that library, default: None If a DBAPI2 object, only sqlite3 is supported. dtype : dict of column name to SQL type, default None Optional specifying the datatype for columns. The SQL type should be a SQLAlchemy type, or a string for sqlite3 fallback connection. schema: str, default: None Optional specifying the schema to be used in creating the table. .. versionadded:: 1.2.0 |
173,497 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
cast,
)
import warnings
from pandas._libs.json import loads
from pandas._libs.tslibs import timezones
from pandas._typing import (
DtypeObj,
JSONSerializable,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.base import _registry as registry
from pandas.core.dtypes.common import (
is_bool_dtype,
is_categorical_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_numeric_dtype,
is_period_dtype,
is_string_dtype,
is_timedelta64_dtype,
)
from pandas.core.dtypes.dtypes import CategoricalDtype
from pandas import DataFrame
import pandas.core.common as com
TABLE_SCHEMA_VERSION = "1.4.0"
def set_default_names(data):
"""Sets index names to 'index' for regular, or 'level_x' for Multi"""
if com.all_not_none(*data.index.names):
nms = data.index.names
if len(nms) == 1 and data.index.name == "index":
warnings.warn(
"Index name of 'index' is not round-trippable.",
stacklevel=find_stack_level(),
)
elif len(nms) > 1 and any(x.startswith("level_") for x in nms):
warnings.warn(
"Index names beginning with 'level_' are not round-trippable.",
stacklevel=find_stack_level(),
)
return data
data = data.copy()
if data.index.nlevels > 1:
data.index.names = com.fill_missing_names(data.index.names)
else:
data.index.name = data.index.name or "index"
return data
def convert_pandas_type_to_json_field(arr) -> dict[str, JSONSerializable]:
dtype = arr.dtype
name: JSONSerializable
if arr.name is None:
name = "values"
else:
name = arr.name
field: dict[str, JSONSerializable] = {
"name": name,
"type": as_json_table_type(dtype),
}
if is_categorical_dtype(dtype):
cats = dtype.categories
ordered = dtype.ordered
field["constraints"] = {"enum": list(cats)}
field["ordered"] = ordered
elif is_period_dtype(dtype):
field["freq"] = dtype.freq.freqstr
elif is_datetime64tz_dtype(dtype):
if timezones.is_utc(dtype.tz):
# timezone.utc has no "zone" attr
field["tz"] = "UTC"
else:
field["tz"] = dtype.tz.zone
elif is_extension_array_dtype(dtype):
field["extDtype"] = dtype.name
return field
Any = object()
def cast(typ: Type[_T], val: Any) -> _T: ...
def cast(typ: str, val: Any) -> Any: ...
def cast(typ: object, val: Any) -> Any: ...
JSONSerializable = Optional[Union[PythonScalar, List, Dict]]
The provided code snippet includes necessary dependencies for implementing the `build_table_schema` function. Write a Python function `def build_table_schema( data: DataFrame | Series, index: bool = True, primary_key: bool | None = None, version: bool = True, ) -> dict[str, JSONSerializable]` to solve the following problem:
Create a Table schema from ``data``. Parameters ---------- data : Series, DataFrame index : bool, default True Whether to include ``data.index`` in the schema. primary_key : bool or None, default True Column names to designate as the primary key. The default `None` will set `'primaryKey'` to the index level or levels if the index is unique. version : bool, default True Whether to include a field `pandas_version` with the version of pandas that last revised the table schema. This version can be different from the installed pandas version. Returns ------- dict Notes ----- See `Table Schema <https://pandas.pydata.org/docs/user_guide/io.html#table-schema>`__ for conversion types. Timedeltas as converted to ISO8601 duration format with 9 decimal places after the seconds field for nanosecond precision. Categoricals are converted to the `any` dtype, and use the `enum` field constraint to list the allowed values. The `ordered` attribute is included in an `ordered` field. Examples -------- >>> from pandas.io.json._table_schema import build_table_schema >>> df = pd.DataFrame( ... {'A': [1, 2, 3], ... 'B': ['a', 'b', 'c'], ... 'C': pd.date_range('2016-01-01', freq='d', periods=3), ... }, index=pd.Index(range(3), name='idx')) >>> build_table_schema(df) {'fields': \ [{'name': 'idx', 'type': 'integer'}, \ {'name': 'A', 'type': 'integer'}, \ {'name': 'B', 'type': 'string'}, \ {'name': 'C', 'type': 'datetime'}], \ 'primaryKey': ['idx'], \ 'pandas_version': '1.4.0'}
Here is the function:
def build_table_schema(
data: DataFrame | Series,
index: bool = True,
primary_key: bool | None = None,
version: bool = True,
) -> dict[str, JSONSerializable]:
"""
Create a Table schema from ``data``.
Parameters
----------
data : Series, DataFrame
index : bool, default True
Whether to include ``data.index`` in the schema.
primary_key : bool or None, default True
Column names to designate as the primary key.
The default `None` will set `'primaryKey'` to the index
level or levels if the index is unique.
version : bool, default True
Whether to include a field `pandas_version` with the version
of pandas that last revised the table schema. This version
can be different from the installed pandas version.
Returns
-------
dict
Notes
-----
See `Table Schema
<https://pandas.pydata.org/docs/user_guide/io.html#table-schema>`__ for
conversion types.
Timedeltas as converted to ISO8601 duration format with
9 decimal places after the seconds field for nanosecond precision.
Categoricals are converted to the `any` dtype, and use the `enum` field
constraint to list the allowed values. The `ordered` attribute is included
in an `ordered` field.
Examples
--------
>>> from pandas.io.json._table_schema import build_table_schema
>>> df = pd.DataFrame(
... {'A': [1, 2, 3],
... 'B': ['a', 'b', 'c'],
... 'C': pd.date_range('2016-01-01', freq='d', periods=3),
... }, index=pd.Index(range(3), name='idx'))
>>> build_table_schema(df)
{'fields': \
[{'name': 'idx', 'type': 'integer'}, \
{'name': 'A', 'type': 'integer'}, \
{'name': 'B', 'type': 'string'}, \
{'name': 'C', 'type': 'datetime'}], \
'primaryKey': ['idx'], \
'pandas_version': '1.4.0'}
"""
if index is True:
data = set_default_names(data)
schema: dict[str, Any] = {}
fields = []
if index:
if data.index.nlevels > 1:
data.index = cast("MultiIndex", data.index)
for level, name in zip(data.index.levels, data.index.names):
new_field = convert_pandas_type_to_json_field(level)
new_field["name"] = name
fields.append(new_field)
else:
fields.append(convert_pandas_type_to_json_field(data.index))
if data.ndim > 1:
for column, s in data.items():
fields.append(convert_pandas_type_to_json_field(s))
else:
fields.append(convert_pandas_type_to_json_field(data))
schema["fields"] = fields
if index and data.index.is_unique and primary_key is None:
if data.index.nlevels == 1:
schema["primaryKey"] = [data.index.name]
else:
schema["primaryKey"] = data.index.names
elif primary_key is not None:
schema["primaryKey"] = primary_key
if version:
schema["pandas_version"] = TABLE_SCHEMA_VERSION
return schema | Create a Table schema from ``data``. Parameters ---------- data : Series, DataFrame index : bool, default True Whether to include ``data.index`` in the schema. primary_key : bool or None, default True Column names to designate as the primary key. The default `None` will set `'primaryKey'` to the index level or levels if the index is unique. version : bool, default True Whether to include a field `pandas_version` with the version of pandas that last revised the table schema. This version can be different from the installed pandas version. Returns ------- dict Notes ----- See `Table Schema <https://pandas.pydata.org/docs/user_guide/io.html#table-schema>`__ for conversion types. Timedeltas as converted to ISO8601 duration format with 9 decimal places after the seconds field for nanosecond precision. Categoricals are converted to the `any` dtype, and use the `enum` field constraint to list the allowed values. The `ordered` attribute is included in an `ordered` field. Examples -------- >>> from pandas.io.json._table_schema import build_table_schema >>> df = pd.DataFrame( ... {'A': [1, 2, 3], ... 'B': ['a', 'b', 'c'], ... 'C': pd.date_range('2016-01-01', freq='d', periods=3), ... }, index=pd.Index(range(3), name='idx')) >>> build_table_schema(df) {'fields': \ [{'name': 'idx', 'type': 'integer'}, \ {'name': 'A', 'type': 'integer'}, \ {'name': 'B', 'type': 'string'}, \ {'name': 'C', 'type': 'datetime'}], \ 'primaryKey': ['idx'], \ 'pandas_version': '1.4.0'} |
173,498 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
cast,
)
import warnings
from pandas._libs.json import loads
from pandas._libs.tslibs import timezones
from pandas._typing import (
DtypeObj,
JSONSerializable,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.base import _registry as registry
from pandas.core.dtypes.common import (
is_bool_dtype,
is_categorical_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_numeric_dtype,
is_period_dtype,
is_string_dtype,
is_timedelta64_dtype,
)
from pandas.core.dtypes.dtypes import CategoricalDtype
from pandas import DataFrame
import pandas.core.common as com
def convert_json_field_to_pandas_type(field) -> str | CategoricalDtype:
"""
Converts a JSON field descriptor into its corresponding NumPy / pandas type
Parameters
----------
field
A JSON field descriptor
Returns
-------
dtype
Raises
------
ValueError
If the type of the provided field is unknown or currently unsupported
Examples
--------
>>> convert_json_field_to_pandas_type({"name": "an_int", "type": "integer"})
'int64'
>>> convert_json_field_to_pandas_type(
... {
... "name": "a_categorical",
... "type": "any",
... "constraints": {"enum": ["a", "b", "c"]},
... "ordered": True,
... }
... )
CategoricalDtype(categories=['a', 'b', 'c'], ordered=True)
>>> convert_json_field_to_pandas_type({"name": "a_datetime", "type": "datetime"})
'datetime64[ns]'
>>> convert_json_field_to_pandas_type(
... {"name": "a_datetime_with_tz", "type": "datetime", "tz": "US/Central"}
... )
'datetime64[ns, US/Central]'
"""
typ = field["type"]
if typ == "string":
return "object"
elif typ == "integer":
return field.get("extDtype", "int64")
elif typ == "number":
return field.get("extDtype", "float64")
elif typ == "boolean":
return field.get("extDtype", "bool")
elif typ == "duration":
return "timedelta64"
elif typ == "datetime":
if field.get("tz"):
return f"datetime64[ns, {field['tz']}]"
elif field.get("freq"):
# GH#47747 using datetime over period to minimize the change surface
return f"period[{field['freq']}]"
else:
return "datetime64[ns]"
elif typ == "any":
if "constraints" in field and "ordered" in field:
return CategoricalDtype(
categories=field["constraints"]["enum"], ordered=field["ordered"]
)
elif "extDtype" in field:
return registry.find(field["extDtype"])
else:
return "object"
raise ValueError(f"Unsupported or invalid field type: {typ}")
The provided code snippet includes necessary dependencies for implementing the `parse_table_schema` function. Write a Python function `def parse_table_schema(json, precise_float)` to solve the following problem:
Builds a DataFrame from a given schema Parameters ---------- json : A JSON table schema precise_float : bool Flag controlling precision when decoding string to double values, as dictated by ``read_json`` Returns ------- df : DataFrame Raises ------ NotImplementedError If the JSON table schema contains either timezone or timedelta data Notes ----- Because :func:`DataFrame.to_json` uses the string 'index' to denote a name-less :class:`Index`, this function sets the name of the returned :class:`DataFrame` to ``None`` when said string is encountered with a normal :class:`Index`. For a :class:`MultiIndex`, the same limitation applies to any strings beginning with 'level_'. Therefore, an :class:`Index` name of 'index' and :class:`MultiIndex` names starting with 'level_' are not supported. See Also -------- build_table_schema : Inverse function. pandas.read_json
Here is the function:
def parse_table_schema(json, precise_float):
"""
Builds a DataFrame from a given schema
Parameters
----------
json :
A JSON table schema
precise_float : bool
Flag controlling precision when decoding string to double values, as
dictated by ``read_json``
Returns
-------
df : DataFrame
Raises
------
NotImplementedError
If the JSON table schema contains either timezone or timedelta data
Notes
-----
Because :func:`DataFrame.to_json` uses the string 'index' to denote a
name-less :class:`Index`, this function sets the name of the returned
:class:`DataFrame` to ``None`` when said string is encountered with a
normal :class:`Index`. For a :class:`MultiIndex`, the same limitation
applies to any strings beginning with 'level_'. Therefore, an
:class:`Index` name of 'index' and :class:`MultiIndex` names starting
with 'level_' are not supported.
See Also
--------
build_table_schema : Inverse function.
pandas.read_json
"""
table = loads(json, precise_float=precise_float)
col_order = [field["name"] for field in table["schema"]["fields"]]
df = DataFrame(table["data"], columns=col_order)[col_order]
dtypes = {
field["name"]: convert_json_field_to_pandas_type(field)
for field in table["schema"]["fields"]
}
# No ISO constructor for Timedelta as of yet, so need to raise
if "timedelta64" in dtypes.values():
raise NotImplementedError(
'table="orient" can not yet read ISO-formatted Timedelta data'
)
df = df.astype(dtypes)
if "primaryKey" in table["schema"]:
df = df.set_index(table["schema"]["primaryKey"])
if len(df.index.names) == 1:
if df.index.name == "index":
df.index.name = None
else:
df.index.names = [
None if x.startswith("level_") else x for x in df.index.names
]
return df | Builds a DataFrame from a given schema Parameters ---------- json : A JSON table schema precise_float : bool Flag controlling precision when decoding string to double values, as dictated by ``read_json`` Returns ------- df : DataFrame Raises ------ NotImplementedError If the JSON table schema contains either timezone or timedelta data Notes ----- Because :func:`DataFrame.to_json` uses the string 'index' to denote a name-less :class:`Index`, this function sets the name of the returned :class:`DataFrame` to ``None`` when said string is encountered with a normal :class:`Index`. For a :class:`MultiIndex`, the same limitation applies to any strings beginning with 'level_'. Therefore, an :class:`Index` name of 'index' and :class:`MultiIndex` names starting with 'level_' are not supported. See Also -------- build_table_schema : Inverse function. pandas.read_json |
173,499 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
Any = object()
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
Literal: _SpecialForm = ...
JSONSerializable = Optional[Union[PythonScalar, List, Dict]]
class WriteBuffer(BaseBuffer, Protocol[AnyStr_contra]):
def write(self, __b: AnyStr_contra) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
def flush(self) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
class NDFrame(PandasObject, indexing.IndexingMixin):
"""
N-dimensional analogue of DataFrame. Store multi-dimensional in a
size-mutable, labeled data structure
Parameters
----------
data : BlockManager
axes : list
copy : bool, default False
"""
_internal_names: list[str] = [
"_mgr",
"_cacher",
"_item_cache",
"_cache",
"_is_copy",
"_subtyp",
"_name",
"_default_kind",
"_default_fill_value",
"_metadata",
"__array_struct__",
"__array_interface__",
"_flags",
]
_internal_names_set: set[str] = set(_internal_names)
_accessors: set[str] = set()
_hidden_attrs: frozenset[str] = frozenset([])
_metadata: list[str] = []
_is_copy: weakref.ReferenceType[NDFrame] | None = None
_mgr: Manager
_attrs: dict[Hashable, Any]
_typ: str
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data: Manager,
copy: bool_t = False,
attrs: Mapping[Hashable, Any] | None = None,
) -> None:
# copy kwarg is retained for mypy compat, is not used
object.__setattr__(self, "_is_copy", None)
object.__setattr__(self, "_mgr", data)
object.__setattr__(self, "_item_cache", {})
if attrs is None:
attrs = {}
else:
attrs = dict(attrs)
object.__setattr__(self, "_attrs", attrs)
object.__setattr__(self, "_flags", Flags(self, allows_duplicate_labels=True))
def _init_mgr(
cls,
mgr: Manager,
axes,
dtype: Dtype | None = None,
copy: bool_t = False,
) -> Manager:
"""passed a manager and a axes dict"""
for a, axe in axes.items():
if axe is not None:
axe = ensure_index(axe)
bm_axis = cls._get_block_manager_axis(a)
mgr = mgr.reindex_axis(axe, axis=bm_axis)
# make a copy if explicitly requested
if copy:
mgr = mgr.copy()
if dtype is not None:
# avoid further copies if we can
if (
isinstance(mgr, BlockManager)
and len(mgr.blocks) == 1
and is_dtype_equal(mgr.blocks[0].values.dtype, dtype)
):
pass
else:
mgr = mgr.astype(dtype=dtype)
return mgr
def _as_manager(self: NDFrameT, typ: str, copy: bool_t = True) -> NDFrameT:
"""
Private helper function to create a DataFrame with specific manager.
Parameters
----------
typ : {"block", "array"}
copy : bool, default True
Only controls whether the conversion from Block->ArrayManager
copies the 1D arrays (to ensure proper/contiguous memory layout).
Returns
-------
DataFrame
New DataFrame using specified manager type. Is not guaranteed
to be a copy or not.
"""
new_mgr: Manager
new_mgr = mgr_to_mgr(self._mgr, typ=typ, copy=copy)
# fastpath of passing a manager doesn't check the option/manager class
return self._constructor(new_mgr).__finalize__(self)
# ----------------------------------------------------------------------
# attrs and flags
def attrs(self) -> dict[Hashable, Any]:
"""
Dictionary of global attributes of this dataset.
.. warning::
attrs is experimental and may change without warning.
See Also
--------
DataFrame.flags : Global flags applying to this object.
"""
if self._attrs is None:
self._attrs = {}
return self._attrs
def attrs(self, value: Mapping[Hashable, Any]) -> None:
self._attrs = dict(value)
def flags(self) -> Flags:
"""
Get the properties associated with this pandas object.
The available flags are
* :attr:`Flags.allows_duplicate_labels`
See Also
--------
Flags : Flags that apply to pandas objects.
DataFrame.attrs : Global metadata applying to this dataset.
Notes
-----
"Flags" differ from "metadata". Flags reflect properties of the
pandas object (the Series or DataFrame). Metadata refer to properties
of the dataset, and should be stored in :attr:`DataFrame.attrs`.
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2]})
>>> df.flags
<Flags(allows_duplicate_labels=True)>
Flags can be get or set using ``.``
>>> df.flags.allows_duplicate_labels
True
>>> df.flags.allows_duplicate_labels = False
Or by slicing with a key
>>> df.flags["allows_duplicate_labels"]
False
>>> df.flags["allows_duplicate_labels"] = True
"""
return self._flags
def set_flags(
self: NDFrameT,
*,
copy: bool_t = False,
allows_duplicate_labels: bool_t | None = None,
) -> NDFrameT:
"""
Return a new object with updated flags.
Parameters
----------
copy : bool, default False
Specify if a copy of the object should be made.
allows_duplicate_labels : bool, optional
Whether the returned object allows duplicate labels.
Returns
-------
Series or DataFrame
The same type as the caller.
See Also
--------
DataFrame.attrs : Global metadata applying to this dataset.
DataFrame.flags : Global flags applying to this object.
Notes
-----
This method returns a new object that's a view on the same data
as the input. Mutating the input or the output values will be reflected
in the other.
This method is intended to be used in method chains.
"Flags" differ from "metadata". Flags reflect properties of the
pandas object (the Series or DataFrame). Metadata refer to properties
of the dataset, and should be stored in :attr:`DataFrame.attrs`.
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2]})
>>> df.flags.allows_duplicate_labels
True
>>> df2 = df.set_flags(allows_duplicate_labels=False)
>>> df2.flags.allows_duplicate_labels
False
"""
df = self.copy(deep=copy and not using_copy_on_write())
if allows_duplicate_labels is not None:
df.flags["allows_duplicate_labels"] = allows_duplicate_labels
return df
def _validate_dtype(cls, dtype) -> DtypeObj | None:
"""validate the passed dtype"""
if dtype is not None:
dtype = pandas_dtype(dtype)
# a compound dtype
if dtype.kind == "V":
raise NotImplementedError(
"compound dtypes are not implemented "
f"in the {cls.__name__} constructor"
)
return dtype
# ----------------------------------------------------------------------
# Construction
def _constructor(self: NDFrameT) -> Callable[..., NDFrameT]:
"""
Used when a manipulation result has the same dimensions as the
original.
"""
raise AbstractMethodError(self)
# ----------------------------------------------------------------------
# Internals
def _data(self):
# GH#33054 retained because some downstream packages uses this,
# e.g. fastparquet
return self._mgr
# ----------------------------------------------------------------------
# Axis
_stat_axis_number = 0
_stat_axis_name = "index"
_AXIS_ORDERS: list[Literal["index", "columns"]]
_AXIS_TO_AXIS_NUMBER: dict[Axis, AxisInt] = {0: 0, "index": 0, "rows": 0}
_info_axis_number: int
_info_axis_name: Literal["index", "columns"]
_AXIS_LEN: int
def _construct_axes_dict(self, axes: Sequence[Axis] | None = None, **kwargs):
"""Return an axes dictionary for myself."""
d = {a: self._get_axis(a) for a in (axes or self._AXIS_ORDERS)}
# error: Argument 1 to "update" of "MutableMapping" has incompatible type
# "Dict[str, Any]"; expected "SupportsKeysAndGetItem[Union[int, str], Any]"
d.update(kwargs) # type: ignore[arg-type]
return d
def _get_axis_number(cls, axis: Axis) -> AxisInt:
try:
return cls._AXIS_TO_AXIS_NUMBER[axis]
except KeyError:
raise ValueError(f"No axis named {axis} for object type {cls.__name__}")
def _get_axis_name(cls, axis: Axis) -> Literal["index", "columns"]:
axis_number = cls._get_axis_number(axis)
return cls._AXIS_ORDERS[axis_number]
def _get_axis(self, axis: Axis) -> Index:
axis_number = self._get_axis_number(axis)
assert axis_number in {0, 1}
return self.index if axis_number == 0 else self.columns
def _get_block_manager_axis(cls, axis: Axis) -> AxisInt:
"""Map the axis to the block_manager axis."""
axis = cls._get_axis_number(axis)
ndim = cls._AXIS_LEN
if ndim == 2:
# i.e. DataFrame
return 1 - axis
return axis
def _get_axis_resolvers(self, axis: str) -> dict[str, Series | MultiIndex]:
# index or columns
axis_index = getattr(self, axis)
d = {}
prefix = axis[0]
for i, name in enumerate(axis_index.names):
if name is not None:
key = level = name
else:
# prefix with 'i' or 'c' depending on the input axis
# e.g., you must do ilevel_0 for the 0th level of an unnamed
# multiiindex
key = f"{prefix}level_{i}"
level = i
level_values = axis_index.get_level_values(level)
s = level_values.to_series()
s.index = axis_index
d[key] = s
# put the index/columns itself in the dict
if isinstance(axis_index, MultiIndex):
dindex = axis_index
else:
dindex = axis_index.to_series()
d[axis] = dindex
return d
def _get_index_resolvers(self) -> dict[Hashable, Series | MultiIndex]:
from pandas.core.computation.parsing import clean_column_name
d: dict[str, Series | MultiIndex] = {}
for axis_name in self._AXIS_ORDERS:
d.update(self._get_axis_resolvers(axis_name))
return {clean_column_name(k): v for k, v in d.items() if not isinstance(k, int)}
def _get_cleaned_column_resolvers(self) -> dict[Hashable, Series]:
"""
Return the special character free column resolvers of a dataframe.
Column names with special characters are 'cleaned up' so that they can
be referred to by backtick quoting.
Used in :meth:`DataFrame.eval`.
"""
from pandas.core.computation.parsing import clean_column_name
if isinstance(self, ABCSeries):
return {clean_column_name(self.name): self}
return {
clean_column_name(k): v for k, v in self.items() if not isinstance(k, int)
}
def _info_axis(self) -> Index:
return getattr(self, self._info_axis_name)
def _stat_axis(self) -> Index:
return getattr(self, self._stat_axis_name)
def shape(self) -> tuple[int, ...]:
"""
Return a tuple of axis dimensions
"""
return tuple(len(self._get_axis(a)) for a in self._AXIS_ORDERS)
def axes(self) -> list[Index]:
"""
Return index label(s) of the internal NDFrame
"""
# we do it this way because if we have reversed axes, then
# the block manager shows then reversed
return [self._get_axis(a) for a in self._AXIS_ORDERS]
def ndim(self) -> int:
"""
Return an int representing the number of axes / array dimensions.
Return 1 if Series. Otherwise return 2 if DataFrame.
See Also
--------
ndarray.ndim : Number of array dimensions.
Examples
--------
>>> s = pd.Series({'a': 1, 'b': 2, 'c': 3})
>>> s.ndim
1
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.ndim
2
"""
return self._mgr.ndim
def size(self) -> int:
"""
Return an int representing the number of elements in this object.
Return the number of rows if Series. Otherwise return the number of
rows times number of columns if DataFrame.
See Also
--------
ndarray.size : Number of elements in the array.
Examples
--------
>>> s = pd.Series({'a': 1, 'b': 2, 'c': 3})
>>> s.size
3
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.size
4
"""
# error: Incompatible return value type (got "signedinteger[_64Bit]",
# expected "int") [return-value]
return np.prod(self.shape) # type: ignore[return-value]
def set_axis(
self: NDFrameT,
labels,
*,
axis: Axis = 0,
copy: bool_t | None = None,
) -> NDFrameT:
"""
Assign desired index to given axis.
Indexes for%(extended_summary_sub)s row labels can be changed by assigning
a list-like or Index.
Parameters
----------
labels : list-like, Index
The values for the new index.
axis : %(axes_single_arg)s, default 0
The axis to update. The value 0 identifies the rows. For `Series`
this parameter is unused and defaults to 0.
copy : bool, default True
Whether to make a copy of the underlying data.
.. versionadded:: 1.5.0
Returns
-------
%(klass)s
An object of type %(klass)s.
See Also
--------
%(klass)s.rename_axis : Alter the name of the index%(see_also_sub)s.
"""
return self._set_axis_nocheck(labels, axis, inplace=False, copy=copy)
def _set_axis_nocheck(
self, labels, axis: Axis, inplace: bool_t, copy: bool_t | None
):
if inplace:
setattr(self, self._get_axis_name(axis), labels)
else:
# With copy=False, we create a new object but don't copy the
# underlying data.
obj = self.copy(deep=copy and not using_copy_on_write())
setattr(obj, obj._get_axis_name(axis), labels)
return obj
def _set_axis(self, axis: AxisInt, labels: AnyArrayLike | list) -> None:
"""
This is called from the cython code when we set the `index` attribute
directly, e.g. `series.index = [1, 2, 3]`.
"""
labels = ensure_index(labels)
self._mgr.set_axis(axis, labels)
self._clear_item_cache()
def swapaxes(
self: NDFrameT, axis1: Axis, axis2: Axis, copy: bool_t | None = None
) -> NDFrameT:
"""
Interchange axes and swap values axes appropriately.
Returns
-------
same as input
"""
i = self._get_axis_number(axis1)
j = self._get_axis_number(axis2)
if i == j:
return self.copy(deep=copy and not using_copy_on_write())
mapping = {i: j, j: i}
new_axes = [self._get_axis(mapping.get(k, k)) for k in range(self._AXIS_LEN)]
new_values = self._values.swapaxes(i, j) # type: ignore[union-attr]
if (
using_copy_on_write()
and self._mgr.is_single_block
and isinstance(self._mgr, BlockManager)
):
# This should only get hit in case of having a single block, otherwise a
# copy is made, we don't have to set up references.
new_mgr = ndarray_to_mgr(
new_values,
new_axes[0],
new_axes[1],
dtype=None,
copy=False,
typ="block",
)
assert isinstance(new_mgr, BlockManager)
assert isinstance(self._mgr, BlockManager)
new_mgr.blocks[0].refs = self._mgr.blocks[0].refs
new_mgr.blocks[0].refs.add_reference(
new_mgr.blocks[0] # type: ignore[arg-type]
)
return self._constructor(new_mgr).__finalize__(self, method="swapaxes")
elif (copy or copy is None) and self._mgr.is_single_block:
new_values = new_values.copy()
return self._constructor(
new_values,
*new_axes,
# The no-copy case for CoW is handled above
copy=False,
).__finalize__(self, method="swapaxes")
def droplevel(self: NDFrameT, level: IndexLabel, axis: Axis = 0) -> NDFrameT:
"""
Return {klass} with requested index / column level(s) removed.
Parameters
----------
level : int, str, or list-like
If a string is given, must be the name of a level
If list-like, elements must be names or positional indexes
of levels.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
Axis along which the level(s) is removed:
* 0 or 'index': remove level(s) in column.
* 1 or 'columns': remove level(s) in row.
For `Series` this parameter is unused and defaults to 0.
Returns
-------
{klass}
{klass} with requested index / column level(s) removed.
Examples
--------
>>> df = pd.DataFrame([
... [1, 2, 3, 4],
... [5, 6, 7, 8],
... [9, 10, 11, 12]
... ]).set_index([0, 1]).rename_axis(['a', 'b'])
>>> df.columns = pd.MultiIndex.from_tuples([
... ('c', 'e'), ('d', 'f')
... ], names=['level_1', 'level_2'])
>>> df
level_1 c d
level_2 e f
a b
1 2 3 4
5 6 7 8
9 10 11 12
>>> df.droplevel('a')
level_1 c d
level_2 e f
b
2 3 4
6 7 8
10 11 12
>>> df.droplevel('level_2', axis=1)
level_1 c d
a b
1 2 3 4
5 6 7 8
9 10 11 12
"""
labels = self._get_axis(axis)
new_labels = labels.droplevel(level)
return self.set_axis(new_labels, axis=axis, copy=None)
def pop(self, item: Hashable) -> Series | Any:
result = self[item]
del self[item]
return result
def squeeze(self, axis: Axis | None = None):
"""
Squeeze 1 dimensional axis objects into scalars.
Series or DataFrames with a single element are squeezed to a scalar.
DataFrames with a single column or a single row are squeezed to a
Series. Otherwise the object is unchanged.
This method is most useful when you don't know if your
object is a Series or DataFrame, but you do know it has just a single
column. In that case you can safely call `squeeze` to ensure you have a
Series.
Parameters
----------
axis : {0 or 'index', 1 or 'columns', None}, default None
A specific axis to squeeze. By default, all length-1 axes are
squeezed. For `Series` this parameter is unused and defaults to `None`.
Returns
-------
DataFrame, Series, or scalar
The projection after squeezing `axis` or all the axes.
See Also
--------
Series.iloc : Integer-location based indexing for selecting scalars.
DataFrame.iloc : Integer-location based indexing for selecting Series.
Series.to_frame : Inverse of DataFrame.squeeze for a
single-column DataFrame.
Examples
--------
>>> primes = pd.Series([2, 3, 5, 7])
Slicing might produce a Series with a single value:
>>> even_primes = primes[primes % 2 == 0]
>>> even_primes
0 2
dtype: int64
>>> even_primes.squeeze()
2
Squeezing objects with more than one value in every axis does nothing:
>>> odd_primes = primes[primes % 2 == 1]
>>> odd_primes
1 3
2 5
3 7
dtype: int64
>>> odd_primes.squeeze()
1 3
2 5
3 7
dtype: int64
Squeezing is even more effective when used with DataFrames.
>>> df = pd.DataFrame([[1, 2], [3, 4]], columns=['a', 'b'])
>>> df
a b
0 1 2
1 3 4
Slicing a single column will produce a DataFrame with the columns
having only one value:
>>> df_a = df[['a']]
>>> df_a
a
0 1
1 3
So the columns can be squeezed down, resulting in a Series:
>>> df_a.squeeze('columns')
0 1
1 3
Name: a, dtype: int64
Slicing a single row from a single column will produce a single
scalar DataFrame:
>>> df_0a = df.loc[df.index < 1, ['a']]
>>> df_0a
a
0 1
Squeezing the rows produces a single scalar Series:
>>> df_0a.squeeze('rows')
a 1
Name: 0, dtype: int64
Squeezing all axes will project directly into a scalar:
>>> df_0a.squeeze()
1
"""
axes = range(self._AXIS_LEN) if axis is None else (self._get_axis_number(axis),)
return self.iloc[
tuple(
0 if i in axes and len(a) == 1 else slice(None)
for i, a in enumerate(self.axes)
)
]
# ----------------------------------------------------------------------
# Rename
def _rename(
self: NDFrameT,
mapper: Renamer | None = None,
*,
index: Renamer | None = None,
columns: Renamer | None = None,
axis: Axis | None = None,
copy: bool_t | None = None,
inplace: bool_t = False,
level: Level | None = None,
errors: str = "ignore",
) -> NDFrameT | None:
# called by Series.rename and DataFrame.rename
if mapper is None and index is None and columns is None:
raise TypeError("must pass an index to rename")
if index is not None or columns is not None:
if axis is not None:
raise TypeError(
"Cannot specify both 'axis' and any of 'index' or 'columns'"
)
if mapper is not None:
raise TypeError(
"Cannot specify both 'mapper' and any of 'index' or 'columns'"
)
else:
# use the mapper argument
if axis and self._get_axis_number(axis) == 1:
columns = mapper
else:
index = mapper
self._check_inplace_and_allows_duplicate_labels(inplace)
result = self if inplace else self.copy(deep=copy and not using_copy_on_write())
for axis_no, replacements in enumerate((index, columns)):
if replacements is None:
continue
ax = self._get_axis(axis_no)
f = common.get_rename_function(replacements)
if level is not None:
level = ax._get_level_number(level)
# GH 13473
if not callable(replacements):
if ax._is_multi and level is not None:
indexer = ax.get_level_values(level).get_indexer_for(replacements)
else:
indexer = ax.get_indexer_for(replacements)
if errors == "raise" and len(indexer[indexer == -1]):
missing_labels = [
label
for index, label in enumerate(replacements)
if indexer[index] == -1
]
raise KeyError(f"{missing_labels} not found in axis")
new_index = ax._transform_index(f, level=level)
result._set_axis_nocheck(new_index, axis=axis_no, inplace=True, copy=False)
result._clear_item_cache()
if inplace:
self._update_inplace(result)
return None
else:
return result.__finalize__(self, method="rename")
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: Literal[False] = ...,
) -> NDFrameT:
...
def rename_axis(
self,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: Literal[True],
) -> None:
...
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: bool_t = ...,
) -> NDFrameT | None:
...
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = lib.no_default,
*,
index=lib.no_default,
columns=lib.no_default,
axis: Axis = 0,
copy: bool_t | None = None,
inplace: bool_t = False,
) -> NDFrameT | None:
"""
Set the name of the axis for the index or columns.
Parameters
----------
mapper : scalar, list-like, optional
Value to set the axis name attribute.
index, columns : scalar, list-like, dict-like or function, optional
A scalar, list-like, dict-like or functions transformations to
apply to that axis' values.
Note that the ``columns`` parameter is not allowed if the
object is a Series. This parameter only apply for DataFrame
type objects.
Use either ``mapper`` and ``axis`` to
specify the axis to target with ``mapper``, or ``index``
and/or ``columns``.
axis : {0 or 'index', 1 or 'columns'}, default 0
The axis to rename. For `Series` this parameter is unused and defaults to 0.
copy : bool, default None
Also copy underlying data.
inplace : bool, default False
Modifies the object directly, instead of creating a new Series
or DataFrame.
Returns
-------
Series, DataFrame, or None
The same type as the caller or None if ``inplace=True``.
See Also
--------
Series.rename : Alter Series index labels or name.
DataFrame.rename : Alter DataFrame index labels or name.
Index.rename : Set new names on index.
Notes
-----
``DataFrame.rename_axis`` supports two calling conventions
* ``(index=index_mapper, columns=columns_mapper, ...)``
* ``(mapper, axis={'index', 'columns'}, ...)``
The first calling convention will only modify the names of
the index and/or the names of the Index object that is the columns.
In this case, the parameter ``copy`` is ignored.
The second calling convention will modify the names of the
corresponding index if mapper is a list or a scalar.
However, if mapper is dict-like or a function, it will use the
deprecated behavior of modifying the axis *labels*.
We *highly* recommend using keyword arguments to clarify your
intent.
Examples
--------
**Series**
>>> s = pd.Series(["dog", "cat", "monkey"])
>>> s
0 dog
1 cat
2 monkey
dtype: object
>>> s.rename_axis("animal")
animal
0 dog
1 cat
2 monkey
dtype: object
**DataFrame**
>>> df = pd.DataFrame({"num_legs": [4, 4, 2],
... "num_arms": [0, 0, 2]},
... ["dog", "cat", "monkey"])
>>> df
num_legs num_arms
dog 4 0
cat 4 0
monkey 2 2
>>> df = df.rename_axis("animal")
>>> df
num_legs num_arms
animal
dog 4 0
cat 4 0
monkey 2 2
>>> df = df.rename_axis("limbs", axis="columns")
>>> df
limbs num_legs num_arms
animal
dog 4 0
cat 4 0
monkey 2 2
**MultiIndex**
>>> df.index = pd.MultiIndex.from_product([['mammal'],
... ['dog', 'cat', 'monkey']],
... names=['type', 'name'])
>>> df
limbs num_legs num_arms
type name
mammal dog 4 0
cat 4 0
monkey 2 2
>>> df.rename_axis(index={'type': 'class'})
limbs num_legs num_arms
class name
mammal dog 4 0
cat 4 0
monkey 2 2
>>> df.rename_axis(columns=str.upper)
LIMBS num_legs num_arms
type name
mammal dog 4 0
cat 4 0
monkey 2 2
"""
axes = {"index": index, "columns": columns}
if axis is not None:
axis = self._get_axis_number(axis)
inplace = validate_bool_kwarg(inplace, "inplace")
if copy and using_copy_on_write():
copy = False
if mapper is not lib.no_default:
# Use v0.23 behavior if a scalar or list
non_mapper = is_scalar(mapper) or (
is_list_like(mapper) and not is_dict_like(mapper)
)
if non_mapper:
return self._set_axis_name(
mapper, axis=axis, inplace=inplace, copy=copy
)
else:
raise ValueError("Use `.rename` to alter labels with a mapper.")
else:
# Use new behavior. Means that index and/or columns
# is specified
result = self if inplace else self.copy(deep=copy)
for axis in range(self._AXIS_LEN):
v = axes.get(self._get_axis_name(axis))
if v is lib.no_default:
continue
non_mapper = is_scalar(v) or (is_list_like(v) and not is_dict_like(v))
if non_mapper:
newnames = v
else:
f = common.get_rename_function(v)
curnames = self._get_axis(axis).names
newnames = [f(name) for name in curnames]
result._set_axis_name(newnames, axis=axis, inplace=True, copy=copy)
if not inplace:
return result
return None
def _set_axis_name(
self, name, axis: Axis = 0, inplace: bool_t = False, copy: bool_t | None = True
):
"""
Set the name(s) of the axis.
Parameters
----------
name : str or list of str
Name(s) to set.
axis : {0 or 'index', 1 or 'columns'}, default 0
The axis to set the label. The value 0 or 'index' specifies index,
and the value 1 or 'columns' specifies columns.
inplace : bool, default False
If `True`, do operation inplace and return None.
copy:
Whether to make a copy of the result.
Returns
-------
Series, DataFrame, or None
The same type as the caller or `None` if `inplace` is `True`.
See Also
--------
DataFrame.rename : Alter the axis labels of :class:`DataFrame`.
Series.rename : Alter the index labels or set the index name
of :class:`Series`.
Index.rename : Set the name of :class:`Index` or :class:`MultiIndex`.
Examples
--------
>>> df = pd.DataFrame({"num_legs": [4, 4, 2]},
... ["dog", "cat", "monkey"])
>>> df
num_legs
dog 4
cat 4
monkey 2
>>> df._set_axis_name("animal")
num_legs
animal
dog 4
cat 4
monkey 2
>>> df.index = pd.MultiIndex.from_product(
... [["mammal"], ['dog', 'cat', 'monkey']])
>>> df._set_axis_name(["type", "name"])
num_legs
type name
mammal dog 4
cat 4
monkey 2
"""
axis = self._get_axis_number(axis)
idx = self._get_axis(axis).set_names(name)
inplace = validate_bool_kwarg(inplace, "inplace")
renamed = self if inplace else self.copy(deep=copy)
if axis == 0:
renamed.index = idx
else:
renamed.columns = idx
if not inplace:
return renamed
# ----------------------------------------------------------------------
# Comparison Methods
def _indexed_same(self, other) -> bool_t:
return all(
self._get_axis(a).equals(other._get_axis(a)) for a in self._AXIS_ORDERS
)
def equals(self, other: object) -> bool_t:
"""
Test whether two objects contain the same elements.
This function allows two Series or DataFrames to be compared against
each other to see if they have the same shape and elements. NaNs in
the same location are considered equal.
The row/column index do not need to have the same type, as long
as the values are considered equal. Corresponding columns must be of
the same dtype.
Parameters
----------
other : Series or DataFrame
The other Series or DataFrame to be compared with the first.
Returns
-------
bool
True if all elements are the same in both objects, False
otherwise.
See Also
--------
Series.eq : Compare two Series objects of the same length
and return a Series where each element is True if the element
in each Series is equal, False otherwise.
DataFrame.eq : Compare two DataFrame objects of the same shape and
return a DataFrame where each element is True if the respective
element in each DataFrame is equal, False otherwise.
testing.assert_series_equal : Raises an AssertionError if left and
right are not equal. Provides an easy interface to ignore
inequality in dtypes, indexes and precision among others.
testing.assert_frame_equal : Like assert_series_equal, but targets
DataFrames.
numpy.array_equal : Return True if two arrays have the same shape
and elements, False otherwise.
Examples
--------
>>> df = pd.DataFrame({1: [10], 2: [20]})
>>> df
1 2
0 10 20
DataFrames df and exactly_equal have the same types and values for
their elements and column labels, which will return True.
>>> exactly_equal = pd.DataFrame({1: [10], 2: [20]})
>>> exactly_equal
1 2
0 10 20
>>> df.equals(exactly_equal)
True
DataFrames df and different_column_type have the same element
types and values, but have different types for the column labels,
which will still return True.
>>> different_column_type = pd.DataFrame({1.0: [10], 2.0: [20]})
>>> different_column_type
1.0 2.0
0 10 20
>>> df.equals(different_column_type)
True
DataFrames df and different_data_type have different types for the
same values for their elements, and will return False even though
their column labels are the same values and types.
>>> different_data_type = pd.DataFrame({1: [10.0], 2: [20.0]})
>>> different_data_type
1 2
0 10.0 20.0
>>> df.equals(different_data_type)
False
"""
if not (isinstance(other, type(self)) or isinstance(self, type(other))):
return False
other = cast(NDFrame, other)
return self._mgr.equals(other._mgr)
# -------------------------------------------------------------------------
# Unary Methods
def __neg__(self: NDFrameT) -> NDFrameT:
def blk_func(values: ArrayLike):
if is_bool_dtype(values.dtype):
# error: Argument 1 to "inv" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsInversion[ndarray[Any, dtype[bool_]]]"
return operator.inv(values) # type: ignore[arg-type]
else:
# error: Argument 1 to "neg" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsNeg[ndarray[Any, dtype[Any]]]"
return operator.neg(values) # type: ignore[arg-type]
new_data = self._mgr.apply(blk_func)
res = self._constructor(new_data)
return res.__finalize__(self, method="__neg__")
def __pos__(self: NDFrameT) -> NDFrameT:
def blk_func(values: ArrayLike):
if is_bool_dtype(values.dtype):
return values.copy()
else:
# error: Argument 1 to "pos" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsPos[ndarray[Any, dtype[Any]]]"
return operator.pos(values) # type: ignore[arg-type]
new_data = self._mgr.apply(blk_func)
res = self._constructor(new_data)
return res.__finalize__(self, method="__pos__")
def __invert__(self: NDFrameT) -> NDFrameT:
if not self.size:
# inv fails with 0 len
return self.copy(deep=False)
new_data = self._mgr.apply(operator.invert)
return self._constructor(new_data).__finalize__(self, method="__invert__")
def __nonzero__(self) -> NoReturn:
raise ValueError(
f"The truth value of a {type(self).__name__} is ambiguous. "
"Use a.empty, a.bool(), a.item(), a.any() or a.all()."
)
__bool__ = __nonzero__
def bool(self) -> bool_t:
"""
Return the bool of a single element Series or DataFrame.
This must be a boolean scalar value, either True or False. It will raise a
ValueError if the Series or DataFrame does not have exactly 1 element, or that
element is not boolean (integer values 0 and 1 will also raise an exception).
Returns
-------
bool
The value in the Series or DataFrame.
See Also
--------
Series.astype : Change the data type of a Series, including to boolean.
DataFrame.astype : Change the data type of a DataFrame, including to boolean.
numpy.bool_ : NumPy boolean data type, used by pandas for boolean values.
Examples
--------
The method will only work for single element objects with a boolean value:
>>> pd.Series([True]).bool()
True
>>> pd.Series([False]).bool()
False
>>> pd.DataFrame({'col': [True]}).bool()
True
>>> pd.DataFrame({'col': [False]}).bool()
False
"""
v = self.squeeze()
if isinstance(v, (bool, np.bool_)):
return bool(v)
elif is_scalar(v):
raise ValueError(
"bool cannot act on a non-boolean single element "
f"{type(self).__name__}"
)
self.__nonzero__()
# for mypy (__nonzero__ raises)
return True
def abs(self: NDFrameT) -> NDFrameT:
"""
Return a Series/DataFrame with absolute numeric value of each element.
This function only applies to elements that are all numeric.
Returns
-------
abs
Series/DataFrame containing the absolute value of each element.
See Also
--------
numpy.absolute : Calculate the absolute value element-wise.
Notes
-----
For ``complex`` inputs, ``1.2 + 1j``, the absolute value is
:math:`\\sqrt{ a^2 + b^2 }`.
Examples
--------
Absolute numeric values in a Series.
>>> s = pd.Series([-1.10, 2, -3.33, 4])
>>> s.abs()
0 1.10
1 2.00
2 3.33
3 4.00
dtype: float64
Absolute numeric values in a Series with complex numbers.
>>> s = pd.Series([1.2 + 1j])
>>> s.abs()
0 1.56205
dtype: float64
Absolute numeric values in a Series with a Timedelta element.
>>> s = pd.Series([pd.Timedelta('1 days')])
>>> s.abs()
0 1 days
dtype: timedelta64[ns]
Select rows with data closest to certain value using argsort (from
`StackOverflow <https://stackoverflow.com/a/17758115>`__).
>>> df = pd.DataFrame({
... 'a': [4, 5, 6, 7],
... 'b': [10, 20, 30, 40],
... 'c': [100, 50, -30, -50]
... })
>>> df
a b c
0 4 10 100
1 5 20 50
2 6 30 -30
3 7 40 -50
>>> df.loc[(df.c - 43).abs().argsort()]
a b c
1 5 20 50
0 4 10 100
2 6 30 -30
3 7 40 -50
"""
res_mgr = self._mgr.apply(np.abs)
return self._constructor(res_mgr).__finalize__(self, name="abs")
def __abs__(self: NDFrameT) -> NDFrameT:
return self.abs()
def __round__(self: NDFrameT, decimals: int = 0) -> NDFrameT:
return self.round(decimals).__finalize__(self, method="__round__")
# -------------------------------------------------------------------------
# Label or Level Combination Helpers
#
# A collection of helper methods for DataFrame/Series operations that
# accept a combination of column/index labels and levels. All such
# operations should utilize/extend these methods when possible so that we
# have consistent precedence and validation logic throughout the library.
def _is_level_reference(self, key: Level, axis: Axis = 0) -> bool_t:
"""
Test whether a key is a level reference for a given axis.
To be considered a level reference, `key` must be a string that:
- (axis=0): Matches the name of an index level and does NOT match
a column label.
- (axis=1): Matches the name of a column level and does NOT match
an index label.
Parameters
----------
key : Hashable
Potential level name for the given axis
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
is_level : bool
"""
axis_int = self._get_axis_number(axis)
return (
key is not None
and is_hashable(key)
and key in self.axes[axis_int].names
and not self._is_label_reference(key, axis=axis_int)
)
def _is_label_reference(self, key: Level, axis: Axis = 0) -> bool_t:
"""
Test whether a key is a label reference for a given axis.
To be considered a label reference, `key` must be a string that:
- (axis=0): Matches a column label
- (axis=1): Matches an index label
Parameters
----------
key : Hashable
Potential label name, i.e. Index entry.
axis : int, default 0
Axis perpendicular to the axis that labels are associated with
(0 means search for column labels, 1 means search for index labels)
Returns
-------
is_label: bool
"""
axis_int = self._get_axis_number(axis)
other_axes = (ax for ax in range(self._AXIS_LEN) if ax != axis_int)
return (
key is not None
and is_hashable(key)
and any(key in self.axes[ax] for ax in other_axes)
)
def _is_label_or_level_reference(self, key: Level, axis: AxisInt = 0) -> bool_t:
"""
Test whether a key is a label or level reference for a given axis.
To be considered either a label or a level reference, `key` must be a
string that:
- (axis=0): Matches a column label or an index level
- (axis=1): Matches an index label or a column level
Parameters
----------
key : Hashable
Potential label or level name
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
bool
"""
return self._is_level_reference(key, axis=axis) or self._is_label_reference(
key, axis=axis
)
def _check_label_or_level_ambiguity(self, key: Level, axis: Axis = 0) -> None:
"""
Check whether `key` is ambiguous.
By ambiguous, we mean that it matches both a level of the input
`axis` and a label of the other axis.
Parameters
----------
key : Hashable
Label or level name.
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns).
Raises
------
ValueError: `key` is ambiguous
"""
axis_int = self._get_axis_number(axis)
other_axes = (ax for ax in range(self._AXIS_LEN) if ax != axis_int)
if (
key is not None
and is_hashable(key)
and key in self.axes[axis_int].names
and any(key in self.axes[ax] for ax in other_axes)
):
# Build an informative and grammatical warning
level_article, level_type = (
("an", "index") if axis_int == 0 else ("a", "column")
)
label_article, label_type = (
("a", "column") if axis_int == 0 else ("an", "index")
)
msg = (
f"'{key}' is both {level_article} {level_type} level and "
f"{label_article} {label_type} label, which is ambiguous."
)
raise ValueError(msg)
def _get_label_or_level_values(self, key: Level, axis: AxisInt = 0) -> ArrayLike:
"""
Return a 1-D array of values associated with `key`, a label or level
from the given `axis`.
Retrieval logic:
- (axis=0): Return column values if `key` matches a column label.
Otherwise return index level values if `key` matches an index
level.
- (axis=1): Return row values if `key` matches an index label.
Otherwise return column level values if 'key' matches a column
level
Parameters
----------
key : Hashable
Label or level name.
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
np.ndarray or ExtensionArray
Raises
------
KeyError
if `key` matches neither a label nor a level
ValueError
if `key` matches multiple labels
"""
axis = self._get_axis_number(axis)
other_axes = [ax for ax in range(self._AXIS_LEN) if ax != axis]
if self._is_label_reference(key, axis=axis):
self._check_label_or_level_ambiguity(key, axis=axis)
values = self.xs(key, axis=other_axes[0])._values
elif self._is_level_reference(key, axis=axis):
values = self.axes[axis].get_level_values(key)._values
else:
raise KeyError(key)
# Check for duplicates
if values.ndim > 1:
if other_axes and isinstance(self._get_axis(other_axes[0]), MultiIndex):
multi_message = (
"\n"
"For a multi-index, the label must be a "
"tuple with elements corresponding to each level."
)
else:
multi_message = ""
label_axis_name = "column" if axis == 0 else "index"
raise ValueError(
f"The {label_axis_name} label '{key}' is not unique.{multi_message}"
)
return values
def _drop_labels_or_levels(self, keys, axis: AxisInt = 0):
"""
Drop labels and/or levels for the given `axis`.
For each key in `keys`:
- (axis=0): If key matches a column label then drop the column.
Otherwise if key matches an index level then drop the level.
- (axis=1): If key matches an index label then drop the row.
Otherwise if key matches a column level then drop the level.
Parameters
----------
keys : str or list of str
labels or levels to drop
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
dropped: DataFrame
Raises
------
ValueError
if any `keys` match neither a label nor a level
"""
axis = self._get_axis_number(axis)
# Validate keys
keys = common.maybe_make_list(keys)
invalid_keys = [
k for k in keys if not self._is_label_or_level_reference(k, axis=axis)
]
if invalid_keys:
raise ValueError(
"The following keys are not valid labels or "
f"levels for axis {axis}: {invalid_keys}"
)
# Compute levels and labels to drop
levels_to_drop = [k for k in keys if self._is_level_reference(k, axis=axis)]
labels_to_drop = [k for k in keys if not self._is_level_reference(k, axis=axis)]
# Perform copy upfront and then use inplace operations below.
# This ensures that we always perform exactly one copy.
# ``copy`` and/or ``inplace`` options could be added in the future.
dropped = self.copy(deep=False)
if axis == 0:
# Handle dropping index levels
if levels_to_drop:
dropped.reset_index(levels_to_drop, drop=True, inplace=True)
# Handle dropping columns labels
if labels_to_drop:
dropped.drop(labels_to_drop, axis=1, inplace=True)
else:
# Handle dropping column levels
if levels_to_drop:
if isinstance(dropped.columns, MultiIndex):
# Drop the specified levels from the MultiIndex
dropped.columns = dropped.columns.droplevel(levels_to_drop)
else:
# Drop the last level of Index by replacing with
# a RangeIndex
dropped.columns = RangeIndex(dropped.columns.size)
# Handle dropping index labels
if labels_to_drop:
dropped.drop(labels_to_drop, axis=0, inplace=True)
return dropped
# ----------------------------------------------------------------------
# Iteration
# https://github.com/python/typeshed/issues/2148#issuecomment-520783318
# Incompatible types in assignment (expression has type "None", base class
# "object" defined the type as "Callable[[object], int]")
__hash__: ClassVar[None] # type: ignore[assignment]
def __iter__(self) -> Iterator:
"""
Iterate over info axis.
Returns
-------
iterator
Info axis as iterator.
"""
return iter(self._info_axis)
# can we get a better explanation of this?
def keys(self) -> Index:
"""
Get the 'info axis' (see Indexing for more).
This is index for Series, columns for DataFrame.
Returns
-------
Index
Info axis.
"""
return self._info_axis
def items(self):
"""
Iterate over (label, values) on info axis
This is index for Series and columns for DataFrame.
Returns
-------
Generator
"""
for h in self._info_axis:
yield h, self[h]
def __len__(self) -> int:
"""Returns length of info axis"""
return len(self._info_axis)
def __contains__(self, key) -> bool_t:
"""True if the key is in the info axis"""
return key in self._info_axis
def empty(self) -> bool_t:
"""
Indicator whether Series/DataFrame is empty.
True if Series/DataFrame is entirely empty (no items), meaning any of the
axes are of length 0.
Returns
-------
bool
If Series/DataFrame is empty, return True, if not return False.
See Also
--------
Series.dropna : Return series without null values.
DataFrame.dropna : Return DataFrame with labels on given axis omitted
where (all or any) data are missing.
Notes
-----
If Series/DataFrame contains only NaNs, it is still not considered empty. See
the example below.
Examples
--------
An example of an actual empty DataFrame. Notice the index is empty:
>>> df_empty = pd.DataFrame({'A' : []})
>>> df_empty
Empty DataFrame
Columns: [A]
Index: []
>>> df_empty.empty
True
If we only have NaNs in our DataFrame, it is not considered empty! We
will need to drop the NaNs to make the DataFrame empty:
>>> df = pd.DataFrame({'A' : [np.nan]})
>>> df
A
0 NaN
>>> df.empty
False
>>> df.dropna().empty
True
>>> ser_empty = pd.Series({'A' : []})
>>> ser_empty
A []
dtype: object
>>> ser_empty.empty
False
>>> ser_empty = pd.Series()
>>> ser_empty.empty
True
"""
return any(len(self._get_axis(a)) == 0 for a in self._AXIS_ORDERS)
# ----------------------------------------------------------------------
# Array Interface
# This is also set in IndexOpsMixin
# GH#23114 Ensure ndarray.__op__(DataFrame) returns NotImplemented
__array_priority__: int = 1000
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
values = self._values
arr = np.asarray(values, dtype=dtype)
if (
astype_is_view(values.dtype, arr.dtype)
and using_copy_on_write()
and self._mgr.is_single_block
):
# Check if both conversions can be done without a copy
if astype_is_view(self.dtypes.iloc[0], values.dtype) and astype_is_view(
values.dtype, arr.dtype
):
arr = arr.view()
arr.flags.writeable = False
return arr
def __array_ufunc__(
self, ufunc: np.ufunc, method: str, *inputs: Any, **kwargs: Any
):
return arraylike.array_ufunc(self, ufunc, method, *inputs, **kwargs)
# ----------------------------------------------------------------------
# Picklability
def __getstate__(self) -> dict[str, Any]:
meta = {k: getattr(self, k, None) for k in self._metadata}
return {
"_mgr": self._mgr,
"_typ": self._typ,
"_metadata": self._metadata,
"attrs": self.attrs,
"_flags": {k: self.flags[k] for k in self.flags._keys},
**meta,
}
def __setstate__(self, state) -> None:
if isinstance(state, BlockManager):
self._mgr = state
elif isinstance(state, dict):
if "_data" in state and "_mgr" not in state:
# compat for older pickles
state["_mgr"] = state.pop("_data")
typ = state.get("_typ")
if typ is not None:
attrs = state.get("_attrs", {})
object.__setattr__(self, "_attrs", attrs)
flags = state.get("_flags", {"allows_duplicate_labels": True})
object.__setattr__(self, "_flags", Flags(self, **flags))
# set in the order of internal names
# to avoid definitional recursion
# e.g. say fill_value needing _mgr to be
# defined
meta = set(self._internal_names + self._metadata)
for k in list(meta):
if k in state and k != "_flags":
v = state[k]
object.__setattr__(self, k, v)
for k, v in state.items():
if k not in meta:
object.__setattr__(self, k, v)
else:
raise NotImplementedError("Pre-0.12 pickles are no longer supported")
elif len(state) == 2:
raise NotImplementedError("Pre-0.12 pickles are no longer supported")
self._item_cache: dict[Hashable, Series] = {}
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
# string representation based upon iterating over self
# (since, by definition, `PandasContainers` are iterable)
prepr = f"[{','.join(map(pprint_thing, self))}]"
return f"{type(self).__name__}({prepr})"
def _repr_latex_(self):
"""
Returns a LaTeX representation for a particular object.
Mainly for use with nbconvert (jupyter notebook conversion to pdf).
"""
if config.get_option("styler.render.repr") == "latex":
return self.to_latex()
else:
return None
def _repr_data_resource_(self):
"""
Not a real Jupyter special repr method, but we use the same
naming convention.
"""
if config.get_option("display.html.table_schema"):
data = self.head(config.get_option("display.max_rows"))
as_json = data.to_json(orient="table")
as_json = cast(str, as_json)
return loads(as_json, object_pairs_hook=collections.OrderedDict)
# ----------------------------------------------------------------------
# I/O Methods
klass="object",
storage_options=_shared_docs["storage_options"],
storage_options_versionadded="1.2.0",
)
def to_excel(
self,
excel_writer,
sheet_name: str = "Sheet1",
na_rep: str = "",
float_format: str | None = None,
columns: Sequence[Hashable] | None = None,
header: Sequence[Hashable] | bool_t = True,
index: bool_t = True,
index_label: IndexLabel = None,
startrow: int = 0,
startcol: int = 0,
engine: str | None = None,
merge_cells: bool_t = True,
inf_rep: str = "inf",
freeze_panes: tuple[int, int] | None = None,
storage_options: StorageOptions = None,
) -> None:
"""
Write {klass} to an Excel sheet.
To write a single {klass} to an Excel .xlsx file it is only necessary to
specify a target file name. To write to multiple sheets it is necessary to
create an `ExcelWriter` object with a target file name, and specify a sheet
in the file to write to.
Multiple sheets may be written to by specifying unique `sheet_name`.
With all data written to the file it is necessary to save the changes.
Note that creating an `ExcelWriter` object with a file name that already
exists will result in the contents of the existing file being erased.
Parameters
----------
excel_writer : path-like, file-like, or ExcelWriter object
File path or existing ExcelWriter.
sheet_name : str, default 'Sheet1'
Name of sheet which will contain DataFrame.
na_rep : str, default ''
Missing data representation.
float_format : str, optional
Format string for floating point numbers. For example
``float_format="%.2f"`` will format 0.1234 to 0.12.
columns : sequence or list of str, optional
Columns to write.
header : bool or list of str, default True
Write out the column names. If a list of string is given it is
assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
index_label : str or sequence, optional
Column label for index column(s) if desired. If not specified, and
`header` and `index` are True, then the index names are used. A
sequence should be given if the DataFrame uses MultiIndex.
startrow : int, default 0
Upper left cell row to dump data frame.
startcol : int, default 0
Upper left cell column to dump data frame.
engine : str, optional
Write engine to use, 'openpyxl' or 'xlsxwriter'. You can also set this
via the options ``io.excel.xlsx.writer`` or
``io.excel.xlsm.writer``.
merge_cells : bool, default True
Write MultiIndex and Hierarchical Rows as merged cells.
inf_rep : str, default 'inf'
Representation for infinity (there is no native representation for
infinity in Excel).
freeze_panes : tuple of int (length 2), optional
Specifies the one-based bottommost row and rightmost column that
is to be frozen.
{storage_options}
.. versionadded:: {storage_options_versionadded}
See Also
--------
to_csv : Write DataFrame to a comma-separated values (csv) file.
ExcelWriter : Class for writing DataFrame objects into excel sheets.
read_excel : Read an Excel file into a pandas DataFrame.
read_csv : Read a comma-separated values (csv) file into DataFrame.
io.formats.style.Styler.to_excel : Add styles to Excel sheet.
Notes
-----
For compatibility with :meth:`~DataFrame.to_csv`,
to_excel serializes lists and dicts to strings before writing.
Once a workbook has been saved it is not possible to write further
data without rewriting the whole workbook.
Examples
--------
Create, write to and save a workbook:
>>> df1 = pd.DataFrame([['a', 'b'], ['c', 'd']],
... index=['row 1', 'row 2'],
... columns=['col 1', 'col 2'])
>>> df1.to_excel("output.xlsx") # doctest: +SKIP
To specify the sheet name:
>>> df1.to_excel("output.xlsx",
... sheet_name='Sheet_name_1') # doctest: +SKIP
If you wish to write to more than one sheet in the workbook, it is
necessary to specify an ExcelWriter object:
>>> df2 = df1.copy()
>>> with pd.ExcelWriter('output.xlsx') as writer: # doctest: +SKIP
... df1.to_excel(writer, sheet_name='Sheet_name_1')
... df2.to_excel(writer, sheet_name='Sheet_name_2')
ExcelWriter can also be used to append to an existing Excel file:
>>> with pd.ExcelWriter('output.xlsx',
... mode='a') as writer: # doctest: +SKIP
... df.to_excel(writer, sheet_name='Sheet_name_3')
To set the library that is used to write the Excel file,
you can pass the `engine` keyword (the default engine is
automatically chosen depending on the file extension):
>>> df1.to_excel('output1.xlsx', engine='xlsxwriter') # doctest: +SKIP
"""
df = self if isinstance(self, ABCDataFrame) else self.to_frame()
from pandas.io.formats.excel import ExcelFormatter
formatter = ExcelFormatter(
df,
na_rep=na_rep,
cols=columns,
header=header,
float_format=float_format,
index=index,
index_label=index_label,
merge_cells=merge_cells,
inf_rep=inf_rep,
)
formatter.write(
excel_writer,
sheet_name=sheet_name,
startrow=startrow,
startcol=startcol,
freeze_panes=freeze_panes,
engine=engine,
storage_options=storage_options,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buf",
)
def to_json(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
orient: str | None = None,
date_format: str | None = None,
double_precision: int = 10,
force_ascii: bool_t = True,
date_unit: str = "ms",
default_handler: Callable[[Any], JSONSerializable] | None = None,
lines: bool_t = False,
compression: CompressionOptions = "infer",
index: bool_t = True,
indent: int | None = None,
storage_options: StorageOptions = None,
mode: Literal["a", "w"] = "w",
) -> str | None:
"""
Convert the object to a JSON string.
Note NaN's and None will be converted to null and datetime objects
will be converted to UNIX timestamps.
Parameters
----------
path_or_buf : str, path object, file-like object, or None, default None
String, path object (implementing os.PathLike[str]), or file-like
object implementing a write() function. If None, the result is
returned as a string.
orient : str
Indication of expected JSON string format.
* Series:
- default is 'index'
- allowed values are: {{'split', 'records', 'index', 'table'}}.
* DataFrame:
- default is 'columns'
- allowed values are: {{'split', 'records', 'index', 'columns',
'values', 'table'}}.
* The format of the JSON string:
- 'split' : dict like {{'index' -> [index], 'columns' -> [columns],
'data' -> [values]}}
- 'records' : list like [{{column -> value}}, ... , {{column -> value}}]
- 'index' : dict like {{index -> {{column -> value}}}}
- 'columns' : dict like {{column -> {{index -> value}}}}
- 'values' : just the values array
- 'table' : dict like {{'schema': {{schema}}, 'data': {{data}}}}
Describing the data, where data component is like ``orient='records'``.
date_format : {{None, 'epoch', 'iso'}}
Type of date conversion. 'epoch' = epoch milliseconds,
'iso' = ISO8601. The default depends on the `orient`. For
``orient='table'``, the default is 'iso'. For all other orients,
the default is 'epoch'.
double_precision : int, default 10
The number of decimal places to use when encoding
floating point values.
force_ascii : bool, default True
Force encoded string to be ASCII.
date_unit : str, default 'ms' (milliseconds)
The time unit to encode to, governs timestamp and ISO8601
precision. One of 's', 'ms', 'us', 'ns' for second, millisecond,
microsecond, and nanosecond respectively.
default_handler : callable, default None
Handler to call if object cannot otherwise be converted to a
suitable format for JSON. Should receive a single argument which is
the object to convert and return a serialisable object.
lines : bool, default False
If 'orient' is 'records' write out line-delimited json format. Will
throw ValueError if incorrect 'orient' since others are not
list-like.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
index : bool, default True
Whether to include the index values in the JSON string. Not
including the index (``index=False``) is only supported when
orient is 'split' or 'table'.
indent : int, optional
Length of whitespace used to indent each record.
{storage_options}
.. versionadded:: 1.2.0
mode : str, default 'w' (writing)
Specify the IO mode for output when supplying a path_or_buf.
Accepted args are 'w' (writing) and 'a' (append) only.
mode='a' is only supported when lines is True and orient is 'records'.
Returns
-------
None or str
If path_or_buf is None, returns the resulting json format as a
string. Otherwise returns None.
See Also
--------
read_json : Convert a JSON string to pandas object.
Notes
-----
The behavior of ``indent=0`` varies from the stdlib, which does not
indent the output but does insert newlines. Currently, ``indent=0``
and the default ``indent=None`` are equivalent in pandas, though this
may change in a future release.
``orient='table'`` contains a 'pandas_version' field under 'schema'.
This stores the version of `pandas` used in the latest revision of the
schema.
Examples
--------
>>> from json import loads, dumps
>>> df = pd.DataFrame(
... [["a", "b"], ["c", "d"]],
... index=["row 1", "row 2"],
... columns=["col 1", "col 2"],
... )
>>> result = df.to_json(orient="split")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"columns": [
"col 1",
"col 2"
],
"index": [
"row 1",
"row 2"
],
"data": [
[
"a",
"b"
],
[
"c",
"d"
]
]
}}
Encoding/decoding a Dataframe using ``'records'`` formatted JSON.
Note that index labels are not preserved with this encoding.
>>> result = df.to_json(orient="records")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
[
{{
"col 1": "a",
"col 2": "b"
}},
{{
"col 1": "c",
"col 2": "d"
}}
]
Encoding/decoding a Dataframe using ``'index'`` formatted JSON:
>>> result = df.to_json(orient="index")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"row 1": {{
"col 1": "a",
"col 2": "b"
}},
"row 2": {{
"col 1": "c",
"col 2": "d"
}}
}}
Encoding/decoding a Dataframe using ``'columns'`` formatted JSON:
>>> result = df.to_json(orient="columns")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"col 1": {{
"row 1": "a",
"row 2": "c"
}},
"col 2": {{
"row 1": "b",
"row 2": "d"
}}
}}
Encoding/decoding a Dataframe using ``'values'`` formatted JSON:
>>> result = df.to_json(orient="values")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
[
[
"a",
"b"
],
[
"c",
"d"
]
]
Encoding with Table Schema:
>>> result = df.to_json(orient="table")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"schema": {{
"fields": [
{{
"name": "index",
"type": "string"
}},
{{
"name": "col 1",
"type": "string"
}},
{{
"name": "col 2",
"type": "string"
}}
],
"primaryKey": [
"index"
],
"pandas_version": "1.4.0"
}},
"data": [
{{
"index": "row 1",
"col 1": "a",
"col 2": "b"
}},
{{
"index": "row 2",
"col 1": "c",
"col 2": "d"
}}
]
}}
"""
from pandas.io import json
if date_format is None and orient == "table":
date_format = "iso"
elif date_format is None:
date_format = "epoch"
config.is_nonnegative_int(indent)
indent = indent or 0
return json.to_json(
path_or_buf=path_or_buf,
obj=self,
orient=orient,
date_format=date_format,
double_precision=double_precision,
force_ascii=force_ascii,
date_unit=date_unit,
default_handler=default_handler,
lines=lines,
compression=compression,
index=index,
indent=indent,
storage_options=storage_options,
mode=mode,
)
def to_hdf(
self,
path_or_buf: FilePath | HDFStore,
key: str,
mode: str = "a",
complevel: int | None = None,
complib: str | None = None,
append: bool_t = False,
format: str | None = None,
index: bool_t = True,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
dropna: bool_t | None = None,
data_columns: Literal[True] | list[str] | None = None,
errors: str = "strict",
encoding: str = "UTF-8",
) -> None:
"""
Write the contained data to an HDF5 file using HDFStore.
Hierarchical Data Format (HDF) is self-describing, allowing an
application to interpret the structure and contents of a file with
no outside information. One HDF file can hold a mix of related objects
which can be accessed as a group or as individual objects.
In order to add another DataFrame or Series to an existing HDF file
please use append mode and a different a key.
.. warning::
One can store a subclass of ``DataFrame`` or ``Series`` to HDF5,
but the type of the subclass is lost upon storing.
For more information see the :ref:`user guide <io.hdf5>`.
Parameters
----------
path_or_buf : str or pandas.HDFStore
File path or HDFStore object.
key : str
Identifier for the group in the store.
mode : {'a', 'w', 'r+'}, default 'a'
Mode to open file:
- 'w': write, a new file is created (an existing file with
the same name would be deleted).
- 'a': append, an existing file is opened for reading and
writing, and if the file does not exist it is created.
- 'r+': similar to 'a', but the file must already exist.
complevel : {0-9}, default None
Specifies a compression level for data.
A value of 0 or None disables compression.
complib : {'zlib', 'lzo', 'bzip2', 'blosc'}, default 'zlib'
Specifies the compression library to be used.
As of v0.20.2 these additional compressors for Blosc are supported
(default if no compressor specified: 'blosc:blosclz'):
{'blosc:blosclz', 'blosc:lz4', 'blosc:lz4hc', 'blosc:snappy',
'blosc:zlib', 'blosc:zstd'}.
Specifying a compression library which is not available issues
a ValueError.
append : bool, default False
For Table formats, append the input data to the existing.
format : {'fixed', 'table', None}, default 'fixed'
Possible values:
- 'fixed': Fixed format. Fast writing/reading. Not-appendable,
nor searchable.
- 'table': Table format. Write as a PyTables Table structure
which may perform worse but allow more flexible operations
like searching / selecting subsets of the data.
- If None, pd.get_option('io.hdf.default_format') is checked,
followed by fallback to "fixed".
index : bool, default True
Write DataFrame index as a column.
min_itemsize : dict or int, optional
Map column names to minimum string sizes for columns.
nan_rep : Any, optional
How to represent null values as str.
Not allowed with append=True.
dropna : bool, default False, optional
Remove missing values.
data_columns : list of columns or True, optional
List of columns to create as indexed data columns for on-disk
queries, or True to use all columns. By default only the axes
of the object are indexed. See
:ref:`Query via data columns<io.hdf5-query-data-columns>`. for
more information.
Applicable only to format='table'.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
encoding : str, default "UTF-8"
See Also
--------
read_hdf : Read from HDF file.
DataFrame.to_orc : Write a DataFrame to the binary orc format.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
DataFrame.to_sql : Write to a SQL table.
DataFrame.to_feather : Write out feather-format for DataFrames.
DataFrame.to_csv : Write out to a csv file.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]},
... index=['a', 'b', 'c']) # doctest: +SKIP
>>> df.to_hdf('data.h5', key='df', mode='w') # doctest: +SKIP
We can add another object to the same file:
>>> s = pd.Series([1, 2, 3, 4]) # doctest: +SKIP
>>> s.to_hdf('data.h5', key='s') # doctest: +SKIP
Reading from HDF file:
>>> pd.read_hdf('data.h5', 'df') # doctest: +SKIP
A B
a 1 4
b 2 5
c 3 6
>>> pd.read_hdf('data.h5', 's') # doctest: +SKIP
0 1
1 2
2 3
3 4
dtype: int64
"""
from pandas.io import pytables
# Argument 3 to "to_hdf" has incompatible type "NDFrame"; expected
# "Union[DataFrame, Series]" [arg-type]
pytables.to_hdf(
path_or_buf,
key,
self, # type: ignore[arg-type]
mode=mode,
complevel=complevel,
complib=complib,
append=append,
format=format,
index=index,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
dropna=dropna,
data_columns=data_columns,
errors=errors,
encoding=encoding,
)
def to_sql(
self,
name: str,
con,
schema: str | None = None,
if_exists: Literal["fail", "replace", "append"] = "fail",
index: bool_t = True,
index_label: IndexLabel = None,
chunksize: int | None = None,
dtype: DtypeArg | None = None,
method: str | None = None,
) -> int | None:
"""
Write records stored in a DataFrame to a SQL database.
Databases supported by SQLAlchemy [1]_ are supported. Tables can be
newly created, appended to, or overwritten.
Parameters
----------
name : str
Name of SQL table.
con : sqlalchemy.engine.(Engine or Connection) or sqlite3.Connection
Using SQLAlchemy makes it possible to use any DB supported by that
library. Legacy support is provided for sqlite3.Connection objects. The user
is responsible for engine disposal and connection closure for the SQLAlchemy
connectable. See `here \
<https://docs.sqlalchemy.org/en/20/core/connections.html>`_.
If passing a sqlalchemy.engine.Connection which is already in a transaction,
the transaction will not be committed. If passing a sqlite3.Connection,
it will not be possible to roll back the record insertion.
schema : str, optional
Specify the schema (if database flavor supports this). If None, use
default schema.
if_exists : {'fail', 'replace', 'append'}, default 'fail'
How to behave if the table already exists.
* fail: Raise a ValueError.
* replace: Drop the table before inserting new values.
* append: Insert new values to the existing table.
index : bool, default True
Write DataFrame index as a column. Uses `index_label` as the column
name in the table.
index_label : str or sequence, default None
Column label for index column(s). If None is given (default) and
`index` is True, then the index names are used.
A sequence should be given if the DataFrame uses MultiIndex.
chunksize : int, optional
Specify the number of rows in each batch to be written at a time.
By default, all rows will be written at once.
dtype : dict or scalar, optional
Specifying the datatype for columns. If a dictionary is used, the
keys should be the column names and the values should be the
SQLAlchemy types or strings for the sqlite3 legacy mode. If a
scalar is provided, it will be applied to all columns.
method : {None, 'multi', callable}, optional
Controls the SQL insertion clause used:
* None : Uses standard SQL ``INSERT`` clause (one per row).
* 'multi': Pass multiple values in a single ``INSERT`` clause.
* callable with signature ``(pd_table, conn, keys, data_iter)``.
Details and a sample callable implementation can be found in the
section :ref:`insert method <io.sql.method>`.
Returns
-------
None or int
Number of rows affected by to_sql. None is returned if the callable
passed into ``method`` does not return an integer number of rows.
The number of returned rows affected is the sum of the ``rowcount``
attribute of ``sqlite3.Cursor`` or SQLAlchemy connectable which may not
reflect the exact number of written rows as stipulated in the
`sqlite3 <https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.rowcount>`__ or
`SQLAlchemy <https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.CursorResult.rowcount>`__.
.. versionadded:: 1.4.0
Raises
------
ValueError
When the table already exists and `if_exists` is 'fail' (the
default).
See Also
--------
read_sql : Read a DataFrame from a table.
Notes
-----
Timezone aware datetime columns will be written as
``Timestamp with timezone`` type with SQLAlchemy if supported by the
database. Otherwise, the datetimes will be stored as timezone unaware
timestamps local to the original timezone.
References
----------
.. [1] https://docs.sqlalchemy.org
.. [2] https://www.python.org/dev/peps/pep-0249/
Examples
--------
Create an in-memory SQLite database.
>>> from sqlalchemy import create_engine
>>> engine = create_engine('sqlite://', echo=False)
Create a table from scratch with 3 rows.
>>> df = pd.DataFrame({'name' : ['User 1', 'User 2', 'User 3']})
>>> df
name
0 User 1
1 User 2
2 User 3
>>> df.to_sql('users', con=engine)
3
>>> from sqlalchemy import text
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 1'), (1, 'User 2'), (2, 'User 3')]
An `sqlalchemy.engine.Connection` can also be passed to `con`:
>>> with engine.begin() as connection:
... df1 = pd.DataFrame({'name' : ['User 4', 'User 5']})
... df1.to_sql('users', con=connection, if_exists='append')
2
This is allowed to support operations that require that the same
DBAPI connection is used for the entire operation.
>>> df2 = pd.DataFrame({'name' : ['User 6', 'User 7']})
>>> df2.to_sql('users', con=engine, if_exists='append')
2
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 1'), (1, 'User 2'), (2, 'User 3'),
(0, 'User 4'), (1, 'User 5'), (0, 'User 6'),
(1, 'User 7')]
Overwrite the table with just ``df2``.
>>> df2.to_sql('users', con=engine, if_exists='replace',
... index_label='id')
2
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 6'), (1, 'User 7')]
Specify the dtype (especially useful for integers with missing values).
Notice that while pandas is forced to store the data as floating point,
the database supports nullable integers. When fetching the data with
Python, we get back integer scalars.
>>> df = pd.DataFrame({"A": [1, None, 2]})
>>> df
A
0 1.0
1 NaN
2 2.0
>>> from sqlalchemy.types import Integer
>>> df.to_sql('integers', con=engine, index=False,
... dtype={"A": Integer()})
3
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM integers")).fetchall()
[(1,), (None,), (2,)]
""" # noqa:E501
from pandas.io import sql
return sql.to_sql(
self,
name,
con,
schema=schema,
if_exists=if_exists,
index=index,
index_label=index_label,
chunksize=chunksize,
dtype=dtype,
method=method,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_pickle(
self,
path: FilePath | WriteBuffer[bytes],
compression: CompressionOptions = "infer",
protocol: int = pickle.HIGHEST_PROTOCOL,
storage_options: StorageOptions = None,
) -> None:
"""
Pickle (serialize) object to file.
Parameters
----------
path : str, path object, or file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. File path where
the pickled object will be stored.
{compression_options}
protocol : int
Int which indicates which protocol should be used by the pickler,
default HIGHEST_PROTOCOL (see [1]_ paragraph 12.1.2). The possible
values are 0, 1, 2, 3, 4, 5. A negative value for the protocol
parameter is equivalent to setting its value to HIGHEST_PROTOCOL.
.. [1] https://docs.python.org/3/library/pickle.html.
{storage_options}
.. versionadded:: 1.2.0
See Also
--------
read_pickle : Load pickled pandas object (or any object) from file.
DataFrame.to_hdf : Write DataFrame to an HDF5 file.
DataFrame.to_sql : Write DataFrame to a SQL database.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
Examples
--------
>>> original_df = pd.DataFrame({{"foo": range(5), "bar": range(5, 10)}}) # doctest: +SKIP
>>> original_df # doctest: +SKIP
foo bar
0 0 5
1 1 6
2 2 7
3 3 8
4 4 9
>>> original_df.to_pickle("./dummy.pkl") # doctest: +SKIP
>>> unpickled_df = pd.read_pickle("./dummy.pkl") # doctest: +SKIP
>>> unpickled_df # doctest: +SKIP
foo bar
0 0 5
1 1 6
2 2 7
3 3 8
4 4 9
""" # noqa: E501
from pandas.io.pickle import to_pickle
to_pickle(
self,
path,
compression=compression,
protocol=protocol,
storage_options=storage_options,
)
def to_clipboard(
self, excel: bool_t = True, sep: str | None = None, **kwargs
) -> None:
r"""
Copy object to the system clipboard.
Write a text representation of object to the system clipboard.
This can be pasted into Excel, for example.
Parameters
----------
excel : bool, default True
Produce output in a csv format for easy pasting into excel.
- True, use the provided separator for csv pasting.
- False, write a string representation of the object to the clipboard.
sep : str, default ``'\t'``
Field delimiter.
**kwargs
These parameters will be passed to DataFrame.to_csv.
See Also
--------
DataFrame.to_csv : Write a DataFrame to a comma-separated values
(csv) file.
read_clipboard : Read text from clipboard and pass to read_csv.
Notes
-----
Requirements for your platform.
- Linux : `xclip`, or `xsel` (with `PyQt4` modules)
- Windows : none
- macOS : none
This method uses the processes developed for the package `pyperclip`. A
solution to render any output string format is given in the examples.
Examples
--------
Copy the contents of a DataFrame to the clipboard.
>>> df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=['A', 'B', 'C'])
>>> df.to_clipboard(sep=',') # doctest: +SKIP
... # Wrote the following to the system clipboard:
... # ,A,B,C
... # 0,1,2,3
... # 1,4,5,6
We can omit the index by passing the keyword `index` and setting
it to false.
>>> df.to_clipboard(sep=',', index=False) # doctest: +SKIP
... # Wrote the following to the system clipboard:
... # A,B,C
... # 1,2,3
... # 4,5,6
Using the original `pyperclip` package for any string output format.
.. code-block:: python
import pyperclip
html = df.style.to_html()
pyperclip.copy(html)
"""
from pandas.io import clipboards
clipboards.to_clipboard(self, excel=excel, sep=sep, **kwargs)
def to_xarray(self):
"""
Return an xarray object from the pandas object.
Returns
-------
xarray.DataArray or xarray.Dataset
Data in the pandas structure converted to Dataset if the object is
a DataFrame, or a DataArray if the object is a Series.
See Also
--------
DataFrame.to_hdf : Write DataFrame to an HDF5 file.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
Notes
-----
See the `xarray docs <https://xarray.pydata.org/en/stable/>`__
Examples
--------
>>> df = pd.DataFrame([('falcon', 'bird', 389.0, 2),
... ('parrot', 'bird', 24.0, 2),
... ('lion', 'mammal', 80.5, 4),
... ('monkey', 'mammal', np.nan, 4)],
... columns=['name', 'class', 'max_speed',
... 'num_legs'])
>>> df
name class max_speed num_legs
0 falcon bird 389.0 2
1 parrot bird 24.0 2
2 lion mammal 80.5 4
3 monkey mammal NaN 4
>>> df.to_xarray()
<xarray.Dataset>
Dimensions: (index: 4)
Coordinates:
* index (index) int64 0 1 2 3
Data variables:
name (index) object 'falcon' 'parrot' 'lion' 'monkey'
class (index) object 'bird' 'bird' 'mammal' 'mammal'
max_speed (index) float64 389.0 24.0 80.5 nan
num_legs (index) int64 2 2 4 4
>>> df['max_speed'].to_xarray()
<xarray.DataArray 'max_speed' (index: 4)>
array([389. , 24. , 80.5, nan])
Coordinates:
* index (index) int64 0 1 2 3
>>> dates = pd.to_datetime(['2018-01-01', '2018-01-01',
... '2018-01-02', '2018-01-02'])
>>> df_multiindex = pd.DataFrame({'date': dates,
... 'animal': ['falcon', 'parrot',
... 'falcon', 'parrot'],
... 'speed': [350, 18, 361, 15]})
>>> df_multiindex = df_multiindex.set_index(['date', 'animal'])
>>> df_multiindex
speed
date animal
2018-01-01 falcon 350
parrot 18
2018-01-02 falcon 361
parrot 15
>>> df_multiindex.to_xarray()
<xarray.Dataset>
Dimensions: (date: 2, animal: 2)
Coordinates:
* date (date) datetime64[ns] 2018-01-01 2018-01-02
* animal (animal) object 'falcon' 'parrot'
Data variables:
speed (date, animal) int64 350 18 361 15
"""
xarray = import_optional_dependency("xarray")
if self.ndim == 1:
return xarray.DataArray.from_series(self)
else:
return xarray.Dataset.from_dataframe(self)
def to_latex(
self,
buf: None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | Sequence[str] = ...,
index: bool_t = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool_t | None = ...,
index_names: bool_t = ...,
bold_rows: bool_t = ...,
column_format: str | None = ...,
longtable: bool_t | None = ...,
escape: bool_t | None = ...,
encoding: str | None = ...,
decimal: str = ...,
multicolumn: bool_t | None = ...,
multicolumn_format: str | None = ...,
multirow: bool_t | None = ...,
caption: str | tuple[str, str] | None = ...,
label: str | None = ...,
position: str | None = ...,
) -> str:
...
def to_latex(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Hashable] | None = ...,
header: bool_t | Sequence[str] = ...,
index: bool_t = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool_t | None = ...,
index_names: bool_t = ...,
bold_rows: bool_t = ...,
column_format: str | None = ...,
longtable: bool_t | None = ...,
escape: bool_t | None = ...,
encoding: str | None = ...,
decimal: str = ...,
multicolumn: bool_t | None = ...,
multicolumn_format: str | None = ...,
multirow: bool_t | None = ...,
caption: str | tuple[str, str] | None = ...,
label: str | None = ...,
position: str | None = ...,
) -> None:
...
def to_latex(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Hashable] | None = None,
header: bool_t | Sequence[str] = True,
index: bool_t = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool_t | None = None,
index_names: bool_t = True,
bold_rows: bool_t = False,
column_format: str | None = None,
longtable: bool_t | None = None,
escape: bool_t | None = None,
encoding: str | None = None,
decimal: str = ".",
multicolumn: bool_t | None = None,
multicolumn_format: str | None = None,
multirow: bool_t | None = None,
caption: str | tuple[str, str] | None = None,
label: str | None = None,
position: str | None = None,
) -> str | None:
r"""
Render object to a LaTeX tabular, longtable, or nested table.
Requires ``\usepackage{{booktabs}}``. The output can be copy/pasted
into a main LaTeX document or read from an external file
with ``\input{{table.tex}}``.
.. versionchanged:: 1.2.0
Added position argument, changed meaning of caption argument.
.. versionchanged:: 2.0.0
Refactored to use the Styler implementation via jinja2 templating.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
columns : list of label, optional
The subset of columns to write. Writes all columns by default.
header : bool or list of str, default True
Write out the column names. If a list of strings is given,
it is assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
na_rep : str, default 'NaN'
Missing data representation.
formatters : list of functions or dict of {{str: function}}, optional
Formatter functions to apply to columns' elements by position or
name. The result of each function must be a unicode string.
List must be of length equal to the number of columns.
float_format : one-parameter function or str, optional, default None
Formatter for floating point numbers. For example
``float_format="%.2f"`` and ``float_format="{{:0.2f}}".format`` will
both result in 0.1234 being formatted as 0.12.
sparsify : bool, optional
Set to False for a DataFrame with a hierarchical index to print
every multiindex key at each row. By default, the value will be
read from the config module.
index_names : bool, default True
Prints the names of the indexes.
bold_rows : bool, default False
Make the row labels bold in the output.
column_format : str, optional
The columns format as specified in `LaTeX table format
<https://en.wikibooks.org/wiki/LaTeX/Tables>`__ e.g. 'rcl' for 3
columns. By default, 'l' will be used for all columns except
columns of numbers, which default to 'r'.
longtable : bool, optional
Use a longtable environment instead of tabular. Requires
adding a \usepackage{{longtable}} to your LaTeX preamble.
By default, the value will be read from the pandas config
module, and set to `True` if the option ``styler.latex.environment`` is
`"longtable"`.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed.
escape : bool, optional
By default, the value will be read from the pandas config
module and set to `True` if the option ``styler.format.escape`` is
`"latex"`. When set to False prevents from escaping latex special
characters in column names.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to `False`.
encoding : str, optional
A string representing the encoding to use in the output file,
defaults to 'utf-8'.
decimal : str, default '.'
Character recognized as decimal separator, e.g. ',' in Europe.
multicolumn : bool, default True
Use \multicolumn to enhance MultiIndex columns.
The default will be read from the config module, and is set
as the option ``styler.sparse.columns``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed.
multicolumn_format : str, default 'r'
The alignment for multicolumns, similar to `column_format`
The default will be read from the config module, and is set as the option
``styler.latex.multicol_align``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to "r".
multirow : bool, default True
Use \multirow to enhance MultiIndex rows. Requires adding a
\usepackage{{multirow}} to your LaTeX preamble. Will print
centered labels (instead of top-aligned) across the contained
rows, separating groups via clines. The default will be read
from the pandas config module, and is set as the option
``styler.sparse.index``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to `True`.
caption : str or tuple, optional
Tuple (full_caption, short_caption),
which results in ``\caption[short_caption]{{full_caption}}``;
if a single string is passed, no short caption will be set.
.. versionchanged:: 1.2.0
Optionally allow caption to be a tuple ``(full_caption, short_caption)``.
label : str, optional
The LaTeX label to be placed inside ``\label{{}}`` in the output.
This is used with ``\ref{{}}`` in the main ``.tex`` file.
position : str, optional
The LaTeX positional argument for tables, to be placed after
``\begin{{}}`` in the output.
.. versionadded:: 1.2.0
Returns
-------
str or None
If buf is None, returns the result as a string. Otherwise returns None.
See Also
--------
io.formats.style.Styler.to_latex : Render a DataFrame to LaTeX
with conditional formatting.
DataFrame.to_string : Render a DataFrame to a console-friendly
tabular output.
DataFrame.to_html : Render a DataFrame as an HTML table.
Notes
-----
As of v2.0.0 this method has changed to use the Styler implementation as
part of :meth:`.Styler.to_latex` via ``jinja2`` templating. This means
that ``jinja2`` is a requirement, and needs to be installed, for this method
to function. It is advised that users switch to using Styler, since that
implementation is more frequently updated and contains much more
flexibility with the output.
Examples
--------
Convert a general DataFrame to LaTeX with formatting:
>>> df = pd.DataFrame(dict(name=['Raphael', 'Donatello'],
... age=[26, 45],
... height=[181.23, 177.65]))
>>> print(df.to_latex(index=False,
... formatters={"name": str.upper},
... float_format="{:.1f}".format,
... )) # doctest: +SKIP
\begin{tabular}{lrr}
\toprule
name & age & height \\
\midrule
RAPHAEL & 26 & 181.2 \\
DONATELLO & 45 & 177.7 \\
\bottomrule
\end{tabular}
"""
# Get defaults from the pandas config
if self.ndim == 1:
self = self.to_frame()
if longtable is None:
longtable = config.get_option("styler.latex.environment") == "longtable"
if escape is None:
escape = config.get_option("styler.format.escape") == "latex"
if multicolumn is None:
multicolumn = config.get_option("styler.sparse.columns")
if multicolumn_format is None:
multicolumn_format = config.get_option("styler.latex.multicol_align")
if multirow is None:
multirow = config.get_option("styler.sparse.index")
if column_format is not None and not isinstance(column_format, str):
raise ValueError("`column_format` must be str or unicode")
length = len(self.columns) if columns is None else len(columns)
if isinstance(header, (list, tuple)) and len(header) != length:
raise ValueError(f"Writing {length} cols but got {len(header)} aliases")
# Refactor formatters/float_format/decimal/na_rep/escape to Styler structure
base_format_ = {
"na_rep": na_rep,
"escape": "latex" if escape else None,
"decimal": decimal,
}
index_format_: dict[str, Any] = {"axis": 0, **base_format_}
column_format_: dict[str, Any] = {"axis": 1, **base_format_}
if isinstance(float_format, str):
float_format_: Callable | None = lambda x: float_format % x
else:
float_format_ = float_format
def _wrap(x, alt_format_):
if isinstance(x, (float, complex)) and float_format_ is not None:
return float_format_(x)
else:
return alt_format_(x)
formatters_: list | tuple | dict | Callable | None = None
if isinstance(formatters, list):
formatters_ = {
c: partial(_wrap, alt_format_=formatters[i])
for i, c in enumerate(self.columns)
}
elif isinstance(formatters, dict):
index_formatter = formatters.pop("__index__", None)
column_formatter = formatters.pop("__columns__", None)
if index_formatter is not None:
index_format_.update({"formatter": index_formatter})
if column_formatter is not None:
column_format_.update({"formatter": column_formatter})
formatters_ = formatters
float_columns = self.select_dtypes(include="float").columns
for col in float_columns:
if col not in formatters.keys():
formatters_.update({col: float_format_})
elif formatters is None and float_format is not None:
formatters_ = partial(_wrap, alt_format_=lambda v: v)
format_index_ = [index_format_, column_format_]
# Deal with hiding indexes and relabelling column names
hide_: list[dict] = []
relabel_index_: list[dict] = []
if columns:
hide_.append(
{
"subset": [c for c in self.columns if c not in columns],
"axis": "columns",
}
)
if header is False:
hide_.append({"axis": "columns"})
elif isinstance(header, (list, tuple)):
relabel_index_.append({"labels": header, "axis": "columns"})
format_index_ = [index_format_] # column_format is overwritten
if index is False:
hide_.append({"axis": "index"})
if index_names is False:
hide_.append({"names": True, "axis": "index"})
render_kwargs_ = {
"hrules": True,
"sparse_index": sparsify,
"sparse_columns": sparsify,
"environment": "longtable" if longtable else None,
"multicol_align": multicolumn_format
if multicolumn
else f"naive-{multicolumn_format}",
"multirow_align": "t" if multirow else "naive",
"encoding": encoding,
"caption": caption,
"label": label,
"position": position,
"column_format": column_format,
"clines": "skip-last;data"
if (multirow and isinstance(self.index, MultiIndex))
else None,
"bold_rows": bold_rows,
}
return self._to_latex_via_styler(
buf,
hide=hide_,
relabel_index=relabel_index_,
format={"formatter": formatters_, **base_format_},
format_index=format_index_,
render_kwargs=render_kwargs_,
)
def _to_latex_via_styler(
self,
buf=None,
*,
hide: dict | list[dict] | None = None,
relabel_index: dict | list[dict] | None = None,
format: dict | list[dict] | None = None,
format_index: dict | list[dict] | None = None,
render_kwargs: dict | None = None,
):
"""
Render object to a LaTeX tabular, longtable, or nested table.
Uses the ``Styler`` implementation with the following, ordered, method chaining:
.. code-block:: python
styler = Styler(DataFrame)
styler.hide(**hide)
styler.relabel_index(**relabel_index)
styler.format(**format)
styler.format_index(**format_index)
styler.to_latex(buf=buf, **render_kwargs)
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
hide : dict, list of dict
Keyword args to pass to the method call of ``Styler.hide``. If a list will
call the method numerous times.
relabel_index : dict, list of dict
Keyword args to pass to the method of ``Styler.relabel_index``. If a list
will call the method numerous times.
format : dict, list of dict
Keyword args to pass to the method call of ``Styler.format``. If a list will
call the method numerous times.
format_index : dict, list of dict
Keyword args to pass to the method call of ``Styler.format_index``. If a
list will call the method numerous times.
render_kwargs : dict
Keyword args to pass to the method call of ``Styler.to_latex``.
Returns
-------
str or None
If buf is None, returns the result as a string. Otherwise returns None.
"""
from pandas.io.formats.style import Styler
self = cast("DataFrame", self)
styler = Styler(self, uuid="")
for kw_name in ["hide", "relabel_index", "format", "format_index"]:
kw = vars()[kw_name]
if isinstance(kw, dict):
getattr(styler, kw_name)(**kw)
elif isinstance(kw, list):
for sub_kw in kw:
getattr(styler, kw_name)(**sub_kw)
# bold_rows is not a direct kwarg of Styler.to_latex
render_kwargs = {} if render_kwargs is None else render_kwargs
if render_kwargs.pop("bold_rows"):
styler.applymap_index(lambda v: "textbf:--rwrap;")
return styler.to_latex(buf=buf, **render_kwargs)
def to_csv(
self,
path_or_buf: None = ...,
sep: str = ...,
na_rep: str = ...,
float_format: str | Callable | None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | list[str] = ...,
index: bool_t = ...,
index_label: IndexLabel | None = ...,
mode: str = ...,
encoding: str | None = ...,
compression: CompressionOptions = ...,
quoting: int | None = ...,
quotechar: str = ...,
lineterminator: str | None = ...,
chunksize: int | None = ...,
date_format: str | None = ...,
doublequote: bool_t = ...,
escapechar: str | None = ...,
decimal: str = ...,
errors: str = ...,
storage_options: StorageOptions = ...,
) -> str:
...
def to_csv(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str],
sep: str = ...,
na_rep: str = ...,
float_format: str | Callable | None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | list[str] = ...,
index: bool_t = ...,
index_label: IndexLabel | None = ...,
mode: str = ...,
encoding: str | None = ...,
compression: CompressionOptions = ...,
quoting: int | None = ...,
quotechar: str = ...,
lineterminator: str | None = ...,
chunksize: int | None = ...,
date_format: str | None = ...,
doublequote: bool_t = ...,
escapechar: str | None = ...,
decimal: str = ...,
errors: str = ...,
storage_options: StorageOptions = ...,
) -> None:
...
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buf",
)
def to_csv(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
sep: str = ",",
na_rep: str = "",
float_format: str | Callable | None = None,
columns: Sequence[Hashable] | None = None,
header: bool_t | list[str] = True,
index: bool_t = True,
index_label: IndexLabel | None = None,
mode: str = "w",
encoding: str | None = None,
compression: CompressionOptions = "infer",
quoting: int | None = None,
quotechar: str = '"',
lineterminator: str | None = None,
chunksize: int | None = None,
date_format: str | None = None,
doublequote: bool_t = True,
escapechar: str | None = None,
decimal: str = ".",
errors: str = "strict",
storage_options: StorageOptions = None,
) -> str | None:
r"""
Write object to a comma-separated values (csv) file.
Parameters
----------
path_or_buf : str, path object, file-like object, or None, default None
String, path object (implementing os.PathLike[str]), or file-like
object implementing a write() function. If None, the result is
returned as a string. If a non-binary file object is passed, it should
be opened with `newline=''`, disabling universal newlines. If a binary
file object is passed, `mode` might need to contain a `'b'`.
.. versionchanged:: 1.2.0
Support for binary file objects was introduced.
sep : str, default ','
String of length 1. Field delimiter for the output file.
na_rep : str, default ''
Missing data representation.
float_format : str, Callable, default None
Format string for floating point numbers. If a Callable is given, it takes
precedence over other numeric formatting parameters, like decimal.
columns : sequence, optional
Columns to write.
header : bool or list of str, default True
Write out the column names. If a list of strings is given it is
assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
index_label : str or sequence, or False, default None
Column label for index column(s) if desired. If None is given, and
`header` and `index` are True, then the index names are used. A
sequence should be given if the object uses MultiIndex. If
False do not print fields for index names. Use index_label=False
for easier importing in R.
mode : str, default 'w'
Python write mode. The available write modes are the same as
:py:func:`open`.
encoding : str, optional
A string representing the encoding to use in the output file,
defaults to 'utf-8'. `encoding` is not supported if `path_or_buf`
is a non-binary file object.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other entries as additional compression options if
compression mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is
supported for compression modes 'gzip', 'bz2', 'zstd', and 'zip'.
.. versionchanged:: 1.2.0
Compression is supported for binary file objects.
.. versionchanged:: 1.2.0
Previous versions forwarded dict entries for 'gzip' to
`gzip.open` instead of `gzip.GzipFile` which prevented
setting `mtime`.
quoting : optional constant from csv module
Defaults to csv.QUOTE_MINIMAL. If you have set a `float_format`
then floats are converted to strings and thus csv.QUOTE_NONNUMERIC
will treat them as non-numeric.
quotechar : str, default '\"'
String of length 1. Character used to quote fields.
lineterminator : str, optional
The newline character or character sequence to use in the output
file. Defaults to `os.linesep`, which depends on the OS in which
this method is called ('\\n' for linux, '\\r\\n' for Windows, i.e.).
.. versionchanged:: 1.5.0
Previously was line_terminator, changed for consistency with
read_csv and the standard library 'csv' module.
chunksize : int or None
Rows to write at a time.
date_format : str, default None
Format string for datetime objects.
doublequote : bool, default True
Control quoting of `quotechar` inside a field.
escapechar : str, default None
String of length 1. Character used to escape `sep` and `quotechar`
when appropriate.
decimal : str, default '.'
Character recognized as decimal separator. E.g. use ',' for
European data.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
Returns
-------
None or str
If path_or_buf is None, returns the resulting csv format as a
string. Otherwise returns None.
See Also
--------
read_csv : Load a CSV file into a DataFrame.
to_excel : Write DataFrame to an Excel file.
Examples
--------
>>> df = pd.DataFrame({{'name': ['Raphael', 'Donatello'],
... 'mask': ['red', 'purple'],
... 'weapon': ['sai', 'bo staff']}})
>>> df.to_csv(index=False)
'name,mask,weapon\nRaphael,red,sai\nDonatello,purple,bo staff\n'
Create 'out.zip' containing 'out.csv'
>>> compression_opts = dict(method='zip',
... archive_name='out.csv') # doctest: +SKIP
>>> df.to_csv('out.zip', index=False,
... compression=compression_opts) # doctest: +SKIP
To write a csv file to a new folder or nested folder you will first
need to create it using either Pathlib or os:
>>> from pathlib import Path # doctest: +SKIP
>>> filepath = Path('folder/subfolder/out.csv') # doctest: +SKIP
>>> filepath.parent.mkdir(parents=True, exist_ok=True) # doctest: +SKIP
>>> df.to_csv(filepath) # doctest: +SKIP
>>> import os # doctest: +SKIP
>>> os.makedirs('folder/subfolder', exist_ok=True) # doctest: +SKIP
>>> df.to_csv('folder/subfolder/out.csv') # doctest: +SKIP
"""
df = self if isinstance(self, ABCDataFrame) else self.to_frame()
formatter = DataFrameFormatter(
frame=df,
header=header,
index=index,
na_rep=na_rep,
float_format=float_format,
decimal=decimal,
)
return DataFrameRenderer(formatter).to_csv(
path_or_buf,
lineterminator=lineterminator,
sep=sep,
encoding=encoding,
errors=errors,
compression=compression,
quoting=quoting,
columns=columns,
index_label=index_label,
mode=mode,
chunksize=chunksize,
quotechar=quotechar,
date_format=date_format,
doublequote=doublequote,
escapechar=escapechar,
storage_options=storage_options,
)
# ----------------------------------------------------------------------
# Lookup Caching
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
raise AbstractMethodError(self)
def _maybe_update_cacher(
self,
clear: bool_t = False,
verify_is_copy: bool_t = True,
inplace: bool_t = False,
) -> None:
"""
See if we need to update our parent cacher if clear, then clear our
cache.
Parameters
----------
clear : bool, default False
Clear the item cache.
verify_is_copy : bool, default True
Provide is_copy checks.
"""
if using_copy_on_write():
return
if verify_is_copy:
self._check_setitem_copy(t="referent")
if clear:
self._clear_item_cache()
def _clear_item_cache(self) -> None:
raise AbstractMethodError(self)
# ----------------------------------------------------------------------
# Indexing Methods
def take(self: NDFrameT, indices, axis: Axis = 0, **kwargs) -> NDFrameT:
"""
Return the elements in the given *positional* indices along an axis.
This means that we are not indexing according to actual values in
the index attribute of the object. We are indexing according to the
actual position of the element in the object.
Parameters
----------
indices : array-like
An array of ints indicating which positions to take.
axis : {0 or 'index', 1 or 'columns', None}, default 0
The axis on which to select elements. ``0`` means that we are
selecting rows, ``1`` means that we are selecting columns.
For `Series` this parameter is unused and defaults to 0.
**kwargs
For compatibility with :meth:`numpy.take`. Has no effect on the
output.
Returns
-------
same type as caller
An array-like containing the elements taken from the object.
See Also
--------
DataFrame.loc : Select a subset of a DataFrame by labels.
DataFrame.iloc : Select a subset of a DataFrame by positions.
numpy.take : Take elements from an array along an axis.
Examples
--------
>>> df = pd.DataFrame([('falcon', 'bird', 389.0),
... ('parrot', 'bird', 24.0),
... ('lion', 'mammal', 80.5),
... ('monkey', 'mammal', np.nan)],
... columns=['name', 'class', 'max_speed'],
... index=[0, 2, 3, 1])
>>> df
name class max_speed
0 falcon bird 389.0
2 parrot bird 24.0
3 lion mammal 80.5
1 monkey mammal NaN
Take elements at positions 0 and 3 along the axis 0 (default).
Note how the actual indices selected (0 and 1) do not correspond to
our selected indices 0 and 3. That's because we are selecting the 0th
and 3rd rows, not rows whose indices equal 0 and 3.
>>> df.take([0, 3])
name class max_speed
0 falcon bird 389.0
1 monkey mammal NaN
Take elements at indices 1 and 2 along the axis 1 (column selection).
>>> df.take([1, 2], axis=1)
class max_speed
0 bird 389.0
2 bird 24.0
3 mammal 80.5
1 mammal NaN
We may take elements using negative integers for positive indices,
starting from the end of the object, just like with Python lists.
>>> df.take([-1, -2])
name class max_speed
1 monkey mammal NaN
3 lion mammal 80.5
"""
nv.validate_take((), kwargs)
return self._take(indices, axis)
def _take(
self: NDFrameT,
indices,
axis: Axis = 0,
convert_indices: bool_t = True,
) -> NDFrameT:
"""
Internal version of the `take` allowing specification of additional args.
See the docstring of `take` for full explanation of the parameters.
"""
if not isinstance(indices, slice):
indices = np.asarray(indices, dtype=np.intp)
if (
axis == 0
and indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_data = self._mgr.take(
indices,
axis=self._get_block_manager_axis(axis),
verify=True,
convert_indices=convert_indices,
)
return self._constructor(new_data).__finalize__(self, method="take")
def _take_with_is_copy(self: NDFrameT, indices, axis: Axis = 0) -> NDFrameT:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning).
See the docstring of `take` for full explanation of the parameters.
"""
result = self._take(indices=indices, axis=axis)
# Maybe set copy if we didn't actually change the index.
if not result._get_axis(axis).equals(self._get_axis(axis)):
result._set_is_copy(self)
return result
def xs(
self: NDFrameT,
key: IndexLabel,
axis: Axis = 0,
level: IndexLabel = None,
drop_level: bool_t = True,
) -> NDFrameT:
"""
Return cross-section from the Series/DataFrame.
This method takes a `key` argument to select data at a particular
level of a MultiIndex.
Parameters
----------
key : label or tuple of label
Label contained in the index, or partially in a MultiIndex.
axis : {0 or 'index', 1 or 'columns'}, default 0
Axis to retrieve cross-section on.
level : object, defaults to first n levels (n=1 or len(key))
In case of a key partially contained in a MultiIndex, indicate
which levels are used. Levels can be referred by label or position.
drop_level : bool, default True
If False, returns object with same levels as self.
Returns
-------
Series or DataFrame
Cross-section from the original Series or DataFrame
corresponding to the selected index levels.
See Also
--------
DataFrame.loc : Access a group of rows and columns
by label(s) or a boolean array.
DataFrame.iloc : Purely integer-location based indexing
for selection by position.
Notes
-----
`xs` can not be used to set values.
MultiIndex Slicers is a generic way to get/set values on
any level or levels.
It is a superset of `xs` functionality, see
:ref:`MultiIndex Slicers <advanced.mi_slicers>`.
Examples
--------
>>> d = {'num_legs': [4, 4, 2, 2],
... 'num_wings': [0, 0, 2, 2],
... 'class': ['mammal', 'mammal', 'mammal', 'bird'],
... 'animal': ['cat', 'dog', 'bat', 'penguin'],
... 'locomotion': ['walks', 'walks', 'flies', 'walks']}
>>> df = pd.DataFrame(data=d)
>>> df = df.set_index(['class', 'animal', 'locomotion'])
>>> df
num_legs num_wings
class animal locomotion
mammal cat walks 4 0
dog walks 4 0
bat flies 2 2
bird penguin walks 2 2
Get values at specified index
>>> df.xs('mammal')
num_legs num_wings
animal locomotion
cat walks 4 0
dog walks 4 0
bat flies 2 2
Get values at several indexes
>>> df.xs(('mammal', 'dog', 'walks'))
num_legs 4
num_wings 0
Name: (mammal, dog, walks), dtype: int64
Get values at specified index and level
>>> df.xs('cat', level=1)
num_legs num_wings
class locomotion
mammal walks 4 0
Get values at several indexes and levels
>>> df.xs(('bird', 'walks'),
... level=[0, 'locomotion'])
num_legs num_wings
animal
penguin 2 2
Get values at specified column and axis
>>> df.xs('num_wings', axis=1)
class animal locomotion
mammal cat walks 0
dog walks 0
bat flies 2
bird penguin walks 2
Name: num_wings, dtype: int64
"""
axis = self._get_axis_number(axis)
labels = self._get_axis(axis)
if isinstance(key, list):
raise TypeError("list keys are not supported in xs, pass a tuple instead")
if level is not None:
if not isinstance(labels, MultiIndex):
raise TypeError("Index must be a MultiIndex")
loc, new_ax = labels.get_loc_level(key, level=level, drop_level=drop_level)
# create the tuple of the indexer
_indexer = [slice(None)] * self.ndim
_indexer[axis] = loc
indexer = tuple(_indexer)
result = self.iloc[indexer]
setattr(result, result._get_axis_name(axis), new_ax)
return result
if axis == 1:
if drop_level:
return self[key]
index = self.columns
else:
index = self.index
if isinstance(index, MultiIndex):
loc, new_index = index._get_loc_level(key, level=0)
if not drop_level:
if lib.is_integer(loc):
new_index = index[loc : loc + 1]
else:
new_index = index[loc]
else:
loc = index.get_loc(key)
if isinstance(loc, np.ndarray):
if loc.dtype == np.bool_:
(inds,) = loc.nonzero()
return self._take_with_is_copy(inds, axis=axis)
else:
return self._take_with_is_copy(loc, axis=axis)
if not is_scalar(loc):
new_index = index[loc]
if is_scalar(loc) and axis == 0:
# In this case loc should be an integer
if self.ndim == 1:
# if we encounter an array-like and we only have 1 dim
# that means that their are list/ndarrays inside the Series!
# so just return them (GH 6394)
return self._values[loc]
new_mgr = self._mgr.fast_xs(loc)
result = self._constructor_sliced(
new_mgr, name=self.index[loc]
).__finalize__(self)
elif is_scalar(loc):
result = self.iloc[:, slice(loc, loc + 1)]
elif axis == 1:
result = self.iloc[:, loc]
else:
result = self.iloc[loc]
result.index = new_index
# this could be a view
# but only in a single-dtyped view sliceable case
result._set_is_copy(self, copy=not result._is_view)
return result
def __getitem__(self, item):
raise AbstractMethodError(self)
def _slice(self: NDFrameT, slobj: slice, axis: Axis = 0) -> NDFrameT:
"""
Construct a slice of this container.
Slicing with this method is *always* positional.
"""
assert isinstance(slobj, slice), type(slobj)
axis = self._get_block_manager_axis(axis)
result = self._constructor(self._mgr.get_slice(slobj, axis=axis))
result = result.__finalize__(self)
# this could be a view
# but only in a single-dtyped view sliceable case
is_copy = axis != 0 or result._is_view
result._set_is_copy(self, copy=is_copy)
return result
def _set_is_copy(self, ref: NDFrame, copy: bool_t = True) -> None:
if not copy:
self._is_copy = None
else:
assert ref is not None
self._is_copy = weakref.ref(ref)
def _check_is_chained_assignment_possible(self) -> bool_t:
"""
Check if we are a view, have a cacher, and are of mixed type.
If so, then force a setitem_copy check.
Should be called just near setting a value
Will return a boolean if it we are a view and are cached, but a
single-dtype meaning that the cacher should be updated following
setting.
"""
if self._is_copy:
self._check_setitem_copy(t="referent")
return False
def _check_setitem_copy(self, t: str = "setting", force: bool_t = False):
"""
Parameters
----------
t : str, the type of setting error
force : bool, default False
If True, then force showing an error.
validate if we are doing a setitem on a chained copy.
It is technically possible to figure out that we are setting on
a copy even WITH a multi-dtyped pandas object. In other words, some
blocks may be views while other are not. Currently _is_view will ALWAYS
return False for multi-blocks to avoid having to handle this case.
df = DataFrame(np.arange(0,9), columns=['count'])
df['group'] = 'b'
# This technically need not raise SettingWithCopy if both are view
# (which is not generally guaranteed but is usually True. However,
# this is in general not a good practice and we recommend using .loc.
df.iloc[0:5]['group'] = 'a'
"""
if using_copy_on_write():
return
# return early if the check is not needed
if not (force or self._is_copy):
return
value = config.get_option("mode.chained_assignment")
if value is None:
return
# see if the copy is not actually referred; if so, then dissolve
# the copy weakref
if self._is_copy is not None and not isinstance(self._is_copy, str):
r = self._is_copy()
if not gc.get_referents(r) or (r is not None and r.shape == self.shape):
self._is_copy = None
return
# a custom message
if isinstance(self._is_copy, str):
t = self._is_copy
elif t == "referent":
t = (
"\n"
"A value is trying to be set on a copy of a slice from a "
"DataFrame\n\n"
"See the caveats in the documentation: "
"https://pandas.pydata.org/pandas-docs/stable/user_guide/"
"indexing.html#returning-a-view-versus-a-copy"
)
else:
t = (
"\n"
"A value is trying to be set on a copy of a slice from a "
"DataFrame.\n"
"Try using .loc[row_indexer,col_indexer] = value "
"instead\n\nSee the caveats in the documentation: "
"https://pandas.pydata.org/pandas-docs/stable/user_guide/"
"indexing.html#returning-a-view-versus-a-copy"
)
if value == "raise":
raise SettingWithCopyError(t)
if value == "warn":
warnings.warn(t, SettingWithCopyWarning, stacklevel=find_stack_level())
def __delitem__(self, key) -> None:
"""
Delete item
"""
deleted = False
maybe_shortcut = False
if self.ndim == 2 and isinstance(self.columns, MultiIndex):
try:
# By using engine's __contains__ we effectively
# restrict to same-length tuples
maybe_shortcut = key not in self.columns._engine
except TypeError:
pass
if maybe_shortcut:
# Allow shorthand to delete all columns whose first len(key)
# elements match key:
if not isinstance(key, tuple):
key = (key,)
for col in self.columns:
if isinstance(col, tuple) and col[: len(key)] == key:
del self[col]
deleted = True
if not deleted:
# If the above loop ran and didn't delete anything because
# there was no match, this call should raise the appropriate
# exception:
loc = self.axes[-1].get_loc(key)
self._mgr = self._mgr.idelete(loc)
# delete from the caches
try:
del self._item_cache[key]
except KeyError:
pass
# ----------------------------------------------------------------------
# Unsorted
def _check_inplace_and_allows_duplicate_labels(self, inplace):
if inplace and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'inplace=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
def get(self, key, default=None):
"""
Get item from object for given key (ex: DataFrame column).
Returns default value if not found.
Parameters
----------
key : object
Returns
-------
same type as items contained in object
Examples
--------
>>> df = pd.DataFrame(
... [
... [24.3, 75.7, "high"],
... [31, 87.8, "high"],
... [22, 71.6, "medium"],
... [35, 95, "medium"],
... ],
... columns=["temp_celsius", "temp_fahrenheit", "windspeed"],
... index=pd.date_range(start="2014-02-12", end="2014-02-15", freq="D"),
... )
>>> df
temp_celsius temp_fahrenheit windspeed
2014-02-12 24.3 75.7 high
2014-02-13 31.0 87.8 high
2014-02-14 22.0 71.6 medium
2014-02-15 35.0 95.0 medium
>>> df.get(["temp_celsius", "windspeed"])
temp_celsius windspeed
2014-02-12 24.3 high
2014-02-13 31.0 high
2014-02-14 22.0 medium
2014-02-15 35.0 medium
>>> ser = df['windspeed']
>>> ser.get('2014-02-13')
'high'
If the key isn't found, the default value will be used.
>>> df.get(["temp_celsius", "temp_kelvin"], default="default_value")
'default_value'
>>> ser.get('2014-02-10', '[unknown]')
'[unknown]'
"""
try:
return self[key]
except (KeyError, ValueError, IndexError):
return default
def _is_view(self) -> bool_t:
"""Return boolean indicating if self is view of another array"""
return self._mgr.is_view
def reindex_like(
self: NDFrameT,
other,
method: Literal["backfill", "bfill", "pad", "ffill", "nearest"] | None = None,
copy: bool_t | None = None,
limit=None,
tolerance=None,
) -> NDFrameT:
"""
Return an object with matching indices as other object.
Conform the object to the same index on all axes. Optional
filling logic, placing NaN in locations having no value
in the previous index. A new object is produced unless the
new index is equivalent to the current one and copy=False.
Parameters
----------
other : Object of the same data type
Its row and column indices are used to define the new indices
of this object.
method : {None, 'backfill'/'bfill', 'pad'/'ffill', 'nearest'}
Method to use for filling holes in reindexed DataFrame.
Please note: this is only applicable to DataFrames/Series with a
monotonically increasing/decreasing index.
* None (default): don't fill gaps
* pad / ffill: propagate last valid observation forward to next
valid
* backfill / bfill: use next valid observation to fill gap
* nearest: use nearest valid observations to fill gap.
copy : bool, default True
Return a new object, even if the passed indexes are the same.
limit : int, default None
Maximum number of consecutive labels to fill for inexact matches.
tolerance : optional
Maximum distance between original and new labels for inexact
matches. The values of the index at the matching locations must
satisfy the equation ``abs(index[indexer] - target) <= tolerance``.
Tolerance may be a scalar value, which applies the same tolerance
to all values, or list-like, which applies variable tolerance per
element. List-like includes list, tuple, array, Series, and must be
the same size as the index and its dtype must exactly match the
index's type.
Returns
-------
Series or DataFrame
Same type as caller, but with changed indices on each axis.
See Also
--------
DataFrame.set_index : Set row labels.
DataFrame.reset_index : Remove row labels or move them to new columns.
DataFrame.reindex : Change to new indices or expand indices.
Notes
-----
Same as calling
``.reindex(index=other.index, columns=other.columns,...)``.
Examples
--------
>>> df1 = pd.DataFrame([[24.3, 75.7, 'high'],
... [31, 87.8, 'high'],
... [22, 71.6, 'medium'],
... [35, 95, 'medium']],
... columns=['temp_celsius', 'temp_fahrenheit',
... 'windspeed'],
... index=pd.date_range(start='2014-02-12',
... end='2014-02-15', freq='D'))
>>> df1
temp_celsius temp_fahrenheit windspeed
2014-02-12 24.3 75.7 high
2014-02-13 31.0 87.8 high
2014-02-14 22.0 71.6 medium
2014-02-15 35.0 95.0 medium
>>> df2 = pd.DataFrame([[28, 'low'],
... [30, 'low'],
... [35.1, 'medium']],
... columns=['temp_celsius', 'windspeed'],
... index=pd.DatetimeIndex(['2014-02-12', '2014-02-13',
... '2014-02-15']))
>>> df2
temp_celsius windspeed
2014-02-12 28.0 low
2014-02-13 30.0 low
2014-02-15 35.1 medium
>>> df2.reindex_like(df1)
temp_celsius temp_fahrenheit windspeed
2014-02-12 28.0 NaN low
2014-02-13 30.0 NaN low
2014-02-14 NaN NaN NaN
2014-02-15 35.1 NaN medium
"""
d = other._construct_axes_dict(
axes=self._AXIS_ORDERS,
method=method,
copy=copy,
limit=limit,
tolerance=tolerance,
)
return self.reindex(**d)
def drop(
self,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: Literal[True],
errors: IgnoreRaise = ...,
) -> None:
...
def drop(
self: NDFrameT,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: Literal[False] = ...,
errors: IgnoreRaise = ...,
) -> NDFrameT:
...
def drop(
self: NDFrameT,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: bool_t = ...,
errors: IgnoreRaise = ...,
) -> NDFrameT | None:
...
def drop(
self: NDFrameT,
labels: IndexLabel = None,
*,
axis: Axis = 0,
index: IndexLabel = None,
columns: IndexLabel = None,
level: Level | None = None,
inplace: bool_t = False,
errors: IgnoreRaise = "raise",
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
if labels is not None:
if index is not None or columns is not None:
raise ValueError("Cannot specify both 'labels' and 'index'/'columns'")
axis_name = self._get_axis_name(axis)
axes = {axis_name: labels}
elif index is not None or columns is not None:
axes = {"index": index}
if self.ndim == 2:
axes["columns"] = columns
else:
raise ValueError(
"Need to specify at least one of 'labels', 'index' or 'columns'"
)
obj = self
for axis, labels in axes.items():
if labels is not None:
obj = obj._drop_axis(labels, axis, level=level, errors=errors)
if inplace:
self._update_inplace(obj)
return None
else:
return obj
def _drop_axis(
self: NDFrameT,
labels,
axis,
level=None,
errors: IgnoreRaise = "raise",
only_slice: bool_t = False,
) -> NDFrameT:
"""
Drop labels from specified axis. Used in the ``drop`` method
internally.
Parameters
----------
labels : single label or list-like
axis : int or axis name
level : int or level name, default None
For MultiIndex
errors : {'ignore', 'raise'}, default 'raise'
If 'ignore', suppress error and existing labels are dropped.
only_slice : bool, default False
Whether indexing along columns should be view-only.
"""
axis_num = self._get_axis_number(axis)
axis = self._get_axis(axis)
if axis.is_unique:
if level is not None:
if not isinstance(axis, MultiIndex):
raise AssertionError("axis must be a MultiIndex")
new_axis = axis.drop(labels, level=level, errors=errors)
else:
new_axis = axis.drop(labels, errors=errors)
indexer = axis.get_indexer(new_axis)
# Case for non-unique axis
else:
is_tuple_labels = is_nested_list_like(labels) or isinstance(labels, tuple)
labels = ensure_object(common.index_labels_to_array(labels))
if level is not None:
if not isinstance(axis, MultiIndex):
raise AssertionError("axis must be a MultiIndex")
mask = ~axis.get_level_values(level).isin(labels)
# GH 18561 MultiIndex.drop should raise if label is absent
if errors == "raise" and mask.all():
raise KeyError(f"{labels} not found in axis")
elif (
isinstance(axis, MultiIndex)
and labels.dtype == "object"
and not is_tuple_labels
):
# Set level to zero in case of MultiIndex and label is string,
# because isin can't handle strings for MultiIndexes GH#36293
# In case of tuples we get dtype object but have to use isin GH#42771
mask = ~axis.get_level_values(0).isin(labels)
else:
mask = ~axis.isin(labels)
# Check if label doesn't exist along axis
labels_missing = (axis.get_indexer_for(labels) == -1).any()
if errors == "raise" and labels_missing:
raise KeyError(f"{labels} not found in axis")
if is_extension_array_dtype(mask.dtype):
# GH#45860
mask = mask.to_numpy(dtype=bool)
indexer = mask.nonzero()[0]
new_axis = axis.take(indexer)
bm_axis = self.ndim - axis_num - 1
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=bm_axis,
allow_dups=True,
copy=None,
only_slice=only_slice,
)
result = self._constructor(new_mgr)
if self.ndim == 1:
result.name = self.name
return result.__finalize__(self)
def _update_inplace(self, result, verify_is_copy: bool_t = True) -> None:
"""
Replace self internals with result.
Parameters
----------
result : same type as self
verify_is_copy : bool, default True
Provide is_copy checks.
"""
# NOTE: This does *not* call __finalize__ and that's an explicit
# decision that we may revisit in the future.
self._reset_cache()
self._clear_item_cache()
self._mgr = result._mgr
self._maybe_update_cacher(verify_is_copy=verify_is_copy, inplace=True)
def add_prefix(self: NDFrameT, prefix: str, axis: Axis | None = None) -> NDFrameT:
"""
Prefix labels with string `prefix`.
For Series, the row labels are prefixed.
For DataFrame, the column labels are prefixed.
Parameters
----------
prefix : str
The string to add before each label.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to add prefix on
.. versionadded:: 2.0.0
Returns
-------
Series or DataFrame
New Series or DataFrame with updated labels.
See Also
--------
Series.add_suffix: Suffix row labels with string `suffix`.
DataFrame.add_suffix: Suffix column labels with string `suffix`.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.add_prefix('item_')
item_0 1
item_1 2
item_2 3
item_3 4
dtype: int64
>>> df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [3, 4, 5, 6]})
>>> df
A B
0 1 3
1 2 4
2 3 5
3 4 6
>>> df.add_prefix('col_')
col_A col_B
0 1 3
1 2 4
2 3 5
3 4 6
"""
f = lambda x: f"{prefix}{x}"
axis_name = self._info_axis_name
if axis is not None:
axis_name = self._get_axis_name(axis)
mapper = {axis_name: f}
# error: Incompatible return value type (got "Optional[NDFrameT]",
# expected "NDFrameT")
# error: Argument 1 to "rename" of "NDFrame" has incompatible type
# "**Dict[str, partial[str]]"; expected "Union[str, int, None]"
# error: Keywords must be strings
return self._rename(**mapper) # type: ignore[return-value, arg-type, misc]
def add_suffix(self: NDFrameT, suffix: str, axis: Axis | None = None) -> NDFrameT:
"""
Suffix labels with string `suffix`.
For Series, the row labels are suffixed.
For DataFrame, the column labels are suffixed.
Parameters
----------
suffix : str
The string to add after each label.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to add suffix on
.. versionadded:: 2.0.0
Returns
-------
Series or DataFrame
New Series or DataFrame with updated labels.
See Also
--------
Series.add_prefix: Prefix row labels with string `prefix`.
DataFrame.add_prefix: Prefix column labels with string `prefix`.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.add_suffix('_item')
0_item 1
1_item 2
2_item 3
3_item 4
dtype: int64
>>> df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [3, 4, 5, 6]})
>>> df
A B
0 1 3
1 2 4
2 3 5
3 4 6
>>> df.add_suffix('_col')
A_col B_col
0 1 3
1 2 4
2 3 5
3 4 6
"""
f = lambda x: f"{x}{suffix}"
axis_name = self._info_axis_name
if axis is not None:
axis_name = self._get_axis_name(axis)
mapper = {axis_name: f}
# error: Incompatible return value type (got "Optional[NDFrameT]",
# expected "NDFrameT")
# error: Argument 1 to "rename" of "NDFrame" has incompatible type
# "**Dict[str, partial[str]]"; expected "Union[str, int, None]"
# error: Keywords must be strings
return self._rename(**mapper) # type: ignore[return-value, arg-type, misc]
def sort_values(
self: NDFrameT,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> NDFrameT:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self: NDFrameT,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: bool_t = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> NDFrameT | None:
...
def sort_values(
self: NDFrameT,
*,
axis: Axis = 0,
ascending: bool_t | Sequence[bool_t] = True,
inplace: bool_t = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool_t = False,
key: ValueKeyFunc = None,
) -> NDFrameT | None:
"""
Sort by the values along either axis.
Parameters
----------%(optional_by)s
axis : %(axes_single_arg)s, default 0
Axis to be sorted.
ascending : bool or list of bool, default True
Sort ascending vs. descending. Specify list for multiple sort
orders. If this is a list of bools, must match the length of
the by.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. `mergesort` and `stable` are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
Puts NaNs at the beginning if `first`; `last` puts NaNs at the
end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
Apply the key function to the values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return a Series with the same shape as the input.
It will be applied to each column in `by` independently.
.. versionadded:: 1.1.0
Returns
-------
DataFrame or None
DataFrame with sorted values or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index : Sort a DataFrame by the index.
Series.sort_values : Similar method for a Series.
Examples
--------
>>> df = pd.DataFrame({
... 'col1': ['A', 'A', 'B', np.nan, 'D', 'C'],
... 'col2': [2, 1, 9, 8, 7, 4],
... 'col3': [0, 1, 9, 4, 2, 3],
... 'col4': ['a', 'B', 'c', 'D', 'e', 'F']
... })
>>> df
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
Sort by col1
>>> df.sort_values(by=['col1'])
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
5 C 4 3 F
4 D 7 2 e
3 NaN 8 4 D
Sort by multiple columns
>>> df.sort_values(by=['col1', 'col2'])
col1 col2 col3 col4
1 A 1 1 B
0 A 2 0 a
2 B 9 9 c
5 C 4 3 F
4 D 7 2 e
3 NaN 8 4 D
Sort Descending
>>> df.sort_values(by='col1', ascending=False)
col1 col2 col3 col4
4 D 7 2 e
5 C 4 3 F
2 B 9 9 c
0 A 2 0 a
1 A 1 1 B
3 NaN 8 4 D
Putting NAs first
>>> df.sort_values(by='col1', ascending=False, na_position='first')
col1 col2 col3 col4
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
2 B 9 9 c
0 A 2 0 a
1 A 1 1 B
Sorting with a key function
>>> df.sort_values(by='col4', key=lambda col: col.str.lower())
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
Natural sort with the key argument,
using the `natsort <https://github.com/SethMMorton/natsort>` package.
>>> df = pd.DataFrame({
... "time": ['0hr', '128hr', '72hr', '48hr', '96hr'],
... "value": [10, 20, 30, 40, 50]
... })
>>> df
time value
0 0hr 10
1 128hr 20
2 72hr 30
3 48hr 40
4 96hr 50
>>> from natsort import index_natsorted
>>> df.sort_values(
... by="time",
... key=lambda x: np.argsort(index_natsorted(df["time"]))
... )
time value
0 0hr 10
3 48hr 40
2 72hr 30
4 96hr 50
1 128hr 20
"""
raise AbstractMethodError(self)
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> NDFrameT:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: bool_t = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> NDFrameT | None:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool_t | Sequence[bool_t] = True,
inplace: bool_t = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool_t = True,
ignore_index: bool_t = False,
key: IndexKeyFunc = None,
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
axis = self._get_axis_number(axis)
ascending = validate_ascending(ascending)
target = self._get_axis(axis)
indexer = get_indexer_indexer(
target, level, ascending, kind, na_position, sort_remaining, key
)
if indexer is None:
if inplace:
result = self
else:
result = self.copy(deep=None)
if ignore_index:
result.index = default_index(len(self))
if inplace:
return None
else:
return result
baxis = self._get_block_manager_axis(axis)
new_data = self._mgr.take(indexer, axis=baxis, verify=False)
# reconstruct axis if needed
new_data.set_axis(baxis, new_data.axes[baxis]._sort_levels_monotonic())
if ignore_index:
axis = 1 if isinstance(self, ABCDataFrame) else 0
new_data.set_axis(axis, default_index(len(indexer)))
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="sort_index")
klass=_shared_doc_kwargs["klass"],
optional_reindex="",
)
def reindex(
self: NDFrameT,
labels=None,
index=None,
columns=None,
axis: Axis | None = None,
method: str | None = None,
copy: bool_t | None = None,
level: Level | None = None,
fill_value: Scalar | None = np.nan,
limit: int | None = None,
tolerance=None,
) -> NDFrameT:
"""
Conform {klass} to new index with optional filling logic.
Places NA/NaN in locations having no value in the previous index. A new object
is produced unless the new index is equivalent to the current one and
``copy=False``.
Parameters
----------
{optional_reindex}
method : {{None, 'backfill'/'bfill', 'pad'/'ffill', 'nearest'}}
Method to use for filling holes in reindexed DataFrame.
Please note: this is only applicable to DataFrames/Series with a
monotonically increasing/decreasing index.
* None (default): don't fill gaps
* pad / ffill: Propagate last valid observation forward to next
valid.
* backfill / bfill: Use next valid observation to fill gap.
* nearest: Use nearest valid observations to fill gap.
copy : bool, default True
Return a new object, even if the passed indexes are the same.
level : int or name
Broadcast across a level, matching Index values on the
passed MultiIndex level.
fill_value : scalar, default np.NaN
Value to use for missing values. Defaults to NaN, but can be any
"compatible" value.
limit : int, default None
Maximum number of consecutive elements to forward or backward fill.
tolerance : optional
Maximum distance between original and new labels for inexact
matches. The values of the index at the matching locations most
satisfy the equation ``abs(index[indexer] - target) <= tolerance``.
Tolerance may be a scalar value, which applies the same tolerance
to all values, or list-like, which applies variable tolerance per
element. List-like includes list, tuple, array, Series, and must be
the same size as the index and its dtype must exactly match the
index's type.
Returns
-------
{klass} with changed index.
See Also
--------
DataFrame.set_index : Set row labels.
DataFrame.reset_index : Remove row labels or move them to new columns.
DataFrame.reindex_like : Change to same indices as other DataFrame.
Examples
--------
``DataFrame.reindex`` supports two calling conventions
* ``(index=index_labels, columns=column_labels, ...)``
* ``(labels, axis={{'index', 'columns'}}, ...)``
We *highly* recommend using keyword arguments to clarify your
intent.
Create a dataframe with some fictional data.
>>> index = ['Firefox', 'Chrome', 'Safari', 'IE10', 'Konqueror']
>>> df = pd.DataFrame({{'http_status': [200, 200, 404, 404, 301],
... 'response_time': [0.04, 0.02, 0.07, 0.08, 1.0]}},
... index=index)
>>> df
http_status response_time
Firefox 200 0.04
Chrome 200 0.02
Safari 404 0.07
IE10 404 0.08
Konqueror 301 1.00
Create a new index and reindex the dataframe. By default
values in the new index that do not have corresponding
records in the dataframe are assigned ``NaN``.
>>> new_index = ['Safari', 'Iceweasel', 'Comodo Dragon', 'IE10',
... 'Chrome']
>>> df.reindex(new_index)
http_status response_time
Safari 404.0 0.07
Iceweasel NaN NaN
Comodo Dragon NaN NaN
IE10 404.0 0.08
Chrome 200.0 0.02
We can fill in the missing values by passing a value to
the keyword ``fill_value``. Because the index is not monotonically
increasing or decreasing, we cannot use arguments to the keyword
``method`` to fill the ``NaN`` values.
>>> df.reindex(new_index, fill_value=0)
http_status response_time
Safari 404 0.07
Iceweasel 0 0.00
Comodo Dragon 0 0.00
IE10 404 0.08
Chrome 200 0.02
>>> df.reindex(new_index, fill_value='missing')
http_status response_time
Safari 404 0.07
Iceweasel missing missing
Comodo Dragon missing missing
IE10 404 0.08
Chrome 200 0.02
We can also reindex the columns.
>>> df.reindex(columns=['http_status', 'user_agent'])
http_status user_agent
Firefox 200 NaN
Chrome 200 NaN
Safari 404 NaN
IE10 404 NaN
Konqueror 301 NaN
Or we can use "axis-style" keyword arguments
>>> df.reindex(['http_status', 'user_agent'], axis="columns")
http_status user_agent
Firefox 200 NaN
Chrome 200 NaN
Safari 404 NaN
IE10 404 NaN
Konqueror 301 NaN
To further illustrate the filling functionality in
``reindex``, we will create a dataframe with a
monotonically increasing index (for example, a sequence
of dates).
>>> date_index = pd.date_range('1/1/2010', periods=6, freq='D')
>>> df2 = pd.DataFrame({{"prices": [100, 101, np.nan, 100, 89, 88]}},
... index=date_index)
>>> df2
prices
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
Suppose we decide to expand the dataframe to cover a wider
date range.
>>> date_index2 = pd.date_range('12/29/2009', periods=10, freq='D')
>>> df2.reindex(date_index2)
prices
2009-12-29 NaN
2009-12-30 NaN
2009-12-31 NaN
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
2010-01-07 NaN
The index entries that did not have a value in the original data frame
(for example, '2009-12-29') are by default filled with ``NaN``.
If desired, we can fill in the missing values using one of several
options.
For example, to back-propagate the last valid value to fill the ``NaN``
values, pass ``bfill`` as an argument to the ``method`` keyword.
>>> df2.reindex(date_index2, method='bfill')
prices
2009-12-29 100.0
2009-12-30 100.0
2009-12-31 100.0
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
2010-01-07 NaN
Please note that the ``NaN`` value present in the original dataframe
(at index value 2010-01-03) will not be filled by any of the
value propagation schemes. This is because filling while reindexing
does not look at dataframe values, but only compares the original and
desired indexes. If you do want to fill in the ``NaN`` values present
in the original dataframe, use the ``fillna()`` method.
See the :ref:`user guide <basics.reindexing>` for more.
"""
# TODO: Decide if we care about having different examples for different
# kinds
if index is not None and columns is not None and labels is not None:
raise TypeError("Cannot specify all of 'labels', 'index', 'columns'.")
elif index is not None or columns is not None:
if axis is not None:
raise TypeError(
"Cannot specify both 'axis' and any of 'index' or 'columns'"
)
if labels is not None:
if index is not None:
columns = labels
else:
index = labels
else:
if axis and self._get_axis_number(axis) == 1:
columns = labels
else:
index = labels
axes: dict[Literal["index", "columns"], Any] = {
"index": index,
"columns": columns,
}
method = clean_reindex_fill_method(method)
# if all axes that are requested to reindex are equal, then only copy
# if indicated must have index names equal here as well as values
if copy and using_copy_on_write():
copy = False
if all(
self._get_axis(axis_name).identical(ax)
for axis_name, ax in axes.items()
if ax is not None
):
return self.copy(deep=copy)
# check if we are a multi reindex
if self._needs_reindex_multi(axes, method, level):
return self._reindex_multi(axes, copy, fill_value)
# perform the reindex on the axes
return self._reindex_axes(
axes, level, limit, tolerance, method, fill_value, copy
).__finalize__(self, method="reindex")
def _reindex_axes(
self: NDFrameT, axes, level, limit, tolerance, method, fill_value, copy
) -> NDFrameT:
"""Perform the reindex for all the axes."""
obj = self
for a in self._AXIS_ORDERS:
labels = axes[a]
if labels is None:
continue
ax = self._get_axis(a)
new_index, indexer = ax.reindex(
labels, level=level, limit=limit, tolerance=tolerance, method=method
)
axis = self._get_axis_number(a)
obj = obj._reindex_with_indexers(
{axis: [new_index, indexer]},
fill_value=fill_value,
copy=copy,
allow_dups=False,
)
# If we've made a copy once, no need to make another one
copy = False
return obj
def _needs_reindex_multi(self, axes, method, level) -> bool_t:
"""Check if we do need a multi reindex."""
return (
(common.count_not_none(*axes.values()) == self._AXIS_LEN)
and method is None
and level is None
and not self._is_mixed_type
and not (
self.ndim == 2
and len(self.dtypes) == 1
and is_extension_array_dtype(self.dtypes.iloc[0])
)
)
def _reindex_multi(self, axes, copy, fill_value):
raise AbstractMethodError(self)
def _reindex_with_indexers(
self: NDFrameT,
reindexers,
fill_value=None,
copy: bool_t | None = False,
allow_dups: bool_t = False,
) -> NDFrameT:
"""allow_dups indicates an internal call here"""
# reindex doing multiple operations on different axes if indicated
new_data = self._mgr
for axis in sorted(reindexers.keys()):
index, indexer = reindexers[axis]
baxis = self._get_block_manager_axis(axis)
if index is None:
continue
index = ensure_index(index)
if indexer is not None:
indexer = ensure_platform_int(indexer)
# TODO: speed up on homogeneous DataFrame objects (see _reindex_multi)
new_data = new_data.reindex_indexer(
index,
indexer,
axis=baxis,
fill_value=fill_value,
allow_dups=allow_dups,
copy=copy,
)
# If we've made a copy once, no need to make another one
copy = False
if (
(copy or copy is None)
and new_data is self._mgr
and not using_copy_on_write()
):
new_data = new_data.copy(deep=copy)
elif using_copy_on_write() and new_data is self._mgr:
new_data = new_data.copy(deep=False)
return self._constructor(new_data).__finalize__(self)
def filter(
self: NDFrameT,
items=None,
like: str | None = None,
regex: str | None = None,
axis: Axis | None = None,
) -> NDFrameT:
"""
Subset the dataframe rows or columns according to the specified index labels.
Note that this routine does not filter a dataframe on its
contents. The filter is applied to the labels of the index.
Parameters
----------
items : list-like
Keep labels from axis which are in items.
like : str
Keep labels from axis for which "like in label == True".
regex : str (regular expression)
Keep labels from axis for which re.search(regex, label) == True.
axis : {0 or ‘index’, 1 or ‘columns’, None}, default None
The axis to filter on, expressed either as an index (int)
or axis name (str). By default this is the info axis, 'columns' for
DataFrame. For `Series` this parameter is unused and defaults to `None`.
Returns
-------
same type as input object
See Also
--------
DataFrame.loc : Access a group of rows and columns
by label(s) or a boolean array.
Notes
-----
The ``items``, ``like``, and ``regex`` parameters are
enforced to be mutually exclusive.
``axis`` defaults to the info axis that is used when indexing
with ``[]``.
Examples
--------
>>> df = pd.DataFrame(np.array(([1, 2, 3], [4, 5, 6])),
... index=['mouse', 'rabbit'],
... columns=['one', 'two', 'three'])
>>> df
one two three
mouse 1 2 3
rabbit 4 5 6
>>> # select columns by name
>>> df.filter(items=['one', 'three'])
one three
mouse 1 3
rabbit 4 6
>>> # select columns by regular expression
>>> df.filter(regex='e$', axis=1)
one three
mouse 1 3
rabbit 4 6
>>> # select rows containing 'bbi'
>>> df.filter(like='bbi', axis=0)
one two three
rabbit 4 5 6
"""
nkw = common.count_not_none(items, like, regex)
if nkw > 1:
raise TypeError(
"Keyword arguments `items`, `like`, or `regex` "
"are mutually exclusive"
)
if axis is None:
axis = self._info_axis_name
labels = self._get_axis(axis)
if items is not None:
name = self._get_axis_name(axis)
# error: Keywords must be strings
return self.reindex( # type: ignore[misc]
**{name: [r for r in items if r in labels]} # type: ignore[arg-type]
)
elif like:
def f(x) -> bool_t:
assert like is not None # needed for mypy
return like in ensure_str(x)
values = labels.map(f)
return self.loc(axis=axis)[values]
elif regex:
def f(x) -> bool_t:
return matcher.search(ensure_str(x)) is not None
matcher = re.compile(regex)
values = labels.map(f)
return self.loc(axis=axis)[values]
else:
raise TypeError("Must pass either `items`, `like`, or `regex`")
def head(self: NDFrameT, n: int = 5) -> NDFrameT:
"""
Return the first `n` rows.
This function returns the first `n` rows for the object based
on position. It is useful for quickly testing if your object
has the right type of data in it.
For negative values of `n`, this function returns all rows except
the last `|n|` rows, equivalent to ``df[:n]``.
If n is larger than the number of rows, this function returns all rows.
Parameters
----------
n : int, default 5
Number of rows to select.
Returns
-------
same type as caller
The first `n` rows of the caller object.
See Also
--------
DataFrame.tail: Returns the last `n` rows.
Examples
--------
>>> df = pd.DataFrame({'animal': ['alligator', 'bee', 'falcon', 'lion',
... 'monkey', 'parrot', 'shark', 'whale', 'zebra']})
>>> df
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the first 5 lines
>>> df.head()
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
Viewing the first `n` lines (three in this case)
>>> df.head(3)
animal
0 alligator
1 bee
2 falcon
For negative values of `n`
>>> df.head(-3)
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
"""
return self.iloc[:n]
def tail(self: NDFrameT, n: int = 5) -> NDFrameT:
"""
Return the last `n` rows.
This function returns last `n` rows from the object based on
position. It is useful for quickly verifying data, for example,
after sorting or appending rows.
For negative values of `n`, this function returns all rows except
the first `|n|` rows, equivalent to ``df[|n|:]``.
If n is larger than the number of rows, this function returns all rows.
Parameters
----------
n : int, default 5
Number of rows to select.
Returns
-------
type of caller
The last `n` rows of the caller object.
See Also
--------
DataFrame.head : The first `n` rows of the caller object.
Examples
--------
>>> df = pd.DataFrame({'animal': ['alligator', 'bee', 'falcon', 'lion',
... 'monkey', 'parrot', 'shark', 'whale', 'zebra']})
>>> df
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the last 5 lines
>>> df.tail()
animal
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the last `n` lines (three in this case)
>>> df.tail(3)
animal
6 shark
7 whale
8 zebra
For negative values of `n`
>>> df.tail(-3)
animal
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
"""
if n == 0:
return self.iloc[0:0]
return self.iloc[-n:]
def sample(
self: NDFrameT,
n: int | None = None,
frac: float | None = None,
replace: bool_t = False,
weights=None,
random_state: RandomState | None = None,
axis: Axis | None = None,
ignore_index: bool_t = False,
) -> NDFrameT:
"""
Return a random sample of items from an axis of object.
You can use `random_state` for reproducibility.
Parameters
----------
n : int, optional
Number of items from axis to return. Cannot be used with `frac`.
Default = 1 if `frac` = None.
frac : float, optional
Fraction of axis items to return. Cannot be used with `n`.
replace : bool, default False
Allow or disallow sampling of the same row more than once.
weights : str or ndarray-like, optional
Default 'None' results in equal probability weighting.
If passed a Series, will align with target object on index. Index
values in weights not found in sampled object will be ignored and
index values in sampled object not in weights will be assigned
weights of zero.
If called on a DataFrame, will accept the name of a column
when axis = 0.
Unless weights are a Series, weights must be same length as axis
being sampled.
If weights do not sum to 1, they will be normalized to sum to 1.
Missing values in the weights column will be treated as zero.
Infinite values not allowed.
random_state : int, array-like, BitGenerator, np.random.RandomState, np.random.Generator, optional
If int, array-like, or BitGenerator, seed for random number generator.
If np.random.RandomState or np.random.Generator, use as given.
.. versionchanged:: 1.1.0
array-like and BitGenerator object now passed to np.random.RandomState()
as seed
.. versionchanged:: 1.4.0
np.random.Generator objects now accepted
axis : {0 or ‘index’, 1 or ‘columns’, None}, default None
Axis to sample. Accepts axis number or name. Default is stat axis
for given data type. For `Series` this parameter is unused and defaults to `None`.
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.3.0
Returns
-------
Series or DataFrame
A new object of same type as caller containing `n` items randomly
sampled from the caller object.
See Also
--------
DataFrameGroupBy.sample: Generates random samples from each group of a
DataFrame object.
SeriesGroupBy.sample: Generates random samples from each group of a
Series object.
numpy.random.choice: Generates a random sample from a given 1-D numpy
array.
Notes
-----
If `frac` > 1, `replacement` should be set to `True`.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [2, 4, 8, 0],
... 'num_wings': [2, 0, 0, 0],
... 'num_specimen_seen': [10, 2, 1, 8]},
... index=['falcon', 'dog', 'spider', 'fish'])
>>> df
num_legs num_wings num_specimen_seen
falcon 2 2 10
dog 4 0 2
spider 8 0 1
fish 0 0 8
Extract 3 random elements from the ``Series`` ``df['num_legs']``:
Note that we use `random_state` to ensure the reproducibility of
the examples.
>>> df['num_legs'].sample(n=3, random_state=1)
fish 0
spider 8
falcon 2
Name: num_legs, dtype: int64
A random 50% sample of the ``DataFrame`` with replacement:
>>> df.sample(frac=0.5, replace=True, random_state=1)
num_legs num_wings num_specimen_seen
dog 4 0 2
fish 0 0 8
An upsample sample of the ``DataFrame`` with replacement:
Note that `replace` parameter has to be `True` for `frac` parameter > 1.
>>> df.sample(frac=2, replace=True, random_state=1)
num_legs num_wings num_specimen_seen
dog 4 0 2
fish 0 0 8
falcon 2 2 10
falcon 2 2 10
fish 0 0 8
dog 4 0 2
fish 0 0 8
dog 4 0 2
Using a DataFrame column as weights. Rows with larger value in the
`num_specimen_seen` column are more likely to be sampled.
>>> df.sample(n=2, weights='num_specimen_seen', random_state=1)
num_legs num_wings num_specimen_seen
falcon 2 2 10
fish 0 0 8
""" # noqa:E501
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
obj_len = self.shape[axis]
# Process random_state argument
rs = common.random_state(random_state)
size = sample.process_sampling_size(n, frac, replace)
if size is None:
assert frac is not None
size = round(frac * obj_len)
if weights is not None:
weights = sample.preprocess_weights(self, weights, axis)
sampled_indices = sample.sample(obj_len, size, replace, weights, rs)
result = self.take(sampled_indices, axis=axis)
if ignore_index:
result.index = default_index(len(result))
return result
def pipe(
self,
func: Callable[..., T] | tuple[Callable[..., T], str],
*args,
**kwargs,
) -> T:
r"""
Apply chainable functions that expect Series or DataFrames.
Parameters
----------
func : function
Function to apply to the {klass}.
``args``, and ``kwargs`` are passed into ``func``.
Alternatively a ``(callable, data_keyword)`` tuple where
``data_keyword`` is a string indicating the keyword of
``callable`` that expects the {klass}.
args : iterable, optional
Positional arguments passed into ``func``.
kwargs : mapping, optional
A dictionary of keyword arguments passed into ``func``.
Returns
-------
the return type of ``func``.
See Also
--------
DataFrame.apply : Apply a function along input axis of DataFrame.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Series.map : Apply a mapping correspondence on a
:class:`~pandas.Series`.
Notes
-----
Use ``.pipe`` when chaining together functions that expect
Series, DataFrames or GroupBy objects. Instead of writing
>>> func(g(h(df), arg1=a), arg2=b, arg3=c) # doctest: +SKIP
You can write
>>> (df.pipe(h)
... .pipe(g, arg1=a)
... .pipe(func, arg2=b, arg3=c)
... ) # doctest: +SKIP
If you have a function that takes the data as (say) the second
argument, pass a tuple indicating which keyword expects the
data. For example, suppose ``func`` takes its data as ``arg2``:
>>> (df.pipe(h)
... .pipe(g, arg1=a)
... .pipe((func, 'arg2'), arg1=a, arg3=c)
... ) # doctest: +SKIP
"""
if using_copy_on_write():
return common.pipe(self.copy(deep=None), func, *args, **kwargs)
return common.pipe(self, func, *args, **kwargs)
# ----------------------------------------------------------------------
# Attribute access
def __finalize__(
self: NDFrameT, other, method: str | None = None, **kwargs
) -> NDFrameT:
"""
Propagate metadata from other to self.
Parameters
----------
other : the object from which to get the attributes that we are going
to propagate
method : str, optional
A passed method name providing context on where ``__finalize__``
was called.
.. warning::
The value passed as `method` are not currently considered
stable across pandas releases.
"""
if isinstance(other, NDFrame):
for name in other.attrs:
self.attrs[name] = other.attrs[name]
self.flags.allows_duplicate_labels = other.flags.allows_duplicate_labels
# For subclasses using _metadata.
for name in set(self._metadata) & set(other._metadata):
assert isinstance(name, str)
object.__setattr__(self, name, getattr(other, name, None))
if method == "concat":
attrs = other.objs[0].attrs
check_attrs = all(objs.attrs == attrs for objs in other.objs[1:])
if check_attrs:
for name in attrs:
self.attrs[name] = attrs[name]
allows_duplicate_labels = all(
x.flags.allows_duplicate_labels for x in other.objs
)
self.flags.allows_duplicate_labels = allows_duplicate_labels
return self
def __getattr__(self, name: str):
"""
After regular attribute access, try looking up the name
This allows simpler access to columns for interactive use.
"""
# Note: obj.x will always call obj.__getattribute__('x') prior to
# calling obj.__getattr__('x').
if (
name not in self._internal_names_set
and name not in self._metadata
and name not in self._accessors
and self._info_axis._can_hold_identifiers_and_holds_name(name)
):
return self[name]
return object.__getattribute__(self, name)
def __setattr__(self, name: str, value) -> None:
"""
After regular attribute access, try setting the name
This allows simpler access to columns for interactive use.
"""
# first try regular attribute access via __getattribute__, so that
# e.g. ``obj.x`` and ``obj.x = 4`` will always reference/modify
# the same attribute.
try:
object.__getattribute__(self, name)
return object.__setattr__(self, name, value)
except AttributeError:
pass
# if this fails, go on to more involved attribute setting
# (note that this matches __getattr__, above).
if name in self._internal_names_set:
object.__setattr__(self, name, value)
elif name in self._metadata:
object.__setattr__(self, name, value)
else:
try:
existing = getattr(self, name)
if isinstance(existing, Index):
object.__setattr__(self, name, value)
elif name in self._info_axis:
self[name] = value
else:
object.__setattr__(self, name, value)
except (AttributeError, TypeError):
if isinstance(self, ABCDataFrame) and (is_list_like(value)):
warnings.warn(
"Pandas doesn't allow columns to be "
"created via a new attribute name - see "
"https://pandas.pydata.org/pandas-docs/"
"stable/indexing.html#attribute-access",
stacklevel=find_stack_level(),
)
object.__setattr__(self, name, value)
def _dir_additions(self) -> set[str]:
"""
add the string-like attributes from the info_axis.
If info_axis is a MultiIndex, its first level values are used.
"""
additions = super()._dir_additions()
if self._info_axis._can_hold_strings:
additions.update(self._info_axis._dir_additions_for_owner)
return additions
# ----------------------------------------------------------------------
# Consolidation of internals
def _protect_consolidate(self, f):
"""
Consolidate _mgr -- if the blocks have changed, then clear the
cache
"""
if isinstance(self._mgr, (ArrayManager, SingleArrayManager)):
return f()
blocks_before = len(self._mgr.blocks)
result = f()
if len(self._mgr.blocks) != blocks_before:
self._clear_item_cache()
return result
def _consolidate_inplace(self) -> None:
"""Consolidate data in place and return None"""
def f() -> None:
self._mgr = self._mgr.consolidate()
self._protect_consolidate(f)
def _consolidate(self):
"""
Compute NDFrame with "consolidated" internals (data of each dtype
grouped together in a single ndarray).
Returns
-------
consolidated : same type as caller
"""
f = lambda: self._mgr.consolidate()
cons_data = self._protect_consolidate(f)
return self._constructor(cons_data).__finalize__(self)
def _is_mixed_type(self) -> bool_t:
if self._mgr.is_single_block:
return False
if self._mgr.any_extension_types:
# Even if they have the same dtype, we can't consolidate them,
# so we pretend this is "mixed'"
return True
return self.dtypes.nunique() > 1
def _check_inplace_setting(self, value) -> bool_t:
"""check whether we allow in-place setting with this type of value"""
if self._is_mixed_type and not self._mgr.is_numeric_mixed_type:
# allow an actual np.nan through
if is_float(value) and np.isnan(value) or value is lib.no_default:
return True
raise TypeError(
"Cannot do inplace boolean setting on "
"mixed-types with a non np.nan value"
)
return True
def _get_numeric_data(self: NDFrameT) -> NDFrameT:
return self._constructor(self._mgr.get_numeric_data()).__finalize__(self)
def _get_bool_data(self):
return self._constructor(self._mgr.get_bool_data()).__finalize__(self)
# ----------------------------------------------------------------------
# Internal Interface Methods
def values(self):
raise AbstractMethodError(self)
def _values(self) -> ArrayLike:
"""internal implementation"""
raise AbstractMethodError(self)
def dtypes(self):
"""
Return the dtypes in the DataFrame.
This returns a Series with the data type of each column.
The result's index is the original DataFrame's columns. Columns
with mixed types are stored with the ``object`` dtype. See
:ref:`the User Guide <basics.dtypes>` for more.
Returns
-------
pandas.Series
The data type of each column.
Examples
--------
>>> df = pd.DataFrame({'float': [1.0],
... 'int': [1],
... 'datetime': [pd.Timestamp('20180310')],
... 'string': ['foo']})
>>> df.dtypes
float float64
int int64
datetime datetime64[ns]
string object
dtype: object
"""
data = self._mgr.get_dtypes()
return self._constructor_sliced(data, index=self._info_axis, dtype=np.object_)
def astype(
self: NDFrameT, dtype, copy: bool_t | None = None, errors: IgnoreRaise = "raise"
) -> NDFrameT:
"""
Cast a pandas object to a specified dtype ``dtype``.
Parameters
----------
dtype : str, data type, Series or Mapping of column name -> data type
Use a str, numpy.dtype, pandas.ExtensionDtype or Python type to
cast entire pandas object to the same type. Alternatively, use a
mapping, e.g. {col: dtype, ...}, where col is a column label and dtype is
a numpy.dtype or Python type to cast one or more of the DataFrame's
columns to column-specific types.
copy : bool, default True
Return a copy when ``copy=True`` (be very careful setting
``copy=False`` as changes to values then may propagate to other
pandas objects).
errors : {'raise', 'ignore'}, default 'raise'
Control raising of exceptions on invalid data for provided dtype.
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object.
Returns
-------
same type as caller
See Also
--------
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to a numeric type.
numpy.ndarray.astype : Cast a numpy array to a specified type.
Notes
-----
.. versionchanged:: 2.0.0
Using ``astype`` to convert from timezone-naive dtype to
timezone-aware dtype will raise an exception.
Use :meth:`Series.dt.tz_localize` instead.
Examples
--------
Create a DataFrame:
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df.dtypes
col1 int64
col2 int64
dtype: object
Cast all columns to int32:
>>> df.astype('int32').dtypes
col1 int32
col2 int32
dtype: object
Cast col1 to int32 using a dictionary:
>>> df.astype({'col1': 'int32'}).dtypes
col1 int32
col2 int64
dtype: object
Create a series:
>>> ser = pd.Series([1, 2], dtype='int32')
>>> ser
0 1
1 2
dtype: int32
>>> ser.astype('int64')
0 1
1 2
dtype: int64
Convert to categorical type:
>>> ser.astype('category')
0 1
1 2
dtype: category
Categories (2, int32): [1, 2]
Convert to ordered categorical type with custom ordering:
>>> from pandas.api.types import CategoricalDtype
>>> cat_dtype = CategoricalDtype(
... categories=[2, 1], ordered=True)
>>> ser.astype(cat_dtype)
0 1
1 2
dtype: category
Categories (2, int64): [2 < 1]
Create a series of dates:
>>> ser_date = pd.Series(pd.date_range('20200101', periods=3))
>>> ser_date
0 2020-01-01
1 2020-01-02
2 2020-01-03
dtype: datetime64[ns]
"""
if copy and using_copy_on_write():
copy = False
if is_dict_like(dtype):
if self.ndim == 1: # i.e. Series
if len(dtype) > 1 or self.name not in dtype:
raise KeyError(
"Only the Series name can be used for "
"the key in Series dtype mappings."
)
new_type = dtype[self.name]
return self.astype(new_type, copy, errors)
# GH#44417 cast to Series so we can use .iat below, which will be
# robust in case we
from pandas import Series
dtype_ser = Series(dtype, dtype=object)
for col_name in dtype_ser.index:
if col_name not in self:
raise KeyError(
"Only a column name can be used for the "
"key in a dtype mappings argument. "
f"'{col_name}' not found in columns."
)
dtype_ser = dtype_ser.reindex(self.columns, fill_value=None, copy=False)
results = []
for i, (col_name, col) in enumerate(self.items()):
cdt = dtype_ser.iat[i]
if isna(cdt):
res_col = col.copy(deep=copy)
else:
try:
res_col = col.astype(dtype=cdt, copy=copy, errors=errors)
except ValueError as ex:
ex.args = (
f"{ex}: Error while type casting for column '{col_name}'",
)
raise
results.append(res_col)
elif is_extension_array_dtype(dtype) and self.ndim > 1:
# GH 18099/22869: columnwise conversion to extension dtype
# GH 24704: use iloc to handle duplicate column names
# TODO(EA2D): special case not needed with 2D EAs
results = [
self.iloc[:, i].astype(dtype, copy=copy)
for i in range(len(self.columns))
]
else:
# else, only a single dtype is given
new_data = self._mgr.astype(dtype=dtype, copy=copy, errors=errors)
return self._constructor(new_data).__finalize__(self, method="astype")
# GH 33113: handle empty frame or series
if not results:
return self.copy(deep=None)
# GH 19920: retain column metadata after concat
result = concat(results, axis=1, copy=False)
# GH#40810 retain subclass
# error: Incompatible types in assignment
# (expression has type "NDFrameT", variable has type "DataFrame")
result = self._constructor(result) # type: ignore[assignment]
result.columns = self.columns
result = result.__finalize__(self, method="astype")
# https://github.com/python/mypy/issues/8354
return cast(NDFrameT, result)
def copy(self: NDFrameT, deep: bool_t | None = True) -> NDFrameT:
"""
Make a copy of this object's indices and data.
When ``deep=True`` (default), a new object will be created with a
copy of the calling object's data and indices. Modifications to
the data or indices of the copy will not be reflected in the
original object (see notes below).
When ``deep=False``, a new object will be created without copying
the calling object's data or index (only references to the data
and index are copied). Any changes to the data of the original
will be reflected in the shallow copy (and vice versa).
Parameters
----------
deep : bool, default True
Make a deep copy, including a copy of the data and the indices.
With ``deep=False`` neither the indices nor the data are copied.
Returns
-------
Series or DataFrame
Object type matches caller.
Notes
-----
When ``deep=True``, data is copied but actual Python objects
will not be copied recursively, only the reference to the object.
This is in contrast to `copy.deepcopy` in the Standard Library,
which recursively copies object data (see examples below).
While ``Index`` objects are copied when ``deep=True``, the underlying
numpy array is not copied for performance reasons. Since ``Index`` is
immutable, the underlying data can be safely shared and a copy
is not needed.
Since pandas is not thread safe, see the
:ref:`gotchas <gotchas.thread-safety>` when copying in a threading
environment.
Examples
--------
>>> s = pd.Series([1, 2], index=["a", "b"])
>>> s
a 1
b 2
dtype: int64
>>> s_copy = s.copy()
>>> s_copy
a 1
b 2
dtype: int64
**Shallow copy versus default (deep) copy:**
>>> s = pd.Series([1, 2], index=["a", "b"])
>>> deep = s.copy()
>>> shallow = s.copy(deep=False)
Shallow copy shares data and index with original.
>>> s is shallow
False
>>> s.values is shallow.values and s.index is shallow.index
True
Deep copy has own copy of data and index.
>>> s is deep
False
>>> s.values is deep.values or s.index is deep.index
False
Updates to the data shared by shallow copy and original is reflected
in both; deep copy remains unchanged.
>>> s[0] = 3
>>> shallow[1] = 4
>>> s
a 3
b 4
dtype: int64
>>> shallow
a 3
b 4
dtype: int64
>>> deep
a 1
b 2
dtype: int64
Note that when copying an object containing Python objects, a deep copy
will copy the data, but will not do so recursively. Updating a nested
data object will be reflected in the deep copy.
>>> s = pd.Series([[1, 2], [3, 4]])
>>> deep = s.copy()
>>> s[0][0] = 10
>>> s
0 [10, 2]
1 [3, 4]
dtype: object
>>> deep
0 [10, 2]
1 [3, 4]
dtype: object
"""
data = self._mgr.copy(deep=deep)
self._clear_item_cache()
return self._constructor(data).__finalize__(self, method="copy")
def __copy__(self: NDFrameT, deep: bool_t = True) -> NDFrameT:
return self.copy(deep=deep)
def __deepcopy__(self: NDFrameT, memo=None) -> NDFrameT:
"""
Parameters
----------
memo, default None
Standard signature. Unused
"""
return self.copy(deep=True)
def infer_objects(self: NDFrameT, copy: bool_t | None = None) -> NDFrameT:
"""
Attempt to infer better dtypes for object columns.
Attempts soft conversion of object-dtyped
columns, leaving non-object and unconvertible
columns unchanged. The inference rules are the
same as during normal Series/DataFrame construction.
Parameters
----------
copy : bool, default True
Whether to make a copy for non-object or non-inferrable columns
or Series.
Returns
-------
same type as input object
See Also
--------
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to numeric type.
convert_dtypes : Convert argument to best possible dtype.
Examples
--------
>>> df = pd.DataFrame({"A": ["a", 1, 2, 3]})
>>> df = df.iloc[1:]
>>> df
A
1 1
2 2
3 3
>>> df.dtypes
A object
dtype: object
>>> df.infer_objects().dtypes
A int64
dtype: object
"""
new_mgr = self._mgr.convert(copy=copy)
return self._constructor(new_mgr).__finalize__(self, method="infer_objects")
def convert_dtypes(
self: NDFrameT,
infer_objects: bool_t = True,
convert_string: bool_t = True,
convert_integer: bool_t = True,
convert_boolean: bool_t = True,
convert_floating: bool_t = True,
dtype_backend: DtypeBackend = "numpy_nullable",
) -> NDFrameT:
"""
Convert columns to the best possible dtypes using dtypes supporting ``pd.NA``.
Parameters
----------
infer_objects : bool, default True
Whether object dtypes should be converted to the best possible types.
convert_string : bool, default True
Whether object dtypes should be converted to ``StringDtype()``.
convert_integer : bool, default True
Whether, if possible, conversion can be done to integer extension types.
convert_boolean : bool, defaults True
Whether object dtypes should be converted to ``BooleanDtypes()``.
convert_floating : bool, defaults True
Whether, if possible, conversion can be done to floating extension types.
If `convert_integer` is also True, preference will be give to integer
dtypes if the floats can be faithfully casted to integers.
.. versionadded:: 1.2.0
dtype_backend : {"numpy_nullable", "pyarrow"}, default "numpy_nullable"
Which dtype_backend to use, e.g. whether a DataFrame should use nullable
dtypes for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
Returns
-------
Series or DataFrame
Copy of input object with new dtype.
See Also
--------
infer_objects : Infer dtypes of objects.
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to a numeric type.
Notes
-----
By default, ``convert_dtypes`` will attempt to convert a Series (or each
Series in a DataFrame) to dtypes that support ``pd.NA``. By using the options
``convert_string``, ``convert_integer``, ``convert_boolean`` and
``convert_floating``, it is possible to turn off individual conversions
to ``StringDtype``, the integer extension types, ``BooleanDtype``
or floating extension types, respectively.
For object-dtyped columns, if ``infer_objects`` is ``True``, use the inference
rules as during normal Series/DataFrame construction. Then, if possible,
convert to ``StringDtype``, ``BooleanDtype`` or an appropriate integer
or floating extension type, otherwise leave as ``object``.
If the dtype is integer, convert to an appropriate integer extension type.
If the dtype is numeric, and consists of all integers, convert to an
appropriate integer extension type. Otherwise, convert to an
appropriate floating extension type.
.. versionchanged:: 1.2
Starting with pandas 1.2, this method also converts float columns
to the nullable floating extension type.
In the future, as new dtypes are added that support ``pd.NA``, the results
of this method will change to support those new dtypes.
.. versionadded:: 2.0
The nullable dtype implementation can be configured by calling
``pd.set_option("mode.dtype_backend", "pandas")`` to use
numpy-backed nullable dtypes or
``pd.set_option("mode.dtype_backend", "pyarrow")`` to use
pyarrow-backed nullable dtypes (using ``pd.ArrowDtype``).
Examples
--------
>>> df = pd.DataFrame(
... {
... "a": pd.Series([1, 2, 3], dtype=np.dtype("int32")),
... "b": pd.Series(["x", "y", "z"], dtype=np.dtype("O")),
... "c": pd.Series([True, False, np.nan], dtype=np.dtype("O")),
... "d": pd.Series(["h", "i", np.nan], dtype=np.dtype("O")),
... "e": pd.Series([10, np.nan, 20], dtype=np.dtype("float")),
... "f": pd.Series([np.nan, 100.5, 200], dtype=np.dtype("float")),
... }
... )
Start with a DataFrame with default dtypes.
>>> df
a b c d e f
0 1 x True h 10.0 NaN
1 2 y False i NaN 100.5
2 3 z NaN NaN 20.0 200.0
>>> df.dtypes
a int32
b object
c object
d object
e float64
f float64
dtype: object
Convert the DataFrame to use best possible dtypes.
>>> dfn = df.convert_dtypes()
>>> dfn
a b c d e f
0 1 x True h 10 <NA>
1 2 y False i <NA> 100.5
2 3 z <NA> <NA> 20 200.0
>>> dfn.dtypes
a Int32
b string[python]
c boolean
d string[python]
e Int64
f Float64
dtype: object
Start with a Series of strings and missing data represented by ``np.nan``.
>>> s = pd.Series(["a", "b", np.nan])
>>> s
0 a
1 b
2 NaN
dtype: object
Obtain a Series with dtype ``StringDtype``.
>>> s.convert_dtypes()
0 a
1 b
2 <NA>
dtype: string
"""
check_dtype_backend(dtype_backend)
if self.ndim == 1:
return self._convert_dtypes(
infer_objects,
convert_string,
convert_integer,
convert_boolean,
convert_floating,
dtype_backend=dtype_backend,
)
else:
results = [
col._convert_dtypes(
infer_objects,
convert_string,
convert_integer,
convert_boolean,
convert_floating,
dtype_backend=dtype_backend,
)
for col_name, col in self.items()
]
if len(results) > 0:
result = concat(results, axis=1, copy=False, keys=self.columns)
cons = cast(Type["DataFrame"], self._constructor)
result = cons(result)
result = result.__finalize__(self, method="convert_dtypes")
# https://github.com/python/mypy/issues/8354
return cast(NDFrameT, result)
else:
return self.copy(deep=None)
# ----------------------------------------------------------------------
# Filling NA's
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: Literal[False] = ...,
limit: int | None = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def fillna(
self,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: Literal[True],
limit: int | None = ...,
downcast: dict | None = ...,
) -> None:
...
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: bool_t = ...,
limit: int | None = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = None,
*,
method: FillnaOptions | None = None,
axis: Axis | None = None,
inplace: bool_t = False,
limit: int | None = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Fill NA/NaN values using the specified method.
Parameters
----------
value : scalar, dict, Series, or DataFrame
Value to use to fill holes (e.g. 0), alternately a
dict/Series/DataFrame of values specifying which value to use for
each index (for a Series) or column (for a DataFrame). Values not
in the dict/Series/DataFrame will not be filled. This value cannot
be a list.
method : {{'backfill', 'bfill', 'ffill', None}}, default None
Method to use for filling holes in reindexed Series:
* ffill: propagate last valid observation forward to next valid.
* backfill / bfill: use next valid observation to fill gap.
axis : {axes_single_arg}
Axis along which to fill missing values. For `Series`
this parameter is unused and defaults to 0.
inplace : bool, default False
If True, fill in-place. Note: this will modify any
other views on this object (e.g., a no-copy slice for a column in a
DataFrame).
limit : int, default None
If method is specified, this is the maximum number of consecutive
NaN values to forward/backward fill. In other words, if there is
a gap with more than this number of consecutive NaNs, it will only
be partially filled. If method is not specified, this is the
maximum number of entries along the entire axis where NaNs will be
filled. Must be greater than 0 if not None.
downcast : dict, default is None
A dict of item->dtype of what to downcast if possible,
or the string 'infer' which will try to downcast to an appropriate
equal type (e.g. float64 to int64 if possible).
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
See Also
--------
interpolate : Fill NaN values using interpolation.
reindex : Conform object to new index.
asfreq : Convert TimeSeries to specified frequency.
Examples
--------
>>> df = pd.DataFrame([[np.nan, 2, np.nan, 0],
... [3, 4, np.nan, 1],
... [np.nan, np.nan, np.nan, np.nan],
... [np.nan, 3, np.nan, 4]],
... columns=list("ABCD"))
>>> df
A B C D
0 NaN 2.0 NaN 0.0
1 3.0 4.0 NaN 1.0
2 NaN NaN NaN NaN
3 NaN 3.0 NaN 4.0
Replace all NaN elements with 0s.
>>> df.fillna(0)
A B C D
0 0.0 2.0 0.0 0.0
1 3.0 4.0 0.0 1.0
2 0.0 0.0 0.0 0.0
3 0.0 3.0 0.0 4.0
We can also propagate non-null values forward or backward.
>>> df.fillna(method="ffill")
A B C D
0 NaN 2.0 NaN 0.0
1 3.0 4.0 NaN 1.0
2 3.0 4.0 NaN 1.0
3 3.0 3.0 NaN 4.0
Replace all NaN elements in column 'A', 'B', 'C', and 'D', with 0, 1,
2, and 3 respectively.
>>> values = {{"A": 0, "B": 1, "C": 2, "D": 3}}
>>> df.fillna(value=values)
A B C D
0 0.0 2.0 2.0 0.0
1 3.0 4.0 2.0 1.0
2 0.0 1.0 2.0 3.0
3 0.0 3.0 2.0 4.0
Only replace the first NaN element.
>>> df.fillna(value=values, limit=1)
A B C D
0 0.0 2.0 2.0 0.0
1 3.0 4.0 NaN 1.0
2 NaN 1.0 NaN 3.0
3 NaN 3.0 NaN 4.0
When filling using a DataFrame, replacement happens along
the same column names and same indices
>>> df2 = pd.DataFrame(np.zeros((4, 4)), columns=list("ABCE"))
>>> df.fillna(df2)
A B C D
0 0.0 2.0 0.0 0.0
1 3.0 4.0 0.0 1.0
2 0.0 0.0 0.0 NaN
3 0.0 3.0 0.0 4.0
Note that column D is not affected since it is not present in df2.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
value, method = validate_fillna_kwargs(value, method)
# set the default here, so functions examining the signaure
# can detect if something was set (e.g. in groupby) (GH9221)
if axis is None:
axis = 0
axis = self._get_axis_number(axis)
if value is None:
if not self._mgr.is_single_block and axis == 1:
if inplace:
raise NotImplementedError()
result = self.T.fillna(method=method, limit=limit).T
return result
new_data = self._mgr.interpolate(
method=method,
axis=axis,
limit=limit,
inplace=inplace,
downcast=downcast,
)
else:
if self.ndim == 1:
if isinstance(value, (dict, ABCSeries)):
if not len(value):
# test_fillna_nonscalar
if inplace:
return None
return self.copy(deep=None)
from pandas import Series
value = Series(value)
value = value.reindex(self.index, copy=False)
value = value._values
elif not is_list_like(value):
pass
else:
raise TypeError(
'"value" parameter must be a scalar, dict '
"or Series, but you passed a "
f'"{type(value).__name__}"'
)
new_data = self._mgr.fillna(
value=value, limit=limit, inplace=inplace, downcast=downcast
)
elif isinstance(value, (dict, ABCSeries)):
if axis == 1:
raise NotImplementedError(
"Currently only can fill "
"with dict/Series column "
"by column"
)
if using_copy_on_write():
result = self.copy(deep=None)
else:
result = self if inplace else self.copy()
is_dict = isinstance(downcast, dict)
for k, v in value.items():
if k not in result:
continue
# error: Item "None" of "Optional[Dict[Any, Any]]" has no
# attribute "get"
downcast_k = (
downcast
if not is_dict
else downcast.get(k) # type: ignore[union-attr]
)
res_k = result[k].fillna(v, limit=limit, downcast=downcast_k)
if not inplace:
result[k] = res_k
else:
# We can write into our existing column(s) iff dtype
# was preserved.
if isinstance(res_k, ABCSeries):
# i.e. 'k' only shows up once in self.columns
if res_k.dtype == result[k].dtype:
result.loc[:, k] = res_k
else:
# Different dtype -> no way to do inplace.
result[k] = res_k
else:
# see test_fillna_dict_inplace_nonunique_columns
locs = result.columns.get_loc(k)
if isinstance(locs, slice):
locs = np.arange(self.shape[1])[locs]
elif (
isinstance(locs, np.ndarray) and locs.dtype.kind == "b"
):
locs = locs.nonzero()[0]
elif not (
isinstance(locs, np.ndarray) and locs.dtype.kind == "i"
):
# Should never be reached, but let's cover our bases
raise NotImplementedError(
"Unexpected get_loc result, please report a bug at "
"https://github.com/pandas-dev/pandas"
)
for i, loc in enumerate(locs):
res_loc = res_k.iloc[:, i]
target = self.iloc[:, loc]
if res_loc.dtype == target.dtype:
result.iloc[:, loc] = res_loc
else:
result.isetitem(loc, res_loc)
if inplace:
return self._update_inplace(result)
else:
return result
elif not is_list_like(value):
if axis == 1:
result = self.T.fillna(value=value, limit=limit).T
new_data = result
else:
new_data = self._mgr.fillna(
value=value, limit=limit, inplace=inplace, downcast=downcast
)
elif isinstance(value, ABCDataFrame) and self.ndim == 2:
new_data = self.where(self.notna(), value)._mgr
else:
raise ValueError(f"invalid fill value with a {type(value)}")
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="fillna")
def ffill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: Literal[False] = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def ffill(
self,
*,
axis: None | Axis = ...,
inplace: Literal[True],
limit: None | int = ...,
downcast: dict | None = ...,
) -> None:
...
def ffill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: bool_t = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def ffill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='ffill'``.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
return self.fillna(
method="ffill", axis=axis, inplace=inplace, limit=limit, downcast=downcast
)
def pad(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='ffill'``.
.. deprecated:: 2.0
{klass}.pad is deprecated. Use {klass}.ffill instead.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
warnings.warn(
"DataFrame.pad/Series.pad is deprecated. Use "
"DataFrame.ffill/Series.ffill instead",
FutureWarning,
stacklevel=find_stack_level(),
)
return self.ffill(axis=axis, inplace=inplace, limit=limit, downcast=downcast)
def bfill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: Literal[False] = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def bfill(
self,
*,
axis: None | Axis = ...,
inplace: Literal[True],
limit: None | int = ...,
downcast: dict | None = ...,
) -> None:
...
def bfill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: bool_t = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def bfill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='bfill'``.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
return self.fillna(
method="bfill", axis=axis, inplace=inplace, limit=limit, downcast=downcast
)
def backfill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='bfill'``.
.. deprecated:: 2.0
{klass}.backfill is deprecated. Use {klass}.bfill instead.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
warnings.warn(
"DataFrame.backfill/Series.backfill is deprecated. Use "
"DataFrame.bfill/Series.bfill instead",
FutureWarning,
stacklevel=find_stack_level(),
)
return self.bfill(axis=axis, inplace=inplace, limit=limit, downcast=downcast)
def replace(
self: NDFrameT,
to_replace=...,
value=...,
*,
inplace: Literal[False] = ...,
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> NDFrameT:
...
def replace(
self,
to_replace=...,
value=...,
*,
inplace: Literal[True],
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> None:
...
def replace(
self: NDFrameT,
to_replace=...,
value=...,
*,
inplace: bool_t = ...,
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> NDFrameT | None:
...
_shared_docs["replace"],
klass=_shared_doc_kwargs["klass"],
inplace=_shared_doc_kwargs["inplace"],
replace_iloc=_shared_doc_kwargs["replace_iloc"],
)
def replace(
self: NDFrameT,
to_replace=None,
value=lib.no_default,
*,
inplace: bool_t = False,
limit: int | None = None,
regex: bool_t = False,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = lib.no_default,
) -> NDFrameT | None:
if not (
is_scalar(to_replace)
or is_re_compilable(to_replace)
or is_list_like(to_replace)
):
raise TypeError(
"Expecting 'to_replace' to be either a scalar, array-like, "
"dict or None, got invalid type "
f"{repr(type(to_replace).__name__)}"
)
inplace = validate_bool_kwarg(inplace, "inplace")
if not is_bool(regex) and to_replace is not None:
raise ValueError("'to_replace' must be 'None' if 'regex' is not a bool")
if value is lib.no_default or method is not lib.no_default:
# GH#36984 if the user explicitly passes value=None we want to
# respect that. We have the corner case where the user explicitly
# passes value=None *and* a method, which we interpret as meaning
# they want the (documented) default behavior.
if method is lib.no_default:
# TODO: get this to show up as the default in the docs?
method = "pad"
# passing a single value that is scalar like
# when value is None (GH5319), for compat
if not is_dict_like(to_replace) and not is_dict_like(regex):
to_replace = [to_replace]
if isinstance(to_replace, (tuple, list)):
# TODO: Consider copy-on-write for non-replaced columns's here
if isinstance(self, ABCDataFrame):
from pandas import Series
result = self.apply(
Series._replace_single,
args=(to_replace, method, inplace, limit),
)
if inplace:
return None
return result
return self._replace_single(to_replace, method, inplace, limit)
if not is_dict_like(to_replace):
if not is_dict_like(regex):
raise TypeError(
'If "to_replace" and "value" are both None '
'and "to_replace" is not a list, then '
"regex must be a mapping"
)
to_replace = regex
regex = True
items = list(to_replace.items())
if items:
keys, values = zip(*items)
else:
keys, values = ([], [])
are_mappings = [is_dict_like(v) for v in values]
if any(are_mappings):
if not all(are_mappings):
raise TypeError(
"If a nested mapping is passed, all values "
"of the top level mapping must be mappings"
)
# passed a nested dict/Series
to_rep_dict = {}
value_dict = {}
for k, v in items:
keys, values = list(zip(*v.items())) or ([], [])
to_rep_dict[k] = list(keys)
value_dict[k] = list(values)
to_replace, value = to_rep_dict, value_dict
else:
to_replace, value = keys, values
return self.replace(
to_replace, value, inplace=inplace, limit=limit, regex=regex
)
else:
# need a non-zero len on all axes
if not self.size:
if inplace:
return None
return self.copy(deep=None)
if is_dict_like(to_replace):
if is_dict_like(value): # {'A' : NA} -> {'A' : 0}
# Note: Checking below for `in foo.keys()` instead of
# `in foo` is needed for when we have a Series and not dict
mapping = {
col: (to_replace[col], value[col])
for col in to_replace.keys()
if col in value.keys() and col in self
}
return self._replace_columnwise(mapping, inplace, regex)
# {'A': NA} -> 0
elif not is_list_like(value):
# Operate column-wise
if self.ndim == 1:
raise ValueError(
"Series.replace cannot use dict-like to_replace "
"and non-None value"
)
mapping = {
col: (to_rep, value) for col, to_rep in to_replace.items()
}
return self._replace_columnwise(mapping, inplace, regex)
else:
raise TypeError("value argument must be scalar, dict, or Series")
elif is_list_like(to_replace):
if not is_list_like(value):
# e.g. to_replace = [NA, ''] and value is 0,
# so we replace NA with 0 and then replace '' with 0
value = [value] * len(to_replace)
# e.g. we have to_replace = [NA, ''] and value = [0, 'missing']
if len(to_replace) != len(value):
raise ValueError(
f"Replacement lists must match in length. "
f"Expecting {len(to_replace)} got {len(value)} "
)
new_data = self._mgr.replace_list(
src_list=to_replace,
dest_list=value,
inplace=inplace,
regex=regex,
)
elif to_replace is None:
if not (
is_re_compilable(regex)
or is_list_like(regex)
or is_dict_like(regex)
):
raise TypeError(
f"'regex' must be a string or a compiled regular expression "
f"or a list or dict of strings or regular expressions, "
f"you passed a {repr(type(regex).__name__)}"
)
return self.replace(
regex, value, inplace=inplace, limit=limit, regex=True
)
else:
# dest iterable dict-like
if is_dict_like(value): # NA -> {'A' : 0, 'B' : -1}
# Operate column-wise
if self.ndim == 1:
raise ValueError(
"Series.replace cannot use dict-value and "
"non-None to_replace"
)
mapping = {col: (to_replace, val) for col, val in value.items()}
return self._replace_columnwise(mapping, inplace, regex)
elif not is_list_like(value): # NA -> 0
regex = should_use_regex(regex, to_replace)
if regex:
new_data = self._mgr.replace_regex(
to_replace=to_replace,
value=value,
inplace=inplace,
)
else:
new_data = self._mgr.replace(
to_replace=to_replace, value=value, inplace=inplace
)
else:
raise TypeError(
f'Invalid "to_replace" type: {repr(type(to_replace).__name__)}'
)
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="replace")
def interpolate(
self: NDFrameT,
method: str = "linear",
*,
axis: Axis = 0,
limit: int | None = None,
inplace: bool_t = False,
limit_direction: str | None = None,
limit_area: str | None = None,
downcast: str | None = None,
**kwargs,
) -> NDFrameT | None:
"""
Fill NaN values using an interpolation method.
Please note that only ``method='linear'`` is supported for
DataFrame/Series with a MultiIndex.
Parameters
----------
method : str, default 'linear'
Interpolation technique to use. One of:
* 'linear': Ignore the index and treat the values as equally
spaced. This is the only method supported on MultiIndexes.
* 'time': Works on daily and higher resolution data to interpolate
given length of interval.
* 'index', 'values': use the actual numerical values of the index.
* 'pad': Fill in NaNs using existing values.
* 'nearest', 'zero', 'slinear', 'quadratic', 'cubic',
'barycentric', 'polynomial': Passed to
`scipy.interpolate.interp1d`, whereas 'spline' is passed to
`scipy.interpolate.UnivariateSpline`. These methods use the numerical
values of the index. Both 'polynomial' and 'spline' require that
you also specify an `order` (int), e.g.
``df.interpolate(method='polynomial', order=5)``. Note that,
`slinear` method in Pandas refers to the Scipy first order `spline`
instead of Pandas first order `spline`.
* 'krogh', 'piecewise_polynomial', 'spline', 'pchip', 'akima',
'cubicspline': Wrappers around the SciPy interpolation methods of
similar names. See `Notes`.
* 'from_derivatives': Refers to
`scipy.interpolate.BPoly.from_derivatives` which
replaces 'piecewise_polynomial' interpolation method in
scipy 0.18.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to interpolate along. For `Series` this parameter is unused
and defaults to 0.
limit : int, optional
Maximum number of consecutive NaNs to fill. Must be greater than
0.
inplace : bool, default False
Update the data in place if possible.
limit_direction : {{'forward', 'backward', 'both'}}, Optional
Consecutive NaNs will be filled in this direction.
If limit is specified:
* If 'method' is 'pad' or 'ffill', 'limit_direction' must be 'forward'.
* If 'method' is 'backfill' or 'bfill', 'limit_direction' must be
'backwards'.
If 'limit' is not specified:
* If 'method' is 'backfill' or 'bfill', the default is 'backward'
* else the default is 'forward'
.. versionchanged:: 1.1.0
raises ValueError if `limit_direction` is 'forward' or 'both' and
method is 'backfill' or 'bfill'.
raises ValueError if `limit_direction` is 'backward' or 'both' and
method is 'pad' or 'ffill'.
limit_area : {{`None`, 'inside', 'outside'}}, default None
If limit is specified, consecutive NaNs will be filled with this
restriction.
* ``None``: No fill restriction.
* 'inside': Only fill NaNs surrounded by valid values
(interpolate).
* 'outside': Only fill NaNs outside valid values (extrapolate).
downcast : optional, 'infer' or None, defaults to None
Downcast dtypes if possible.
``**kwargs`` : optional
Keyword arguments to pass on to the interpolating function.
Returns
-------
Series or DataFrame or None
Returns the same object type as the caller, interpolated at
some or all ``NaN`` values or None if ``inplace=True``.
See Also
--------
fillna : Fill missing values using different methods.
scipy.interpolate.Akima1DInterpolator : Piecewise cubic polynomials
(Akima interpolator).
scipy.interpolate.BPoly.from_derivatives : Piecewise polynomial in the
Bernstein basis.
scipy.interpolate.interp1d : Interpolate a 1-D function.
scipy.interpolate.KroghInterpolator : Interpolate polynomial (Krogh
interpolator).
scipy.interpolate.PchipInterpolator : PCHIP 1-d monotonic cubic
interpolation.
scipy.interpolate.CubicSpline : Cubic spline data interpolator.
Notes
-----
The 'krogh', 'piecewise_polynomial', 'spline', 'pchip' and 'akima'
methods are wrappers around the respective SciPy implementations of
similar names. These use the actual numerical values of the index.
For more information on their behavior, see the
`SciPy documentation
<https://docs.scipy.org/doc/scipy/reference/interpolate.html#univariate-interpolation>`__.
Examples
--------
Filling in ``NaN`` in a :class:`~pandas.Series` via linear
interpolation.
>>> s = pd.Series([0, 1, np.nan, 3])
>>> s
0 0.0
1 1.0
2 NaN
3 3.0
dtype: float64
>>> s.interpolate()
0 0.0
1 1.0
2 2.0
3 3.0
dtype: float64
Filling in ``NaN`` in a Series by padding, but filling at most two
consecutive ``NaN`` at a time.
>>> s = pd.Series([np.nan, "single_one", np.nan,
... "fill_two_more", np.nan, np.nan, np.nan,
... 4.71, np.nan])
>>> s
0 NaN
1 single_one
2 NaN
3 fill_two_more
4 NaN
5 NaN
6 NaN
7 4.71
8 NaN
dtype: object
>>> s.interpolate(method='pad', limit=2)
0 NaN
1 single_one
2 single_one
3 fill_two_more
4 fill_two_more
5 fill_two_more
6 NaN
7 4.71
8 4.71
dtype: object
Filling in ``NaN`` in a Series via polynomial interpolation or splines:
Both 'polynomial' and 'spline' methods require that you also specify
an ``order`` (int).
>>> s = pd.Series([0, 2, np.nan, 8])
>>> s.interpolate(method='polynomial', order=2)
0 0.000000
1 2.000000
2 4.666667
3 8.000000
dtype: float64
Fill the DataFrame forward (that is, going down) along each column
using linear interpolation.
Note how the last entry in column 'a' is interpolated differently,
because there is no entry after it to use for interpolation.
Note how the first entry in column 'b' remains ``NaN``, because there
is no entry before it to use for interpolation.
>>> df = pd.DataFrame([(0.0, np.nan, -1.0, 1.0),
... (np.nan, 2.0, np.nan, np.nan),
... (2.0, 3.0, np.nan, 9.0),
... (np.nan, 4.0, -4.0, 16.0)],
... columns=list('abcd'))
>>> df
a b c d
0 0.0 NaN -1.0 1.0
1 NaN 2.0 NaN NaN
2 2.0 3.0 NaN 9.0
3 NaN 4.0 -4.0 16.0
>>> df.interpolate(method='linear', limit_direction='forward', axis=0)
a b c d
0 0.0 NaN -1.0 1.0
1 1.0 2.0 -2.0 5.0
2 2.0 3.0 -3.0 9.0
3 2.0 4.0 -4.0 16.0
Using polynomial interpolation.
>>> df['d'].interpolate(method='polynomial', order=2)
0 1.0
1 4.0
2 9.0
3 16.0
Name: d, dtype: float64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
axis = self._get_axis_number(axis)
fillna_methods = ["ffill", "bfill", "pad", "backfill"]
should_transpose = axis == 1 and method not in fillna_methods
obj = self.T if should_transpose else self
if obj.empty:
return self.copy()
if method not in fillna_methods:
axis = self._info_axis_number
if isinstance(obj.index, MultiIndex) and method != "linear":
raise ValueError(
"Only `method=linear` interpolation is supported on MultiIndexes."
)
# Set `limit_direction` depending on `method`
if limit_direction is None:
limit_direction = (
"backward" if method in ("backfill", "bfill") else "forward"
)
else:
if method in ("pad", "ffill") and limit_direction != "forward":
raise ValueError(
f"`limit_direction` must be 'forward' for method `{method}`"
)
if method in ("backfill", "bfill") and limit_direction != "backward":
raise ValueError(
f"`limit_direction` must be 'backward' for method `{method}`"
)
if obj.ndim == 2 and np.all(obj.dtypes == np.dtype("object")):
raise TypeError(
"Cannot interpolate with all object-dtype columns "
"in the DataFrame. Try setting at least one "
"column to a numeric dtype."
)
# create/use the index
if method == "linear":
# prior default
index = Index(np.arange(len(obj.index)))
else:
index = obj.index
methods = {"index", "values", "nearest", "time"}
is_numeric_or_datetime = (
is_numeric_dtype(index.dtype)
or is_datetime64_any_dtype(index.dtype)
or is_timedelta64_dtype(index.dtype)
)
if method not in methods and not is_numeric_or_datetime:
raise ValueError(
"Index column must be numeric or datetime type when "
f"using {method} method other than linear. "
"Try setting a numeric or datetime index column before "
"interpolating."
)
if isna(index).any():
raise NotImplementedError(
"Interpolation with NaNs in the index "
"has not been implemented. Try filling "
"those NaNs before interpolating."
)
new_data = obj._mgr.interpolate(
method=method,
axis=axis,
index=index,
limit=limit,
limit_direction=limit_direction,
limit_area=limit_area,
inplace=inplace,
downcast=downcast,
**kwargs,
)
result = self._constructor(new_data)
if should_transpose:
result = result.T
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="interpolate")
# ----------------------------------------------------------------------
# Timeseries methods Methods
def asof(self, where, subset=None):
"""
Return the last row(s) without any NaNs before `where`.
The last row (for each element in `where`, if list) without any
NaN is taken.
In case of a :class:`~pandas.DataFrame`, the last row without NaN
considering only the subset of columns (if not `None`)
If there is no good value, NaN is returned for a Series or
a Series of NaN values for a DataFrame
Parameters
----------
where : date or array-like of dates
Date(s) before which the last row(s) are returned.
subset : str or array-like of str, default `None`
For DataFrame, if not `None`, only use these columns to
check for NaNs.
Returns
-------
scalar, Series, or DataFrame
The return can be:
* scalar : when `self` is a Series and `where` is a scalar
* Series: when `self` is a Series and `where` is an array-like,
or when `self` is a DataFrame and `where` is a scalar
* DataFrame : when `self` is a DataFrame and `where` is an
array-like
Return scalar, Series, or DataFrame.
See Also
--------
merge_asof : Perform an asof merge. Similar to left join.
Notes
-----
Dates are assumed to be sorted. Raises if this is not the case.
Examples
--------
A Series and a scalar `where`.
>>> s = pd.Series([1, 2, np.nan, 4], index=[10, 20, 30, 40])
>>> s
10 1.0
20 2.0
30 NaN
40 4.0
dtype: float64
>>> s.asof(20)
2.0
For a sequence `where`, a Series is returned. The first value is
NaN, because the first element of `where` is before the first
index value.
>>> s.asof([5, 20])
5 NaN
20 2.0
dtype: float64
Missing values are not considered. The following is ``2.0``, not
NaN, even though NaN is at the index location for ``30``.
>>> s.asof(30)
2.0
Take all columns into consideration
>>> df = pd.DataFrame({'a': [10, 20, 30, 40, 50],
... 'b': [None, None, None, None, 500]},
... index=pd.DatetimeIndex(['2018-02-27 09:01:00',
... '2018-02-27 09:02:00',
... '2018-02-27 09:03:00',
... '2018-02-27 09:04:00',
... '2018-02-27 09:05:00']))
>>> df.asof(pd.DatetimeIndex(['2018-02-27 09:03:30',
... '2018-02-27 09:04:30']))
a b
2018-02-27 09:03:30 NaN NaN
2018-02-27 09:04:30 NaN NaN
Take a single column into consideration
>>> df.asof(pd.DatetimeIndex(['2018-02-27 09:03:30',
... '2018-02-27 09:04:30']),
... subset=['a'])
a b
2018-02-27 09:03:30 30 NaN
2018-02-27 09:04:30 40 NaN
"""
if isinstance(where, str):
where = Timestamp(where)
if not self.index.is_monotonic_increasing:
raise ValueError("asof requires a sorted index")
is_series = isinstance(self, ABCSeries)
if is_series:
if subset is not None:
raise ValueError("subset is not valid for Series")
else:
if subset is None:
subset = self.columns
if not is_list_like(subset):
subset = [subset]
is_list = is_list_like(where)
if not is_list:
start = self.index[0]
if isinstance(self.index, PeriodIndex):
where = Period(where, freq=self.index.freq)
if where < start:
if not is_series:
return self._constructor_sliced(
index=self.columns, name=where, dtype=np.float64
)
return np.nan
# It's always much faster to use a *while* loop here for
# Series than pre-computing all the NAs. However a
# *while* loop is extremely expensive for DataFrame
# so we later pre-compute all the NAs and use the same
# code path whether *where* is a scalar or list.
# See PR: https://github.com/pandas-dev/pandas/pull/14476
if is_series:
loc = self.index.searchsorted(where, side="right")
if loc > 0:
loc -= 1
values = self._values
while loc > 0 and isna(values[loc]):
loc -= 1
return values[loc]
if not isinstance(where, Index):
where = Index(where) if is_list else Index([where])
nulls = self.isna() if is_series else self[subset].isna().any(axis=1)
if nulls.all():
if is_series:
self = cast("Series", self)
return self._constructor(np.nan, index=where, name=self.name)
elif is_list:
self = cast("DataFrame", self)
return self._constructor(np.nan, index=where, columns=self.columns)
else:
self = cast("DataFrame", self)
return self._constructor_sliced(
np.nan, index=self.columns, name=where[0]
)
locs = self.index.asof_locs(where, ~(nulls._values))
# mask the missing
missing = locs == -1
data = self.take(locs)
data.index = where
if missing.any():
# GH#16063 only do this setting when necessary, otherwise
# we'd cast e.g. bools to floats
data.loc[missing] = np.nan
return data if is_list else data.iloc[-1]
# ----------------------------------------------------------------------
# Action Methods
def isna(self: NDFrameT) -> NDFrameT:
"""
Detect missing values.
Return a boolean same-sized object indicating if the values are NA.
NA values, such as None or :attr:`numpy.NaN`, gets mapped to True
values.
Everything else gets mapped to False values. Characters such as empty
strings ``''`` or :attr:`numpy.inf` are not considered NA values
(unless you set ``pandas.options.mode.use_inf_as_na = True``).
Returns
-------
{klass}
Mask of bool values for each element in {klass} that
indicates whether an element is an NA value.
See Also
--------
{klass}.isnull : Alias of isna.
{klass}.notna : Boolean inverse of isna.
{klass}.dropna : Omit axes labels with missing values.
isna : Top-level isna.
Examples
--------
Show which entries in a DataFrame are NA.
>>> df = pd.DataFrame(dict(age=[5, 6, np.NaN],
... born=[pd.NaT, pd.Timestamp('1939-05-27'),
... pd.Timestamp('1940-04-25')],
... name=['Alfred', 'Batman', ''],
... toy=[None, 'Batmobile', 'Joker']))
>>> df
age born name toy
0 5.0 NaT Alfred None
1 6.0 1939-05-27 Batman Batmobile
2 NaN 1940-04-25 Joker
>>> df.isna()
age born name toy
0 False True False True
1 False False False False
2 True False False False
Show which entries in a Series are NA.
>>> ser = pd.Series([5, 6, np.NaN])
>>> ser
0 5.0
1 6.0
2 NaN
dtype: float64
>>> ser.isna()
0 False
1 False
2 True
dtype: bool
"""
return isna(self).__finalize__(self, method="isna")
def isnull(self: NDFrameT) -> NDFrameT:
return isna(self).__finalize__(self, method="isnull")
def notna(self: NDFrameT) -> NDFrameT:
"""
Detect existing (non-missing) values.
Return a boolean same-sized object indicating if the values are not NA.
Non-missing values get mapped to True. Characters such as empty
strings ``''`` or :attr:`numpy.inf` are not considered NA values
(unless you set ``pandas.options.mode.use_inf_as_na = True``).
NA values, such as None or :attr:`numpy.NaN`, get mapped to False
values.
Returns
-------
{klass}
Mask of bool values for each element in {klass} that
indicates whether an element is not an NA value.
See Also
--------
{klass}.notnull : Alias of notna.
{klass}.isna : Boolean inverse of notna.
{klass}.dropna : Omit axes labels with missing values.
notna : Top-level notna.
Examples
--------
Show which entries in a DataFrame are not NA.
>>> df = pd.DataFrame(dict(age=[5, 6, np.NaN],
... born=[pd.NaT, pd.Timestamp('1939-05-27'),
... pd.Timestamp('1940-04-25')],
... name=['Alfred', 'Batman', ''],
... toy=[None, 'Batmobile', 'Joker']))
>>> df
age born name toy
0 5.0 NaT Alfred None
1 6.0 1939-05-27 Batman Batmobile
2 NaN 1940-04-25 Joker
>>> df.notna()
age born name toy
0 True False True False
1 True True True True
2 False True True True
Show which entries in a Series are not NA.
>>> ser = pd.Series([5, 6, np.NaN])
>>> ser
0 5.0
1 6.0
2 NaN
dtype: float64
>>> ser.notna()
0 True
1 True
2 False
dtype: bool
"""
return notna(self).__finalize__(self, method="notna")
def notnull(self: NDFrameT) -> NDFrameT:
return notna(self).__finalize__(self, method="notnull")
def _clip_with_scalar(self, lower, upper, inplace: bool_t = False):
if (lower is not None and np.any(isna(lower))) or (
upper is not None and np.any(isna(upper))
):
raise ValueError("Cannot use an NA value as a clip threshold")
result = self
mask = isna(self._values)
with np.errstate(all="ignore"):
if upper is not None:
subset = self <= upper
result = result.where(subset, upper, axis=None, inplace=False)
if lower is not None:
subset = self >= lower
result = result.where(subset, lower, axis=None, inplace=False)
if np.any(mask):
result[mask] = np.nan
if inplace:
return self._update_inplace(result)
else:
return result
def _clip_with_one_bound(self, threshold, method, axis, inplace):
if axis is not None:
axis = self._get_axis_number(axis)
# method is self.le for upper bound and self.ge for lower bound
if is_scalar(threshold) and is_number(threshold):
if method.__name__ == "le":
return self._clip_with_scalar(None, threshold, inplace=inplace)
return self._clip_with_scalar(threshold, None, inplace=inplace)
# GH #15390
# In order for where method to work, the threshold must
# be transformed to NDFrame from other array like structure.
if (not isinstance(threshold, ABCSeries)) and is_list_like(threshold):
if isinstance(self, ABCSeries):
threshold = self._constructor(threshold, index=self.index)
else:
threshold = align_method_FRAME(self, threshold, axis, flex=None)[1]
# GH 40420
# Treat missing thresholds as no bounds, not clipping the values
if is_list_like(threshold):
fill_value = np.inf if method.__name__ == "le" else -np.inf
threshold_inf = threshold.fillna(fill_value)
else:
threshold_inf = threshold
subset = method(threshold_inf, axis=axis) | isna(self)
# GH 40420
return self.where(subset, threshold, axis=axis, inplace=inplace)
def clip(
self: NDFrameT,
lower=None,
upper=None,
*,
axis: Axis | None = None,
inplace: bool_t = False,
**kwargs,
) -> NDFrameT | None:
"""
Trim values at input threshold(s).
Assigns values outside boundary to boundary values. Thresholds
can be singular values or array like, and in the latter case
the clipping is performed element-wise in the specified axis.
Parameters
----------
lower : float or array-like, default None
Minimum threshold value. All values below this
threshold will be set to it. A missing
threshold (e.g `NA`) will not clip the value.
upper : float or array-like, default None
Maximum threshold value. All values above this
threshold will be set to it. A missing
threshold (e.g `NA`) will not clip the value.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Align object with lower and upper along the given axis.
For `Series` this parameter is unused and defaults to `None`.
inplace : bool, default False
Whether to perform the operation in place on the data.
*args, **kwargs
Additional keywords have no effect but might be accepted
for compatibility with numpy.
Returns
-------
Series or DataFrame or None
Same type as calling object with the values outside the
clip boundaries replaced or None if ``inplace=True``.
See Also
--------
Series.clip : Trim values at input threshold in series.
DataFrame.clip : Trim values at input threshold in dataframe.
numpy.clip : Clip (limit) the values in an array.
Examples
--------
>>> data = {'col_0': [9, -3, 0, -1, 5], 'col_1': [-2, -7, 6, 8, -5]}
>>> df = pd.DataFrame(data)
>>> df
col_0 col_1
0 9 -2
1 -3 -7
2 0 6
3 -1 8
4 5 -5
Clips per column using lower and upper thresholds:
>>> df.clip(-4, 6)
col_0 col_1
0 6 -2
1 -3 -4
2 0 6
3 -1 6
4 5 -4
Clips using specific lower and upper thresholds per column element:
>>> t = pd.Series([2, -4, -1, 6, 3])
>>> t
0 2
1 -4
2 -1
3 6
4 3
dtype: int64
>>> df.clip(t, t + 4, axis=0)
col_0 col_1
0 6 2
1 -3 -4
2 0 3
3 6 8
4 5 3
Clips using specific lower threshold per column element, with missing values:
>>> t = pd.Series([2, -4, np.NaN, 6, 3])
>>> t
0 2.0
1 -4.0
2 NaN
3 6.0
4 3.0
dtype: float64
>>> df.clip(t, axis=0)
col_0 col_1
0 9 2
1 -3 -4
2 0 6
3 6 8
4 5 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
axis = nv.validate_clip_with_axis(axis, (), kwargs)
if axis is not None:
axis = self._get_axis_number(axis)
# GH 17276
# numpy doesn't like NaN as a clip value
# so ignore
# GH 19992
# numpy doesn't drop a list-like bound containing NaN
isna_lower = isna(lower)
if not is_list_like(lower):
if np.any(isna_lower):
lower = None
elif np.all(isna_lower):
lower = None
isna_upper = isna(upper)
if not is_list_like(upper):
if np.any(isna_upper):
upper = None
elif np.all(isna_upper):
upper = None
# GH 2747 (arguments were reversed)
if (
lower is not None
and upper is not None
and is_scalar(lower)
and is_scalar(upper)
):
lower, upper = min(lower, upper), max(lower, upper)
# fast-path for scalars
if (lower is None or (is_scalar(lower) and is_number(lower))) and (
upper is None or (is_scalar(upper) and is_number(upper))
):
return self._clip_with_scalar(lower, upper, inplace=inplace)
result = self
if lower is not None:
result = result._clip_with_one_bound(
lower, method=self.ge, axis=axis, inplace=inplace
)
if upper is not None:
if inplace:
result = self
result = result._clip_with_one_bound(
upper, method=self.le, axis=axis, inplace=inplace
)
return result
def asfreq(
self: NDFrameT,
freq: Frequency,
method: FillnaOptions | None = None,
how: str | None = None,
normalize: bool_t = False,
fill_value: Hashable = None,
) -> NDFrameT:
"""
Convert time series to specified frequency.
Returns the original data conformed to a new index with the specified
frequency.
If the index of this {klass} is a :class:`~pandas.PeriodIndex`, the new index
is the result of transforming the original index with
:meth:`PeriodIndex.asfreq <pandas.PeriodIndex.asfreq>` (so the original index
will map one-to-one to the new index).
Otherwise, the new index will be equivalent to ``pd.date_range(start, end,
freq=freq)`` where ``start`` and ``end`` are, respectively, the first and
last entries in the original index (see :func:`pandas.date_range`). The
values corresponding to any timesteps in the new index which were not present
in the original index will be null (``NaN``), unless a method for filling
such unknowns is provided (see the ``method`` parameter below).
The :meth:`resample` method is more appropriate if an operation on each group of
timesteps (such as an aggregate) is necessary to represent the data at the new
frequency.
Parameters
----------
freq : DateOffset or str
Frequency DateOffset or string.
method : {{'backfill'/'bfill', 'pad'/'ffill'}}, default None
Method to use for filling holes in reindexed Series (note this
does not fill NaNs that already were present):
* 'pad' / 'ffill': propagate last valid observation forward to next
valid
* 'backfill' / 'bfill': use NEXT valid observation to fill.
how : {{'start', 'end'}}, default end
For PeriodIndex only (see PeriodIndex.asfreq).
normalize : bool, default False
Whether to reset output index to midnight.
fill_value : scalar, optional
Value to use for missing values, applied during upsampling (note
this does not fill NaNs that already were present).
Returns
-------
{klass}
{klass} object reindexed to the specified frequency.
See Also
--------
reindex : Conform DataFrame to new index with optional filling logic.
Notes
-----
To learn more about the frequency strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__.
Examples
--------
Start by creating a series with 4 one minute timestamps.
>>> index = pd.date_range('1/1/2000', periods=4, freq='T')
>>> series = pd.Series([0.0, None, 2.0, 3.0], index=index)
>>> df = pd.DataFrame({{'s': series}})
>>> df
s
2000-01-01 00:00:00 0.0
2000-01-01 00:01:00 NaN
2000-01-01 00:02:00 2.0
2000-01-01 00:03:00 3.0
Upsample the series into 30 second bins.
>>> df.asfreq(freq='30S')
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 NaN
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 NaN
2000-01-01 00:03:00 3.0
Upsample again, providing a ``fill value``.
>>> df.asfreq(freq='30S', fill_value=9.0)
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 9.0
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 9.0
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 9.0
2000-01-01 00:03:00 3.0
Upsample again, providing a ``method``.
>>> df.asfreq(freq='30S', method='bfill')
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 2.0
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 3.0
2000-01-01 00:03:00 3.0
"""
from pandas.core.resample import asfreq
return asfreq(
self,
freq,
method=method,
how=how,
normalize=normalize,
fill_value=fill_value,
)
def at_time(
self: NDFrameT, time, asof: bool_t = False, axis: Axis | None = None
) -> NDFrameT:
"""
Select values at particular time of day (e.g., 9:30AM).
Parameters
----------
time : datetime.time or str
The values to select.
axis : {0 or 'index', 1 or 'columns'}, default 0
For `Series` this parameter is unused and defaults to 0.
Returns
-------
Series or DataFrame
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
between_time : Select values between particular times of the day.
first : Select initial periods of time series based on a date offset.
last : Select final periods of time series based on a date offset.
DatetimeIndex.indexer_at_time : Get just the index locations for
values at particular time of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='12H')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 00:00:00 1
2018-04-09 12:00:00 2
2018-04-10 00:00:00 3
2018-04-10 12:00:00 4
>>> ts.at_time('12:00')
A
2018-04-09 12:00:00 2
2018-04-10 12:00:00 4
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
index = self._get_axis(axis)
if not isinstance(index, DatetimeIndex):
raise TypeError("Index must be DatetimeIndex")
indexer = index.indexer_at_time(time, asof=asof)
return self._take_with_is_copy(indexer, axis=axis)
def between_time(
self: NDFrameT,
start_time,
end_time,
inclusive: IntervalClosedType = "both",
axis: Axis | None = None,
) -> NDFrameT:
"""
Select values between particular times of the day (e.g., 9:00-9:30 AM).
By setting ``start_time`` to be later than ``end_time``,
you can get the times that are *not* between the two times.
Parameters
----------
start_time : datetime.time or str
Initial time as a time filter limit.
end_time : datetime.time or str
End time as a time filter limit.
inclusive : {"both", "neither", "left", "right"}, default "both"
Include boundaries; whether to set each bound as closed or open.
axis : {0 or 'index', 1 or 'columns'}, default 0
Determine range time on index or columns value.
For `Series` this parameter is unused and defaults to 0.
Returns
-------
Series or DataFrame
Data from the original object filtered to the specified dates range.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
at_time : Select values at a particular time of the day.
first : Select initial periods of time series based on a date offset.
last : Select final periods of time series based on a date offset.
DatetimeIndex.indexer_between_time : Get just the index locations for
values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='1D20min')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 00:00:00 1
2018-04-10 00:20:00 2
2018-04-11 00:40:00 3
2018-04-12 01:00:00 4
>>> ts.between_time('0:15', '0:45')
A
2018-04-10 00:20:00 2
2018-04-11 00:40:00 3
You get the times that are *not* between two times by setting
``start_time`` later than ``end_time``:
>>> ts.between_time('0:45', '0:15')
A
2018-04-09 00:00:00 1
2018-04-12 01:00:00 4
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
index = self._get_axis(axis)
if not isinstance(index, DatetimeIndex):
raise TypeError("Index must be DatetimeIndex")
left_inclusive, right_inclusive = validate_inclusive(inclusive)
indexer = index.indexer_between_time(
start_time,
end_time,
include_start=left_inclusive,
include_end=right_inclusive,
)
return self._take_with_is_copy(indexer, axis=axis)
def resample(
self,
rule,
axis: Axis = 0,
closed: str | None = None,
label: str | None = None,
convention: str = "start",
kind: str | None = None,
on: Level = None,
level: Level = None,
origin: str | TimestampConvertibleTypes = "start_day",
offset: TimedeltaConvertibleTypes | None = None,
group_keys: bool_t = False,
) -> Resampler:
"""
Resample time-series data.
Convenience method for frequency conversion and resampling of time series.
The object must have a datetime-like index (`DatetimeIndex`, `PeriodIndex`,
or `TimedeltaIndex`), or the caller must pass the label of a datetime-like
series/index to the ``on``/``level`` keyword parameter.
Parameters
----------
rule : DateOffset, Timedelta or str
The offset string or object representing target conversion.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
Which axis to use for up- or down-sampling. For `Series` this parameter
is unused and defaults to 0. Must be
`DatetimeIndex`, `TimedeltaIndex` or `PeriodIndex`.
closed : {{'right', 'left'}}, default None
Which side of bin interval is closed. The default is 'left'
for all frequency offsets except for 'M', 'A', 'Q', 'BM',
'BA', 'BQ', and 'W' which all have a default of 'right'.
label : {{'right', 'left'}}, default None
Which bin edge label to label bucket with. The default is 'left'
for all frequency offsets except for 'M', 'A', 'Q', 'BM',
'BA', 'BQ', and 'W' which all have a default of 'right'.
convention : {{'start', 'end', 's', 'e'}}, default 'start'
For `PeriodIndex` only, controls whether to use the start or
end of `rule`.
kind : {{'timestamp', 'period'}}, optional, default None
Pass 'timestamp' to convert the resulting index to a
`DateTimeIndex` or 'period' to convert it to a `PeriodIndex`.
By default the input representation is retained.
on : str, optional
For a DataFrame, column to use instead of index for resampling.
Column must be datetime-like.
level : str or int, optional
For a MultiIndex, level (name or number) to use for
resampling. `level` must be datetime-like.
origin : Timestamp or str, default 'start_day'
The timestamp on which to adjust the grouping. The timezone of origin
must match the timezone of the index.
If string, must be one of the following:
- 'epoch': `origin` is 1970-01-01
- 'start': `origin` is the first value of the timeseries
- 'start_day': `origin` is the first day at midnight of the timeseries
.. versionadded:: 1.1.0
- 'end': `origin` is the last value of the timeseries
- 'end_day': `origin` is the ceiling midnight of the last day
.. versionadded:: 1.3.0
offset : Timedelta or str, default is None
An offset timedelta added to the origin.
.. versionadded:: 1.1.0
group_keys : bool, default False
Whether to include the group keys in the result index when using
``.apply()`` on the resampled object.
.. versionadded:: 1.5.0
Not specifying ``group_keys`` will retain values-dependent behavior
from pandas 1.4 and earlier (see :ref:`pandas 1.5.0 Release notes
<whatsnew_150.enhancements.resample_group_keys>` for examples).
.. versionchanged:: 2.0.0
``group_keys`` now defaults to ``False``.
Returns
-------
pandas.core.Resampler
:class:`~pandas.core.Resampler` object.
See Also
--------
Series.resample : Resample a Series.
DataFrame.resample : Resample a DataFrame.
groupby : Group {klass} by mapping, function, label, or list of labels.
asfreq : Reindex a {klass} with the given frequency without grouping.
Notes
-----
See the `user guide
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#resampling>`__
for more.
To learn more about the offset strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#dateoffset-objects>`__.
Examples
--------
Start by creating a series with 9 one minute timestamps.
>>> index = pd.date_range('1/1/2000', periods=9, freq='T')
>>> series = pd.Series(range(9), index=index)
>>> series
2000-01-01 00:00:00 0
2000-01-01 00:01:00 1
2000-01-01 00:02:00 2
2000-01-01 00:03:00 3
2000-01-01 00:04:00 4
2000-01-01 00:05:00 5
2000-01-01 00:06:00 6
2000-01-01 00:07:00 7
2000-01-01 00:08:00 8
Freq: T, dtype: int64
Downsample the series into 3 minute bins and sum the values
of the timestamps falling into a bin.
>>> series.resample('3T').sum()
2000-01-01 00:00:00 3
2000-01-01 00:03:00 12
2000-01-01 00:06:00 21
Freq: 3T, dtype: int64
Downsample the series into 3 minute bins as above, but label each
bin using the right edge instead of the left. Please note that the
value in the bucket used as the label is not included in the bucket,
which it labels. For example, in the original series the
bucket ``2000-01-01 00:03:00`` contains the value 3, but the summed
value in the resampled bucket with the label ``2000-01-01 00:03:00``
does not include 3 (if it did, the summed value would be 6, not 3).
To include this value close the right side of the bin interval as
illustrated in the example below this one.
>>> series.resample('3T', label='right').sum()
2000-01-01 00:03:00 3
2000-01-01 00:06:00 12
2000-01-01 00:09:00 21
Freq: 3T, dtype: int64
Downsample the series into 3 minute bins as above, but close the right
side of the bin interval.
>>> series.resample('3T', label='right', closed='right').sum()
2000-01-01 00:00:00 0
2000-01-01 00:03:00 6
2000-01-01 00:06:00 15
2000-01-01 00:09:00 15
Freq: 3T, dtype: int64
Upsample the series into 30 second bins.
>>> series.resample('30S').asfreq()[0:5] # Select first 5 rows
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 1.0
2000-01-01 00:01:30 NaN
2000-01-01 00:02:00 2.0
Freq: 30S, dtype: float64
Upsample the series into 30 second bins and fill the ``NaN``
values using the ``ffill`` method.
>>> series.resample('30S').ffill()[0:5]
2000-01-01 00:00:00 0
2000-01-01 00:00:30 0
2000-01-01 00:01:00 1
2000-01-01 00:01:30 1
2000-01-01 00:02:00 2
Freq: 30S, dtype: int64
Upsample the series into 30 second bins and fill the
``NaN`` values using the ``bfill`` method.
>>> series.resample('30S').bfill()[0:5]
2000-01-01 00:00:00 0
2000-01-01 00:00:30 1
2000-01-01 00:01:00 1
2000-01-01 00:01:30 2
2000-01-01 00:02:00 2
Freq: 30S, dtype: int64
Pass a custom function via ``apply``
>>> def custom_resampler(arraylike):
... return np.sum(arraylike) + 5
...
>>> series.resample('3T').apply(custom_resampler)
2000-01-01 00:00:00 8
2000-01-01 00:03:00 17
2000-01-01 00:06:00 26
Freq: 3T, dtype: int64
For a Series with a PeriodIndex, the keyword `convention` can be
used to control whether to use the start or end of `rule`.
Resample a year by quarter using 'start' `convention`. Values are
assigned to the first quarter of the period.
>>> s = pd.Series([1, 2], index=pd.period_range('2012-01-01',
... freq='A',
... periods=2))
>>> s
2012 1
2013 2
Freq: A-DEC, dtype: int64
>>> s.resample('Q', convention='start').asfreq()
2012Q1 1.0
2012Q2 NaN
2012Q3 NaN
2012Q4 NaN
2013Q1 2.0
2013Q2 NaN
2013Q3 NaN
2013Q4 NaN
Freq: Q-DEC, dtype: float64
Resample quarters by month using 'end' `convention`. Values are
assigned to the last month of the period.
>>> q = pd.Series([1, 2, 3, 4], index=pd.period_range('2018-01-01',
... freq='Q',
... periods=4))
>>> q
2018Q1 1
2018Q2 2
2018Q3 3
2018Q4 4
Freq: Q-DEC, dtype: int64
>>> q.resample('M', convention='end').asfreq()
2018-03 1.0
2018-04 NaN
2018-05 NaN
2018-06 2.0
2018-07 NaN
2018-08 NaN
2018-09 3.0
2018-10 NaN
2018-11 NaN
2018-12 4.0
Freq: M, dtype: float64
For DataFrame objects, the keyword `on` can be used to specify the
column instead of the index for resampling.
>>> d = {{'price': [10, 11, 9, 13, 14, 18, 17, 19],
... 'volume': [50, 60, 40, 100, 50, 100, 40, 50]}}
>>> df = pd.DataFrame(d)
>>> df['week_starting'] = pd.date_range('01/01/2018',
... periods=8,
... freq='W')
>>> df
price volume week_starting
0 10 50 2018-01-07
1 11 60 2018-01-14
2 9 40 2018-01-21
3 13 100 2018-01-28
4 14 50 2018-02-04
5 18 100 2018-02-11
6 17 40 2018-02-18
7 19 50 2018-02-25
>>> df.resample('M', on='week_starting').mean()
price volume
week_starting
2018-01-31 10.75 62.5
2018-02-28 17.00 60.0
For a DataFrame with MultiIndex, the keyword `level` can be used to
specify on which level the resampling needs to take place.
>>> days = pd.date_range('1/1/2000', periods=4, freq='D')
>>> d2 = {{'price': [10, 11, 9, 13, 14, 18, 17, 19],
... 'volume': [50, 60, 40, 100, 50, 100, 40, 50]}}
>>> df2 = pd.DataFrame(
... d2,
... index=pd.MultiIndex.from_product(
... [days, ['morning', 'afternoon']]
... )
... )
>>> df2
price volume
2000-01-01 morning 10 50
afternoon 11 60
2000-01-02 morning 9 40
afternoon 13 100
2000-01-03 morning 14 50
afternoon 18 100
2000-01-04 morning 17 40
afternoon 19 50
>>> df2.resample('D', level=0).sum()
price volume
2000-01-01 21 110
2000-01-02 22 140
2000-01-03 32 150
2000-01-04 36 90
If you want to adjust the start of the bins based on a fixed timestamp:
>>> start, end = '2000-10-01 23:30:00', '2000-10-02 00:30:00'
>>> rng = pd.date_range(start, end, freq='7min')
>>> ts = pd.Series(np.arange(len(rng)) * 3, index=rng)
>>> ts
2000-10-01 23:30:00 0
2000-10-01 23:37:00 3
2000-10-01 23:44:00 6
2000-10-01 23:51:00 9
2000-10-01 23:58:00 12
2000-10-02 00:05:00 15
2000-10-02 00:12:00 18
2000-10-02 00:19:00 21
2000-10-02 00:26:00 24
Freq: 7T, dtype: int64
>>> ts.resample('17min').sum()
2000-10-01 23:14:00 0
2000-10-01 23:31:00 9
2000-10-01 23:48:00 21
2000-10-02 00:05:00 54
2000-10-02 00:22:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', origin='epoch').sum()
2000-10-01 23:18:00 0
2000-10-01 23:35:00 18
2000-10-01 23:52:00 27
2000-10-02 00:09:00 39
2000-10-02 00:26:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', origin='2000-01-01').sum()
2000-10-01 23:24:00 3
2000-10-01 23:41:00 15
2000-10-01 23:58:00 45
2000-10-02 00:15:00 45
Freq: 17T, dtype: int64
If you want to adjust the start of the bins with an `offset` Timedelta, the two
following lines are equivalent:
>>> ts.resample('17min', origin='start').sum()
2000-10-01 23:30:00 9
2000-10-01 23:47:00 21
2000-10-02 00:04:00 54
2000-10-02 00:21:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', offset='23h30min').sum()
2000-10-01 23:30:00 9
2000-10-01 23:47:00 21
2000-10-02 00:04:00 54
2000-10-02 00:21:00 24
Freq: 17T, dtype: int64
If you want to take the largest Timestamp as the end of the bins:
>>> ts.resample('17min', origin='end').sum()
2000-10-01 23:35:00 0
2000-10-01 23:52:00 18
2000-10-02 00:09:00 27
2000-10-02 00:26:00 63
Freq: 17T, dtype: int64
In contrast with the `start_day`, you can use `end_day` to take the ceiling
midnight of the largest Timestamp as the end of the bins and drop the bins
not containing data:
>>> ts.resample('17min', origin='end_day').sum()
2000-10-01 23:38:00 3
2000-10-01 23:55:00 15
2000-10-02 00:12:00 45
2000-10-02 00:29:00 45
Freq: 17T, dtype: int64
"""
from pandas.core.resample import get_resampler
axis = self._get_axis_number(axis)
return get_resampler(
cast("Series | DataFrame", self),
freq=rule,
label=label,
closed=closed,
axis=axis,
kind=kind,
convention=convention,
key=on,
level=level,
origin=origin,
offset=offset,
group_keys=group_keys,
)
def first(self: NDFrameT, offset) -> NDFrameT:
"""
Select initial periods of time series data based on a date offset.
When having a DataFrame with dates as index, this function can
select the first few rows based on a date offset.
Parameters
----------
offset : str, DateOffset or dateutil.relativedelta
The offset length of the data that will be selected. For instance,
'1M' will display all the rows having their index within the first month.
Returns
-------
Series or DataFrame
A subset of the caller.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
last : Select final periods of time series based on a date offset.
at_time : Select values at a particular time of the day.
between_time : Select values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='2D')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 1
2018-04-11 2
2018-04-13 3
2018-04-15 4
Get the rows for the first 3 days:
>>> ts.first('3D')
A
2018-04-09 1
2018-04-11 2
Notice the data for 3 first calendar days were returned, not the first
3 days observed in the dataset, and therefore data for 2018-04-13 was
not returned.
"""
if not isinstance(self.index, DatetimeIndex):
raise TypeError("'first' only supports a DatetimeIndex index")
if len(self.index) == 0:
return self.copy(deep=False)
offset = to_offset(offset)
if not isinstance(offset, Tick) and offset.is_on_offset(self.index[0]):
# GH#29623 if first value is end of period, remove offset with n = 1
# before adding the real offset
end_date = end = self.index[0] - offset.base + offset
else:
end_date = end = self.index[0] + offset
# Tick-like, e.g. 3 weeks
if isinstance(offset, Tick) and end_date in self.index:
end = self.index.searchsorted(end_date, side="left")
return self.iloc[:end]
return self.loc[:end]
def last(self: NDFrameT, offset) -> NDFrameT:
"""
Select final periods of time series data based on a date offset.
For a DataFrame with a sorted DatetimeIndex, this function
selects the last few rows based on a date offset.
Parameters
----------
offset : str, DateOffset, dateutil.relativedelta
The offset length of the data that will be selected. For instance,
'3D' will display all the rows having their index within the last 3 days.
Returns
-------
Series or DataFrame
A subset of the caller.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
first : Select initial periods of time series based on a date offset.
at_time : Select values at a particular time of the day.
between_time : Select values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='2D')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 1
2018-04-11 2
2018-04-13 3
2018-04-15 4
Get the rows for the last 3 days:
>>> ts.last('3D')
A
2018-04-13 3
2018-04-15 4
Notice the data for 3 last calendar days were returned, not the last
3 observed days in the dataset, and therefore data for 2018-04-11 was
not returned.
"""
if not isinstance(self.index, DatetimeIndex):
raise TypeError("'last' only supports a DatetimeIndex index")
if len(self.index) == 0:
return self.copy(deep=False)
offset = to_offset(offset)
start_date = self.index[-1] - offset
start = self.index.searchsorted(start_date, side="right")
return self.iloc[start:]
def rank(
self: NDFrameT,
axis: Axis = 0,
method: str = "average",
numeric_only: bool_t = False,
na_option: str = "keep",
ascending: bool_t = True,
pct: bool_t = False,
) -> NDFrameT:
"""
Compute numerical data ranks (1 through n) along axis.
By default, equal values are assigned a rank that is the average of the
ranks of those values.
Parameters
----------
axis : {0 or 'index', 1 or 'columns'}, default 0
Index to direct ranking.
For `Series` this parameter is unused and defaults to 0.
method : {'average', 'min', 'max', 'first', 'dense'}, default 'average'
How to rank the group of records that have the same value (i.e. ties):
* average: average rank of the group
* min: lowest rank in the group
* max: highest rank in the group
* first: ranks assigned in order they appear in the array
* dense: like 'min', but rank always increases by 1 between groups.
numeric_only : bool, default False
For DataFrame objects, rank only numeric columns if set to True.
.. versionchanged:: 2.0.0
The default value of ``numeric_only`` is now ``False``.
na_option : {'keep', 'top', 'bottom'}, default 'keep'
How to rank NaN values:
* keep: assign NaN rank to NaN values
* top: assign lowest rank to NaN values
* bottom: assign highest rank to NaN values
ascending : bool, default True
Whether or not the elements should be ranked in ascending order.
pct : bool, default False
Whether or not to display the returned rankings in percentile
form.
Returns
-------
same type as caller
Return a Series or DataFrame with data ranks as values.
See Also
--------
core.groupby.DataFrameGroupBy.rank : Rank of values within each group.
core.groupby.SeriesGroupBy.rank : Rank of values within each group.
Examples
--------
>>> df = pd.DataFrame(data={'Animal': ['cat', 'penguin', 'dog',
... 'spider', 'snake'],
... 'Number_legs': [4, 2, 4, 8, np.nan]})
>>> df
Animal Number_legs
0 cat 4.0
1 penguin 2.0
2 dog 4.0
3 spider 8.0
4 snake NaN
Ties are assigned the mean of the ranks (by default) for the group.
>>> s = pd.Series(range(5), index=list("abcde"))
>>> s["d"] = s["b"]
>>> s.rank()
a 1.0
b 2.5
c 4.0
d 2.5
e 5.0
dtype: float64
The following example shows how the method behaves with the above
parameters:
* default_rank: this is the default behaviour obtained without using
any parameter.
* max_rank: setting ``method = 'max'`` the records that have the
same values are ranked using the highest rank (e.g.: since 'cat'
and 'dog' are both in the 2nd and 3rd position, rank 3 is assigned.)
* NA_bottom: choosing ``na_option = 'bottom'``, if there are records
with NaN values they are placed at the bottom of the ranking.
* pct_rank: when setting ``pct = True``, the ranking is expressed as
percentile rank.
>>> df['default_rank'] = df['Number_legs'].rank()
>>> df['max_rank'] = df['Number_legs'].rank(method='max')
>>> df['NA_bottom'] = df['Number_legs'].rank(na_option='bottom')
>>> df['pct_rank'] = df['Number_legs'].rank(pct=True)
>>> df
Animal Number_legs default_rank max_rank NA_bottom pct_rank
0 cat 4.0 2.5 3.0 2.5 0.625
1 penguin 2.0 1.0 1.0 1.0 0.250
2 dog 4.0 2.5 3.0 2.5 0.625
3 spider 8.0 4.0 4.0 4.0 1.000
4 snake NaN NaN NaN 5.0 NaN
"""
axis_int = self._get_axis_number(axis)
if na_option not in {"keep", "top", "bottom"}:
msg = "na_option must be one of 'keep', 'top', or 'bottom'"
raise ValueError(msg)
def ranker(data):
if data.ndim == 2:
# i.e. DataFrame, we cast to ndarray
values = data.values
else:
# i.e. Series, can dispatch to EA
values = data._values
if isinstance(values, ExtensionArray):
ranks = values._rank(
axis=axis_int,
method=method,
ascending=ascending,
na_option=na_option,
pct=pct,
)
else:
ranks = algos.rank(
values,
axis=axis_int,
method=method,
ascending=ascending,
na_option=na_option,
pct=pct,
)
ranks_obj = self._constructor(ranks, **data._construct_axes_dict())
return ranks_obj.__finalize__(self, method="rank")
if numeric_only:
if self.ndim == 1 and not is_numeric_dtype(self.dtype):
# GH#47500
raise TypeError(
"Series.rank does not allow numeric_only=True with "
"non-numeric dtype."
)
data = self._get_numeric_data()
else:
data = self
return ranker(data)
def compare(
self,
other,
align_axis: Axis = 1,
keep_shape: bool_t = False,
keep_equal: bool_t = False,
result_names: Suffixes = ("self", "other"),
):
if type(self) is not type(other):
cls_self, cls_other = type(self).__name__, type(other).__name__
raise TypeError(
f"can only compare '{cls_self}' (not '{cls_other}') with '{cls_self}'"
)
mask = ~((self == other) | (self.isna() & other.isna()))
mask.fillna(True, inplace=True)
if not keep_equal:
self = self.where(mask)
other = other.where(mask)
if not keep_shape:
if isinstance(self, ABCDataFrame):
cmask = mask.any()
rmask = mask.any(axis=1)
self = self.loc[rmask, cmask]
other = other.loc[rmask, cmask]
else:
self = self[mask]
other = other[mask]
if not isinstance(result_names, tuple):
raise TypeError(
f"Passing 'result_names' as a {type(result_names)} is not "
"supported. Provide 'result_names' as a tuple instead."
)
if align_axis in (1, "columns"): # This is needed for Series
axis = 1
else:
axis = self._get_axis_number(align_axis)
diff = concat([self, other], axis=axis, keys=result_names)
if axis >= self.ndim:
# No need to reorganize data if stacking on new axis
# This currently applies for stacking two Series on columns
return diff
ax = diff._get_axis(axis)
ax_names = np.array(ax.names)
# set index names to positions to avoid confusion
ax.names = np.arange(len(ax_names))
# bring self-other to inner level
order = list(range(1, ax.nlevels)) + [0]
if isinstance(diff, ABCDataFrame):
diff = diff.reorder_levels(order, axis=axis)
else:
diff = diff.reorder_levels(order)
# restore the index names in order
diff._get_axis(axis=axis).names = ax_names[order]
# reorder axis to keep things organized
indices = (
np.arange(diff.shape[axis]).reshape([2, diff.shape[axis] // 2]).T.flatten()
)
diff = diff.take(indices, axis=axis)
return diff
def align(
self: NDFrameT,
other: NDFrameT,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool_t | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> NDFrameT:
"""
Align two objects on their axes with the specified join method.
Join method is specified for each axis Index.
Parameters
----------
other : DataFrame or Series
join : {{'outer', 'inner', 'left', 'right'}}, default 'outer'
axis : allowed axis of the other object, default None
Align on index (0), columns (1), or both (None).
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
copy : bool, default True
Always returns new objects. If copy=False and no reindexing is
required then original objects are returned.
fill_value : scalar, default np.NaN
Value to use for missing values. Defaults to NaN, but can be any
"compatible" value.
method : {{'backfill', 'bfill', 'pad', 'ffill', None}}, default None
Method to use for filling holes in reindexed Series:
- pad / ffill: propagate last valid observation forward to next valid.
- backfill / bfill: use NEXT valid observation to fill gap.
limit : int, default None
If method is specified, this is the maximum number of consecutive
NaN values to forward/backward fill. In other words, if there is
a gap with more than this number of consecutive NaNs, it will only
be partially filled. If method is not specified, this is the
maximum number of entries along the entire axis where NaNs will be
filled. Must be greater than 0 if not None.
fill_axis : {axes_single_arg}, default 0
Filling axis, method and limit.
broadcast_axis : {axes_single_arg}, default None
Broadcast values along this axis, if aligning two objects of
different dimensions.
Returns
-------
tuple of ({klass}, type of other)
Aligned objects.
Examples
--------
>>> df = pd.DataFrame(
... [[1, 2, 3, 4], [6, 7, 8, 9]], columns=["D", "B", "E", "A"], index=[1, 2]
... )
>>> other = pd.DataFrame(
... [[10, 20, 30, 40], [60, 70, 80, 90], [600, 700, 800, 900]],
... columns=["A", "B", "C", "D"],
... index=[2, 3, 4],
... )
>>> df
D B E A
1 1 2 3 4
2 6 7 8 9
>>> other
A B C D
2 10 20 30 40
3 60 70 80 90
4 600 700 800 900
Align on columns:
>>> left, right = df.align(other, join="outer", axis=1)
>>> left
A B C D E
1 4 2 NaN 1 3
2 9 7 NaN 6 8
>>> right
A B C D E
2 10 20 30 40 NaN
3 60 70 80 90 NaN
4 600 700 800 900 NaN
We can also align on the index:
>>> left, right = df.align(other, join="outer", axis=0)
>>> left
D B E A
1 1.0 2.0 3.0 4.0
2 6.0 7.0 8.0 9.0
3 NaN NaN NaN NaN
4 NaN NaN NaN NaN
>>> right
A B C D
1 NaN NaN NaN NaN
2 10.0 20.0 30.0 40.0
3 60.0 70.0 80.0 90.0
4 600.0 700.0 800.0 900.0
Finally, the default `axis=None` will align on both index and columns:
>>> left, right = df.align(other, join="outer", axis=None)
>>> left
A B C D E
1 4.0 2.0 NaN 1.0 3.0
2 9.0 7.0 NaN 6.0 8.0
3 NaN NaN NaN NaN NaN
4 NaN NaN NaN NaN NaN
>>> right
A B C D E
1 NaN NaN NaN NaN NaN
2 10.0 20.0 30.0 40.0 NaN
3 60.0 70.0 80.0 90.0 NaN
4 600.0 700.0 800.0 900.0 NaN
"""
method = clean_fill_method(method)
if broadcast_axis == 1 and self.ndim != other.ndim:
if isinstance(self, ABCSeries):
# this means other is a DataFrame, and we need to broadcast
# self
cons = self._constructor_expanddim
df = cons(
{c: self for c in other.columns}, **other._construct_axes_dict()
)
return df._align_frame(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
elif isinstance(other, ABCSeries):
# this means self is a DataFrame, and we need to broadcast
# other
cons = other._constructor_expanddim
df = cons(
{c: other for c in self.columns}, **self._construct_axes_dict()
)
return self._align_frame(
df,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
if axis is not None:
axis = self._get_axis_number(axis)
if isinstance(other, ABCDataFrame):
return self._align_frame(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
elif isinstance(other, ABCSeries):
return self._align_series(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def _align_frame(
self,
other,
join: AlignJoin = "outer",
axis: Axis | None = None,
level=None,
copy: bool_t | None = None,
fill_value=None,
method=None,
limit=None,
fill_axis: Axis = 0,
):
# defaults
join_index, join_columns = None, None
ilidx, iridx = None, None
clidx, cridx = None, None
is_series = isinstance(self, ABCSeries)
if (axis is None or axis == 0) and not self.index.equals(other.index):
join_index, ilidx, iridx = self.index.join(
other.index, how=join, level=level, return_indexers=True
)
if (
(axis is None or axis == 1)
and not is_series
and not self.columns.equals(other.columns)
):
join_columns, clidx, cridx = self.columns.join(
other.columns, how=join, level=level, return_indexers=True
)
if is_series:
reindexers = {0: [join_index, ilidx]}
else:
reindexers = {0: [join_index, ilidx], 1: [join_columns, clidx]}
left = self._reindex_with_indexers(
reindexers, copy=copy, fill_value=fill_value, allow_dups=True
)
# other must be always DataFrame
right = other._reindex_with_indexers(
{0: [join_index, iridx], 1: [join_columns, cridx]},
copy=copy,
fill_value=fill_value,
allow_dups=True,
)
if method is not None:
_left = left.fillna(method=method, axis=fill_axis, limit=limit)
assert _left is not None # needed for mypy
left = _left
right = right.fillna(method=method, axis=fill_axis, limit=limit)
# if DatetimeIndex have different tz, convert to UTC
left, right = _align_as_utc(left, right, join_index)
return (
left.__finalize__(self),
right.__finalize__(other),
)
def _align_series(
self,
other,
join: AlignJoin = "outer",
axis: Axis | None = None,
level=None,
copy: bool_t | None = None,
fill_value=None,
method=None,
limit=None,
fill_axis: Axis = 0,
):
is_series = isinstance(self, ABCSeries)
if copy and using_copy_on_write():
copy = False
if (not is_series and axis is None) or axis not in [None, 0, 1]:
raise ValueError("Must specify axis=0 or 1")
if is_series and axis == 1:
raise ValueError("cannot align series to a series other than axis 0")
# series/series compat, other must always be a Series
if not axis:
# equal
if self.index.equals(other.index):
join_index, lidx, ridx = None, None, None
else:
join_index, lidx, ridx = self.index.join(
other.index, how=join, level=level, return_indexers=True
)
if is_series:
left = self._reindex_indexer(join_index, lidx, copy)
elif lidx is None or join_index is None:
left = self.copy(deep=copy)
else:
left = self._constructor(
self._mgr.reindex_indexer(join_index, lidx, axis=1, copy=copy)
)
right = other._reindex_indexer(join_index, ridx, copy)
else:
# one has > 1 ndim
fdata = self._mgr
join_index = self.axes[1]
lidx, ridx = None, None
if not join_index.equals(other.index):
join_index, lidx, ridx = join_index.join(
other.index, how=join, level=level, return_indexers=True
)
if lidx is not None:
bm_axis = self._get_block_manager_axis(1)
fdata = fdata.reindex_indexer(join_index, lidx, axis=bm_axis)
if copy and fdata is self._mgr:
fdata = fdata.copy()
left = self._constructor(fdata)
if ridx is None:
right = other.copy(deep=copy)
else:
right = other.reindex(join_index, level=level)
# fill
fill_na = notna(fill_value) or (method is not None)
if fill_na:
left = left.fillna(fill_value, method=method, limit=limit, axis=fill_axis)
right = right.fillna(fill_value, method=method, limit=limit)
# if DatetimeIndex have different tz, convert to UTC
if is_series or (not is_series and axis == 0):
left, right = _align_as_utc(left, right, join_index)
return (
left.__finalize__(self),
right.__finalize__(other),
)
def _where(
self,
cond,
other=lib.no_default,
inplace: bool_t = False,
axis: Axis | None = None,
level=None,
):
"""
Equivalent to public method `where`, except that `other` is not
applied as a function even if callable. Used in __setitem__.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if axis is not None:
axis = self._get_axis_number(axis)
# align the cond to same shape as myself
cond = common.apply_if_callable(cond, self)
if isinstance(cond, NDFrame):
# CoW: Make sure reference is not kept alive
cond = cond.align(self, join="right", broadcast_axis=1, copy=False)[0]
else:
if not hasattr(cond, "shape"):
cond = np.asanyarray(cond)
if cond.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
cond = self._constructor(cond, **self._construct_axes_dict(), copy=False)
# make sure we are boolean
fill_value = bool(inplace)
cond = cond.fillna(fill_value)
msg = "Boolean array expected for the condition, not {dtype}"
if not cond.empty:
if not isinstance(cond, ABCDataFrame):
# This is a single-dimensional object.
if not is_bool_dtype(cond):
raise ValueError(msg.format(dtype=cond.dtype))
else:
for _dt in cond.dtypes:
if not is_bool_dtype(_dt):
raise ValueError(msg.format(dtype=_dt))
else:
# GH#21947 we have an empty DataFrame/Series, could be object-dtype
cond = cond.astype(bool)
cond = -cond if inplace else cond
cond = cond.reindex(self._info_axis, axis=self._info_axis_number, copy=False)
# try to align with other
if isinstance(other, NDFrame):
# align with me
if other.ndim <= self.ndim:
# CoW: Make sure reference is not kept alive
other = self.align(
other,
join="left",
axis=axis,
level=level,
fill_value=None,
copy=False,
)[1]
# if we are NOT aligned, raise as we cannot where index
if axis is None and not other._indexed_same(self):
raise InvalidIndexError
if other.ndim < self.ndim:
# TODO(EA2D): avoid object-dtype cast in EA case GH#38729
other = other._values
if axis == 0:
other = np.reshape(other, (-1, 1))
elif axis == 1:
other = np.reshape(other, (1, -1))
other = np.broadcast_to(other, self.shape)
# slice me out of the other
else:
raise NotImplementedError(
"cannot align with a higher dimensional NDFrame"
)
elif not isinstance(other, (MultiIndex, NDFrame)):
# mainly just catching Index here
other = extract_array(other, extract_numpy=True)
if isinstance(other, (np.ndarray, ExtensionArray)):
if other.shape != self.shape:
if self.ndim != 1:
# In the ndim == 1 case we may have
# other length 1, which we treat as scalar (GH#2745, GH#4192)
# or len(other) == icond.sum(), which we treat like
# __setitem__ (GH#3235)
raise ValueError(
"other must be the same shape as self when an ndarray"
)
# we are the same shape, so create an actual object for alignment
else:
other = self._constructor(
other, **self._construct_axes_dict(), copy=False
)
if axis is None:
axis = 0
if self.ndim == getattr(other, "ndim", 0):
align = True
else:
align = self._get_axis_number(axis) == 1
if inplace:
# we may have different type blocks come out of putmask, so
# reconstruct the block manager
self._check_inplace_setting(other)
new_data = self._mgr.putmask(mask=cond, new=other, align=align)
result = self._constructor(new_data)
return self._update_inplace(result)
else:
new_data = self._mgr.where(
other=other,
cond=cond,
align=align,
)
result = self._constructor(new_data)
return result.__finalize__(self)
def where(
self: NDFrameT,
cond,
other=...,
*,
inplace: Literal[False] = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT:
...
def where(
self,
cond,
other=...,
*,
inplace: Literal[True],
axis: Axis | None = ...,
level: Level = ...,
) -> None:
...
def where(
self: NDFrameT,
cond,
other=...,
*,
inplace: bool_t = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT | None:
...
klass=_shared_doc_kwargs["klass"],
cond="True",
cond_rev="False",
name="where",
name_other="mask",
)
def where(
self: NDFrameT,
cond,
other=np.nan,
*,
inplace: bool_t = False,
axis: Axis | None = None,
level: Level = None,
) -> NDFrameT | None:
"""
Replace values where the condition is {cond_rev}.
Parameters
----------
cond : bool {klass}, array-like, or callable
Where `cond` is {cond}, keep the original value. Where
{cond_rev}, replace with corresponding value from `other`.
If `cond` is callable, it is computed on the {klass} and
should return boolean {klass} or array. The callable must
not change input {klass} (though pandas doesn't check it).
other : scalar, {klass}, or callable
Entries where `cond` is {cond_rev} are replaced with
corresponding value from `other`.
If other is callable, it is computed on the {klass} and
should return scalar or {klass}. The callable must not
change input {klass} (though pandas doesn't check it).
If not specified, entries will be filled with the corresponding
NULL value (``np.nan`` for numpy dtypes, ``pd.NA`` for extension
dtypes).
inplace : bool, default False
Whether to perform the operation in place on the data.
axis : int, default None
Alignment axis if needed. For `Series` this parameter is
unused and defaults to 0.
level : int, default None
Alignment level if needed.
Returns
-------
Same type as caller or None if ``inplace=True``.
See Also
--------
:func:`DataFrame.{name_other}` : Return an object of same shape as
self.
Notes
-----
The {name} method is an application of the if-then idiom. For each
element in the calling DataFrame, if ``cond`` is ``{cond}`` the
element is used; otherwise the corresponding element from the DataFrame
``other`` is used. If the axis of ``other`` does not align with axis of
``cond`` {klass}, the misaligned index positions will be filled with
{cond_rev}.
The signature for :func:`DataFrame.where` differs from
:func:`numpy.where`. Roughly ``df1.where(m, df2)`` is equivalent to
``np.where(m, df1, df2)``.
For further details and examples see the ``{name}`` documentation in
:ref:`indexing <indexing.where_mask>`.
The dtype of the object takes precedence. The fill value is casted to
the object's dtype, if this can be done losslessly.
Examples
--------
>>> s = pd.Series(range(5))
>>> s.where(s > 0)
0 NaN
1 1.0
2 2.0
3 3.0
4 4.0
dtype: float64
>>> s.mask(s > 0)
0 0.0
1 NaN
2 NaN
3 NaN
4 NaN
dtype: float64
>>> s = pd.Series(range(5))
>>> t = pd.Series([True, False])
>>> s.where(t, 99)
0 0
1 99
2 99
3 99
4 99
dtype: int64
>>> s.mask(t, 99)
0 99
1 1
2 99
3 99
4 99
dtype: int64
>>> s.where(s > 1, 10)
0 10
1 10
2 2
3 3
4 4
dtype: int64
>>> s.mask(s > 1, 10)
0 0
1 1
2 10
3 10
4 10
dtype: int64
>>> df = pd.DataFrame(np.arange(10).reshape(-1, 2), columns=['A', 'B'])
>>> df
A B
0 0 1
1 2 3
2 4 5
3 6 7
4 8 9
>>> m = df % 3 == 0
>>> df.where(m, -df)
A B
0 0 -1
1 -2 3
2 -4 -5
3 6 -7
4 -8 9
>>> df.where(m, -df) == np.where(m, df, -df)
A B
0 True True
1 True True
2 True True
3 True True
4 True True
>>> df.where(m, -df) == df.mask(~m, -df)
A B
0 True True
1 True True
2 True True
3 True True
4 True True
"""
other = common.apply_if_callable(other, self)
return self._where(cond, other, inplace, axis, level)
def mask(
self: NDFrameT,
cond,
other=...,
*,
inplace: Literal[False] = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT:
...
def mask(
self,
cond,
other=...,
*,
inplace: Literal[True],
axis: Axis | None = ...,
level: Level = ...,
) -> None:
...
def mask(
self: NDFrameT,
cond,
other=...,
*,
inplace: bool_t = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT | None:
...
where,
klass=_shared_doc_kwargs["klass"],
cond="False",
cond_rev="True",
name="mask",
name_other="where",
)
def mask(
self: NDFrameT,
cond,
other=lib.no_default,
*,
inplace: bool_t = False,
axis: Axis | None = None,
level: Level = None,
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
cond = common.apply_if_callable(cond, self)
# see gh-21891
if not hasattr(cond, "__invert__"):
cond = np.array(cond)
return self.where(
~cond,
other=other,
inplace=inplace,
axis=axis,
level=level,
)
def shift(
self: NDFrameT,
periods: int = 1,
freq=None,
axis: Axis = 0,
fill_value: Hashable = None,
) -> NDFrameT:
"""
Shift index by desired number of periods with an optional time `freq`.
When `freq` is not passed, shift the index without realigning the data.
If `freq` is passed (in this case, the index must be date or datetime,
or it will raise a `NotImplementedError`), the index will be
increased using the periods and the `freq`. `freq` can be inferred
when specified as "infer" as long as either freq or inferred_freq
attribute is set in the index.
Parameters
----------
periods : int
Number of periods to shift. Can be positive or negative.
freq : DateOffset, tseries.offsets, timedelta, or str, optional
Offset to use from the tseries module or time rule (e.g. 'EOM').
If `freq` is specified then the index values are shifted but the
data is not realigned. That is, use `freq` if you would like to
extend the index when shifting and preserve the original data.
If `freq` is specified as "infer" then it will be inferred from
the freq or inferred_freq attributes of the index. If neither of
those attributes exist, a ValueError is thrown.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Shift direction. For `Series` this parameter is unused and defaults to 0.
fill_value : object, optional
The scalar value to use for newly introduced missing values.
the default depends on the dtype of `self`.
For numeric data, ``np.nan`` is used.
For datetime, timedelta, or period data, etc. :attr:`NaT` is used.
For extension dtypes, ``self.dtype.na_value`` is used.
.. versionchanged:: 1.1.0
Returns
-------
{klass}
Copy of input object, shifted.
See Also
--------
Index.shift : Shift values of Index.
DatetimeIndex.shift : Shift values of DatetimeIndex.
PeriodIndex.shift : Shift values of PeriodIndex.
Examples
--------
>>> df = pd.DataFrame({{"Col1": [10, 20, 15, 30, 45],
... "Col2": [13, 23, 18, 33, 48],
... "Col3": [17, 27, 22, 37, 52]}},
... index=pd.date_range("2020-01-01", "2020-01-05"))
>>> df
Col1 Col2 Col3
2020-01-01 10 13 17
2020-01-02 20 23 27
2020-01-03 15 18 22
2020-01-04 30 33 37
2020-01-05 45 48 52
>>> df.shift(periods=3)
Col1 Col2 Col3
2020-01-01 NaN NaN NaN
2020-01-02 NaN NaN NaN
2020-01-03 NaN NaN NaN
2020-01-04 10.0 13.0 17.0
2020-01-05 20.0 23.0 27.0
>>> df.shift(periods=1, axis="columns")
Col1 Col2 Col3
2020-01-01 NaN 10 13
2020-01-02 NaN 20 23
2020-01-03 NaN 15 18
2020-01-04 NaN 30 33
2020-01-05 NaN 45 48
>>> df.shift(periods=3, fill_value=0)
Col1 Col2 Col3
2020-01-01 0 0 0
2020-01-02 0 0 0
2020-01-03 0 0 0
2020-01-04 10 13 17
2020-01-05 20 23 27
>>> df.shift(periods=3, freq="D")
Col1 Col2 Col3
2020-01-04 10 13 17
2020-01-05 20 23 27
2020-01-06 15 18 22
2020-01-07 30 33 37
2020-01-08 45 48 52
>>> df.shift(periods=3, freq="infer")
Col1 Col2 Col3
2020-01-04 10 13 17
2020-01-05 20 23 27
2020-01-06 15 18 22
2020-01-07 30 33 37
2020-01-08 45 48 52
"""
if periods == 0:
return self.copy(deep=None)
if freq is None:
# when freq is None, data is shifted, index is not
axis = self._get_axis_number(axis)
new_data = self._mgr.shift(
periods=periods, axis=axis, fill_value=fill_value
)
return self._constructor(new_data).__finalize__(self, method="shift")
# when freq is given, index is shifted, data is not
index = self._get_axis(axis)
if freq == "infer":
freq = getattr(index, "freq", None)
if freq is None:
freq = getattr(index, "inferred_freq", None)
if freq is None:
msg = "Freq was not set in the index hence cannot be inferred"
raise ValueError(msg)
elif isinstance(freq, str):
freq = to_offset(freq)
if isinstance(index, PeriodIndex):
orig_freq = to_offset(index.freq)
if freq != orig_freq:
assert orig_freq is not None # for mypy
raise ValueError(
f"Given freq {freq.rule_code} does not match "
f"PeriodIndex freq {orig_freq.rule_code}"
)
new_ax = index.shift(periods)
else:
new_ax = index.shift(periods, freq)
result = self.set_axis(new_ax, axis=axis)
return result.__finalize__(self, method="shift")
def truncate(
self: NDFrameT,
before=None,
after=None,
axis: Axis | None = None,
copy: bool_t | None = None,
) -> NDFrameT:
"""
Truncate a Series or DataFrame before and after some index value.
This is a useful shorthand for boolean indexing based on index
values above or below certain thresholds.
Parameters
----------
before : date, str, int
Truncate all rows before this index value.
after : date, str, int
Truncate all rows after this index value.
axis : {0 or 'index', 1 or 'columns'}, optional
Axis to truncate. Truncates the index (rows) by default.
For `Series` this parameter is unused and defaults to 0.
copy : bool, default is True,
Return a copy of the truncated section.
Returns
-------
type of caller
The truncated Series or DataFrame.
See Also
--------
DataFrame.loc : Select a subset of a DataFrame by label.
DataFrame.iloc : Select a subset of a DataFrame by position.
Notes
-----
If the index being truncated contains only datetime values,
`before` and `after` may be specified as strings instead of
Timestamps.
Examples
--------
>>> df = pd.DataFrame({'A': ['a', 'b', 'c', 'd', 'e'],
... 'B': ['f', 'g', 'h', 'i', 'j'],
... 'C': ['k', 'l', 'm', 'n', 'o']},
... index=[1, 2, 3, 4, 5])
>>> df
A B C
1 a f k
2 b g l
3 c h m
4 d i n
5 e j o
>>> df.truncate(before=2, after=4)
A B C
2 b g l
3 c h m
4 d i n
The columns of a DataFrame can be truncated.
>>> df.truncate(before="A", after="B", axis="columns")
A B
1 a f
2 b g
3 c h
4 d i
5 e j
For Series, only rows can be truncated.
>>> df['A'].truncate(before=2, after=4)
2 b
3 c
4 d
Name: A, dtype: object
The index values in ``truncate`` can be datetimes or string
dates.
>>> dates = pd.date_range('2016-01-01', '2016-02-01', freq='s')
>>> df = pd.DataFrame(index=dates, data={'A': 1})
>>> df.tail()
A
2016-01-31 23:59:56 1
2016-01-31 23:59:57 1
2016-01-31 23:59:58 1
2016-01-31 23:59:59 1
2016-02-01 00:00:00 1
>>> df.truncate(before=pd.Timestamp('2016-01-05'),
... after=pd.Timestamp('2016-01-10')).tail()
A
2016-01-09 23:59:56 1
2016-01-09 23:59:57 1
2016-01-09 23:59:58 1
2016-01-09 23:59:59 1
2016-01-10 00:00:00 1
Because the index is a DatetimeIndex containing only dates, we can
specify `before` and `after` as strings. They will be coerced to
Timestamps before truncation.
>>> df.truncate('2016-01-05', '2016-01-10').tail()
A
2016-01-09 23:59:56 1
2016-01-09 23:59:57 1
2016-01-09 23:59:58 1
2016-01-09 23:59:59 1
2016-01-10 00:00:00 1
Note that ``truncate`` assumes a 0 value for any unspecified time
component (midnight). This differs from partial string slicing, which
returns any partially matching dates.
>>> df.loc['2016-01-05':'2016-01-10', :].tail()
A
2016-01-10 23:59:55 1
2016-01-10 23:59:56 1
2016-01-10 23:59:57 1
2016-01-10 23:59:58 1
2016-01-10 23:59:59 1
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
# GH 17935
# Check that index is sorted
if not ax.is_monotonic_increasing and not ax.is_monotonic_decreasing:
raise ValueError("truncate requires a sorted index")
# if we have a date index, convert to dates, otherwise
# treat like a slice
if ax._is_all_dates:
from pandas.core.tools.datetimes import to_datetime
before = to_datetime(before)
after = to_datetime(after)
if before is not None and after is not None and before > after:
raise ValueError(f"Truncate: {after} must be after {before}")
if len(ax) > 1 and ax.is_monotonic_decreasing and ax.nunique() > 1:
before, after = after, before
slicer = [slice(None, None)] * self._AXIS_LEN
slicer[axis] = slice(before, after)
result = self.loc[tuple(slicer)]
if isinstance(ax, MultiIndex):
setattr(result, self._get_axis_name(axis), ax.truncate(before, after))
result = result.copy(deep=copy and not using_copy_on_write())
return result
def tz_convert(
self: NDFrameT, tz, axis: Axis = 0, level=None, copy: bool_t | None = None
) -> NDFrameT:
"""
Convert tz-aware axis to target time zone.
Parameters
----------
tz : str or tzinfo object or None
Target time zone. Passing ``None`` will convert to
UTC and remove the timezone information.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
The axis to convert
level : int, str, default None
If axis is a MultiIndex, convert a specific level. Otherwise
must be None.
copy : bool, default True
Also make a copy of the underlying data.
Returns
-------
{klass}
Object with time zone converted axis.
Raises
------
TypeError
If the axis is tz-naive.
Examples
--------
Change to another time zone:
>>> s = pd.Series(
... [1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']),
... )
>>> s.tz_convert('Asia/Shanghai')
2018-09-15 07:30:00+08:00 1
dtype: int64
Pass None to convert to UTC and get a tz-naive index:
>>> s = pd.Series([1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']))
>>> s.tz_convert(None)
2018-09-14 23:30:00 1
dtype: int64
"""
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
def _tz_convert(ax, tz):
if not hasattr(ax, "tz_convert"):
if len(ax) > 0:
ax_name = self._get_axis_name(axis)
raise TypeError(
f"{ax_name} is not a valid DatetimeIndex or PeriodIndex"
)
ax = DatetimeIndex([], tz=tz)
else:
ax = ax.tz_convert(tz)
return ax
# if a level is given it must be a MultiIndex level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
new_level = _tz_convert(ax.levels[level], tz)
ax = ax.set_levels(new_level, level=level)
else:
if level not in (None, 0, ax.name):
raise ValueError(f"The level {level} is not valid")
ax = _tz_convert(ax, tz)
result = self.copy(deep=copy and not using_copy_on_write())
result = result.set_axis(ax, axis=axis, copy=False)
return result.__finalize__(self, method="tz_convert")
def tz_localize(
self: NDFrameT,
tz,
axis: Axis = 0,
level=None,
copy: bool_t | None = None,
ambiguous: TimeAmbiguous = "raise",
nonexistent: TimeNonexistent = "raise",
) -> NDFrameT:
"""
Localize tz-naive index of a Series or DataFrame to target time zone.
This operation localizes the Index. To localize the values in a
timezone-naive Series, use :meth:`Series.dt.tz_localize`.
Parameters
----------
tz : str or tzinfo or None
Time zone to localize. Passing ``None`` will remove the
time zone information and preserve local time.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
The axis to localize
level : int, str, default None
If axis ia a MultiIndex, localize a specific level. Otherwise
must be None.
copy : bool, default True
Also make a copy of the underlying data.
ambiguous : 'infer', bool-ndarray, 'NaT', default 'raise'
When clocks moved backward due to DST, ambiguous times may arise.
For example in Central European Time (UTC+01), when going from
03:00 DST to 02:00 non-DST, 02:30:00 local time occurs both at
00:30:00 UTC and at 01:30:00 UTC. In such a situation, the
`ambiguous` parameter dictates how ambiguous times should be
handled.
- 'infer' will attempt to infer fall dst-transition hours based on
order
- bool-ndarray where True signifies a DST time, False designates
a non-DST time (note that this flag is only applicable for
ambiguous times)
- 'NaT' will return NaT where there are ambiguous times
- 'raise' will raise an AmbiguousTimeError if there are ambiguous
times.
nonexistent : str, default 'raise'
A nonexistent time does not exist in a particular timezone
where clocks moved forward due to DST. Valid values are:
- 'shift_forward' will shift the nonexistent time forward to the
closest existing time
- 'shift_backward' will shift the nonexistent time backward to the
closest existing time
- 'NaT' will return NaT where there are nonexistent times
- timedelta objects will shift nonexistent times by the timedelta
- 'raise' will raise an NonExistentTimeError if there are
nonexistent times.
Returns
-------
{klass}
Same type as the input.
Raises
------
TypeError
If the TimeSeries is tz-aware and tz is not None.
Examples
--------
Localize local times:
>>> s = pd.Series(
... [1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00']),
... )
>>> s.tz_localize('CET')
2018-09-15 01:30:00+02:00 1
dtype: int64
Pass None to convert to tz-naive index and preserve local time:
>>> s = pd.Series([1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']))
>>> s.tz_localize(None)
2018-09-15 01:30:00 1
dtype: int64
Be careful with DST changes. When there is sequential data, pandas
can infer the DST time:
>>> s = pd.Series(range(7),
... index=pd.DatetimeIndex(['2018-10-28 01:30:00',
... '2018-10-28 02:00:00',
... '2018-10-28 02:30:00',
... '2018-10-28 02:00:00',
... '2018-10-28 02:30:00',
... '2018-10-28 03:00:00',
... '2018-10-28 03:30:00']))
>>> s.tz_localize('CET', ambiguous='infer')
2018-10-28 01:30:00+02:00 0
2018-10-28 02:00:00+02:00 1
2018-10-28 02:30:00+02:00 2
2018-10-28 02:00:00+01:00 3
2018-10-28 02:30:00+01:00 4
2018-10-28 03:00:00+01:00 5
2018-10-28 03:30:00+01:00 6
dtype: int64
In some cases, inferring the DST is impossible. In such cases, you can
pass an ndarray to the ambiguous parameter to set the DST explicitly
>>> s = pd.Series(range(3),
... index=pd.DatetimeIndex(['2018-10-28 01:20:00',
... '2018-10-28 02:36:00',
... '2018-10-28 03:46:00']))
>>> s.tz_localize('CET', ambiguous=np.array([True, True, False]))
2018-10-28 01:20:00+02:00 0
2018-10-28 02:36:00+02:00 1
2018-10-28 03:46:00+01:00 2
dtype: int64
If the DST transition causes nonexistent times, you can shift these
dates forward or backward with a timedelta object or `'shift_forward'`
or `'shift_backward'`.
>>> s = pd.Series(range(2),
... index=pd.DatetimeIndex(['2015-03-29 02:30:00',
... '2015-03-29 03:30:00']))
>>> s.tz_localize('Europe/Warsaw', nonexistent='shift_forward')
2015-03-29 03:00:00+02:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
>>> s.tz_localize('Europe/Warsaw', nonexistent='shift_backward')
2015-03-29 01:59:59.999999999+01:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
>>> s.tz_localize('Europe/Warsaw', nonexistent=pd.Timedelta('1H'))
2015-03-29 03:30:00+02:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
"""
nonexistent_options = ("raise", "NaT", "shift_forward", "shift_backward")
if nonexistent not in nonexistent_options and not isinstance(
nonexistent, dt.timedelta
):
raise ValueError(
"The nonexistent argument must be one of 'raise', "
"'NaT', 'shift_forward', 'shift_backward' or "
"a timedelta object"
)
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
def _tz_localize(ax, tz, ambiguous, nonexistent):
if not hasattr(ax, "tz_localize"):
if len(ax) > 0:
ax_name = self._get_axis_name(axis)
raise TypeError(
f"{ax_name} is not a valid DatetimeIndex or PeriodIndex"
)
ax = DatetimeIndex([], tz=tz)
else:
ax = ax.tz_localize(tz, ambiguous=ambiguous, nonexistent=nonexistent)
return ax
# if a level is given it must be a MultiIndex level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
new_level = _tz_localize(ax.levels[level], tz, ambiguous, nonexistent)
ax = ax.set_levels(new_level, level=level)
else:
if level not in (None, 0, ax.name):
raise ValueError(f"The level {level} is not valid")
ax = _tz_localize(ax, tz, ambiguous, nonexistent)
result = self.copy(deep=copy and not using_copy_on_write())
result = result.set_axis(ax, axis=axis, copy=False)
return result.__finalize__(self, method="tz_localize")
# ----------------------------------------------------------------------
# Numeric Methods
def describe(
self: NDFrameT,
percentiles=None,
include=None,
exclude=None,
) -> NDFrameT:
"""
Generate descriptive statistics.
Descriptive statistics include those that summarize the central
tendency, dispersion and shape of a
dataset's distribution, excluding ``NaN`` values.
Analyzes both numeric and object series, as well
as ``DataFrame`` column sets of mixed data types. The output
will vary depending on what is provided. Refer to the notes
below for more detail.
Parameters
----------
percentiles : list-like of numbers, optional
The percentiles to include in the output. All should
fall between 0 and 1. The default is
``[.25, .5, .75]``, which returns the 25th, 50th, and
75th percentiles.
include : 'all', list-like of dtypes or None (default), optional
A white list of data types to include in the result. Ignored
for ``Series``. Here are the options:
- 'all' : All columns of the input will be included in the output.
- A list-like of dtypes : Limits the results to the
provided data types.
To limit the result to numeric types submit
``numpy.number``. To limit it instead to object columns submit
the ``numpy.object`` data type. Strings
can also be used in the style of
``select_dtypes`` (e.g. ``df.describe(include=['O'])``). To
select pandas categorical columns, use ``'category'``
- None (default) : The result will include all numeric columns.
exclude : list-like of dtypes or None (default), optional,
A black list of data types to omit from the result. Ignored
for ``Series``. Here are the options:
- A list-like of dtypes : Excludes the provided data types
from the result. To exclude numeric types submit
``numpy.number``. To exclude object columns submit the data
type ``numpy.object``. Strings can also be used in the style of
``select_dtypes`` (e.g. ``df.describe(exclude=['O'])``). To
exclude pandas categorical columns, use ``'category'``
- None (default) : The result will exclude nothing.
Returns
-------
Series or DataFrame
Summary statistics of the Series or Dataframe provided.
See Also
--------
DataFrame.count: Count number of non-NA/null observations.
DataFrame.max: Maximum of the values in the object.
DataFrame.min: Minimum of the values in the object.
DataFrame.mean: Mean of the values.
DataFrame.std: Standard deviation of the observations.
DataFrame.select_dtypes: Subset of a DataFrame including/excluding
columns based on their dtype.
Notes
-----
For numeric data, the result's index will include ``count``,
``mean``, ``std``, ``min``, ``max`` as well as lower, ``50`` and
upper percentiles. By default the lower percentile is ``25`` and the
upper percentile is ``75``. The ``50`` percentile is the
same as the median.
For object data (e.g. strings or timestamps), the result's index
will include ``count``, ``unique``, ``top``, and ``freq``. The ``top``
is the most common value. The ``freq`` is the most common value's
frequency. Timestamps also include the ``first`` and ``last`` items.
If multiple object values have the highest count, then the
``count`` and ``top`` results will be arbitrarily chosen from
among those with the highest count.
For mixed data types provided via a ``DataFrame``, the default is to
return only an analysis of numeric columns. If the dataframe consists
only of object and categorical data without any numeric columns, the
default is to return an analysis of both the object and categorical
columns. If ``include='all'`` is provided as an option, the result
will include a union of attributes of each type.
The `include` and `exclude` parameters can be used to limit
which columns in a ``DataFrame`` are analyzed for the output.
The parameters are ignored when analyzing a ``Series``.
Examples
--------
Describing a numeric ``Series``.
>>> s = pd.Series([1, 2, 3])
>>> s.describe()
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
dtype: float64
Describing a categorical ``Series``.
>>> s = pd.Series(['a', 'a', 'b', 'c'])
>>> s.describe()
count 4
unique 3
top a
freq 2
dtype: object
Describing a timestamp ``Series``.
>>> s = pd.Series([
... np.datetime64("2000-01-01"),
... np.datetime64("2010-01-01"),
... np.datetime64("2010-01-01")
... ])
>>> s.describe()
count 3
mean 2006-09-01 08:00:00
min 2000-01-01 00:00:00
25% 2004-12-31 12:00:00
50% 2010-01-01 00:00:00
75% 2010-01-01 00:00:00
max 2010-01-01 00:00:00
dtype: object
Describing a ``DataFrame``. By default only numeric fields
are returned.
>>> df = pd.DataFrame({'categorical': pd.Categorical(['d','e','f']),
... 'numeric': [1, 2, 3],
... 'object': ['a', 'b', 'c']
... })
>>> df.describe()
numeric
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Describing all columns of a ``DataFrame`` regardless of data type.
>>> df.describe(include='all') # doctest: +SKIP
categorical numeric object
count 3 3.0 3
unique 3 NaN 3
top f NaN a
freq 1 NaN 1
mean NaN 2.0 NaN
std NaN 1.0 NaN
min NaN 1.0 NaN
25% NaN 1.5 NaN
50% NaN 2.0 NaN
75% NaN 2.5 NaN
max NaN 3.0 NaN
Describing a column from a ``DataFrame`` by accessing it as
an attribute.
>>> df.numeric.describe()
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Name: numeric, dtype: float64
Including only numeric columns in a ``DataFrame`` description.
>>> df.describe(include=[np.number])
numeric
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Including only string columns in a ``DataFrame`` description.
>>> df.describe(include=[object]) # doctest: +SKIP
object
count 3
unique 3
top a
freq 1
Including only categorical columns from a ``DataFrame`` description.
>>> df.describe(include=['category'])
categorical
count 3
unique 3
top d
freq 1
Excluding numeric columns from a ``DataFrame`` description.
>>> df.describe(exclude=[np.number]) # doctest: +SKIP
categorical object
count 3 3
unique 3 3
top f a
freq 1 1
Excluding object columns from a ``DataFrame`` description.
>>> df.describe(exclude=[object]) # doctest: +SKIP
categorical numeric
count 3 3.0
unique 3 NaN
top f NaN
freq 1 NaN
mean NaN 2.0
std NaN 1.0
min NaN 1.0
25% NaN 1.5
50% NaN 2.0
75% NaN 2.5
max NaN 3.0
"""
return describe_ndframe(
obj=self,
include=include,
exclude=exclude,
percentiles=percentiles,
)
def pct_change(
self: NDFrameT,
periods: int = 1,
fill_method: Literal["backfill", "bfill", "pad", "ffill"] | None = "pad",
limit=None,
freq=None,
**kwargs,
) -> NDFrameT:
"""
Percentage change between the current and a prior element.
Computes the percentage change from the immediately previous row by
default. This is useful in comparing the percentage of change in a time
series of elements.
Parameters
----------
periods : int, default 1
Periods to shift for forming percent change.
fill_method : {'backfill', 'bfill', 'pad', 'ffill', None}, default 'pad'
How to handle NAs **before** computing percent changes.
limit : int, default None
The number of consecutive NAs to fill before stopping.
freq : DateOffset, timedelta, or str, optional
Increment to use from time series API (e.g. 'M' or BDay()).
**kwargs
Additional keyword arguments are passed into
`DataFrame.shift` or `Series.shift`.
Returns
-------
Series or DataFrame
The same type as the calling object.
See Also
--------
Series.diff : Compute the difference of two elements in a Series.
DataFrame.diff : Compute the difference of two elements in a DataFrame.
Series.shift : Shift the index by some number of periods.
DataFrame.shift : Shift the index by some number of periods.
Examples
--------
**Series**
>>> s = pd.Series([90, 91, 85])
>>> s
0 90
1 91
2 85
dtype: int64
>>> s.pct_change()
0 NaN
1 0.011111
2 -0.065934
dtype: float64
>>> s.pct_change(periods=2)
0 NaN
1 NaN
2 -0.055556
dtype: float64
See the percentage change in a Series where filling NAs with last
valid observation forward to next valid.
>>> s = pd.Series([90, 91, None, 85])
>>> s
0 90.0
1 91.0
2 NaN
3 85.0
dtype: float64
>>> s.pct_change(fill_method='ffill')
0 NaN
1 0.011111
2 0.000000
3 -0.065934
dtype: float64
**DataFrame**
Percentage change in French franc, Deutsche Mark, and Italian lira from
1980-01-01 to 1980-03-01.
>>> df = pd.DataFrame({
... 'FR': [4.0405, 4.0963, 4.3149],
... 'GR': [1.7246, 1.7482, 1.8519],
... 'IT': [804.74, 810.01, 860.13]},
... index=['1980-01-01', '1980-02-01', '1980-03-01'])
>>> df
FR GR IT
1980-01-01 4.0405 1.7246 804.74
1980-02-01 4.0963 1.7482 810.01
1980-03-01 4.3149 1.8519 860.13
>>> df.pct_change()
FR GR IT
1980-01-01 NaN NaN NaN
1980-02-01 0.013810 0.013684 0.006549
1980-03-01 0.053365 0.059318 0.061876
Percentage of change in GOOG and APPL stock volume. Shows computing
the percentage change between columns.
>>> df = pd.DataFrame({
... '2016': [1769950, 30586265],
... '2015': [1500923, 40912316],
... '2014': [1371819, 41403351]},
... index=['GOOG', 'APPL'])
>>> df
2016 2015 2014
GOOG 1769950 1500923 1371819
APPL 30586265 40912316 41403351
>>> df.pct_change(axis='columns', periods=-1)
2016 2015 2014
GOOG 0.179241 0.094112 NaN
APPL -0.252395 -0.011860 NaN
"""
axis = self._get_axis_number(kwargs.pop("axis", self._stat_axis_name))
if fill_method is None:
data = self
else:
_data = self.fillna(method=fill_method, axis=axis, limit=limit)
assert _data is not None # needed for mypy
data = _data
shifted = data.shift(periods=periods, freq=freq, axis=axis, **kwargs)
# Unsupported left operand type for / ("NDFrameT")
rs = data / shifted - 1 # type: ignore[operator]
if freq is not None:
# Shift method is implemented differently when freq is not None
# We want to restore the original index
rs = rs.loc[~rs.index.duplicated()]
rs = rs.reindex_like(data)
return rs.__finalize__(self, method="pct_change")
def _logical_func(
self,
name: str,
func,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> Series | bool_t:
nv.validate_logical_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if self.ndim > 1 and axis is None:
# Reduce along one dimension then the other, to simplify DataFrame._reduce
res = self._logical_func(
name, func, axis=0, bool_only=bool_only, skipna=skipna, **kwargs
)
return res._logical_func(name, func, skipna=skipna, **kwargs)
if (
self.ndim > 1
and axis == 1
and len(self._mgr.arrays) > 1
# TODO(EA2D): special-case not needed
and all(x.ndim == 2 for x in self._mgr.arrays)
and not kwargs
):
# Fastpath avoiding potentially expensive transpose
obj = self
if bool_only:
obj = self._get_bool_data()
return obj._reduce_axis1(name, func, skipna=skipna)
return self._reduce(
func,
name=name,
axis=axis,
skipna=skipna,
numeric_only=bool_only,
filter_type="bool",
)
def any(
self,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> DataFrame | Series | bool_t:
return self._logical_func(
"any", nanops.nanany, axis, bool_only, skipna, **kwargs
)
def all(
self,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> Series | bool_t:
return self._logical_func(
"all", nanops.nanall, axis, bool_only, skipna, **kwargs
)
def _accum_func(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
*args,
**kwargs,
):
skipna = nv.validate_cum_func_with_skipna(skipna, args, kwargs, name)
if axis is None:
axis = self._stat_axis_number
else:
axis = self._get_axis_number(axis)
if axis == 1:
return self.T._accum_func(
name, func, axis=0, skipna=skipna, *args, **kwargs # noqa: B026
).T
def block_accum_func(blk_values):
values = blk_values.T if hasattr(blk_values, "T") else blk_values
result: np.ndarray | ExtensionArray
if isinstance(values, ExtensionArray):
result = values._accumulate(name, skipna=skipna, **kwargs)
else:
result = nanops.na_accum_func(values, func, skipna=skipna)
result = result.T if hasattr(result, "T") else result
return result
result = self._mgr.apply(block_accum_func)
return self._constructor(result).__finalize__(self, method=name)
def cummax(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func(
"cummax", np.maximum.accumulate, axis, skipna, *args, **kwargs
)
def cummin(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func(
"cummin", np.minimum.accumulate, axis, skipna, *args, **kwargs
)
def cumsum(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func("cumsum", np.cumsum, axis, skipna, *args, **kwargs)
def cumprod(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func("cumprod", np.cumprod, axis, skipna, *args, **kwargs)
def _stat_function_ddof(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
nv.validate_stat_ddof_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if axis is None:
axis = self._stat_axis_number
return self._reduce(
func, name, axis=axis, numeric_only=numeric_only, skipna=skipna, ddof=ddof
)
def sem(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"sem", nanops.nansem, axis, skipna, ddof, numeric_only, **kwargs
)
def var(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"var", nanops.nanvar, axis, skipna, ddof, numeric_only, **kwargs
)
def std(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"std", nanops.nanstd, axis, skipna, ddof, numeric_only, **kwargs
)
def _stat_function(
self,
name: str,
func,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
if name == "median":
nv.validate_median((), kwargs)
else:
nv.validate_stat_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
return self._reduce(
func, name=name, axis=axis, skipna=skipna, numeric_only=numeric_only
)
def min(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return self._stat_function(
"min",
nanops.nanmin,
axis,
skipna,
numeric_only,
**kwargs,
)
def max(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return self._stat_function(
"max",
nanops.nanmax,
axis,
skipna,
numeric_only,
**kwargs,
)
def mean(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"mean", nanops.nanmean, axis, skipna, numeric_only, **kwargs
)
def median(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"median", nanops.nanmedian, axis, skipna, numeric_only, **kwargs
)
def skew(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"skew", nanops.nanskew, axis, skipna, numeric_only, **kwargs
)
def kurt(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"kurt", nanops.nankurt, axis, skipna, numeric_only, **kwargs
)
kurtosis = kurt
def _min_count_stat_function(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
if name == "sum":
nv.validate_sum((), kwargs)
elif name == "prod":
nv.validate_prod((), kwargs)
else:
nv.validate_stat_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if axis is None:
axis = self._stat_axis_number
return self._reduce(
func,
name=name,
axis=axis,
skipna=skipna,
numeric_only=numeric_only,
min_count=min_count,
)
def sum(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return self._min_count_stat_function(
"sum", nanops.nansum, axis, skipna, numeric_only, min_count, **kwargs
)
def prod(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return self._min_count_stat_function(
"prod",
nanops.nanprod,
axis,
skipna,
numeric_only,
min_count,
**kwargs,
)
product = prod
def _add_numeric_operations(cls) -> None:
"""
Add the operations to the cls; evaluate the doc strings again
"""
axis_descr, name1, name2 = _doc_params(cls)
_bool_doc,
desc=_any_desc,
name1=name1,
name2=name2,
axis_descr=axis_descr,
see_also=_any_see_also,
examples=_any_examples,
empty_value=False,
)
def any(
self,
*,
axis: Axis = 0,
bool_only=None,
skipna: bool_t = True,
**kwargs,
):
return NDFrame.any(
self,
axis=axis,
bool_only=bool_only,
skipna=skipna,
**kwargs,
)
setattr(cls, "any", any)
_bool_doc,
desc=_all_desc,
name1=name1,
name2=name2,
axis_descr=axis_descr,
see_also=_all_see_also,
examples=_all_examples,
empty_value=True,
)
def all(
self,
axis: Axis = 0,
bool_only=None,
skipna: bool_t = True,
**kwargs,
):
return NDFrame.all(self, axis, bool_only, skipna, **kwargs)
setattr(cls, "all", all)
_num_ddof_doc,
desc="Return unbiased standard error of the mean over requested "
"axis.\n\nNormalized by N-1 by default. This can be changed "
"using the ddof argument",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes="",
examples="",
)
def sem(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.sem(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "sem", sem)
_num_ddof_doc,
desc="Return unbiased variance over requested axis.\n\nNormalized by "
"N-1 by default. This can be changed using the ddof argument.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes="",
examples=_var_examples,
)
def var(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.var(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "var", var)
_num_ddof_doc,
desc="Return sample standard deviation over requested axis."
"\n\nNormalized by N-1 by default. This can be changed using the "
"ddof argument.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes=_std_notes,
examples=_std_examples,
)
def std(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.std(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "std", std)
_cnum_doc,
desc="minimum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="min",
examples=_cummin_examples,
)
def cummin(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cummin(self, axis, skipna, *args, **kwargs)
setattr(cls, "cummin", cummin)
_cnum_doc,
desc="maximum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="max",
examples=_cummax_examples,
)
def cummax(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cummax(self, axis, skipna, *args, **kwargs)
setattr(cls, "cummax", cummax)
_cnum_doc,
desc="sum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="sum",
examples=_cumsum_examples,
)
def cumsum(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cumsum(self, axis, skipna, *args, **kwargs)
setattr(cls, "cumsum", cumsum)
_cnum_doc,
desc="product",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="prod",
examples=_cumprod_examples,
)
def cumprod(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cumprod(self, axis, skipna, *args, **kwargs)
setattr(cls, "cumprod", cumprod)
# error: Untyped decorator makes function "sum" untyped
_num_doc,
desc="Return the sum of the values over the requested axis.\n\n"
"This is equivalent to the method ``numpy.sum``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count=_min_count_stub,
see_also=_stat_func_see_also,
examples=_sum_examples,
)
def sum(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return NDFrame.sum(self, axis, skipna, numeric_only, min_count, **kwargs)
setattr(cls, "sum", sum)
_num_doc,
desc="Return the product of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count=_min_count_stub,
see_also=_stat_func_see_also,
examples=_prod_examples,
)
def prod(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return NDFrame.prod(self, axis, skipna, numeric_only, min_count, **kwargs)
setattr(cls, "prod", prod)
cls.product = prod
_num_doc,
desc="Return the mean of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def mean(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.mean(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "mean", mean)
_num_doc,
desc="Return unbiased skew over requested axis.\n\nNormalized by N-1.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def skew(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.skew(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "skew", skew)
_num_doc,
desc="Return unbiased kurtosis over requested axis.\n\n"
"Kurtosis obtained using Fisher's definition of\n"
"kurtosis (kurtosis of normal == 0.0). Normalized "
"by N-1.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def kurt(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.kurt(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "kurt", kurt)
cls.kurtosis = kurt
_num_doc,
desc="Return the median of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def median(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.median(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "median", median)
_num_doc,
desc="Return the maximum of the values over the requested axis.\n\n"
"If you want the *index* of the maximum, use ``idxmax``. This is "
"the equivalent of the ``numpy.ndarray`` method ``argmax``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also=_stat_func_see_also,
examples=_max_examples,
)
def max(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.max(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "max", max)
_num_doc,
desc="Return the minimum of the values over the requested axis.\n\n"
"If you want the *index* of the minimum, use ``idxmin``. This is "
"the equivalent of the ``numpy.ndarray`` method ``argmin``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also=_stat_func_see_also,
examples=_min_examples,
)
def min(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.min(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "min", min)
def rolling(
self,
window: int | dt.timedelta | str | BaseOffset | BaseIndexer,
min_periods: int | None = None,
center: bool_t = False,
win_type: str | None = None,
on: str | None = None,
axis: Axis = 0,
closed: str | None = None,
step: int | None = None,
method: str = "single",
) -> Window | Rolling:
axis = self._get_axis_number(axis)
if win_type is not None:
return Window(
self,
window=window,
min_periods=min_periods,
center=center,
win_type=win_type,
on=on,
axis=axis,
closed=closed,
step=step,
method=method,
)
return Rolling(
self,
window=window,
min_periods=min_periods,
center=center,
win_type=win_type,
on=on,
axis=axis,
closed=closed,
step=step,
method=method,
)
def expanding(
self,
min_periods: int = 1,
axis: Axis = 0,
method: str = "single",
) -> Expanding:
axis = self._get_axis_number(axis)
return Expanding(self, min_periods=min_periods, axis=axis, method=method)
def ewm(
self,
com: float | None = None,
span: float | None = None,
halflife: float | TimedeltaConvertibleTypes | None = None,
alpha: float | None = None,
min_periods: int | None = 0,
adjust: bool_t = True,
ignore_na: bool_t = False,
axis: Axis = 0,
times: np.ndarray | DataFrame | Series | None = None,
method: str = "single",
) -> ExponentialMovingWindow:
axis = self._get_axis_number(axis)
return ExponentialMovingWindow(
self,
com=com,
span=span,
halflife=halflife,
alpha=alpha,
min_periods=min_periods,
adjust=adjust,
ignore_na=ignore_na,
axis=axis,
times=times,
method=method,
)
# ----------------------------------------------------------------------
# Arithmetic Methods
def _inplace_method(self, other, op):
"""
Wrap arithmetic method to operate inplace.
"""
result = op(self, other)
if (
self.ndim == 1
and result._indexed_same(self)
and is_dtype_equal(result.dtype, self.dtype)
):
# GH#36498 this inplace op can _actually_ be inplace.
# Item "ArrayManager" of "Union[ArrayManager, SingleArrayManager,
# BlockManager, SingleBlockManager]" has no attribute "setitem_inplace"
self._mgr.setitem_inplace( # type: ignore[union-attr]
slice(None), result._values
)
return self
# Delete cacher
self._reset_cacher()
# this makes sure that we are aligned like the input
# we are updating inplace so we want to ignore is_copy
self._update_inplace(
result.reindex_like(self, copy=False), verify_is_copy=False
)
return self
def __iadd__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for + ("Type[NDFrame]")
return self._inplace_method(other, type(self).__add__) # type: ignore[operator]
def __isub__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for - ("Type[NDFrame]")
return self._inplace_method(other, type(self).__sub__) # type: ignore[operator]
def __imul__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for * ("Type[NDFrame]")
return self._inplace_method(other, type(self).__mul__) # type: ignore[operator]
def __itruediv__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for / ("Type[NDFrame]")
return self._inplace_method(
other, type(self).__truediv__ # type: ignore[operator]
)
def __ifloordiv__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for // ("Type[NDFrame]")
return self._inplace_method(
other, type(self).__floordiv__ # type: ignore[operator]
)
def __imod__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for % ("Type[NDFrame]")
return self._inplace_method(other, type(self).__mod__) # type: ignore[operator]
def __ipow__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for ** ("Type[NDFrame]")
return self._inplace_method(other, type(self).__pow__) # type: ignore[operator]
def __iand__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for & ("Type[NDFrame]")
return self._inplace_method(other, type(self).__and__) # type: ignore[operator]
def __ior__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for | ("Type[NDFrame]")
return self._inplace_method(other, type(self).__or__) # type: ignore[operator]
def __ixor__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for ^ ("Type[NDFrame]")
return self._inplace_method(other, type(self).__xor__) # type: ignore[operator]
# ----------------------------------------------------------------------
# Misc methods
def _find_valid_index(self, *, how: str) -> Hashable | None:
"""
Retrieves the index of the first valid value.
Parameters
----------
how : {'first', 'last'}
Use this parameter to change between the first or last valid index.
Returns
-------
idx_first_valid : type of index
"""
idxpos = find_valid_index(self._values, how=how, is_valid=~isna(self._values))
if idxpos is None:
return None
return self.index[idxpos]
def first_valid_index(self) -> Hashable | None:
"""
Return index for {position} non-NA value or None, if no non-NA value is found.
Returns
-------
type of index
Notes
-----
If all elements are non-NA/null, returns None.
Also returns None for empty {klass}.
"""
return self._find_valid_index(how="first")
def last_valid_index(self) -> Hashable | None:
return self._find_valid_index(how="last")
def to_json(
path_or_buf: FilePath | WriteBuffer[str] | WriteBuffer[bytes],
obj: NDFrame,
orient: str | None = ...,
date_format: str = ...,
double_precision: int = ...,
force_ascii: bool = ...,
date_unit: str = ...,
default_handler: Callable[[Any], JSONSerializable] | None = ...,
lines: bool = ...,
compression: CompressionOptions = ...,
index: bool = ...,
indent: int = ...,
storage_options: StorageOptions = ...,
mode: Literal["a", "w"] = ...,
) -> None:
... | null |
173,500 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
Any = object()
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
Literal: _SpecialForm = ...
JSONSerializable = Optional[Union[PythonScalar, List, Dict]]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
class NDFrame(PandasObject, indexing.IndexingMixin):
"""
N-dimensional analogue of DataFrame. Store multi-dimensional in a
size-mutable, labeled data structure
Parameters
----------
data : BlockManager
axes : list
copy : bool, default False
"""
_internal_names: list[str] = [
"_mgr",
"_cacher",
"_item_cache",
"_cache",
"_is_copy",
"_subtyp",
"_name",
"_default_kind",
"_default_fill_value",
"_metadata",
"__array_struct__",
"__array_interface__",
"_flags",
]
_internal_names_set: set[str] = set(_internal_names)
_accessors: set[str] = set()
_hidden_attrs: frozenset[str] = frozenset([])
_metadata: list[str] = []
_is_copy: weakref.ReferenceType[NDFrame] | None = None
_mgr: Manager
_attrs: dict[Hashable, Any]
_typ: str
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data: Manager,
copy: bool_t = False,
attrs: Mapping[Hashable, Any] | None = None,
) -> None:
# copy kwarg is retained for mypy compat, is not used
object.__setattr__(self, "_is_copy", None)
object.__setattr__(self, "_mgr", data)
object.__setattr__(self, "_item_cache", {})
if attrs is None:
attrs = {}
else:
attrs = dict(attrs)
object.__setattr__(self, "_attrs", attrs)
object.__setattr__(self, "_flags", Flags(self, allows_duplicate_labels=True))
def _init_mgr(
cls,
mgr: Manager,
axes,
dtype: Dtype | None = None,
copy: bool_t = False,
) -> Manager:
"""passed a manager and a axes dict"""
for a, axe in axes.items():
if axe is not None:
axe = ensure_index(axe)
bm_axis = cls._get_block_manager_axis(a)
mgr = mgr.reindex_axis(axe, axis=bm_axis)
# make a copy if explicitly requested
if copy:
mgr = mgr.copy()
if dtype is not None:
# avoid further copies if we can
if (
isinstance(mgr, BlockManager)
and len(mgr.blocks) == 1
and is_dtype_equal(mgr.blocks[0].values.dtype, dtype)
):
pass
else:
mgr = mgr.astype(dtype=dtype)
return mgr
def _as_manager(self: NDFrameT, typ: str, copy: bool_t = True) -> NDFrameT:
"""
Private helper function to create a DataFrame with specific manager.
Parameters
----------
typ : {"block", "array"}
copy : bool, default True
Only controls whether the conversion from Block->ArrayManager
copies the 1D arrays (to ensure proper/contiguous memory layout).
Returns
-------
DataFrame
New DataFrame using specified manager type. Is not guaranteed
to be a copy or not.
"""
new_mgr: Manager
new_mgr = mgr_to_mgr(self._mgr, typ=typ, copy=copy)
# fastpath of passing a manager doesn't check the option/manager class
return self._constructor(new_mgr).__finalize__(self)
# ----------------------------------------------------------------------
# attrs and flags
def attrs(self) -> dict[Hashable, Any]:
"""
Dictionary of global attributes of this dataset.
.. warning::
attrs is experimental and may change without warning.
See Also
--------
DataFrame.flags : Global flags applying to this object.
"""
if self._attrs is None:
self._attrs = {}
return self._attrs
def attrs(self, value: Mapping[Hashable, Any]) -> None:
self._attrs = dict(value)
def flags(self) -> Flags:
"""
Get the properties associated with this pandas object.
The available flags are
* :attr:`Flags.allows_duplicate_labels`
See Also
--------
Flags : Flags that apply to pandas objects.
DataFrame.attrs : Global metadata applying to this dataset.
Notes
-----
"Flags" differ from "metadata". Flags reflect properties of the
pandas object (the Series or DataFrame). Metadata refer to properties
of the dataset, and should be stored in :attr:`DataFrame.attrs`.
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2]})
>>> df.flags
<Flags(allows_duplicate_labels=True)>
Flags can be get or set using ``.``
>>> df.flags.allows_duplicate_labels
True
>>> df.flags.allows_duplicate_labels = False
Or by slicing with a key
>>> df.flags["allows_duplicate_labels"]
False
>>> df.flags["allows_duplicate_labels"] = True
"""
return self._flags
def set_flags(
self: NDFrameT,
*,
copy: bool_t = False,
allows_duplicate_labels: bool_t | None = None,
) -> NDFrameT:
"""
Return a new object with updated flags.
Parameters
----------
copy : bool, default False
Specify if a copy of the object should be made.
allows_duplicate_labels : bool, optional
Whether the returned object allows duplicate labels.
Returns
-------
Series or DataFrame
The same type as the caller.
See Also
--------
DataFrame.attrs : Global metadata applying to this dataset.
DataFrame.flags : Global flags applying to this object.
Notes
-----
This method returns a new object that's a view on the same data
as the input. Mutating the input or the output values will be reflected
in the other.
This method is intended to be used in method chains.
"Flags" differ from "metadata". Flags reflect properties of the
pandas object (the Series or DataFrame). Metadata refer to properties
of the dataset, and should be stored in :attr:`DataFrame.attrs`.
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2]})
>>> df.flags.allows_duplicate_labels
True
>>> df2 = df.set_flags(allows_duplicate_labels=False)
>>> df2.flags.allows_duplicate_labels
False
"""
df = self.copy(deep=copy and not using_copy_on_write())
if allows_duplicate_labels is not None:
df.flags["allows_duplicate_labels"] = allows_duplicate_labels
return df
def _validate_dtype(cls, dtype) -> DtypeObj | None:
"""validate the passed dtype"""
if dtype is not None:
dtype = pandas_dtype(dtype)
# a compound dtype
if dtype.kind == "V":
raise NotImplementedError(
"compound dtypes are not implemented "
f"in the {cls.__name__} constructor"
)
return dtype
# ----------------------------------------------------------------------
# Construction
def _constructor(self: NDFrameT) -> Callable[..., NDFrameT]:
"""
Used when a manipulation result has the same dimensions as the
original.
"""
raise AbstractMethodError(self)
# ----------------------------------------------------------------------
# Internals
def _data(self):
# GH#33054 retained because some downstream packages uses this,
# e.g. fastparquet
return self._mgr
# ----------------------------------------------------------------------
# Axis
_stat_axis_number = 0
_stat_axis_name = "index"
_AXIS_ORDERS: list[Literal["index", "columns"]]
_AXIS_TO_AXIS_NUMBER: dict[Axis, AxisInt] = {0: 0, "index": 0, "rows": 0}
_info_axis_number: int
_info_axis_name: Literal["index", "columns"]
_AXIS_LEN: int
def _construct_axes_dict(self, axes: Sequence[Axis] | None = None, **kwargs):
"""Return an axes dictionary for myself."""
d = {a: self._get_axis(a) for a in (axes or self._AXIS_ORDERS)}
# error: Argument 1 to "update" of "MutableMapping" has incompatible type
# "Dict[str, Any]"; expected "SupportsKeysAndGetItem[Union[int, str], Any]"
d.update(kwargs) # type: ignore[arg-type]
return d
def _get_axis_number(cls, axis: Axis) -> AxisInt:
try:
return cls._AXIS_TO_AXIS_NUMBER[axis]
except KeyError:
raise ValueError(f"No axis named {axis} for object type {cls.__name__}")
def _get_axis_name(cls, axis: Axis) -> Literal["index", "columns"]:
axis_number = cls._get_axis_number(axis)
return cls._AXIS_ORDERS[axis_number]
def _get_axis(self, axis: Axis) -> Index:
axis_number = self._get_axis_number(axis)
assert axis_number in {0, 1}
return self.index if axis_number == 0 else self.columns
def _get_block_manager_axis(cls, axis: Axis) -> AxisInt:
"""Map the axis to the block_manager axis."""
axis = cls._get_axis_number(axis)
ndim = cls._AXIS_LEN
if ndim == 2:
# i.e. DataFrame
return 1 - axis
return axis
def _get_axis_resolvers(self, axis: str) -> dict[str, Series | MultiIndex]:
# index or columns
axis_index = getattr(self, axis)
d = {}
prefix = axis[0]
for i, name in enumerate(axis_index.names):
if name is not None:
key = level = name
else:
# prefix with 'i' or 'c' depending on the input axis
# e.g., you must do ilevel_0 for the 0th level of an unnamed
# multiiindex
key = f"{prefix}level_{i}"
level = i
level_values = axis_index.get_level_values(level)
s = level_values.to_series()
s.index = axis_index
d[key] = s
# put the index/columns itself in the dict
if isinstance(axis_index, MultiIndex):
dindex = axis_index
else:
dindex = axis_index.to_series()
d[axis] = dindex
return d
def _get_index_resolvers(self) -> dict[Hashable, Series | MultiIndex]:
from pandas.core.computation.parsing import clean_column_name
d: dict[str, Series | MultiIndex] = {}
for axis_name in self._AXIS_ORDERS:
d.update(self._get_axis_resolvers(axis_name))
return {clean_column_name(k): v for k, v in d.items() if not isinstance(k, int)}
def _get_cleaned_column_resolvers(self) -> dict[Hashable, Series]:
"""
Return the special character free column resolvers of a dataframe.
Column names with special characters are 'cleaned up' so that they can
be referred to by backtick quoting.
Used in :meth:`DataFrame.eval`.
"""
from pandas.core.computation.parsing import clean_column_name
if isinstance(self, ABCSeries):
return {clean_column_name(self.name): self}
return {
clean_column_name(k): v for k, v in self.items() if not isinstance(k, int)
}
def _info_axis(self) -> Index:
return getattr(self, self._info_axis_name)
def _stat_axis(self) -> Index:
return getattr(self, self._stat_axis_name)
def shape(self) -> tuple[int, ...]:
"""
Return a tuple of axis dimensions
"""
return tuple(len(self._get_axis(a)) for a in self._AXIS_ORDERS)
def axes(self) -> list[Index]:
"""
Return index label(s) of the internal NDFrame
"""
# we do it this way because if we have reversed axes, then
# the block manager shows then reversed
return [self._get_axis(a) for a in self._AXIS_ORDERS]
def ndim(self) -> int:
"""
Return an int representing the number of axes / array dimensions.
Return 1 if Series. Otherwise return 2 if DataFrame.
See Also
--------
ndarray.ndim : Number of array dimensions.
Examples
--------
>>> s = pd.Series({'a': 1, 'b': 2, 'c': 3})
>>> s.ndim
1
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.ndim
2
"""
return self._mgr.ndim
def size(self) -> int:
"""
Return an int representing the number of elements in this object.
Return the number of rows if Series. Otherwise return the number of
rows times number of columns if DataFrame.
See Also
--------
ndarray.size : Number of elements in the array.
Examples
--------
>>> s = pd.Series({'a': 1, 'b': 2, 'c': 3})
>>> s.size
3
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.size
4
"""
# error: Incompatible return value type (got "signedinteger[_64Bit]",
# expected "int") [return-value]
return np.prod(self.shape) # type: ignore[return-value]
def set_axis(
self: NDFrameT,
labels,
*,
axis: Axis = 0,
copy: bool_t | None = None,
) -> NDFrameT:
"""
Assign desired index to given axis.
Indexes for%(extended_summary_sub)s row labels can be changed by assigning
a list-like or Index.
Parameters
----------
labels : list-like, Index
The values for the new index.
axis : %(axes_single_arg)s, default 0
The axis to update. The value 0 identifies the rows. For `Series`
this parameter is unused and defaults to 0.
copy : bool, default True
Whether to make a copy of the underlying data.
.. versionadded:: 1.5.0
Returns
-------
%(klass)s
An object of type %(klass)s.
See Also
--------
%(klass)s.rename_axis : Alter the name of the index%(see_also_sub)s.
"""
return self._set_axis_nocheck(labels, axis, inplace=False, copy=copy)
def _set_axis_nocheck(
self, labels, axis: Axis, inplace: bool_t, copy: bool_t | None
):
if inplace:
setattr(self, self._get_axis_name(axis), labels)
else:
# With copy=False, we create a new object but don't copy the
# underlying data.
obj = self.copy(deep=copy and not using_copy_on_write())
setattr(obj, obj._get_axis_name(axis), labels)
return obj
def _set_axis(self, axis: AxisInt, labels: AnyArrayLike | list) -> None:
"""
This is called from the cython code when we set the `index` attribute
directly, e.g. `series.index = [1, 2, 3]`.
"""
labels = ensure_index(labels)
self._mgr.set_axis(axis, labels)
self._clear_item_cache()
def swapaxes(
self: NDFrameT, axis1: Axis, axis2: Axis, copy: bool_t | None = None
) -> NDFrameT:
"""
Interchange axes and swap values axes appropriately.
Returns
-------
same as input
"""
i = self._get_axis_number(axis1)
j = self._get_axis_number(axis2)
if i == j:
return self.copy(deep=copy and not using_copy_on_write())
mapping = {i: j, j: i}
new_axes = [self._get_axis(mapping.get(k, k)) for k in range(self._AXIS_LEN)]
new_values = self._values.swapaxes(i, j) # type: ignore[union-attr]
if (
using_copy_on_write()
and self._mgr.is_single_block
and isinstance(self._mgr, BlockManager)
):
# This should only get hit in case of having a single block, otherwise a
# copy is made, we don't have to set up references.
new_mgr = ndarray_to_mgr(
new_values,
new_axes[0],
new_axes[1],
dtype=None,
copy=False,
typ="block",
)
assert isinstance(new_mgr, BlockManager)
assert isinstance(self._mgr, BlockManager)
new_mgr.blocks[0].refs = self._mgr.blocks[0].refs
new_mgr.blocks[0].refs.add_reference(
new_mgr.blocks[0] # type: ignore[arg-type]
)
return self._constructor(new_mgr).__finalize__(self, method="swapaxes")
elif (copy or copy is None) and self._mgr.is_single_block:
new_values = new_values.copy()
return self._constructor(
new_values,
*new_axes,
# The no-copy case for CoW is handled above
copy=False,
).__finalize__(self, method="swapaxes")
def droplevel(self: NDFrameT, level: IndexLabel, axis: Axis = 0) -> NDFrameT:
"""
Return {klass} with requested index / column level(s) removed.
Parameters
----------
level : int, str, or list-like
If a string is given, must be the name of a level
If list-like, elements must be names or positional indexes
of levels.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
Axis along which the level(s) is removed:
* 0 or 'index': remove level(s) in column.
* 1 or 'columns': remove level(s) in row.
For `Series` this parameter is unused and defaults to 0.
Returns
-------
{klass}
{klass} with requested index / column level(s) removed.
Examples
--------
>>> df = pd.DataFrame([
... [1, 2, 3, 4],
... [5, 6, 7, 8],
... [9, 10, 11, 12]
... ]).set_index([0, 1]).rename_axis(['a', 'b'])
>>> df.columns = pd.MultiIndex.from_tuples([
... ('c', 'e'), ('d', 'f')
... ], names=['level_1', 'level_2'])
>>> df
level_1 c d
level_2 e f
a b
1 2 3 4
5 6 7 8
9 10 11 12
>>> df.droplevel('a')
level_1 c d
level_2 e f
b
2 3 4
6 7 8
10 11 12
>>> df.droplevel('level_2', axis=1)
level_1 c d
a b
1 2 3 4
5 6 7 8
9 10 11 12
"""
labels = self._get_axis(axis)
new_labels = labels.droplevel(level)
return self.set_axis(new_labels, axis=axis, copy=None)
def pop(self, item: Hashable) -> Series | Any:
result = self[item]
del self[item]
return result
def squeeze(self, axis: Axis | None = None):
"""
Squeeze 1 dimensional axis objects into scalars.
Series or DataFrames with a single element are squeezed to a scalar.
DataFrames with a single column or a single row are squeezed to a
Series. Otherwise the object is unchanged.
This method is most useful when you don't know if your
object is a Series or DataFrame, but you do know it has just a single
column. In that case you can safely call `squeeze` to ensure you have a
Series.
Parameters
----------
axis : {0 or 'index', 1 or 'columns', None}, default None
A specific axis to squeeze. By default, all length-1 axes are
squeezed. For `Series` this parameter is unused and defaults to `None`.
Returns
-------
DataFrame, Series, or scalar
The projection after squeezing `axis` or all the axes.
See Also
--------
Series.iloc : Integer-location based indexing for selecting scalars.
DataFrame.iloc : Integer-location based indexing for selecting Series.
Series.to_frame : Inverse of DataFrame.squeeze for a
single-column DataFrame.
Examples
--------
>>> primes = pd.Series([2, 3, 5, 7])
Slicing might produce a Series with a single value:
>>> even_primes = primes[primes % 2 == 0]
>>> even_primes
0 2
dtype: int64
>>> even_primes.squeeze()
2
Squeezing objects with more than one value in every axis does nothing:
>>> odd_primes = primes[primes % 2 == 1]
>>> odd_primes
1 3
2 5
3 7
dtype: int64
>>> odd_primes.squeeze()
1 3
2 5
3 7
dtype: int64
Squeezing is even more effective when used with DataFrames.
>>> df = pd.DataFrame([[1, 2], [3, 4]], columns=['a', 'b'])
>>> df
a b
0 1 2
1 3 4
Slicing a single column will produce a DataFrame with the columns
having only one value:
>>> df_a = df[['a']]
>>> df_a
a
0 1
1 3
So the columns can be squeezed down, resulting in a Series:
>>> df_a.squeeze('columns')
0 1
1 3
Name: a, dtype: int64
Slicing a single row from a single column will produce a single
scalar DataFrame:
>>> df_0a = df.loc[df.index < 1, ['a']]
>>> df_0a
a
0 1
Squeezing the rows produces a single scalar Series:
>>> df_0a.squeeze('rows')
a 1
Name: 0, dtype: int64
Squeezing all axes will project directly into a scalar:
>>> df_0a.squeeze()
1
"""
axes = range(self._AXIS_LEN) if axis is None else (self._get_axis_number(axis),)
return self.iloc[
tuple(
0 if i in axes and len(a) == 1 else slice(None)
for i, a in enumerate(self.axes)
)
]
# ----------------------------------------------------------------------
# Rename
def _rename(
self: NDFrameT,
mapper: Renamer | None = None,
*,
index: Renamer | None = None,
columns: Renamer | None = None,
axis: Axis | None = None,
copy: bool_t | None = None,
inplace: bool_t = False,
level: Level | None = None,
errors: str = "ignore",
) -> NDFrameT | None:
# called by Series.rename and DataFrame.rename
if mapper is None and index is None and columns is None:
raise TypeError("must pass an index to rename")
if index is not None or columns is not None:
if axis is not None:
raise TypeError(
"Cannot specify both 'axis' and any of 'index' or 'columns'"
)
if mapper is not None:
raise TypeError(
"Cannot specify both 'mapper' and any of 'index' or 'columns'"
)
else:
# use the mapper argument
if axis and self._get_axis_number(axis) == 1:
columns = mapper
else:
index = mapper
self._check_inplace_and_allows_duplicate_labels(inplace)
result = self if inplace else self.copy(deep=copy and not using_copy_on_write())
for axis_no, replacements in enumerate((index, columns)):
if replacements is None:
continue
ax = self._get_axis(axis_no)
f = common.get_rename_function(replacements)
if level is not None:
level = ax._get_level_number(level)
# GH 13473
if not callable(replacements):
if ax._is_multi and level is not None:
indexer = ax.get_level_values(level).get_indexer_for(replacements)
else:
indexer = ax.get_indexer_for(replacements)
if errors == "raise" and len(indexer[indexer == -1]):
missing_labels = [
label
for index, label in enumerate(replacements)
if indexer[index] == -1
]
raise KeyError(f"{missing_labels} not found in axis")
new_index = ax._transform_index(f, level=level)
result._set_axis_nocheck(new_index, axis=axis_no, inplace=True, copy=False)
result._clear_item_cache()
if inplace:
self._update_inplace(result)
return None
else:
return result.__finalize__(self, method="rename")
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: Literal[False] = ...,
) -> NDFrameT:
...
def rename_axis(
self,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: Literal[True],
) -> None:
...
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: bool_t = ...,
) -> NDFrameT | None:
...
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = lib.no_default,
*,
index=lib.no_default,
columns=lib.no_default,
axis: Axis = 0,
copy: bool_t | None = None,
inplace: bool_t = False,
) -> NDFrameT | None:
"""
Set the name of the axis for the index or columns.
Parameters
----------
mapper : scalar, list-like, optional
Value to set the axis name attribute.
index, columns : scalar, list-like, dict-like or function, optional
A scalar, list-like, dict-like or functions transformations to
apply to that axis' values.
Note that the ``columns`` parameter is not allowed if the
object is a Series. This parameter only apply for DataFrame
type objects.
Use either ``mapper`` and ``axis`` to
specify the axis to target with ``mapper``, or ``index``
and/or ``columns``.
axis : {0 or 'index', 1 or 'columns'}, default 0
The axis to rename. For `Series` this parameter is unused and defaults to 0.
copy : bool, default None
Also copy underlying data.
inplace : bool, default False
Modifies the object directly, instead of creating a new Series
or DataFrame.
Returns
-------
Series, DataFrame, or None
The same type as the caller or None if ``inplace=True``.
See Also
--------
Series.rename : Alter Series index labels or name.
DataFrame.rename : Alter DataFrame index labels or name.
Index.rename : Set new names on index.
Notes
-----
``DataFrame.rename_axis`` supports two calling conventions
* ``(index=index_mapper, columns=columns_mapper, ...)``
* ``(mapper, axis={'index', 'columns'}, ...)``
The first calling convention will only modify the names of
the index and/or the names of the Index object that is the columns.
In this case, the parameter ``copy`` is ignored.
The second calling convention will modify the names of the
corresponding index if mapper is a list or a scalar.
However, if mapper is dict-like or a function, it will use the
deprecated behavior of modifying the axis *labels*.
We *highly* recommend using keyword arguments to clarify your
intent.
Examples
--------
**Series**
>>> s = pd.Series(["dog", "cat", "monkey"])
>>> s
0 dog
1 cat
2 monkey
dtype: object
>>> s.rename_axis("animal")
animal
0 dog
1 cat
2 monkey
dtype: object
**DataFrame**
>>> df = pd.DataFrame({"num_legs": [4, 4, 2],
... "num_arms": [0, 0, 2]},
... ["dog", "cat", "monkey"])
>>> df
num_legs num_arms
dog 4 0
cat 4 0
monkey 2 2
>>> df = df.rename_axis("animal")
>>> df
num_legs num_arms
animal
dog 4 0
cat 4 0
monkey 2 2
>>> df = df.rename_axis("limbs", axis="columns")
>>> df
limbs num_legs num_arms
animal
dog 4 0
cat 4 0
monkey 2 2
**MultiIndex**
>>> df.index = pd.MultiIndex.from_product([['mammal'],
... ['dog', 'cat', 'monkey']],
... names=['type', 'name'])
>>> df
limbs num_legs num_arms
type name
mammal dog 4 0
cat 4 0
monkey 2 2
>>> df.rename_axis(index={'type': 'class'})
limbs num_legs num_arms
class name
mammal dog 4 0
cat 4 0
monkey 2 2
>>> df.rename_axis(columns=str.upper)
LIMBS num_legs num_arms
type name
mammal dog 4 0
cat 4 0
monkey 2 2
"""
axes = {"index": index, "columns": columns}
if axis is not None:
axis = self._get_axis_number(axis)
inplace = validate_bool_kwarg(inplace, "inplace")
if copy and using_copy_on_write():
copy = False
if mapper is not lib.no_default:
# Use v0.23 behavior if a scalar or list
non_mapper = is_scalar(mapper) or (
is_list_like(mapper) and not is_dict_like(mapper)
)
if non_mapper:
return self._set_axis_name(
mapper, axis=axis, inplace=inplace, copy=copy
)
else:
raise ValueError("Use `.rename` to alter labels with a mapper.")
else:
# Use new behavior. Means that index and/or columns
# is specified
result = self if inplace else self.copy(deep=copy)
for axis in range(self._AXIS_LEN):
v = axes.get(self._get_axis_name(axis))
if v is lib.no_default:
continue
non_mapper = is_scalar(v) or (is_list_like(v) and not is_dict_like(v))
if non_mapper:
newnames = v
else:
f = common.get_rename_function(v)
curnames = self._get_axis(axis).names
newnames = [f(name) for name in curnames]
result._set_axis_name(newnames, axis=axis, inplace=True, copy=copy)
if not inplace:
return result
return None
def _set_axis_name(
self, name, axis: Axis = 0, inplace: bool_t = False, copy: bool_t | None = True
):
"""
Set the name(s) of the axis.
Parameters
----------
name : str or list of str
Name(s) to set.
axis : {0 or 'index', 1 or 'columns'}, default 0
The axis to set the label. The value 0 or 'index' specifies index,
and the value 1 or 'columns' specifies columns.
inplace : bool, default False
If `True`, do operation inplace and return None.
copy:
Whether to make a copy of the result.
Returns
-------
Series, DataFrame, or None
The same type as the caller or `None` if `inplace` is `True`.
See Also
--------
DataFrame.rename : Alter the axis labels of :class:`DataFrame`.
Series.rename : Alter the index labels or set the index name
of :class:`Series`.
Index.rename : Set the name of :class:`Index` or :class:`MultiIndex`.
Examples
--------
>>> df = pd.DataFrame({"num_legs": [4, 4, 2]},
... ["dog", "cat", "monkey"])
>>> df
num_legs
dog 4
cat 4
monkey 2
>>> df._set_axis_name("animal")
num_legs
animal
dog 4
cat 4
monkey 2
>>> df.index = pd.MultiIndex.from_product(
... [["mammal"], ['dog', 'cat', 'monkey']])
>>> df._set_axis_name(["type", "name"])
num_legs
type name
mammal dog 4
cat 4
monkey 2
"""
axis = self._get_axis_number(axis)
idx = self._get_axis(axis).set_names(name)
inplace = validate_bool_kwarg(inplace, "inplace")
renamed = self if inplace else self.copy(deep=copy)
if axis == 0:
renamed.index = idx
else:
renamed.columns = idx
if not inplace:
return renamed
# ----------------------------------------------------------------------
# Comparison Methods
def _indexed_same(self, other) -> bool_t:
return all(
self._get_axis(a).equals(other._get_axis(a)) for a in self._AXIS_ORDERS
)
def equals(self, other: object) -> bool_t:
"""
Test whether two objects contain the same elements.
This function allows two Series or DataFrames to be compared against
each other to see if they have the same shape and elements. NaNs in
the same location are considered equal.
The row/column index do not need to have the same type, as long
as the values are considered equal. Corresponding columns must be of
the same dtype.
Parameters
----------
other : Series or DataFrame
The other Series or DataFrame to be compared with the first.
Returns
-------
bool
True if all elements are the same in both objects, False
otherwise.
See Also
--------
Series.eq : Compare two Series objects of the same length
and return a Series where each element is True if the element
in each Series is equal, False otherwise.
DataFrame.eq : Compare two DataFrame objects of the same shape and
return a DataFrame where each element is True if the respective
element in each DataFrame is equal, False otherwise.
testing.assert_series_equal : Raises an AssertionError if left and
right are not equal. Provides an easy interface to ignore
inequality in dtypes, indexes and precision among others.
testing.assert_frame_equal : Like assert_series_equal, but targets
DataFrames.
numpy.array_equal : Return True if two arrays have the same shape
and elements, False otherwise.
Examples
--------
>>> df = pd.DataFrame({1: [10], 2: [20]})
>>> df
1 2
0 10 20
DataFrames df and exactly_equal have the same types and values for
their elements and column labels, which will return True.
>>> exactly_equal = pd.DataFrame({1: [10], 2: [20]})
>>> exactly_equal
1 2
0 10 20
>>> df.equals(exactly_equal)
True
DataFrames df and different_column_type have the same element
types and values, but have different types for the column labels,
which will still return True.
>>> different_column_type = pd.DataFrame({1.0: [10], 2.0: [20]})
>>> different_column_type
1.0 2.0
0 10 20
>>> df.equals(different_column_type)
True
DataFrames df and different_data_type have different types for the
same values for their elements, and will return False even though
their column labels are the same values and types.
>>> different_data_type = pd.DataFrame({1: [10.0], 2: [20.0]})
>>> different_data_type
1 2
0 10.0 20.0
>>> df.equals(different_data_type)
False
"""
if not (isinstance(other, type(self)) or isinstance(self, type(other))):
return False
other = cast(NDFrame, other)
return self._mgr.equals(other._mgr)
# -------------------------------------------------------------------------
# Unary Methods
def __neg__(self: NDFrameT) -> NDFrameT:
def blk_func(values: ArrayLike):
if is_bool_dtype(values.dtype):
# error: Argument 1 to "inv" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsInversion[ndarray[Any, dtype[bool_]]]"
return operator.inv(values) # type: ignore[arg-type]
else:
# error: Argument 1 to "neg" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsNeg[ndarray[Any, dtype[Any]]]"
return operator.neg(values) # type: ignore[arg-type]
new_data = self._mgr.apply(blk_func)
res = self._constructor(new_data)
return res.__finalize__(self, method="__neg__")
def __pos__(self: NDFrameT) -> NDFrameT:
def blk_func(values: ArrayLike):
if is_bool_dtype(values.dtype):
return values.copy()
else:
# error: Argument 1 to "pos" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsPos[ndarray[Any, dtype[Any]]]"
return operator.pos(values) # type: ignore[arg-type]
new_data = self._mgr.apply(blk_func)
res = self._constructor(new_data)
return res.__finalize__(self, method="__pos__")
def __invert__(self: NDFrameT) -> NDFrameT:
if not self.size:
# inv fails with 0 len
return self.copy(deep=False)
new_data = self._mgr.apply(operator.invert)
return self._constructor(new_data).__finalize__(self, method="__invert__")
def __nonzero__(self) -> NoReturn:
raise ValueError(
f"The truth value of a {type(self).__name__} is ambiguous. "
"Use a.empty, a.bool(), a.item(), a.any() or a.all()."
)
__bool__ = __nonzero__
def bool(self) -> bool_t:
"""
Return the bool of a single element Series or DataFrame.
This must be a boolean scalar value, either True or False. It will raise a
ValueError if the Series or DataFrame does not have exactly 1 element, or that
element is not boolean (integer values 0 and 1 will also raise an exception).
Returns
-------
bool
The value in the Series or DataFrame.
See Also
--------
Series.astype : Change the data type of a Series, including to boolean.
DataFrame.astype : Change the data type of a DataFrame, including to boolean.
numpy.bool_ : NumPy boolean data type, used by pandas for boolean values.
Examples
--------
The method will only work for single element objects with a boolean value:
>>> pd.Series([True]).bool()
True
>>> pd.Series([False]).bool()
False
>>> pd.DataFrame({'col': [True]}).bool()
True
>>> pd.DataFrame({'col': [False]}).bool()
False
"""
v = self.squeeze()
if isinstance(v, (bool, np.bool_)):
return bool(v)
elif is_scalar(v):
raise ValueError(
"bool cannot act on a non-boolean single element "
f"{type(self).__name__}"
)
self.__nonzero__()
# for mypy (__nonzero__ raises)
return True
def abs(self: NDFrameT) -> NDFrameT:
"""
Return a Series/DataFrame with absolute numeric value of each element.
This function only applies to elements that are all numeric.
Returns
-------
abs
Series/DataFrame containing the absolute value of each element.
See Also
--------
numpy.absolute : Calculate the absolute value element-wise.
Notes
-----
For ``complex`` inputs, ``1.2 + 1j``, the absolute value is
:math:`\\sqrt{ a^2 + b^2 }`.
Examples
--------
Absolute numeric values in a Series.
>>> s = pd.Series([-1.10, 2, -3.33, 4])
>>> s.abs()
0 1.10
1 2.00
2 3.33
3 4.00
dtype: float64
Absolute numeric values in a Series with complex numbers.
>>> s = pd.Series([1.2 + 1j])
>>> s.abs()
0 1.56205
dtype: float64
Absolute numeric values in a Series with a Timedelta element.
>>> s = pd.Series([pd.Timedelta('1 days')])
>>> s.abs()
0 1 days
dtype: timedelta64[ns]
Select rows with data closest to certain value using argsort (from
`StackOverflow <https://stackoverflow.com/a/17758115>`__).
>>> df = pd.DataFrame({
... 'a': [4, 5, 6, 7],
... 'b': [10, 20, 30, 40],
... 'c': [100, 50, -30, -50]
... })
>>> df
a b c
0 4 10 100
1 5 20 50
2 6 30 -30
3 7 40 -50
>>> df.loc[(df.c - 43).abs().argsort()]
a b c
1 5 20 50
0 4 10 100
2 6 30 -30
3 7 40 -50
"""
res_mgr = self._mgr.apply(np.abs)
return self._constructor(res_mgr).__finalize__(self, name="abs")
def __abs__(self: NDFrameT) -> NDFrameT:
return self.abs()
def __round__(self: NDFrameT, decimals: int = 0) -> NDFrameT:
return self.round(decimals).__finalize__(self, method="__round__")
# -------------------------------------------------------------------------
# Label or Level Combination Helpers
#
# A collection of helper methods for DataFrame/Series operations that
# accept a combination of column/index labels and levels. All such
# operations should utilize/extend these methods when possible so that we
# have consistent precedence and validation logic throughout the library.
def _is_level_reference(self, key: Level, axis: Axis = 0) -> bool_t:
"""
Test whether a key is a level reference for a given axis.
To be considered a level reference, `key` must be a string that:
- (axis=0): Matches the name of an index level and does NOT match
a column label.
- (axis=1): Matches the name of a column level and does NOT match
an index label.
Parameters
----------
key : Hashable
Potential level name for the given axis
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
is_level : bool
"""
axis_int = self._get_axis_number(axis)
return (
key is not None
and is_hashable(key)
and key in self.axes[axis_int].names
and not self._is_label_reference(key, axis=axis_int)
)
def _is_label_reference(self, key: Level, axis: Axis = 0) -> bool_t:
"""
Test whether a key is a label reference for a given axis.
To be considered a label reference, `key` must be a string that:
- (axis=0): Matches a column label
- (axis=1): Matches an index label
Parameters
----------
key : Hashable
Potential label name, i.e. Index entry.
axis : int, default 0
Axis perpendicular to the axis that labels are associated with
(0 means search for column labels, 1 means search for index labels)
Returns
-------
is_label: bool
"""
axis_int = self._get_axis_number(axis)
other_axes = (ax for ax in range(self._AXIS_LEN) if ax != axis_int)
return (
key is not None
and is_hashable(key)
and any(key in self.axes[ax] for ax in other_axes)
)
def _is_label_or_level_reference(self, key: Level, axis: AxisInt = 0) -> bool_t:
"""
Test whether a key is a label or level reference for a given axis.
To be considered either a label or a level reference, `key` must be a
string that:
- (axis=0): Matches a column label or an index level
- (axis=1): Matches an index label or a column level
Parameters
----------
key : Hashable
Potential label or level name
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
bool
"""
return self._is_level_reference(key, axis=axis) or self._is_label_reference(
key, axis=axis
)
def _check_label_or_level_ambiguity(self, key: Level, axis: Axis = 0) -> None:
"""
Check whether `key` is ambiguous.
By ambiguous, we mean that it matches both a level of the input
`axis` and a label of the other axis.
Parameters
----------
key : Hashable
Label or level name.
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns).
Raises
------
ValueError: `key` is ambiguous
"""
axis_int = self._get_axis_number(axis)
other_axes = (ax for ax in range(self._AXIS_LEN) if ax != axis_int)
if (
key is not None
and is_hashable(key)
and key in self.axes[axis_int].names
and any(key in self.axes[ax] for ax in other_axes)
):
# Build an informative and grammatical warning
level_article, level_type = (
("an", "index") if axis_int == 0 else ("a", "column")
)
label_article, label_type = (
("a", "column") if axis_int == 0 else ("an", "index")
)
msg = (
f"'{key}' is both {level_article} {level_type} level and "
f"{label_article} {label_type} label, which is ambiguous."
)
raise ValueError(msg)
def _get_label_or_level_values(self, key: Level, axis: AxisInt = 0) -> ArrayLike:
"""
Return a 1-D array of values associated with `key`, a label or level
from the given `axis`.
Retrieval logic:
- (axis=0): Return column values if `key` matches a column label.
Otherwise return index level values if `key` matches an index
level.
- (axis=1): Return row values if `key` matches an index label.
Otherwise return column level values if 'key' matches a column
level
Parameters
----------
key : Hashable
Label or level name.
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
np.ndarray or ExtensionArray
Raises
------
KeyError
if `key` matches neither a label nor a level
ValueError
if `key` matches multiple labels
"""
axis = self._get_axis_number(axis)
other_axes = [ax for ax in range(self._AXIS_LEN) if ax != axis]
if self._is_label_reference(key, axis=axis):
self._check_label_or_level_ambiguity(key, axis=axis)
values = self.xs(key, axis=other_axes[0])._values
elif self._is_level_reference(key, axis=axis):
values = self.axes[axis].get_level_values(key)._values
else:
raise KeyError(key)
# Check for duplicates
if values.ndim > 1:
if other_axes and isinstance(self._get_axis(other_axes[0]), MultiIndex):
multi_message = (
"\n"
"For a multi-index, the label must be a "
"tuple with elements corresponding to each level."
)
else:
multi_message = ""
label_axis_name = "column" if axis == 0 else "index"
raise ValueError(
f"The {label_axis_name} label '{key}' is not unique.{multi_message}"
)
return values
def _drop_labels_or_levels(self, keys, axis: AxisInt = 0):
"""
Drop labels and/or levels for the given `axis`.
For each key in `keys`:
- (axis=0): If key matches a column label then drop the column.
Otherwise if key matches an index level then drop the level.
- (axis=1): If key matches an index label then drop the row.
Otherwise if key matches a column level then drop the level.
Parameters
----------
keys : str or list of str
labels or levels to drop
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
dropped: DataFrame
Raises
------
ValueError
if any `keys` match neither a label nor a level
"""
axis = self._get_axis_number(axis)
# Validate keys
keys = common.maybe_make_list(keys)
invalid_keys = [
k for k in keys if not self._is_label_or_level_reference(k, axis=axis)
]
if invalid_keys:
raise ValueError(
"The following keys are not valid labels or "
f"levels for axis {axis}: {invalid_keys}"
)
# Compute levels and labels to drop
levels_to_drop = [k for k in keys if self._is_level_reference(k, axis=axis)]
labels_to_drop = [k for k in keys if not self._is_level_reference(k, axis=axis)]
# Perform copy upfront and then use inplace operations below.
# This ensures that we always perform exactly one copy.
# ``copy`` and/or ``inplace`` options could be added in the future.
dropped = self.copy(deep=False)
if axis == 0:
# Handle dropping index levels
if levels_to_drop:
dropped.reset_index(levels_to_drop, drop=True, inplace=True)
# Handle dropping columns labels
if labels_to_drop:
dropped.drop(labels_to_drop, axis=1, inplace=True)
else:
# Handle dropping column levels
if levels_to_drop:
if isinstance(dropped.columns, MultiIndex):
# Drop the specified levels from the MultiIndex
dropped.columns = dropped.columns.droplevel(levels_to_drop)
else:
# Drop the last level of Index by replacing with
# a RangeIndex
dropped.columns = RangeIndex(dropped.columns.size)
# Handle dropping index labels
if labels_to_drop:
dropped.drop(labels_to_drop, axis=0, inplace=True)
return dropped
# ----------------------------------------------------------------------
# Iteration
# https://github.com/python/typeshed/issues/2148#issuecomment-520783318
# Incompatible types in assignment (expression has type "None", base class
# "object" defined the type as "Callable[[object], int]")
__hash__: ClassVar[None] # type: ignore[assignment]
def __iter__(self) -> Iterator:
"""
Iterate over info axis.
Returns
-------
iterator
Info axis as iterator.
"""
return iter(self._info_axis)
# can we get a better explanation of this?
def keys(self) -> Index:
"""
Get the 'info axis' (see Indexing for more).
This is index for Series, columns for DataFrame.
Returns
-------
Index
Info axis.
"""
return self._info_axis
def items(self):
"""
Iterate over (label, values) on info axis
This is index for Series and columns for DataFrame.
Returns
-------
Generator
"""
for h in self._info_axis:
yield h, self[h]
def __len__(self) -> int:
"""Returns length of info axis"""
return len(self._info_axis)
def __contains__(self, key) -> bool_t:
"""True if the key is in the info axis"""
return key in self._info_axis
def empty(self) -> bool_t:
"""
Indicator whether Series/DataFrame is empty.
True if Series/DataFrame is entirely empty (no items), meaning any of the
axes are of length 0.
Returns
-------
bool
If Series/DataFrame is empty, return True, if not return False.
See Also
--------
Series.dropna : Return series without null values.
DataFrame.dropna : Return DataFrame with labels on given axis omitted
where (all or any) data are missing.
Notes
-----
If Series/DataFrame contains only NaNs, it is still not considered empty. See
the example below.
Examples
--------
An example of an actual empty DataFrame. Notice the index is empty:
>>> df_empty = pd.DataFrame({'A' : []})
>>> df_empty
Empty DataFrame
Columns: [A]
Index: []
>>> df_empty.empty
True
If we only have NaNs in our DataFrame, it is not considered empty! We
will need to drop the NaNs to make the DataFrame empty:
>>> df = pd.DataFrame({'A' : [np.nan]})
>>> df
A
0 NaN
>>> df.empty
False
>>> df.dropna().empty
True
>>> ser_empty = pd.Series({'A' : []})
>>> ser_empty
A []
dtype: object
>>> ser_empty.empty
False
>>> ser_empty = pd.Series()
>>> ser_empty.empty
True
"""
return any(len(self._get_axis(a)) == 0 for a in self._AXIS_ORDERS)
# ----------------------------------------------------------------------
# Array Interface
# This is also set in IndexOpsMixin
# GH#23114 Ensure ndarray.__op__(DataFrame) returns NotImplemented
__array_priority__: int = 1000
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
values = self._values
arr = np.asarray(values, dtype=dtype)
if (
astype_is_view(values.dtype, arr.dtype)
and using_copy_on_write()
and self._mgr.is_single_block
):
# Check if both conversions can be done without a copy
if astype_is_view(self.dtypes.iloc[0], values.dtype) and astype_is_view(
values.dtype, arr.dtype
):
arr = arr.view()
arr.flags.writeable = False
return arr
def __array_ufunc__(
self, ufunc: np.ufunc, method: str, *inputs: Any, **kwargs: Any
):
return arraylike.array_ufunc(self, ufunc, method, *inputs, **kwargs)
# ----------------------------------------------------------------------
# Picklability
def __getstate__(self) -> dict[str, Any]:
meta = {k: getattr(self, k, None) for k in self._metadata}
return {
"_mgr": self._mgr,
"_typ": self._typ,
"_metadata": self._metadata,
"attrs": self.attrs,
"_flags": {k: self.flags[k] for k in self.flags._keys},
**meta,
}
def __setstate__(self, state) -> None:
if isinstance(state, BlockManager):
self._mgr = state
elif isinstance(state, dict):
if "_data" in state and "_mgr" not in state:
# compat for older pickles
state["_mgr"] = state.pop("_data")
typ = state.get("_typ")
if typ is not None:
attrs = state.get("_attrs", {})
object.__setattr__(self, "_attrs", attrs)
flags = state.get("_flags", {"allows_duplicate_labels": True})
object.__setattr__(self, "_flags", Flags(self, **flags))
# set in the order of internal names
# to avoid definitional recursion
# e.g. say fill_value needing _mgr to be
# defined
meta = set(self._internal_names + self._metadata)
for k in list(meta):
if k in state and k != "_flags":
v = state[k]
object.__setattr__(self, k, v)
for k, v in state.items():
if k not in meta:
object.__setattr__(self, k, v)
else:
raise NotImplementedError("Pre-0.12 pickles are no longer supported")
elif len(state) == 2:
raise NotImplementedError("Pre-0.12 pickles are no longer supported")
self._item_cache: dict[Hashable, Series] = {}
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
# string representation based upon iterating over self
# (since, by definition, `PandasContainers` are iterable)
prepr = f"[{','.join(map(pprint_thing, self))}]"
return f"{type(self).__name__}({prepr})"
def _repr_latex_(self):
"""
Returns a LaTeX representation for a particular object.
Mainly for use with nbconvert (jupyter notebook conversion to pdf).
"""
if config.get_option("styler.render.repr") == "latex":
return self.to_latex()
else:
return None
def _repr_data_resource_(self):
"""
Not a real Jupyter special repr method, but we use the same
naming convention.
"""
if config.get_option("display.html.table_schema"):
data = self.head(config.get_option("display.max_rows"))
as_json = data.to_json(orient="table")
as_json = cast(str, as_json)
return loads(as_json, object_pairs_hook=collections.OrderedDict)
# ----------------------------------------------------------------------
# I/O Methods
klass="object",
storage_options=_shared_docs["storage_options"],
storage_options_versionadded="1.2.0",
)
def to_excel(
self,
excel_writer,
sheet_name: str = "Sheet1",
na_rep: str = "",
float_format: str | None = None,
columns: Sequence[Hashable] | None = None,
header: Sequence[Hashable] | bool_t = True,
index: bool_t = True,
index_label: IndexLabel = None,
startrow: int = 0,
startcol: int = 0,
engine: str | None = None,
merge_cells: bool_t = True,
inf_rep: str = "inf",
freeze_panes: tuple[int, int] | None = None,
storage_options: StorageOptions = None,
) -> None:
"""
Write {klass} to an Excel sheet.
To write a single {klass} to an Excel .xlsx file it is only necessary to
specify a target file name. To write to multiple sheets it is necessary to
create an `ExcelWriter` object with a target file name, and specify a sheet
in the file to write to.
Multiple sheets may be written to by specifying unique `sheet_name`.
With all data written to the file it is necessary to save the changes.
Note that creating an `ExcelWriter` object with a file name that already
exists will result in the contents of the existing file being erased.
Parameters
----------
excel_writer : path-like, file-like, or ExcelWriter object
File path or existing ExcelWriter.
sheet_name : str, default 'Sheet1'
Name of sheet which will contain DataFrame.
na_rep : str, default ''
Missing data representation.
float_format : str, optional
Format string for floating point numbers. For example
``float_format="%.2f"`` will format 0.1234 to 0.12.
columns : sequence or list of str, optional
Columns to write.
header : bool or list of str, default True
Write out the column names. If a list of string is given it is
assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
index_label : str or sequence, optional
Column label for index column(s) if desired. If not specified, and
`header` and `index` are True, then the index names are used. A
sequence should be given if the DataFrame uses MultiIndex.
startrow : int, default 0
Upper left cell row to dump data frame.
startcol : int, default 0
Upper left cell column to dump data frame.
engine : str, optional
Write engine to use, 'openpyxl' or 'xlsxwriter'. You can also set this
via the options ``io.excel.xlsx.writer`` or
``io.excel.xlsm.writer``.
merge_cells : bool, default True
Write MultiIndex and Hierarchical Rows as merged cells.
inf_rep : str, default 'inf'
Representation for infinity (there is no native representation for
infinity in Excel).
freeze_panes : tuple of int (length 2), optional
Specifies the one-based bottommost row and rightmost column that
is to be frozen.
{storage_options}
.. versionadded:: {storage_options_versionadded}
See Also
--------
to_csv : Write DataFrame to a comma-separated values (csv) file.
ExcelWriter : Class for writing DataFrame objects into excel sheets.
read_excel : Read an Excel file into a pandas DataFrame.
read_csv : Read a comma-separated values (csv) file into DataFrame.
io.formats.style.Styler.to_excel : Add styles to Excel sheet.
Notes
-----
For compatibility with :meth:`~DataFrame.to_csv`,
to_excel serializes lists and dicts to strings before writing.
Once a workbook has been saved it is not possible to write further
data without rewriting the whole workbook.
Examples
--------
Create, write to and save a workbook:
>>> df1 = pd.DataFrame([['a', 'b'], ['c', 'd']],
... index=['row 1', 'row 2'],
... columns=['col 1', 'col 2'])
>>> df1.to_excel("output.xlsx") # doctest: +SKIP
To specify the sheet name:
>>> df1.to_excel("output.xlsx",
... sheet_name='Sheet_name_1') # doctest: +SKIP
If you wish to write to more than one sheet in the workbook, it is
necessary to specify an ExcelWriter object:
>>> df2 = df1.copy()
>>> with pd.ExcelWriter('output.xlsx') as writer: # doctest: +SKIP
... df1.to_excel(writer, sheet_name='Sheet_name_1')
... df2.to_excel(writer, sheet_name='Sheet_name_2')
ExcelWriter can also be used to append to an existing Excel file:
>>> with pd.ExcelWriter('output.xlsx',
... mode='a') as writer: # doctest: +SKIP
... df.to_excel(writer, sheet_name='Sheet_name_3')
To set the library that is used to write the Excel file,
you can pass the `engine` keyword (the default engine is
automatically chosen depending on the file extension):
>>> df1.to_excel('output1.xlsx', engine='xlsxwriter') # doctest: +SKIP
"""
df = self if isinstance(self, ABCDataFrame) else self.to_frame()
from pandas.io.formats.excel import ExcelFormatter
formatter = ExcelFormatter(
df,
na_rep=na_rep,
cols=columns,
header=header,
float_format=float_format,
index=index,
index_label=index_label,
merge_cells=merge_cells,
inf_rep=inf_rep,
)
formatter.write(
excel_writer,
sheet_name=sheet_name,
startrow=startrow,
startcol=startcol,
freeze_panes=freeze_panes,
engine=engine,
storage_options=storage_options,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buf",
)
def to_json(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
orient: str | None = None,
date_format: str | None = None,
double_precision: int = 10,
force_ascii: bool_t = True,
date_unit: str = "ms",
default_handler: Callable[[Any], JSONSerializable] | None = None,
lines: bool_t = False,
compression: CompressionOptions = "infer",
index: bool_t = True,
indent: int | None = None,
storage_options: StorageOptions = None,
mode: Literal["a", "w"] = "w",
) -> str | None:
"""
Convert the object to a JSON string.
Note NaN's and None will be converted to null and datetime objects
will be converted to UNIX timestamps.
Parameters
----------
path_or_buf : str, path object, file-like object, or None, default None
String, path object (implementing os.PathLike[str]), or file-like
object implementing a write() function. If None, the result is
returned as a string.
orient : str
Indication of expected JSON string format.
* Series:
- default is 'index'
- allowed values are: {{'split', 'records', 'index', 'table'}}.
* DataFrame:
- default is 'columns'
- allowed values are: {{'split', 'records', 'index', 'columns',
'values', 'table'}}.
* The format of the JSON string:
- 'split' : dict like {{'index' -> [index], 'columns' -> [columns],
'data' -> [values]}}
- 'records' : list like [{{column -> value}}, ... , {{column -> value}}]
- 'index' : dict like {{index -> {{column -> value}}}}
- 'columns' : dict like {{column -> {{index -> value}}}}
- 'values' : just the values array
- 'table' : dict like {{'schema': {{schema}}, 'data': {{data}}}}
Describing the data, where data component is like ``orient='records'``.
date_format : {{None, 'epoch', 'iso'}}
Type of date conversion. 'epoch' = epoch milliseconds,
'iso' = ISO8601. The default depends on the `orient`. For
``orient='table'``, the default is 'iso'. For all other orients,
the default is 'epoch'.
double_precision : int, default 10
The number of decimal places to use when encoding
floating point values.
force_ascii : bool, default True
Force encoded string to be ASCII.
date_unit : str, default 'ms' (milliseconds)
The time unit to encode to, governs timestamp and ISO8601
precision. One of 's', 'ms', 'us', 'ns' for second, millisecond,
microsecond, and nanosecond respectively.
default_handler : callable, default None
Handler to call if object cannot otherwise be converted to a
suitable format for JSON. Should receive a single argument which is
the object to convert and return a serialisable object.
lines : bool, default False
If 'orient' is 'records' write out line-delimited json format. Will
throw ValueError if incorrect 'orient' since others are not
list-like.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
index : bool, default True
Whether to include the index values in the JSON string. Not
including the index (``index=False``) is only supported when
orient is 'split' or 'table'.
indent : int, optional
Length of whitespace used to indent each record.
{storage_options}
.. versionadded:: 1.2.0
mode : str, default 'w' (writing)
Specify the IO mode for output when supplying a path_or_buf.
Accepted args are 'w' (writing) and 'a' (append) only.
mode='a' is only supported when lines is True and orient is 'records'.
Returns
-------
None or str
If path_or_buf is None, returns the resulting json format as a
string. Otherwise returns None.
See Also
--------
read_json : Convert a JSON string to pandas object.
Notes
-----
The behavior of ``indent=0`` varies from the stdlib, which does not
indent the output but does insert newlines. Currently, ``indent=0``
and the default ``indent=None`` are equivalent in pandas, though this
may change in a future release.
``orient='table'`` contains a 'pandas_version' field under 'schema'.
This stores the version of `pandas` used in the latest revision of the
schema.
Examples
--------
>>> from json import loads, dumps
>>> df = pd.DataFrame(
... [["a", "b"], ["c", "d"]],
... index=["row 1", "row 2"],
... columns=["col 1", "col 2"],
... )
>>> result = df.to_json(orient="split")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"columns": [
"col 1",
"col 2"
],
"index": [
"row 1",
"row 2"
],
"data": [
[
"a",
"b"
],
[
"c",
"d"
]
]
}}
Encoding/decoding a Dataframe using ``'records'`` formatted JSON.
Note that index labels are not preserved with this encoding.
>>> result = df.to_json(orient="records")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
[
{{
"col 1": "a",
"col 2": "b"
}},
{{
"col 1": "c",
"col 2": "d"
}}
]
Encoding/decoding a Dataframe using ``'index'`` formatted JSON:
>>> result = df.to_json(orient="index")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"row 1": {{
"col 1": "a",
"col 2": "b"
}},
"row 2": {{
"col 1": "c",
"col 2": "d"
}}
}}
Encoding/decoding a Dataframe using ``'columns'`` formatted JSON:
>>> result = df.to_json(orient="columns")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"col 1": {{
"row 1": "a",
"row 2": "c"
}},
"col 2": {{
"row 1": "b",
"row 2": "d"
}}
}}
Encoding/decoding a Dataframe using ``'values'`` formatted JSON:
>>> result = df.to_json(orient="values")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
[
[
"a",
"b"
],
[
"c",
"d"
]
]
Encoding with Table Schema:
>>> result = df.to_json(orient="table")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"schema": {{
"fields": [
{{
"name": "index",
"type": "string"
}},
{{
"name": "col 1",
"type": "string"
}},
{{
"name": "col 2",
"type": "string"
}}
],
"primaryKey": [
"index"
],
"pandas_version": "1.4.0"
}},
"data": [
{{
"index": "row 1",
"col 1": "a",
"col 2": "b"
}},
{{
"index": "row 2",
"col 1": "c",
"col 2": "d"
}}
]
}}
"""
from pandas.io import json
if date_format is None and orient == "table":
date_format = "iso"
elif date_format is None:
date_format = "epoch"
config.is_nonnegative_int(indent)
indent = indent or 0
return json.to_json(
path_or_buf=path_or_buf,
obj=self,
orient=orient,
date_format=date_format,
double_precision=double_precision,
force_ascii=force_ascii,
date_unit=date_unit,
default_handler=default_handler,
lines=lines,
compression=compression,
index=index,
indent=indent,
storage_options=storage_options,
mode=mode,
)
def to_hdf(
self,
path_or_buf: FilePath | HDFStore,
key: str,
mode: str = "a",
complevel: int | None = None,
complib: str | None = None,
append: bool_t = False,
format: str | None = None,
index: bool_t = True,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
dropna: bool_t | None = None,
data_columns: Literal[True] | list[str] | None = None,
errors: str = "strict",
encoding: str = "UTF-8",
) -> None:
"""
Write the contained data to an HDF5 file using HDFStore.
Hierarchical Data Format (HDF) is self-describing, allowing an
application to interpret the structure and contents of a file with
no outside information. One HDF file can hold a mix of related objects
which can be accessed as a group or as individual objects.
In order to add another DataFrame or Series to an existing HDF file
please use append mode and a different a key.
.. warning::
One can store a subclass of ``DataFrame`` or ``Series`` to HDF5,
but the type of the subclass is lost upon storing.
For more information see the :ref:`user guide <io.hdf5>`.
Parameters
----------
path_or_buf : str or pandas.HDFStore
File path or HDFStore object.
key : str
Identifier for the group in the store.
mode : {'a', 'w', 'r+'}, default 'a'
Mode to open file:
- 'w': write, a new file is created (an existing file with
the same name would be deleted).
- 'a': append, an existing file is opened for reading and
writing, and if the file does not exist it is created.
- 'r+': similar to 'a', but the file must already exist.
complevel : {0-9}, default None
Specifies a compression level for data.
A value of 0 or None disables compression.
complib : {'zlib', 'lzo', 'bzip2', 'blosc'}, default 'zlib'
Specifies the compression library to be used.
As of v0.20.2 these additional compressors for Blosc are supported
(default if no compressor specified: 'blosc:blosclz'):
{'blosc:blosclz', 'blosc:lz4', 'blosc:lz4hc', 'blosc:snappy',
'blosc:zlib', 'blosc:zstd'}.
Specifying a compression library which is not available issues
a ValueError.
append : bool, default False
For Table formats, append the input data to the existing.
format : {'fixed', 'table', None}, default 'fixed'
Possible values:
- 'fixed': Fixed format. Fast writing/reading. Not-appendable,
nor searchable.
- 'table': Table format. Write as a PyTables Table structure
which may perform worse but allow more flexible operations
like searching / selecting subsets of the data.
- If None, pd.get_option('io.hdf.default_format') is checked,
followed by fallback to "fixed".
index : bool, default True
Write DataFrame index as a column.
min_itemsize : dict or int, optional
Map column names to minimum string sizes for columns.
nan_rep : Any, optional
How to represent null values as str.
Not allowed with append=True.
dropna : bool, default False, optional
Remove missing values.
data_columns : list of columns or True, optional
List of columns to create as indexed data columns for on-disk
queries, or True to use all columns. By default only the axes
of the object are indexed. See
:ref:`Query via data columns<io.hdf5-query-data-columns>`. for
more information.
Applicable only to format='table'.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
encoding : str, default "UTF-8"
See Also
--------
read_hdf : Read from HDF file.
DataFrame.to_orc : Write a DataFrame to the binary orc format.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
DataFrame.to_sql : Write to a SQL table.
DataFrame.to_feather : Write out feather-format for DataFrames.
DataFrame.to_csv : Write out to a csv file.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]},
... index=['a', 'b', 'c']) # doctest: +SKIP
>>> df.to_hdf('data.h5', key='df', mode='w') # doctest: +SKIP
We can add another object to the same file:
>>> s = pd.Series([1, 2, 3, 4]) # doctest: +SKIP
>>> s.to_hdf('data.h5', key='s') # doctest: +SKIP
Reading from HDF file:
>>> pd.read_hdf('data.h5', 'df') # doctest: +SKIP
A B
a 1 4
b 2 5
c 3 6
>>> pd.read_hdf('data.h5', 's') # doctest: +SKIP
0 1
1 2
2 3
3 4
dtype: int64
"""
from pandas.io import pytables
# Argument 3 to "to_hdf" has incompatible type "NDFrame"; expected
# "Union[DataFrame, Series]" [arg-type]
pytables.to_hdf(
path_or_buf,
key,
self, # type: ignore[arg-type]
mode=mode,
complevel=complevel,
complib=complib,
append=append,
format=format,
index=index,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
dropna=dropna,
data_columns=data_columns,
errors=errors,
encoding=encoding,
)
def to_sql(
self,
name: str,
con,
schema: str | None = None,
if_exists: Literal["fail", "replace", "append"] = "fail",
index: bool_t = True,
index_label: IndexLabel = None,
chunksize: int | None = None,
dtype: DtypeArg | None = None,
method: str | None = None,
) -> int | None:
"""
Write records stored in a DataFrame to a SQL database.
Databases supported by SQLAlchemy [1]_ are supported. Tables can be
newly created, appended to, or overwritten.
Parameters
----------
name : str
Name of SQL table.
con : sqlalchemy.engine.(Engine or Connection) or sqlite3.Connection
Using SQLAlchemy makes it possible to use any DB supported by that
library. Legacy support is provided for sqlite3.Connection objects. The user
is responsible for engine disposal and connection closure for the SQLAlchemy
connectable. See `here \
<https://docs.sqlalchemy.org/en/20/core/connections.html>`_.
If passing a sqlalchemy.engine.Connection which is already in a transaction,
the transaction will not be committed. If passing a sqlite3.Connection,
it will not be possible to roll back the record insertion.
schema : str, optional
Specify the schema (if database flavor supports this). If None, use
default schema.
if_exists : {'fail', 'replace', 'append'}, default 'fail'
How to behave if the table already exists.
* fail: Raise a ValueError.
* replace: Drop the table before inserting new values.
* append: Insert new values to the existing table.
index : bool, default True
Write DataFrame index as a column. Uses `index_label` as the column
name in the table.
index_label : str or sequence, default None
Column label for index column(s). If None is given (default) and
`index` is True, then the index names are used.
A sequence should be given if the DataFrame uses MultiIndex.
chunksize : int, optional
Specify the number of rows in each batch to be written at a time.
By default, all rows will be written at once.
dtype : dict or scalar, optional
Specifying the datatype for columns. If a dictionary is used, the
keys should be the column names and the values should be the
SQLAlchemy types or strings for the sqlite3 legacy mode. If a
scalar is provided, it will be applied to all columns.
method : {None, 'multi', callable}, optional
Controls the SQL insertion clause used:
* None : Uses standard SQL ``INSERT`` clause (one per row).
* 'multi': Pass multiple values in a single ``INSERT`` clause.
* callable with signature ``(pd_table, conn, keys, data_iter)``.
Details and a sample callable implementation can be found in the
section :ref:`insert method <io.sql.method>`.
Returns
-------
None or int
Number of rows affected by to_sql. None is returned if the callable
passed into ``method`` does not return an integer number of rows.
The number of returned rows affected is the sum of the ``rowcount``
attribute of ``sqlite3.Cursor`` or SQLAlchemy connectable which may not
reflect the exact number of written rows as stipulated in the
`sqlite3 <https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.rowcount>`__ or
`SQLAlchemy <https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.CursorResult.rowcount>`__.
.. versionadded:: 1.4.0
Raises
------
ValueError
When the table already exists and `if_exists` is 'fail' (the
default).
See Also
--------
read_sql : Read a DataFrame from a table.
Notes
-----
Timezone aware datetime columns will be written as
``Timestamp with timezone`` type with SQLAlchemy if supported by the
database. Otherwise, the datetimes will be stored as timezone unaware
timestamps local to the original timezone.
References
----------
.. [1] https://docs.sqlalchemy.org
.. [2] https://www.python.org/dev/peps/pep-0249/
Examples
--------
Create an in-memory SQLite database.
>>> from sqlalchemy import create_engine
>>> engine = create_engine('sqlite://', echo=False)
Create a table from scratch with 3 rows.
>>> df = pd.DataFrame({'name' : ['User 1', 'User 2', 'User 3']})
>>> df
name
0 User 1
1 User 2
2 User 3
>>> df.to_sql('users', con=engine)
3
>>> from sqlalchemy import text
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 1'), (1, 'User 2'), (2, 'User 3')]
An `sqlalchemy.engine.Connection` can also be passed to `con`:
>>> with engine.begin() as connection:
... df1 = pd.DataFrame({'name' : ['User 4', 'User 5']})
... df1.to_sql('users', con=connection, if_exists='append')
2
This is allowed to support operations that require that the same
DBAPI connection is used for the entire operation.
>>> df2 = pd.DataFrame({'name' : ['User 6', 'User 7']})
>>> df2.to_sql('users', con=engine, if_exists='append')
2
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 1'), (1, 'User 2'), (2, 'User 3'),
(0, 'User 4'), (1, 'User 5'), (0, 'User 6'),
(1, 'User 7')]
Overwrite the table with just ``df2``.
>>> df2.to_sql('users', con=engine, if_exists='replace',
... index_label='id')
2
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 6'), (1, 'User 7')]
Specify the dtype (especially useful for integers with missing values).
Notice that while pandas is forced to store the data as floating point,
the database supports nullable integers. When fetching the data with
Python, we get back integer scalars.
>>> df = pd.DataFrame({"A": [1, None, 2]})
>>> df
A
0 1.0
1 NaN
2 2.0
>>> from sqlalchemy.types import Integer
>>> df.to_sql('integers', con=engine, index=False,
... dtype={"A": Integer()})
3
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM integers")).fetchall()
[(1,), (None,), (2,)]
""" # noqa:E501
from pandas.io import sql
return sql.to_sql(
self,
name,
con,
schema=schema,
if_exists=if_exists,
index=index,
index_label=index_label,
chunksize=chunksize,
dtype=dtype,
method=method,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_pickle(
self,
path: FilePath | WriteBuffer[bytes],
compression: CompressionOptions = "infer",
protocol: int = pickle.HIGHEST_PROTOCOL,
storage_options: StorageOptions = None,
) -> None:
"""
Pickle (serialize) object to file.
Parameters
----------
path : str, path object, or file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. File path where
the pickled object will be stored.
{compression_options}
protocol : int
Int which indicates which protocol should be used by the pickler,
default HIGHEST_PROTOCOL (see [1]_ paragraph 12.1.2). The possible
values are 0, 1, 2, 3, 4, 5. A negative value for the protocol
parameter is equivalent to setting its value to HIGHEST_PROTOCOL.
.. [1] https://docs.python.org/3/library/pickle.html.
{storage_options}
.. versionadded:: 1.2.0
See Also
--------
read_pickle : Load pickled pandas object (or any object) from file.
DataFrame.to_hdf : Write DataFrame to an HDF5 file.
DataFrame.to_sql : Write DataFrame to a SQL database.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
Examples
--------
>>> original_df = pd.DataFrame({{"foo": range(5), "bar": range(5, 10)}}) # doctest: +SKIP
>>> original_df # doctest: +SKIP
foo bar
0 0 5
1 1 6
2 2 7
3 3 8
4 4 9
>>> original_df.to_pickle("./dummy.pkl") # doctest: +SKIP
>>> unpickled_df = pd.read_pickle("./dummy.pkl") # doctest: +SKIP
>>> unpickled_df # doctest: +SKIP
foo bar
0 0 5
1 1 6
2 2 7
3 3 8
4 4 9
""" # noqa: E501
from pandas.io.pickle import to_pickle
to_pickle(
self,
path,
compression=compression,
protocol=protocol,
storage_options=storage_options,
)
def to_clipboard(
self, excel: bool_t = True, sep: str | None = None, **kwargs
) -> None:
r"""
Copy object to the system clipboard.
Write a text representation of object to the system clipboard.
This can be pasted into Excel, for example.
Parameters
----------
excel : bool, default True
Produce output in a csv format for easy pasting into excel.
- True, use the provided separator for csv pasting.
- False, write a string representation of the object to the clipboard.
sep : str, default ``'\t'``
Field delimiter.
**kwargs
These parameters will be passed to DataFrame.to_csv.
See Also
--------
DataFrame.to_csv : Write a DataFrame to a comma-separated values
(csv) file.
read_clipboard : Read text from clipboard and pass to read_csv.
Notes
-----
Requirements for your platform.
- Linux : `xclip`, or `xsel` (with `PyQt4` modules)
- Windows : none
- macOS : none
This method uses the processes developed for the package `pyperclip`. A
solution to render any output string format is given in the examples.
Examples
--------
Copy the contents of a DataFrame to the clipboard.
>>> df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=['A', 'B', 'C'])
>>> df.to_clipboard(sep=',') # doctest: +SKIP
... # Wrote the following to the system clipboard:
... # ,A,B,C
... # 0,1,2,3
... # 1,4,5,6
We can omit the index by passing the keyword `index` and setting
it to false.
>>> df.to_clipboard(sep=',', index=False) # doctest: +SKIP
... # Wrote the following to the system clipboard:
... # A,B,C
... # 1,2,3
... # 4,5,6
Using the original `pyperclip` package for any string output format.
.. code-block:: python
import pyperclip
html = df.style.to_html()
pyperclip.copy(html)
"""
from pandas.io import clipboards
clipboards.to_clipboard(self, excel=excel, sep=sep, **kwargs)
def to_xarray(self):
"""
Return an xarray object from the pandas object.
Returns
-------
xarray.DataArray or xarray.Dataset
Data in the pandas structure converted to Dataset if the object is
a DataFrame, or a DataArray if the object is a Series.
See Also
--------
DataFrame.to_hdf : Write DataFrame to an HDF5 file.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
Notes
-----
See the `xarray docs <https://xarray.pydata.org/en/stable/>`__
Examples
--------
>>> df = pd.DataFrame([('falcon', 'bird', 389.0, 2),
... ('parrot', 'bird', 24.0, 2),
... ('lion', 'mammal', 80.5, 4),
... ('monkey', 'mammal', np.nan, 4)],
... columns=['name', 'class', 'max_speed',
... 'num_legs'])
>>> df
name class max_speed num_legs
0 falcon bird 389.0 2
1 parrot bird 24.0 2
2 lion mammal 80.5 4
3 monkey mammal NaN 4
>>> df.to_xarray()
<xarray.Dataset>
Dimensions: (index: 4)
Coordinates:
* index (index) int64 0 1 2 3
Data variables:
name (index) object 'falcon' 'parrot' 'lion' 'monkey'
class (index) object 'bird' 'bird' 'mammal' 'mammal'
max_speed (index) float64 389.0 24.0 80.5 nan
num_legs (index) int64 2 2 4 4
>>> df['max_speed'].to_xarray()
<xarray.DataArray 'max_speed' (index: 4)>
array([389. , 24. , 80.5, nan])
Coordinates:
* index (index) int64 0 1 2 3
>>> dates = pd.to_datetime(['2018-01-01', '2018-01-01',
... '2018-01-02', '2018-01-02'])
>>> df_multiindex = pd.DataFrame({'date': dates,
... 'animal': ['falcon', 'parrot',
... 'falcon', 'parrot'],
... 'speed': [350, 18, 361, 15]})
>>> df_multiindex = df_multiindex.set_index(['date', 'animal'])
>>> df_multiindex
speed
date animal
2018-01-01 falcon 350
parrot 18
2018-01-02 falcon 361
parrot 15
>>> df_multiindex.to_xarray()
<xarray.Dataset>
Dimensions: (date: 2, animal: 2)
Coordinates:
* date (date) datetime64[ns] 2018-01-01 2018-01-02
* animal (animal) object 'falcon' 'parrot'
Data variables:
speed (date, animal) int64 350 18 361 15
"""
xarray = import_optional_dependency("xarray")
if self.ndim == 1:
return xarray.DataArray.from_series(self)
else:
return xarray.Dataset.from_dataframe(self)
def to_latex(
self,
buf: None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | Sequence[str] = ...,
index: bool_t = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool_t | None = ...,
index_names: bool_t = ...,
bold_rows: bool_t = ...,
column_format: str | None = ...,
longtable: bool_t | None = ...,
escape: bool_t | None = ...,
encoding: str | None = ...,
decimal: str = ...,
multicolumn: bool_t | None = ...,
multicolumn_format: str | None = ...,
multirow: bool_t | None = ...,
caption: str | tuple[str, str] | None = ...,
label: str | None = ...,
position: str | None = ...,
) -> str:
...
def to_latex(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Hashable] | None = ...,
header: bool_t | Sequence[str] = ...,
index: bool_t = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool_t | None = ...,
index_names: bool_t = ...,
bold_rows: bool_t = ...,
column_format: str | None = ...,
longtable: bool_t | None = ...,
escape: bool_t | None = ...,
encoding: str | None = ...,
decimal: str = ...,
multicolumn: bool_t | None = ...,
multicolumn_format: str | None = ...,
multirow: bool_t | None = ...,
caption: str | tuple[str, str] | None = ...,
label: str | None = ...,
position: str | None = ...,
) -> None:
...
def to_latex(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Hashable] | None = None,
header: bool_t | Sequence[str] = True,
index: bool_t = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool_t | None = None,
index_names: bool_t = True,
bold_rows: bool_t = False,
column_format: str | None = None,
longtable: bool_t | None = None,
escape: bool_t | None = None,
encoding: str | None = None,
decimal: str = ".",
multicolumn: bool_t | None = None,
multicolumn_format: str | None = None,
multirow: bool_t | None = None,
caption: str | tuple[str, str] | None = None,
label: str | None = None,
position: str | None = None,
) -> str | None:
r"""
Render object to a LaTeX tabular, longtable, or nested table.
Requires ``\usepackage{{booktabs}}``. The output can be copy/pasted
into a main LaTeX document or read from an external file
with ``\input{{table.tex}}``.
.. versionchanged:: 1.2.0
Added position argument, changed meaning of caption argument.
.. versionchanged:: 2.0.0
Refactored to use the Styler implementation via jinja2 templating.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
columns : list of label, optional
The subset of columns to write. Writes all columns by default.
header : bool or list of str, default True
Write out the column names. If a list of strings is given,
it is assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
na_rep : str, default 'NaN'
Missing data representation.
formatters : list of functions or dict of {{str: function}}, optional
Formatter functions to apply to columns' elements by position or
name. The result of each function must be a unicode string.
List must be of length equal to the number of columns.
float_format : one-parameter function or str, optional, default None
Formatter for floating point numbers. For example
``float_format="%.2f"`` and ``float_format="{{:0.2f}}".format`` will
both result in 0.1234 being formatted as 0.12.
sparsify : bool, optional
Set to False for a DataFrame with a hierarchical index to print
every multiindex key at each row. By default, the value will be
read from the config module.
index_names : bool, default True
Prints the names of the indexes.
bold_rows : bool, default False
Make the row labels bold in the output.
column_format : str, optional
The columns format as specified in `LaTeX table format
<https://en.wikibooks.org/wiki/LaTeX/Tables>`__ e.g. 'rcl' for 3
columns. By default, 'l' will be used for all columns except
columns of numbers, which default to 'r'.
longtable : bool, optional
Use a longtable environment instead of tabular. Requires
adding a \usepackage{{longtable}} to your LaTeX preamble.
By default, the value will be read from the pandas config
module, and set to `True` if the option ``styler.latex.environment`` is
`"longtable"`.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed.
escape : bool, optional
By default, the value will be read from the pandas config
module and set to `True` if the option ``styler.format.escape`` is
`"latex"`. When set to False prevents from escaping latex special
characters in column names.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to `False`.
encoding : str, optional
A string representing the encoding to use in the output file,
defaults to 'utf-8'.
decimal : str, default '.'
Character recognized as decimal separator, e.g. ',' in Europe.
multicolumn : bool, default True
Use \multicolumn to enhance MultiIndex columns.
The default will be read from the config module, and is set
as the option ``styler.sparse.columns``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed.
multicolumn_format : str, default 'r'
The alignment for multicolumns, similar to `column_format`
The default will be read from the config module, and is set as the option
``styler.latex.multicol_align``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to "r".
multirow : bool, default True
Use \multirow to enhance MultiIndex rows. Requires adding a
\usepackage{{multirow}} to your LaTeX preamble. Will print
centered labels (instead of top-aligned) across the contained
rows, separating groups via clines. The default will be read
from the pandas config module, and is set as the option
``styler.sparse.index``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to `True`.
caption : str or tuple, optional
Tuple (full_caption, short_caption),
which results in ``\caption[short_caption]{{full_caption}}``;
if a single string is passed, no short caption will be set.
.. versionchanged:: 1.2.0
Optionally allow caption to be a tuple ``(full_caption, short_caption)``.
label : str, optional
The LaTeX label to be placed inside ``\label{{}}`` in the output.
This is used with ``\ref{{}}`` in the main ``.tex`` file.
position : str, optional
The LaTeX positional argument for tables, to be placed after
``\begin{{}}`` in the output.
.. versionadded:: 1.2.0
Returns
-------
str or None
If buf is None, returns the result as a string. Otherwise returns None.
See Also
--------
io.formats.style.Styler.to_latex : Render a DataFrame to LaTeX
with conditional formatting.
DataFrame.to_string : Render a DataFrame to a console-friendly
tabular output.
DataFrame.to_html : Render a DataFrame as an HTML table.
Notes
-----
As of v2.0.0 this method has changed to use the Styler implementation as
part of :meth:`.Styler.to_latex` via ``jinja2`` templating. This means
that ``jinja2`` is a requirement, and needs to be installed, for this method
to function. It is advised that users switch to using Styler, since that
implementation is more frequently updated and contains much more
flexibility with the output.
Examples
--------
Convert a general DataFrame to LaTeX with formatting:
>>> df = pd.DataFrame(dict(name=['Raphael', 'Donatello'],
... age=[26, 45],
... height=[181.23, 177.65]))
>>> print(df.to_latex(index=False,
... formatters={"name": str.upper},
... float_format="{:.1f}".format,
... )) # doctest: +SKIP
\begin{tabular}{lrr}
\toprule
name & age & height \\
\midrule
RAPHAEL & 26 & 181.2 \\
DONATELLO & 45 & 177.7 \\
\bottomrule
\end{tabular}
"""
# Get defaults from the pandas config
if self.ndim == 1:
self = self.to_frame()
if longtable is None:
longtable = config.get_option("styler.latex.environment") == "longtable"
if escape is None:
escape = config.get_option("styler.format.escape") == "latex"
if multicolumn is None:
multicolumn = config.get_option("styler.sparse.columns")
if multicolumn_format is None:
multicolumn_format = config.get_option("styler.latex.multicol_align")
if multirow is None:
multirow = config.get_option("styler.sparse.index")
if column_format is not None and not isinstance(column_format, str):
raise ValueError("`column_format` must be str or unicode")
length = len(self.columns) if columns is None else len(columns)
if isinstance(header, (list, tuple)) and len(header) != length:
raise ValueError(f"Writing {length} cols but got {len(header)} aliases")
# Refactor formatters/float_format/decimal/na_rep/escape to Styler structure
base_format_ = {
"na_rep": na_rep,
"escape": "latex" if escape else None,
"decimal": decimal,
}
index_format_: dict[str, Any] = {"axis": 0, **base_format_}
column_format_: dict[str, Any] = {"axis": 1, **base_format_}
if isinstance(float_format, str):
float_format_: Callable | None = lambda x: float_format % x
else:
float_format_ = float_format
def _wrap(x, alt_format_):
if isinstance(x, (float, complex)) and float_format_ is not None:
return float_format_(x)
else:
return alt_format_(x)
formatters_: list | tuple | dict | Callable | None = None
if isinstance(formatters, list):
formatters_ = {
c: partial(_wrap, alt_format_=formatters[i])
for i, c in enumerate(self.columns)
}
elif isinstance(formatters, dict):
index_formatter = formatters.pop("__index__", None)
column_formatter = formatters.pop("__columns__", None)
if index_formatter is not None:
index_format_.update({"formatter": index_formatter})
if column_formatter is not None:
column_format_.update({"formatter": column_formatter})
formatters_ = formatters
float_columns = self.select_dtypes(include="float").columns
for col in float_columns:
if col not in formatters.keys():
formatters_.update({col: float_format_})
elif formatters is None and float_format is not None:
formatters_ = partial(_wrap, alt_format_=lambda v: v)
format_index_ = [index_format_, column_format_]
# Deal with hiding indexes and relabelling column names
hide_: list[dict] = []
relabel_index_: list[dict] = []
if columns:
hide_.append(
{
"subset": [c for c in self.columns if c not in columns],
"axis": "columns",
}
)
if header is False:
hide_.append({"axis": "columns"})
elif isinstance(header, (list, tuple)):
relabel_index_.append({"labels": header, "axis": "columns"})
format_index_ = [index_format_] # column_format is overwritten
if index is False:
hide_.append({"axis": "index"})
if index_names is False:
hide_.append({"names": True, "axis": "index"})
render_kwargs_ = {
"hrules": True,
"sparse_index": sparsify,
"sparse_columns": sparsify,
"environment": "longtable" if longtable else None,
"multicol_align": multicolumn_format
if multicolumn
else f"naive-{multicolumn_format}",
"multirow_align": "t" if multirow else "naive",
"encoding": encoding,
"caption": caption,
"label": label,
"position": position,
"column_format": column_format,
"clines": "skip-last;data"
if (multirow and isinstance(self.index, MultiIndex))
else None,
"bold_rows": bold_rows,
}
return self._to_latex_via_styler(
buf,
hide=hide_,
relabel_index=relabel_index_,
format={"formatter": formatters_, **base_format_},
format_index=format_index_,
render_kwargs=render_kwargs_,
)
def _to_latex_via_styler(
self,
buf=None,
*,
hide: dict | list[dict] | None = None,
relabel_index: dict | list[dict] | None = None,
format: dict | list[dict] | None = None,
format_index: dict | list[dict] | None = None,
render_kwargs: dict | None = None,
):
"""
Render object to a LaTeX tabular, longtable, or nested table.
Uses the ``Styler`` implementation with the following, ordered, method chaining:
.. code-block:: python
styler = Styler(DataFrame)
styler.hide(**hide)
styler.relabel_index(**relabel_index)
styler.format(**format)
styler.format_index(**format_index)
styler.to_latex(buf=buf, **render_kwargs)
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
hide : dict, list of dict
Keyword args to pass to the method call of ``Styler.hide``. If a list will
call the method numerous times.
relabel_index : dict, list of dict
Keyword args to pass to the method of ``Styler.relabel_index``. If a list
will call the method numerous times.
format : dict, list of dict
Keyword args to pass to the method call of ``Styler.format``. If a list will
call the method numerous times.
format_index : dict, list of dict
Keyword args to pass to the method call of ``Styler.format_index``. If a
list will call the method numerous times.
render_kwargs : dict
Keyword args to pass to the method call of ``Styler.to_latex``.
Returns
-------
str or None
If buf is None, returns the result as a string. Otherwise returns None.
"""
from pandas.io.formats.style import Styler
self = cast("DataFrame", self)
styler = Styler(self, uuid="")
for kw_name in ["hide", "relabel_index", "format", "format_index"]:
kw = vars()[kw_name]
if isinstance(kw, dict):
getattr(styler, kw_name)(**kw)
elif isinstance(kw, list):
for sub_kw in kw:
getattr(styler, kw_name)(**sub_kw)
# bold_rows is not a direct kwarg of Styler.to_latex
render_kwargs = {} if render_kwargs is None else render_kwargs
if render_kwargs.pop("bold_rows"):
styler.applymap_index(lambda v: "textbf:--rwrap;")
return styler.to_latex(buf=buf, **render_kwargs)
def to_csv(
self,
path_or_buf: None = ...,
sep: str = ...,
na_rep: str = ...,
float_format: str | Callable | None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | list[str] = ...,
index: bool_t = ...,
index_label: IndexLabel | None = ...,
mode: str = ...,
encoding: str | None = ...,
compression: CompressionOptions = ...,
quoting: int | None = ...,
quotechar: str = ...,
lineterminator: str | None = ...,
chunksize: int | None = ...,
date_format: str | None = ...,
doublequote: bool_t = ...,
escapechar: str | None = ...,
decimal: str = ...,
errors: str = ...,
storage_options: StorageOptions = ...,
) -> str:
...
def to_csv(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str],
sep: str = ...,
na_rep: str = ...,
float_format: str | Callable | None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | list[str] = ...,
index: bool_t = ...,
index_label: IndexLabel | None = ...,
mode: str = ...,
encoding: str | None = ...,
compression: CompressionOptions = ...,
quoting: int | None = ...,
quotechar: str = ...,
lineterminator: str | None = ...,
chunksize: int | None = ...,
date_format: str | None = ...,
doublequote: bool_t = ...,
escapechar: str | None = ...,
decimal: str = ...,
errors: str = ...,
storage_options: StorageOptions = ...,
) -> None:
...
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buf",
)
def to_csv(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
sep: str = ",",
na_rep: str = "",
float_format: str | Callable | None = None,
columns: Sequence[Hashable] | None = None,
header: bool_t | list[str] = True,
index: bool_t = True,
index_label: IndexLabel | None = None,
mode: str = "w",
encoding: str | None = None,
compression: CompressionOptions = "infer",
quoting: int | None = None,
quotechar: str = '"',
lineterminator: str | None = None,
chunksize: int | None = None,
date_format: str | None = None,
doublequote: bool_t = True,
escapechar: str | None = None,
decimal: str = ".",
errors: str = "strict",
storage_options: StorageOptions = None,
) -> str | None:
r"""
Write object to a comma-separated values (csv) file.
Parameters
----------
path_or_buf : str, path object, file-like object, or None, default None
String, path object (implementing os.PathLike[str]), or file-like
object implementing a write() function. If None, the result is
returned as a string. If a non-binary file object is passed, it should
be opened with `newline=''`, disabling universal newlines. If a binary
file object is passed, `mode` might need to contain a `'b'`.
.. versionchanged:: 1.2.0
Support for binary file objects was introduced.
sep : str, default ','
String of length 1. Field delimiter for the output file.
na_rep : str, default ''
Missing data representation.
float_format : str, Callable, default None
Format string for floating point numbers. If a Callable is given, it takes
precedence over other numeric formatting parameters, like decimal.
columns : sequence, optional
Columns to write.
header : bool or list of str, default True
Write out the column names. If a list of strings is given it is
assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
index_label : str or sequence, or False, default None
Column label for index column(s) if desired. If None is given, and
`header` and `index` are True, then the index names are used. A
sequence should be given if the object uses MultiIndex. If
False do not print fields for index names. Use index_label=False
for easier importing in R.
mode : str, default 'w'
Python write mode. The available write modes are the same as
:py:func:`open`.
encoding : str, optional
A string representing the encoding to use in the output file,
defaults to 'utf-8'. `encoding` is not supported if `path_or_buf`
is a non-binary file object.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other entries as additional compression options if
compression mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is
supported for compression modes 'gzip', 'bz2', 'zstd', and 'zip'.
.. versionchanged:: 1.2.0
Compression is supported for binary file objects.
.. versionchanged:: 1.2.0
Previous versions forwarded dict entries for 'gzip' to
`gzip.open` instead of `gzip.GzipFile` which prevented
setting `mtime`.
quoting : optional constant from csv module
Defaults to csv.QUOTE_MINIMAL. If you have set a `float_format`
then floats are converted to strings and thus csv.QUOTE_NONNUMERIC
will treat them as non-numeric.
quotechar : str, default '\"'
String of length 1. Character used to quote fields.
lineterminator : str, optional
The newline character or character sequence to use in the output
file. Defaults to `os.linesep`, which depends on the OS in which
this method is called ('\\n' for linux, '\\r\\n' for Windows, i.e.).
.. versionchanged:: 1.5.0
Previously was line_terminator, changed for consistency with
read_csv and the standard library 'csv' module.
chunksize : int or None
Rows to write at a time.
date_format : str, default None
Format string for datetime objects.
doublequote : bool, default True
Control quoting of `quotechar` inside a field.
escapechar : str, default None
String of length 1. Character used to escape `sep` and `quotechar`
when appropriate.
decimal : str, default '.'
Character recognized as decimal separator. E.g. use ',' for
European data.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
Returns
-------
None or str
If path_or_buf is None, returns the resulting csv format as a
string. Otherwise returns None.
See Also
--------
read_csv : Load a CSV file into a DataFrame.
to_excel : Write DataFrame to an Excel file.
Examples
--------
>>> df = pd.DataFrame({{'name': ['Raphael', 'Donatello'],
... 'mask': ['red', 'purple'],
... 'weapon': ['sai', 'bo staff']}})
>>> df.to_csv(index=False)
'name,mask,weapon\nRaphael,red,sai\nDonatello,purple,bo staff\n'
Create 'out.zip' containing 'out.csv'
>>> compression_opts = dict(method='zip',
... archive_name='out.csv') # doctest: +SKIP
>>> df.to_csv('out.zip', index=False,
... compression=compression_opts) # doctest: +SKIP
To write a csv file to a new folder or nested folder you will first
need to create it using either Pathlib or os:
>>> from pathlib import Path # doctest: +SKIP
>>> filepath = Path('folder/subfolder/out.csv') # doctest: +SKIP
>>> filepath.parent.mkdir(parents=True, exist_ok=True) # doctest: +SKIP
>>> df.to_csv(filepath) # doctest: +SKIP
>>> import os # doctest: +SKIP
>>> os.makedirs('folder/subfolder', exist_ok=True) # doctest: +SKIP
>>> df.to_csv('folder/subfolder/out.csv') # doctest: +SKIP
"""
df = self if isinstance(self, ABCDataFrame) else self.to_frame()
formatter = DataFrameFormatter(
frame=df,
header=header,
index=index,
na_rep=na_rep,
float_format=float_format,
decimal=decimal,
)
return DataFrameRenderer(formatter).to_csv(
path_or_buf,
lineterminator=lineterminator,
sep=sep,
encoding=encoding,
errors=errors,
compression=compression,
quoting=quoting,
columns=columns,
index_label=index_label,
mode=mode,
chunksize=chunksize,
quotechar=quotechar,
date_format=date_format,
doublequote=doublequote,
escapechar=escapechar,
storage_options=storage_options,
)
# ----------------------------------------------------------------------
# Lookup Caching
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
raise AbstractMethodError(self)
def _maybe_update_cacher(
self,
clear: bool_t = False,
verify_is_copy: bool_t = True,
inplace: bool_t = False,
) -> None:
"""
See if we need to update our parent cacher if clear, then clear our
cache.
Parameters
----------
clear : bool, default False
Clear the item cache.
verify_is_copy : bool, default True
Provide is_copy checks.
"""
if using_copy_on_write():
return
if verify_is_copy:
self._check_setitem_copy(t="referent")
if clear:
self._clear_item_cache()
def _clear_item_cache(self) -> None:
raise AbstractMethodError(self)
# ----------------------------------------------------------------------
# Indexing Methods
def take(self: NDFrameT, indices, axis: Axis = 0, **kwargs) -> NDFrameT:
"""
Return the elements in the given *positional* indices along an axis.
This means that we are not indexing according to actual values in
the index attribute of the object. We are indexing according to the
actual position of the element in the object.
Parameters
----------
indices : array-like
An array of ints indicating which positions to take.
axis : {0 or 'index', 1 or 'columns', None}, default 0
The axis on which to select elements. ``0`` means that we are
selecting rows, ``1`` means that we are selecting columns.
For `Series` this parameter is unused and defaults to 0.
**kwargs
For compatibility with :meth:`numpy.take`. Has no effect on the
output.
Returns
-------
same type as caller
An array-like containing the elements taken from the object.
See Also
--------
DataFrame.loc : Select a subset of a DataFrame by labels.
DataFrame.iloc : Select a subset of a DataFrame by positions.
numpy.take : Take elements from an array along an axis.
Examples
--------
>>> df = pd.DataFrame([('falcon', 'bird', 389.0),
... ('parrot', 'bird', 24.0),
... ('lion', 'mammal', 80.5),
... ('monkey', 'mammal', np.nan)],
... columns=['name', 'class', 'max_speed'],
... index=[0, 2, 3, 1])
>>> df
name class max_speed
0 falcon bird 389.0
2 parrot bird 24.0
3 lion mammal 80.5
1 monkey mammal NaN
Take elements at positions 0 and 3 along the axis 0 (default).
Note how the actual indices selected (0 and 1) do not correspond to
our selected indices 0 and 3. That's because we are selecting the 0th
and 3rd rows, not rows whose indices equal 0 and 3.
>>> df.take([0, 3])
name class max_speed
0 falcon bird 389.0
1 monkey mammal NaN
Take elements at indices 1 and 2 along the axis 1 (column selection).
>>> df.take([1, 2], axis=1)
class max_speed
0 bird 389.0
2 bird 24.0
3 mammal 80.5
1 mammal NaN
We may take elements using negative integers for positive indices,
starting from the end of the object, just like with Python lists.
>>> df.take([-1, -2])
name class max_speed
1 monkey mammal NaN
3 lion mammal 80.5
"""
nv.validate_take((), kwargs)
return self._take(indices, axis)
def _take(
self: NDFrameT,
indices,
axis: Axis = 0,
convert_indices: bool_t = True,
) -> NDFrameT:
"""
Internal version of the `take` allowing specification of additional args.
See the docstring of `take` for full explanation of the parameters.
"""
if not isinstance(indices, slice):
indices = np.asarray(indices, dtype=np.intp)
if (
axis == 0
and indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_data = self._mgr.take(
indices,
axis=self._get_block_manager_axis(axis),
verify=True,
convert_indices=convert_indices,
)
return self._constructor(new_data).__finalize__(self, method="take")
def _take_with_is_copy(self: NDFrameT, indices, axis: Axis = 0) -> NDFrameT:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning).
See the docstring of `take` for full explanation of the parameters.
"""
result = self._take(indices=indices, axis=axis)
# Maybe set copy if we didn't actually change the index.
if not result._get_axis(axis).equals(self._get_axis(axis)):
result._set_is_copy(self)
return result
def xs(
self: NDFrameT,
key: IndexLabel,
axis: Axis = 0,
level: IndexLabel = None,
drop_level: bool_t = True,
) -> NDFrameT:
"""
Return cross-section from the Series/DataFrame.
This method takes a `key` argument to select data at a particular
level of a MultiIndex.
Parameters
----------
key : label or tuple of label
Label contained in the index, or partially in a MultiIndex.
axis : {0 or 'index', 1 or 'columns'}, default 0
Axis to retrieve cross-section on.
level : object, defaults to first n levels (n=1 or len(key))
In case of a key partially contained in a MultiIndex, indicate
which levels are used. Levels can be referred by label or position.
drop_level : bool, default True
If False, returns object with same levels as self.
Returns
-------
Series or DataFrame
Cross-section from the original Series or DataFrame
corresponding to the selected index levels.
See Also
--------
DataFrame.loc : Access a group of rows and columns
by label(s) or a boolean array.
DataFrame.iloc : Purely integer-location based indexing
for selection by position.
Notes
-----
`xs` can not be used to set values.
MultiIndex Slicers is a generic way to get/set values on
any level or levels.
It is a superset of `xs` functionality, see
:ref:`MultiIndex Slicers <advanced.mi_slicers>`.
Examples
--------
>>> d = {'num_legs': [4, 4, 2, 2],
... 'num_wings': [0, 0, 2, 2],
... 'class': ['mammal', 'mammal', 'mammal', 'bird'],
... 'animal': ['cat', 'dog', 'bat', 'penguin'],
... 'locomotion': ['walks', 'walks', 'flies', 'walks']}
>>> df = pd.DataFrame(data=d)
>>> df = df.set_index(['class', 'animal', 'locomotion'])
>>> df
num_legs num_wings
class animal locomotion
mammal cat walks 4 0
dog walks 4 0
bat flies 2 2
bird penguin walks 2 2
Get values at specified index
>>> df.xs('mammal')
num_legs num_wings
animal locomotion
cat walks 4 0
dog walks 4 0
bat flies 2 2
Get values at several indexes
>>> df.xs(('mammal', 'dog', 'walks'))
num_legs 4
num_wings 0
Name: (mammal, dog, walks), dtype: int64
Get values at specified index and level
>>> df.xs('cat', level=1)
num_legs num_wings
class locomotion
mammal walks 4 0
Get values at several indexes and levels
>>> df.xs(('bird', 'walks'),
... level=[0, 'locomotion'])
num_legs num_wings
animal
penguin 2 2
Get values at specified column and axis
>>> df.xs('num_wings', axis=1)
class animal locomotion
mammal cat walks 0
dog walks 0
bat flies 2
bird penguin walks 2
Name: num_wings, dtype: int64
"""
axis = self._get_axis_number(axis)
labels = self._get_axis(axis)
if isinstance(key, list):
raise TypeError("list keys are not supported in xs, pass a tuple instead")
if level is not None:
if not isinstance(labels, MultiIndex):
raise TypeError("Index must be a MultiIndex")
loc, new_ax = labels.get_loc_level(key, level=level, drop_level=drop_level)
# create the tuple of the indexer
_indexer = [slice(None)] * self.ndim
_indexer[axis] = loc
indexer = tuple(_indexer)
result = self.iloc[indexer]
setattr(result, result._get_axis_name(axis), new_ax)
return result
if axis == 1:
if drop_level:
return self[key]
index = self.columns
else:
index = self.index
if isinstance(index, MultiIndex):
loc, new_index = index._get_loc_level(key, level=0)
if not drop_level:
if lib.is_integer(loc):
new_index = index[loc : loc + 1]
else:
new_index = index[loc]
else:
loc = index.get_loc(key)
if isinstance(loc, np.ndarray):
if loc.dtype == np.bool_:
(inds,) = loc.nonzero()
return self._take_with_is_copy(inds, axis=axis)
else:
return self._take_with_is_copy(loc, axis=axis)
if not is_scalar(loc):
new_index = index[loc]
if is_scalar(loc) and axis == 0:
# In this case loc should be an integer
if self.ndim == 1:
# if we encounter an array-like and we only have 1 dim
# that means that their are list/ndarrays inside the Series!
# so just return them (GH 6394)
return self._values[loc]
new_mgr = self._mgr.fast_xs(loc)
result = self._constructor_sliced(
new_mgr, name=self.index[loc]
).__finalize__(self)
elif is_scalar(loc):
result = self.iloc[:, slice(loc, loc + 1)]
elif axis == 1:
result = self.iloc[:, loc]
else:
result = self.iloc[loc]
result.index = new_index
# this could be a view
# but only in a single-dtyped view sliceable case
result._set_is_copy(self, copy=not result._is_view)
return result
def __getitem__(self, item):
raise AbstractMethodError(self)
def _slice(self: NDFrameT, slobj: slice, axis: Axis = 0) -> NDFrameT:
"""
Construct a slice of this container.
Slicing with this method is *always* positional.
"""
assert isinstance(slobj, slice), type(slobj)
axis = self._get_block_manager_axis(axis)
result = self._constructor(self._mgr.get_slice(slobj, axis=axis))
result = result.__finalize__(self)
# this could be a view
# but only in a single-dtyped view sliceable case
is_copy = axis != 0 or result._is_view
result._set_is_copy(self, copy=is_copy)
return result
def _set_is_copy(self, ref: NDFrame, copy: bool_t = True) -> None:
if not copy:
self._is_copy = None
else:
assert ref is not None
self._is_copy = weakref.ref(ref)
def _check_is_chained_assignment_possible(self) -> bool_t:
"""
Check if we are a view, have a cacher, and are of mixed type.
If so, then force a setitem_copy check.
Should be called just near setting a value
Will return a boolean if it we are a view and are cached, but a
single-dtype meaning that the cacher should be updated following
setting.
"""
if self._is_copy:
self._check_setitem_copy(t="referent")
return False
def _check_setitem_copy(self, t: str = "setting", force: bool_t = False):
"""
Parameters
----------
t : str, the type of setting error
force : bool, default False
If True, then force showing an error.
validate if we are doing a setitem on a chained copy.
It is technically possible to figure out that we are setting on
a copy even WITH a multi-dtyped pandas object. In other words, some
blocks may be views while other are not. Currently _is_view will ALWAYS
return False for multi-blocks to avoid having to handle this case.
df = DataFrame(np.arange(0,9), columns=['count'])
df['group'] = 'b'
# This technically need not raise SettingWithCopy if both are view
# (which is not generally guaranteed but is usually True. However,
# this is in general not a good practice and we recommend using .loc.
df.iloc[0:5]['group'] = 'a'
"""
if using_copy_on_write():
return
# return early if the check is not needed
if not (force or self._is_copy):
return
value = config.get_option("mode.chained_assignment")
if value is None:
return
# see if the copy is not actually referred; if so, then dissolve
# the copy weakref
if self._is_copy is not None and not isinstance(self._is_copy, str):
r = self._is_copy()
if not gc.get_referents(r) or (r is not None and r.shape == self.shape):
self._is_copy = None
return
# a custom message
if isinstance(self._is_copy, str):
t = self._is_copy
elif t == "referent":
t = (
"\n"
"A value is trying to be set on a copy of a slice from a "
"DataFrame\n\n"
"See the caveats in the documentation: "
"https://pandas.pydata.org/pandas-docs/stable/user_guide/"
"indexing.html#returning-a-view-versus-a-copy"
)
else:
t = (
"\n"
"A value is trying to be set on a copy of a slice from a "
"DataFrame.\n"
"Try using .loc[row_indexer,col_indexer] = value "
"instead\n\nSee the caveats in the documentation: "
"https://pandas.pydata.org/pandas-docs/stable/user_guide/"
"indexing.html#returning-a-view-versus-a-copy"
)
if value == "raise":
raise SettingWithCopyError(t)
if value == "warn":
warnings.warn(t, SettingWithCopyWarning, stacklevel=find_stack_level())
def __delitem__(self, key) -> None:
"""
Delete item
"""
deleted = False
maybe_shortcut = False
if self.ndim == 2 and isinstance(self.columns, MultiIndex):
try:
# By using engine's __contains__ we effectively
# restrict to same-length tuples
maybe_shortcut = key not in self.columns._engine
except TypeError:
pass
if maybe_shortcut:
# Allow shorthand to delete all columns whose first len(key)
# elements match key:
if not isinstance(key, tuple):
key = (key,)
for col in self.columns:
if isinstance(col, tuple) and col[: len(key)] == key:
del self[col]
deleted = True
if not deleted:
# If the above loop ran and didn't delete anything because
# there was no match, this call should raise the appropriate
# exception:
loc = self.axes[-1].get_loc(key)
self._mgr = self._mgr.idelete(loc)
# delete from the caches
try:
del self._item_cache[key]
except KeyError:
pass
# ----------------------------------------------------------------------
# Unsorted
def _check_inplace_and_allows_duplicate_labels(self, inplace):
if inplace and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'inplace=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
def get(self, key, default=None):
"""
Get item from object for given key (ex: DataFrame column).
Returns default value if not found.
Parameters
----------
key : object
Returns
-------
same type as items contained in object
Examples
--------
>>> df = pd.DataFrame(
... [
... [24.3, 75.7, "high"],
... [31, 87.8, "high"],
... [22, 71.6, "medium"],
... [35, 95, "medium"],
... ],
... columns=["temp_celsius", "temp_fahrenheit", "windspeed"],
... index=pd.date_range(start="2014-02-12", end="2014-02-15", freq="D"),
... )
>>> df
temp_celsius temp_fahrenheit windspeed
2014-02-12 24.3 75.7 high
2014-02-13 31.0 87.8 high
2014-02-14 22.0 71.6 medium
2014-02-15 35.0 95.0 medium
>>> df.get(["temp_celsius", "windspeed"])
temp_celsius windspeed
2014-02-12 24.3 high
2014-02-13 31.0 high
2014-02-14 22.0 medium
2014-02-15 35.0 medium
>>> ser = df['windspeed']
>>> ser.get('2014-02-13')
'high'
If the key isn't found, the default value will be used.
>>> df.get(["temp_celsius", "temp_kelvin"], default="default_value")
'default_value'
>>> ser.get('2014-02-10', '[unknown]')
'[unknown]'
"""
try:
return self[key]
except (KeyError, ValueError, IndexError):
return default
def _is_view(self) -> bool_t:
"""Return boolean indicating if self is view of another array"""
return self._mgr.is_view
def reindex_like(
self: NDFrameT,
other,
method: Literal["backfill", "bfill", "pad", "ffill", "nearest"] | None = None,
copy: bool_t | None = None,
limit=None,
tolerance=None,
) -> NDFrameT:
"""
Return an object with matching indices as other object.
Conform the object to the same index on all axes. Optional
filling logic, placing NaN in locations having no value
in the previous index. A new object is produced unless the
new index is equivalent to the current one and copy=False.
Parameters
----------
other : Object of the same data type
Its row and column indices are used to define the new indices
of this object.
method : {None, 'backfill'/'bfill', 'pad'/'ffill', 'nearest'}
Method to use for filling holes in reindexed DataFrame.
Please note: this is only applicable to DataFrames/Series with a
monotonically increasing/decreasing index.
* None (default): don't fill gaps
* pad / ffill: propagate last valid observation forward to next
valid
* backfill / bfill: use next valid observation to fill gap
* nearest: use nearest valid observations to fill gap.
copy : bool, default True
Return a new object, even if the passed indexes are the same.
limit : int, default None
Maximum number of consecutive labels to fill for inexact matches.
tolerance : optional
Maximum distance between original and new labels for inexact
matches. The values of the index at the matching locations must
satisfy the equation ``abs(index[indexer] - target) <= tolerance``.
Tolerance may be a scalar value, which applies the same tolerance
to all values, or list-like, which applies variable tolerance per
element. List-like includes list, tuple, array, Series, and must be
the same size as the index and its dtype must exactly match the
index's type.
Returns
-------
Series or DataFrame
Same type as caller, but with changed indices on each axis.
See Also
--------
DataFrame.set_index : Set row labels.
DataFrame.reset_index : Remove row labels or move them to new columns.
DataFrame.reindex : Change to new indices or expand indices.
Notes
-----
Same as calling
``.reindex(index=other.index, columns=other.columns,...)``.
Examples
--------
>>> df1 = pd.DataFrame([[24.3, 75.7, 'high'],
... [31, 87.8, 'high'],
... [22, 71.6, 'medium'],
... [35, 95, 'medium']],
... columns=['temp_celsius', 'temp_fahrenheit',
... 'windspeed'],
... index=pd.date_range(start='2014-02-12',
... end='2014-02-15', freq='D'))
>>> df1
temp_celsius temp_fahrenheit windspeed
2014-02-12 24.3 75.7 high
2014-02-13 31.0 87.8 high
2014-02-14 22.0 71.6 medium
2014-02-15 35.0 95.0 medium
>>> df2 = pd.DataFrame([[28, 'low'],
... [30, 'low'],
... [35.1, 'medium']],
... columns=['temp_celsius', 'windspeed'],
... index=pd.DatetimeIndex(['2014-02-12', '2014-02-13',
... '2014-02-15']))
>>> df2
temp_celsius windspeed
2014-02-12 28.0 low
2014-02-13 30.0 low
2014-02-15 35.1 medium
>>> df2.reindex_like(df1)
temp_celsius temp_fahrenheit windspeed
2014-02-12 28.0 NaN low
2014-02-13 30.0 NaN low
2014-02-14 NaN NaN NaN
2014-02-15 35.1 NaN medium
"""
d = other._construct_axes_dict(
axes=self._AXIS_ORDERS,
method=method,
copy=copy,
limit=limit,
tolerance=tolerance,
)
return self.reindex(**d)
def drop(
self,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: Literal[True],
errors: IgnoreRaise = ...,
) -> None:
...
def drop(
self: NDFrameT,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: Literal[False] = ...,
errors: IgnoreRaise = ...,
) -> NDFrameT:
...
def drop(
self: NDFrameT,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: bool_t = ...,
errors: IgnoreRaise = ...,
) -> NDFrameT | None:
...
def drop(
self: NDFrameT,
labels: IndexLabel = None,
*,
axis: Axis = 0,
index: IndexLabel = None,
columns: IndexLabel = None,
level: Level | None = None,
inplace: bool_t = False,
errors: IgnoreRaise = "raise",
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
if labels is not None:
if index is not None or columns is not None:
raise ValueError("Cannot specify both 'labels' and 'index'/'columns'")
axis_name = self._get_axis_name(axis)
axes = {axis_name: labels}
elif index is not None or columns is not None:
axes = {"index": index}
if self.ndim == 2:
axes["columns"] = columns
else:
raise ValueError(
"Need to specify at least one of 'labels', 'index' or 'columns'"
)
obj = self
for axis, labels in axes.items():
if labels is not None:
obj = obj._drop_axis(labels, axis, level=level, errors=errors)
if inplace:
self._update_inplace(obj)
return None
else:
return obj
def _drop_axis(
self: NDFrameT,
labels,
axis,
level=None,
errors: IgnoreRaise = "raise",
only_slice: bool_t = False,
) -> NDFrameT:
"""
Drop labels from specified axis. Used in the ``drop`` method
internally.
Parameters
----------
labels : single label or list-like
axis : int or axis name
level : int or level name, default None
For MultiIndex
errors : {'ignore', 'raise'}, default 'raise'
If 'ignore', suppress error and existing labels are dropped.
only_slice : bool, default False
Whether indexing along columns should be view-only.
"""
axis_num = self._get_axis_number(axis)
axis = self._get_axis(axis)
if axis.is_unique:
if level is not None:
if not isinstance(axis, MultiIndex):
raise AssertionError("axis must be a MultiIndex")
new_axis = axis.drop(labels, level=level, errors=errors)
else:
new_axis = axis.drop(labels, errors=errors)
indexer = axis.get_indexer(new_axis)
# Case for non-unique axis
else:
is_tuple_labels = is_nested_list_like(labels) or isinstance(labels, tuple)
labels = ensure_object(common.index_labels_to_array(labels))
if level is not None:
if not isinstance(axis, MultiIndex):
raise AssertionError("axis must be a MultiIndex")
mask = ~axis.get_level_values(level).isin(labels)
# GH 18561 MultiIndex.drop should raise if label is absent
if errors == "raise" and mask.all():
raise KeyError(f"{labels} not found in axis")
elif (
isinstance(axis, MultiIndex)
and labels.dtype == "object"
and not is_tuple_labels
):
# Set level to zero in case of MultiIndex and label is string,
# because isin can't handle strings for MultiIndexes GH#36293
# In case of tuples we get dtype object but have to use isin GH#42771
mask = ~axis.get_level_values(0).isin(labels)
else:
mask = ~axis.isin(labels)
# Check if label doesn't exist along axis
labels_missing = (axis.get_indexer_for(labels) == -1).any()
if errors == "raise" and labels_missing:
raise KeyError(f"{labels} not found in axis")
if is_extension_array_dtype(mask.dtype):
# GH#45860
mask = mask.to_numpy(dtype=bool)
indexer = mask.nonzero()[0]
new_axis = axis.take(indexer)
bm_axis = self.ndim - axis_num - 1
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=bm_axis,
allow_dups=True,
copy=None,
only_slice=only_slice,
)
result = self._constructor(new_mgr)
if self.ndim == 1:
result.name = self.name
return result.__finalize__(self)
def _update_inplace(self, result, verify_is_copy: bool_t = True) -> None:
"""
Replace self internals with result.
Parameters
----------
result : same type as self
verify_is_copy : bool, default True
Provide is_copy checks.
"""
# NOTE: This does *not* call __finalize__ and that's an explicit
# decision that we may revisit in the future.
self._reset_cache()
self._clear_item_cache()
self._mgr = result._mgr
self._maybe_update_cacher(verify_is_copy=verify_is_copy, inplace=True)
def add_prefix(self: NDFrameT, prefix: str, axis: Axis | None = None) -> NDFrameT:
"""
Prefix labels with string `prefix`.
For Series, the row labels are prefixed.
For DataFrame, the column labels are prefixed.
Parameters
----------
prefix : str
The string to add before each label.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to add prefix on
.. versionadded:: 2.0.0
Returns
-------
Series or DataFrame
New Series or DataFrame with updated labels.
See Also
--------
Series.add_suffix: Suffix row labels with string `suffix`.
DataFrame.add_suffix: Suffix column labels with string `suffix`.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.add_prefix('item_')
item_0 1
item_1 2
item_2 3
item_3 4
dtype: int64
>>> df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [3, 4, 5, 6]})
>>> df
A B
0 1 3
1 2 4
2 3 5
3 4 6
>>> df.add_prefix('col_')
col_A col_B
0 1 3
1 2 4
2 3 5
3 4 6
"""
f = lambda x: f"{prefix}{x}"
axis_name = self._info_axis_name
if axis is not None:
axis_name = self._get_axis_name(axis)
mapper = {axis_name: f}
# error: Incompatible return value type (got "Optional[NDFrameT]",
# expected "NDFrameT")
# error: Argument 1 to "rename" of "NDFrame" has incompatible type
# "**Dict[str, partial[str]]"; expected "Union[str, int, None]"
# error: Keywords must be strings
return self._rename(**mapper) # type: ignore[return-value, arg-type, misc]
def add_suffix(self: NDFrameT, suffix: str, axis: Axis | None = None) -> NDFrameT:
"""
Suffix labels with string `suffix`.
For Series, the row labels are suffixed.
For DataFrame, the column labels are suffixed.
Parameters
----------
suffix : str
The string to add after each label.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to add suffix on
.. versionadded:: 2.0.0
Returns
-------
Series or DataFrame
New Series or DataFrame with updated labels.
See Also
--------
Series.add_prefix: Prefix row labels with string `prefix`.
DataFrame.add_prefix: Prefix column labels with string `prefix`.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.add_suffix('_item')
0_item 1
1_item 2
2_item 3
3_item 4
dtype: int64
>>> df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [3, 4, 5, 6]})
>>> df
A B
0 1 3
1 2 4
2 3 5
3 4 6
>>> df.add_suffix('_col')
A_col B_col
0 1 3
1 2 4
2 3 5
3 4 6
"""
f = lambda x: f"{x}{suffix}"
axis_name = self._info_axis_name
if axis is not None:
axis_name = self._get_axis_name(axis)
mapper = {axis_name: f}
# error: Incompatible return value type (got "Optional[NDFrameT]",
# expected "NDFrameT")
# error: Argument 1 to "rename" of "NDFrame" has incompatible type
# "**Dict[str, partial[str]]"; expected "Union[str, int, None]"
# error: Keywords must be strings
return self._rename(**mapper) # type: ignore[return-value, arg-type, misc]
def sort_values(
self: NDFrameT,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> NDFrameT:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self: NDFrameT,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: bool_t = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> NDFrameT | None:
...
def sort_values(
self: NDFrameT,
*,
axis: Axis = 0,
ascending: bool_t | Sequence[bool_t] = True,
inplace: bool_t = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool_t = False,
key: ValueKeyFunc = None,
) -> NDFrameT | None:
"""
Sort by the values along either axis.
Parameters
----------%(optional_by)s
axis : %(axes_single_arg)s, default 0
Axis to be sorted.
ascending : bool or list of bool, default True
Sort ascending vs. descending. Specify list for multiple sort
orders. If this is a list of bools, must match the length of
the by.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. `mergesort` and `stable` are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
Puts NaNs at the beginning if `first`; `last` puts NaNs at the
end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
Apply the key function to the values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return a Series with the same shape as the input.
It will be applied to each column in `by` independently.
.. versionadded:: 1.1.0
Returns
-------
DataFrame or None
DataFrame with sorted values or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index : Sort a DataFrame by the index.
Series.sort_values : Similar method for a Series.
Examples
--------
>>> df = pd.DataFrame({
... 'col1': ['A', 'A', 'B', np.nan, 'D', 'C'],
... 'col2': [2, 1, 9, 8, 7, 4],
... 'col3': [0, 1, 9, 4, 2, 3],
... 'col4': ['a', 'B', 'c', 'D', 'e', 'F']
... })
>>> df
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
Sort by col1
>>> df.sort_values(by=['col1'])
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
5 C 4 3 F
4 D 7 2 e
3 NaN 8 4 D
Sort by multiple columns
>>> df.sort_values(by=['col1', 'col2'])
col1 col2 col3 col4
1 A 1 1 B
0 A 2 0 a
2 B 9 9 c
5 C 4 3 F
4 D 7 2 e
3 NaN 8 4 D
Sort Descending
>>> df.sort_values(by='col1', ascending=False)
col1 col2 col3 col4
4 D 7 2 e
5 C 4 3 F
2 B 9 9 c
0 A 2 0 a
1 A 1 1 B
3 NaN 8 4 D
Putting NAs first
>>> df.sort_values(by='col1', ascending=False, na_position='first')
col1 col2 col3 col4
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
2 B 9 9 c
0 A 2 0 a
1 A 1 1 B
Sorting with a key function
>>> df.sort_values(by='col4', key=lambda col: col.str.lower())
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
Natural sort with the key argument,
using the `natsort <https://github.com/SethMMorton/natsort>` package.
>>> df = pd.DataFrame({
... "time": ['0hr', '128hr', '72hr', '48hr', '96hr'],
... "value": [10, 20, 30, 40, 50]
... })
>>> df
time value
0 0hr 10
1 128hr 20
2 72hr 30
3 48hr 40
4 96hr 50
>>> from natsort import index_natsorted
>>> df.sort_values(
... by="time",
... key=lambda x: np.argsort(index_natsorted(df["time"]))
... )
time value
0 0hr 10
3 48hr 40
2 72hr 30
4 96hr 50
1 128hr 20
"""
raise AbstractMethodError(self)
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> NDFrameT:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: bool_t = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> NDFrameT | None:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool_t | Sequence[bool_t] = True,
inplace: bool_t = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool_t = True,
ignore_index: bool_t = False,
key: IndexKeyFunc = None,
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
axis = self._get_axis_number(axis)
ascending = validate_ascending(ascending)
target = self._get_axis(axis)
indexer = get_indexer_indexer(
target, level, ascending, kind, na_position, sort_remaining, key
)
if indexer is None:
if inplace:
result = self
else:
result = self.copy(deep=None)
if ignore_index:
result.index = default_index(len(self))
if inplace:
return None
else:
return result
baxis = self._get_block_manager_axis(axis)
new_data = self._mgr.take(indexer, axis=baxis, verify=False)
# reconstruct axis if needed
new_data.set_axis(baxis, new_data.axes[baxis]._sort_levels_monotonic())
if ignore_index:
axis = 1 if isinstance(self, ABCDataFrame) else 0
new_data.set_axis(axis, default_index(len(indexer)))
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="sort_index")
klass=_shared_doc_kwargs["klass"],
optional_reindex="",
)
def reindex(
self: NDFrameT,
labels=None,
index=None,
columns=None,
axis: Axis | None = None,
method: str | None = None,
copy: bool_t | None = None,
level: Level | None = None,
fill_value: Scalar | None = np.nan,
limit: int | None = None,
tolerance=None,
) -> NDFrameT:
"""
Conform {klass} to new index with optional filling logic.
Places NA/NaN in locations having no value in the previous index. A new object
is produced unless the new index is equivalent to the current one and
``copy=False``.
Parameters
----------
{optional_reindex}
method : {{None, 'backfill'/'bfill', 'pad'/'ffill', 'nearest'}}
Method to use for filling holes in reindexed DataFrame.
Please note: this is only applicable to DataFrames/Series with a
monotonically increasing/decreasing index.
* None (default): don't fill gaps
* pad / ffill: Propagate last valid observation forward to next
valid.
* backfill / bfill: Use next valid observation to fill gap.
* nearest: Use nearest valid observations to fill gap.
copy : bool, default True
Return a new object, even if the passed indexes are the same.
level : int or name
Broadcast across a level, matching Index values on the
passed MultiIndex level.
fill_value : scalar, default np.NaN
Value to use for missing values. Defaults to NaN, but can be any
"compatible" value.
limit : int, default None
Maximum number of consecutive elements to forward or backward fill.
tolerance : optional
Maximum distance between original and new labels for inexact
matches. The values of the index at the matching locations most
satisfy the equation ``abs(index[indexer] - target) <= tolerance``.
Tolerance may be a scalar value, which applies the same tolerance
to all values, or list-like, which applies variable tolerance per
element. List-like includes list, tuple, array, Series, and must be
the same size as the index and its dtype must exactly match the
index's type.
Returns
-------
{klass} with changed index.
See Also
--------
DataFrame.set_index : Set row labels.
DataFrame.reset_index : Remove row labels or move them to new columns.
DataFrame.reindex_like : Change to same indices as other DataFrame.
Examples
--------
``DataFrame.reindex`` supports two calling conventions
* ``(index=index_labels, columns=column_labels, ...)``
* ``(labels, axis={{'index', 'columns'}}, ...)``
We *highly* recommend using keyword arguments to clarify your
intent.
Create a dataframe with some fictional data.
>>> index = ['Firefox', 'Chrome', 'Safari', 'IE10', 'Konqueror']
>>> df = pd.DataFrame({{'http_status': [200, 200, 404, 404, 301],
... 'response_time': [0.04, 0.02, 0.07, 0.08, 1.0]}},
... index=index)
>>> df
http_status response_time
Firefox 200 0.04
Chrome 200 0.02
Safari 404 0.07
IE10 404 0.08
Konqueror 301 1.00
Create a new index and reindex the dataframe. By default
values in the new index that do not have corresponding
records in the dataframe are assigned ``NaN``.
>>> new_index = ['Safari', 'Iceweasel', 'Comodo Dragon', 'IE10',
... 'Chrome']
>>> df.reindex(new_index)
http_status response_time
Safari 404.0 0.07
Iceweasel NaN NaN
Comodo Dragon NaN NaN
IE10 404.0 0.08
Chrome 200.0 0.02
We can fill in the missing values by passing a value to
the keyword ``fill_value``. Because the index is not monotonically
increasing or decreasing, we cannot use arguments to the keyword
``method`` to fill the ``NaN`` values.
>>> df.reindex(new_index, fill_value=0)
http_status response_time
Safari 404 0.07
Iceweasel 0 0.00
Comodo Dragon 0 0.00
IE10 404 0.08
Chrome 200 0.02
>>> df.reindex(new_index, fill_value='missing')
http_status response_time
Safari 404 0.07
Iceweasel missing missing
Comodo Dragon missing missing
IE10 404 0.08
Chrome 200 0.02
We can also reindex the columns.
>>> df.reindex(columns=['http_status', 'user_agent'])
http_status user_agent
Firefox 200 NaN
Chrome 200 NaN
Safari 404 NaN
IE10 404 NaN
Konqueror 301 NaN
Or we can use "axis-style" keyword arguments
>>> df.reindex(['http_status', 'user_agent'], axis="columns")
http_status user_agent
Firefox 200 NaN
Chrome 200 NaN
Safari 404 NaN
IE10 404 NaN
Konqueror 301 NaN
To further illustrate the filling functionality in
``reindex``, we will create a dataframe with a
monotonically increasing index (for example, a sequence
of dates).
>>> date_index = pd.date_range('1/1/2010', periods=6, freq='D')
>>> df2 = pd.DataFrame({{"prices": [100, 101, np.nan, 100, 89, 88]}},
... index=date_index)
>>> df2
prices
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
Suppose we decide to expand the dataframe to cover a wider
date range.
>>> date_index2 = pd.date_range('12/29/2009', periods=10, freq='D')
>>> df2.reindex(date_index2)
prices
2009-12-29 NaN
2009-12-30 NaN
2009-12-31 NaN
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
2010-01-07 NaN
The index entries that did not have a value in the original data frame
(for example, '2009-12-29') are by default filled with ``NaN``.
If desired, we can fill in the missing values using one of several
options.
For example, to back-propagate the last valid value to fill the ``NaN``
values, pass ``bfill`` as an argument to the ``method`` keyword.
>>> df2.reindex(date_index2, method='bfill')
prices
2009-12-29 100.0
2009-12-30 100.0
2009-12-31 100.0
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
2010-01-07 NaN
Please note that the ``NaN`` value present in the original dataframe
(at index value 2010-01-03) will not be filled by any of the
value propagation schemes. This is because filling while reindexing
does not look at dataframe values, but only compares the original and
desired indexes. If you do want to fill in the ``NaN`` values present
in the original dataframe, use the ``fillna()`` method.
See the :ref:`user guide <basics.reindexing>` for more.
"""
# TODO: Decide if we care about having different examples for different
# kinds
if index is not None and columns is not None and labels is not None:
raise TypeError("Cannot specify all of 'labels', 'index', 'columns'.")
elif index is not None or columns is not None:
if axis is not None:
raise TypeError(
"Cannot specify both 'axis' and any of 'index' or 'columns'"
)
if labels is not None:
if index is not None:
columns = labels
else:
index = labels
else:
if axis and self._get_axis_number(axis) == 1:
columns = labels
else:
index = labels
axes: dict[Literal["index", "columns"], Any] = {
"index": index,
"columns": columns,
}
method = clean_reindex_fill_method(method)
# if all axes that are requested to reindex are equal, then only copy
# if indicated must have index names equal here as well as values
if copy and using_copy_on_write():
copy = False
if all(
self._get_axis(axis_name).identical(ax)
for axis_name, ax in axes.items()
if ax is not None
):
return self.copy(deep=copy)
# check if we are a multi reindex
if self._needs_reindex_multi(axes, method, level):
return self._reindex_multi(axes, copy, fill_value)
# perform the reindex on the axes
return self._reindex_axes(
axes, level, limit, tolerance, method, fill_value, copy
).__finalize__(self, method="reindex")
def _reindex_axes(
self: NDFrameT, axes, level, limit, tolerance, method, fill_value, copy
) -> NDFrameT:
"""Perform the reindex for all the axes."""
obj = self
for a in self._AXIS_ORDERS:
labels = axes[a]
if labels is None:
continue
ax = self._get_axis(a)
new_index, indexer = ax.reindex(
labels, level=level, limit=limit, tolerance=tolerance, method=method
)
axis = self._get_axis_number(a)
obj = obj._reindex_with_indexers(
{axis: [new_index, indexer]},
fill_value=fill_value,
copy=copy,
allow_dups=False,
)
# If we've made a copy once, no need to make another one
copy = False
return obj
def _needs_reindex_multi(self, axes, method, level) -> bool_t:
"""Check if we do need a multi reindex."""
return (
(common.count_not_none(*axes.values()) == self._AXIS_LEN)
and method is None
and level is None
and not self._is_mixed_type
and not (
self.ndim == 2
and len(self.dtypes) == 1
and is_extension_array_dtype(self.dtypes.iloc[0])
)
)
def _reindex_multi(self, axes, copy, fill_value):
raise AbstractMethodError(self)
def _reindex_with_indexers(
self: NDFrameT,
reindexers,
fill_value=None,
copy: bool_t | None = False,
allow_dups: bool_t = False,
) -> NDFrameT:
"""allow_dups indicates an internal call here"""
# reindex doing multiple operations on different axes if indicated
new_data = self._mgr
for axis in sorted(reindexers.keys()):
index, indexer = reindexers[axis]
baxis = self._get_block_manager_axis(axis)
if index is None:
continue
index = ensure_index(index)
if indexer is not None:
indexer = ensure_platform_int(indexer)
# TODO: speed up on homogeneous DataFrame objects (see _reindex_multi)
new_data = new_data.reindex_indexer(
index,
indexer,
axis=baxis,
fill_value=fill_value,
allow_dups=allow_dups,
copy=copy,
)
# If we've made a copy once, no need to make another one
copy = False
if (
(copy or copy is None)
and new_data is self._mgr
and not using_copy_on_write()
):
new_data = new_data.copy(deep=copy)
elif using_copy_on_write() and new_data is self._mgr:
new_data = new_data.copy(deep=False)
return self._constructor(new_data).__finalize__(self)
def filter(
self: NDFrameT,
items=None,
like: str | None = None,
regex: str | None = None,
axis: Axis | None = None,
) -> NDFrameT:
"""
Subset the dataframe rows or columns according to the specified index labels.
Note that this routine does not filter a dataframe on its
contents. The filter is applied to the labels of the index.
Parameters
----------
items : list-like
Keep labels from axis which are in items.
like : str
Keep labels from axis for which "like in label == True".
regex : str (regular expression)
Keep labels from axis for which re.search(regex, label) == True.
axis : {0 or ‘index’, 1 or ‘columns’, None}, default None
The axis to filter on, expressed either as an index (int)
or axis name (str). By default this is the info axis, 'columns' for
DataFrame. For `Series` this parameter is unused and defaults to `None`.
Returns
-------
same type as input object
See Also
--------
DataFrame.loc : Access a group of rows and columns
by label(s) or a boolean array.
Notes
-----
The ``items``, ``like``, and ``regex`` parameters are
enforced to be mutually exclusive.
``axis`` defaults to the info axis that is used when indexing
with ``[]``.
Examples
--------
>>> df = pd.DataFrame(np.array(([1, 2, 3], [4, 5, 6])),
... index=['mouse', 'rabbit'],
... columns=['one', 'two', 'three'])
>>> df
one two three
mouse 1 2 3
rabbit 4 5 6
>>> # select columns by name
>>> df.filter(items=['one', 'three'])
one three
mouse 1 3
rabbit 4 6
>>> # select columns by regular expression
>>> df.filter(regex='e$', axis=1)
one three
mouse 1 3
rabbit 4 6
>>> # select rows containing 'bbi'
>>> df.filter(like='bbi', axis=0)
one two three
rabbit 4 5 6
"""
nkw = common.count_not_none(items, like, regex)
if nkw > 1:
raise TypeError(
"Keyword arguments `items`, `like`, or `regex` "
"are mutually exclusive"
)
if axis is None:
axis = self._info_axis_name
labels = self._get_axis(axis)
if items is not None:
name = self._get_axis_name(axis)
# error: Keywords must be strings
return self.reindex( # type: ignore[misc]
**{name: [r for r in items if r in labels]} # type: ignore[arg-type]
)
elif like:
def f(x) -> bool_t:
assert like is not None # needed for mypy
return like in ensure_str(x)
values = labels.map(f)
return self.loc(axis=axis)[values]
elif regex:
def f(x) -> bool_t:
return matcher.search(ensure_str(x)) is not None
matcher = re.compile(regex)
values = labels.map(f)
return self.loc(axis=axis)[values]
else:
raise TypeError("Must pass either `items`, `like`, or `regex`")
def head(self: NDFrameT, n: int = 5) -> NDFrameT:
"""
Return the first `n` rows.
This function returns the first `n` rows for the object based
on position. It is useful for quickly testing if your object
has the right type of data in it.
For negative values of `n`, this function returns all rows except
the last `|n|` rows, equivalent to ``df[:n]``.
If n is larger than the number of rows, this function returns all rows.
Parameters
----------
n : int, default 5
Number of rows to select.
Returns
-------
same type as caller
The first `n` rows of the caller object.
See Also
--------
DataFrame.tail: Returns the last `n` rows.
Examples
--------
>>> df = pd.DataFrame({'animal': ['alligator', 'bee', 'falcon', 'lion',
... 'monkey', 'parrot', 'shark', 'whale', 'zebra']})
>>> df
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the first 5 lines
>>> df.head()
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
Viewing the first `n` lines (three in this case)
>>> df.head(3)
animal
0 alligator
1 bee
2 falcon
For negative values of `n`
>>> df.head(-3)
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
"""
return self.iloc[:n]
def tail(self: NDFrameT, n: int = 5) -> NDFrameT:
"""
Return the last `n` rows.
This function returns last `n` rows from the object based on
position. It is useful for quickly verifying data, for example,
after sorting or appending rows.
For negative values of `n`, this function returns all rows except
the first `|n|` rows, equivalent to ``df[|n|:]``.
If n is larger than the number of rows, this function returns all rows.
Parameters
----------
n : int, default 5
Number of rows to select.
Returns
-------
type of caller
The last `n` rows of the caller object.
See Also
--------
DataFrame.head : The first `n` rows of the caller object.
Examples
--------
>>> df = pd.DataFrame({'animal': ['alligator', 'bee', 'falcon', 'lion',
... 'monkey', 'parrot', 'shark', 'whale', 'zebra']})
>>> df
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the last 5 lines
>>> df.tail()
animal
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the last `n` lines (three in this case)
>>> df.tail(3)
animal
6 shark
7 whale
8 zebra
For negative values of `n`
>>> df.tail(-3)
animal
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
"""
if n == 0:
return self.iloc[0:0]
return self.iloc[-n:]
def sample(
self: NDFrameT,
n: int | None = None,
frac: float | None = None,
replace: bool_t = False,
weights=None,
random_state: RandomState | None = None,
axis: Axis | None = None,
ignore_index: bool_t = False,
) -> NDFrameT:
"""
Return a random sample of items from an axis of object.
You can use `random_state` for reproducibility.
Parameters
----------
n : int, optional
Number of items from axis to return. Cannot be used with `frac`.
Default = 1 if `frac` = None.
frac : float, optional
Fraction of axis items to return. Cannot be used with `n`.
replace : bool, default False
Allow or disallow sampling of the same row more than once.
weights : str or ndarray-like, optional
Default 'None' results in equal probability weighting.
If passed a Series, will align with target object on index. Index
values in weights not found in sampled object will be ignored and
index values in sampled object not in weights will be assigned
weights of zero.
If called on a DataFrame, will accept the name of a column
when axis = 0.
Unless weights are a Series, weights must be same length as axis
being sampled.
If weights do not sum to 1, they will be normalized to sum to 1.
Missing values in the weights column will be treated as zero.
Infinite values not allowed.
random_state : int, array-like, BitGenerator, np.random.RandomState, np.random.Generator, optional
If int, array-like, or BitGenerator, seed for random number generator.
If np.random.RandomState or np.random.Generator, use as given.
.. versionchanged:: 1.1.0
array-like and BitGenerator object now passed to np.random.RandomState()
as seed
.. versionchanged:: 1.4.0
np.random.Generator objects now accepted
axis : {0 or ‘index’, 1 or ‘columns’, None}, default None
Axis to sample. Accepts axis number or name. Default is stat axis
for given data type. For `Series` this parameter is unused and defaults to `None`.
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.3.0
Returns
-------
Series or DataFrame
A new object of same type as caller containing `n` items randomly
sampled from the caller object.
See Also
--------
DataFrameGroupBy.sample: Generates random samples from each group of a
DataFrame object.
SeriesGroupBy.sample: Generates random samples from each group of a
Series object.
numpy.random.choice: Generates a random sample from a given 1-D numpy
array.
Notes
-----
If `frac` > 1, `replacement` should be set to `True`.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [2, 4, 8, 0],
... 'num_wings': [2, 0, 0, 0],
... 'num_specimen_seen': [10, 2, 1, 8]},
... index=['falcon', 'dog', 'spider', 'fish'])
>>> df
num_legs num_wings num_specimen_seen
falcon 2 2 10
dog 4 0 2
spider 8 0 1
fish 0 0 8
Extract 3 random elements from the ``Series`` ``df['num_legs']``:
Note that we use `random_state` to ensure the reproducibility of
the examples.
>>> df['num_legs'].sample(n=3, random_state=1)
fish 0
spider 8
falcon 2
Name: num_legs, dtype: int64
A random 50% sample of the ``DataFrame`` with replacement:
>>> df.sample(frac=0.5, replace=True, random_state=1)
num_legs num_wings num_specimen_seen
dog 4 0 2
fish 0 0 8
An upsample sample of the ``DataFrame`` with replacement:
Note that `replace` parameter has to be `True` for `frac` parameter > 1.
>>> df.sample(frac=2, replace=True, random_state=1)
num_legs num_wings num_specimen_seen
dog 4 0 2
fish 0 0 8
falcon 2 2 10
falcon 2 2 10
fish 0 0 8
dog 4 0 2
fish 0 0 8
dog 4 0 2
Using a DataFrame column as weights. Rows with larger value in the
`num_specimen_seen` column are more likely to be sampled.
>>> df.sample(n=2, weights='num_specimen_seen', random_state=1)
num_legs num_wings num_specimen_seen
falcon 2 2 10
fish 0 0 8
""" # noqa:E501
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
obj_len = self.shape[axis]
# Process random_state argument
rs = common.random_state(random_state)
size = sample.process_sampling_size(n, frac, replace)
if size is None:
assert frac is not None
size = round(frac * obj_len)
if weights is not None:
weights = sample.preprocess_weights(self, weights, axis)
sampled_indices = sample.sample(obj_len, size, replace, weights, rs)
result = self.take(sampled_indices, axis=axis)
if ignore_index:
result.index = default_index(len(result))
return result
def pipe(
self,
func: Callable[..., T] | tuple[Callable[..., T], str],
*args,
**kwargs,
) -> T:
r"""
Apply chainable functions that expect Series or DataFrames.
Parameters
----------
func : function
Function to apply to the {klass}.
``args``, and ``kwargs`` are passed into ``func``.
Alternatively a ``(callable, data_keyword)`` tuple where
``data_keyword`` is a string indicating the keyword of
``callable`` that expects the {klass}.
args : iterable, optional
Positional arguments passed into ``func``.
kwargs : mapping, optional
A dictionary of keyword arguments passed into ``func``.
Returns
-------
the return type of ``func``.
See Also
--------
DataFrame.apply : Apply a function along input axis of DataFrame.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Series.map : Apply a mapping correspondence on a
:class:`~pandas.Series`.
Notes
-----
Use ``.pipe`` when chaining together functions that expect
Series, DataFrames or GroupBy objects. Instead of writing
>>> func(g(h(df), arg1=a), arg2=b, arg3=c) # doctest: +SKIP
You can write
>>> (df.pipe(h)
... .pipe(g, arg1=a)
... .pipe(func, arg2=b, arg3=c)
... ) # doctest: +SKIP
If you have a function that takes the data as (say) the second
argument, pass a tuple indicating which keyword expects the
data. For example, suppose ``func`` takes its data as ``arg2``:
>>> (df.pipe(h)
... .pipe(g, arg1=a)
... .pipe((func, 'arg2'), arg1=a, arg3=c)
... ) # doctest: +SKIP
"""
if using_copy_on_write():
return common.pipe(self.copy(deep=None), func, *args, **kwargs)
return common.pipe(self, func, *args, **kwargs)
# ----------------------------------------------------------------------
# Attribute access
def __finalize__(
self: NDFrameT, other, method: str | None = None, **kwargs
) -> NDFrameT:
"""
Propagate metadata from other to self.
Parameters
----------
other : the object from which to get the attributes that we are going
to propagate
method : str, optional
A passed method name providing context on where ``__finalize__``
was called.
.. warning::
The value passed as `method` are not currently considered
stable across pandas releases.
"""
if isinstance(other, NDFrame):
for name in other.attrs:
self.attrs[name] = other.attrs[name]
self.flags.allows_duplicate_labels = other.flags.allows_duplicate_labels
# For subclasses using _metadata.
for name in set(self._metadata) & set(other._metadata):
assert isinstance(name, str)
object.__setattr__(self, name, getattr(other, name, None))
if method == "concat":
attrs = other.objs[0].attrs
check_attrs = all(objs.attrs == attrs for objs in other.objs[1:])
if check_attrs:
for name in attrs:
self.attrs[name] = attrs[name]
allows_duplicate_labels = all(
x.flags.allows_duplicate_labels for x in other.objs
)
self.flags.allows_duplicate_labels = allows_duplicate_labels
return self
def __getattr__(self, name: str):
"""
After regular attribute access, try looking up the name
This allows simpler access to columns for interactive use.
"""
# Note: obj.x will always call obj.__getattribute__('x') prior to
# calling obj.__getattr__('x').
if (
name not in self._internal_names_set
and name not in self._metadata
and name not in self._accessors
and self._info_axis._can_hold_identifiers_and_holds_name(name)
):
return self[name]
return object.__getattribute__(self, name)
def __setattr__(self, name: str, value) -> None:
"""
After regular attribute access, try setting the name
This allows simpler access to columns for interactive use.
"""
# first try regular attribute access via __getattribute__, so that
# e.g. ``obj.x`` and ``obj.x = 4`` will always reference/modify
# the same attribute.
try:
object.__getattribute__(self, name)
return object.__setattr__(self, name, value)
except AttributeError:
pass
# if this fails, go on to more involved attribute setting
# (note that this matches __getattr__, above).
if name in self._internal_names_set:
object.__setattr__(self, name, value)
elif name in self._metadata:
object.__setattr__(self, name, value)
else:
try:
existing = getattr(self, name)
if isinstance(existing, Index):
object.__setattr__(self, name, value)
elif name in self._info_axis:
self[name] = value
else:
object.__setattr__(self, name, value)
except (AttributeError, TypeError):
if isinstance(self, ABCDataFrame) and (is_list_like(value)):
warnings.warn(
"Pandas doesn't allow columns to be "
"created via a new attribute name - see "
"https://pandas.pydata.org/pandas-docs/"
"stable/indexing.html#attribute-access",
stacklevel=find_stack_level(),
)
object.__setattr__(self, name, value)
def _dir_additions(self) -> set[str]:
"""
add the string-like attributes from the info_axis.
If info_axis is a MultiIndex, its first level values are used.
"""
additions = super()._dir_additions()
if self._info_axis._can_hold_strings:
additions.update(self._info_axis._dir_additions_for_owner)
return additions
# ----------------------------------------------------------------------
# Consolidation of internals
def _protect_consolidate(self, f):
"""
Consolidate _mgr -- if the blocks have changed, then clear the
cache
"""
if isinstance(self._mgr, (ArrayManager, SingleArrayManager)):
return f()
blocks_before = len(self._mgr.blocks)
result = f()
if len(self._mgr.blocks) != blocks_before:
self._clear_item_cache()
return result
def _consolidate_inplace(self) -> None:
"""Consolidate data in place and return None"""
def f() -> None:
self._mgr = self._mgr.consolidate()
self._protect_consolidate(f)
def _consolidate(self):
"""
Compute NDFrame with "consolidated" internals (data of each dtype
grouped together in a single ndarray).
Returns
-------
consolidated : same type as caller
"""
f = lambda: self._mgr.consolidate()
cons_data = self._protect_consolidate(f)
return self._constructor(cons_data).__finalize__(self)
def _is_mixed_type(self) -> bool_t:
if self._mgr.is_single_block:
return False
if self._mgr.any_extension_types:
# Even if they have the same dtype, we can't consolidate them,
# so we pretend this is "mixed'"
return True
return self.dtypes.nunique() > 1
def _check_inplace_setting(self, value) -> bool_t:
"""check whether we allow in-place setting with this type of value"""
if self._is_mixed_type and not self._mgr.is_numeric_mixed_type:
# allow an actual np.nan through
if is_float(value) and np.isnan(value) or value is lib.no_default:
return True
raise TypeError(
"Cannot do inplace boolean setting on "
"mixed-types with a non np.nan value"
)
return True
def _get_numeric_data(self: NDFrameT) -> NDFrameT:
return self._constructor(self._mgr.get_numeric_data()).__finalize__(self)
def _get_bool_data(self):
return self._constructor(self._mgr.get_bool_data()).__finalize__(self)
# ----------------------------------------------------------------------
# Internal Interface Methods
def values(self):
raise AbstractMethodError(self)
def _values(self) -> ArrayLike:
"""internal implementation"""
raise AbstractMethodError(self)
def dtypes(self):
"""
Return the dtypes in the DataFrame.
This returns a Series with the data type of each column.
The result's index is the original DataFrame's columns. Columns
with mixed types are stored with the ``object`` dtype. See
:ref:`the User Guide <basics.dtypes>` for more.
Returns
-------
pandas.Series
The data type of each column.
Examples
--------
>>> df = pd.DataFrame({'float': [1.0],
... 'int': [1],
... 'datetime': [pd.Timestamp('20180310')],
... 'string': ['foo']})
>>> df.dtypes
float float64
int int64
datetime datetime64[ns]
string object
dtype: object
"""
data = self._mgr.get_dtypes()
return self._constructor_sliced(data, index=self._info_axis, dtype=np.object_)
def astype(
self: NDFrameT, dtype, copy: bool_t | None = None, errors: IgnoreRaise = "raise"
) -> NDFrameT:
"""
Cast a pandas object to a specified dtype ``dtype``.
Parameters
----------
dtype : str, data type, Series or Mapping of column name -> data type
Use a str, numpy.dtype, pandas.ExtensionDtype or Python type to
cast entire pandas object to the same type. Alternatively, use a
mapping, e.g. {col: dtype, ...}, where col is a column label and dtype is
a numpy.dtype or Python type to cast one or more of the DataFrame's
columns to column-specific types.
copy : bool, default True
Return a copy when ``copy=True`` (be very careful setting
``copy=False`` as changes to values then may propagate to other
pandas objects).
errors : {'raise', 'ignore'}, default 'raise'
Control raising of exceptions on invalid data for provided dtype.
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object.
Returns
-------
same type as caller
See Also
--------
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to a numeric type.
numpy.ndarray.astype : Cast a numpy array to a specified type.
Notes
-----
.. versionchanged:: 2.0.0
Using ``astype`` to convert from timezone-naive dtype to
timezone-aware dtype will raise an exception.
Use :meth:`Series.dt.tz_localize` instead.
Examples
--------
Create a DataFrame:
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df.dtypes
col1 int64
col2 int64
dtype: object
Cast all columns to int32:
>>> df.astype('int32').dtypes
col1 int32
col2 int32
dtype: object
Cast col1 to int32 using a dictionary:
>>> df.astype({'col1': 'int32'}).dtypes
col1 int32
col2 int64
dtype: object
Create a series:
>>> ser = pd.Series([1, 2], dtype='int32')
>>> ser
0 1
1 2
dtype: int32
>>> ser.astype('int64')
0 1
1 2
dtype: int64
Convert to categorical type:
>>> ser.astype('category')
0 1
1 2
dtype: category
Categories (2, int32): [1, 2]
Convert to ordered categorical type with custom ordering:
>>> from pandas.api.types import CategoricalDtype
>>> cat_dtype = CategoricalDtype(
... categories=[2, 1], ordered=True)
>>> ser.astype(cat_dtype)
0 1
1 2
dtype: category
Categories (2, int64): [2 < 1]
Create a series of dates:
>>> ser_date = pd.Series(pd.date_range('20200101', periods=3))
>>> ser_date
0 2020-01-01
1 2020-01-02
2 2020-01-03
dtype: datetime64[ns]
"""
if copy and using_copy_on_write():
copy = False
if is_dict_like(dtype):
if self.ndim == 1: # i.e. Series
if len(dtype) > 1 or self.name not in dtype:
raise KeyError(
"Only the Series name can be used for "
"the key in Series dtype mappings."
)
new_type = dtype[self.name]
return self.astype(new_type, copy, errors)
# GH#44417 cast to Series so we can use .iat below, which will be
# robust in case we
from pandas import Series
dtype_ser = Series(dtype, dtype=object)
for col_name in dtype_ser.index:
if col_name not in self:
raise KeyError(
"Only a column name can be used for the "
"key in a dtype mappings argument. "
f"'{col_name}' not found in columns."
)
dtype_ser = dtype_ser.reindex(self.columns, fill_value=None, copy=False)
results = []
for i, (col_name, col) in enumerate(self.items()):
cdt = dtype_ser.iat[i]
if isna(cdt):
res_col = col.copy(deep=copy)
else:
try:
res_col = col.astype(dtype=cdt, copy=copy, errors=errors)
except ValueError as ex:
ex.args = (
f"{ex}: Error while type casting for column '{col_name}'",
)
raise
results.append(res_col)
elif is_extension_array_dtype(dtype) and self.ndim > 1:
# GH 18099/22869: columnwise conversion to extension dtype
# GH 24704: use iloc to handle duplicate column names
# TODO(EA2D): special case not needed with 2D EAs
results = [
self.iloc[:, i].astype(dtype, copy=copy)
for i in range(len(self.columns))
]
else:
# else, only a single dtype is given
new_data = self._mgr.astype(dtype=dtype, copy=copy, errors=errors)
return self._constructor(new_data).__finalize__(self, method="astype")
# GH 33113: handle empty frame or series
if not results:
return self.copy(deep=None)
# GH 19920: retain column metadata after concat
result = concat(results, axis=1, copy=False)
# GH#40810 retain subclass
# error: Incompatible types in assignment
# (expression has type "NDFrameT", variable has type "DataFrame")
result = self._constructor(result) # type: ignore[assignment]
result.columns = self.columns
result = result.__finalize__(self, method="astype")
# https://github.com/python/mypy/issues/8354
return cast(NDFrameT, result)
def copy(self: NDFrameT, deep: bool_t | None = True) -> NDFrameT:
"""
Make a copy of this object's indices and data.
When ``deep=True`` (default), a new object will be created with a
copy of the calling object's data and indices. Modifications to
the data or indices of the copy will not be reflected in the
original object (see notes below).
When ``deep=False``, a new object will be created without copying
the calling object's data or index (only references to the data
and index are copied). Any changes to the data of the original
will be reflected in the shallow copy (and vice versa).
Parameters
----------
deep : bool, default True
Make a deep copy, including a copy of the data and the indices.
With ``deep=False`` neither the indices nor the data are copied.
Returns
-------
Series or DataFrame
Object type matches caller.
Notes
-----
When ``deep=True``, data is copied but actual Python objects
will not be copied recursively, only the reference to the object.
This is in contrast to `copy.deepcopy` in the Standard Library,
which recursively copies object data (see examples below).
While ``Index`` objects are copied when ``deep=True``, the underlying
numpy array is not copied for performance reasons. Since ``Index`` is
immutable, the underlying data can be safely shared and a copy
is not needed.
Since pandas is not thread safe, see the
:ref:`gotchas <gotchas.thread-safety>` when copying in a threading
environment.
Examples
--------
>>> s = pd.Series([1, 2], index=["a", "b"])
>>> s
a 1
b 2
dtype: int64
>>> s_copy = s.copy()
>>> s_copy
a 1
b 2
dtype: int64
**Shallow copy versus default (deep) copy:**
>>> s = pd.Series([1, 2], index=["a", "b"])
>>> deep = s.copy()
>>> shallow = s.copy(deep=False)
Shallow copy shares data and index with original.
>>> s is shallow
False
>>> s.values is shallow.values and s.index is shallow.index
True
Deep copy has own copy of data and index.
>>> s is deep
False
>>> s.values is deep.values or s.index is deep.index
False
Updates to the data shared by shallow copy and original is reflected
in both; deep copy remains unchanged.
>>> s[0] = 3
>>> shallow[1] = 4
>>> s
a 3
b 4
dtype: int64
>>> shallow
a 3
b 4
dtype: int64
>>> deep
a 1
b 2
dtype: int64
Note that when copying an object containing Python objects, a deep copy
will copy the data, but will not do so recursively. Updating a nested
data object will be reflected in the deep copy.
>>> s = pd.Series([[1, 2], [3, 4]])
>>> deep = s.copy()
>>> s[0][0] = 10
>>> s
0 [10, 2]
1 [3, 4]
dtype: object
>>> deep
0 [10, 2]
1 [3, 4]
dtype: object
"""
data = self._mgr.copy(deep=deep)
self._clear_item_cache()
return self._constructor(data).__finalize__(self, method="copy")
def __copy__(self: NDFrameT, deep: bool_t = True) -> NDFrameT:
return self.copy(deep=deep)
def __deepcopy__(self: NDFrameT, memo=None) -> NDFrameT:
"""
Parameters
----------
memo, default None
Standard signature. Unused
"""
return self.copy(deep=True)
def infer_objects(self: NDFrameT, copy: bool_t | None = None) -> NDFrameT:
"""
Attempt to infer better dtypes for object columns.
Attempts soft conversion of object-dtyped
columns, leaving non-object and unconvertible
columns unchanged. The inference rules are the
same as during normal Series/DataFrame construction.
Parameters
----------
copy : bool, default True
Whether to make a copy for non-object or non-inferrable columns
or Series.
Returns
-------
same type as input object
See Also
--------
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to numeric type.
convert_dtypes : Convert argument to best possible dtype.
Examples
--------
>>> df = pd.DataFrame({"A": ["a", 1, 2, 3]})
>>> df = df.iloc[1:]
>>> df
A
1 1
2 2
3 3
>>> df.dtypes
A object
dtype: object
>>> df.infer_objects().dtypes
A int64
dtype: object
"""
new_mgr = self._mgr.convert(copy=copy)
return self._constructor(new_mgr).__finalize__(self, method="infer_objects")
def convert_dtypes(
self: NDFrameT,
infer_objects: bool_t = True,
convert_string: bool_t = True,
convert_integer: bool_t = True,
convert_boolean: bool_t = True,
convert_floating: bool_t = True,
dtype_backend: DtypeBackend = "numpy_nullable",
) -> NDFrameT:
"""
Convert columns to the best possible dtypes using dtypes supporting ``pd.NA``.
Parameters
----------
infer_objects : bool, default True
Whether object dtypes should be converted to the best possible types.
convert_string : bool, default True
Whether object dtypes should be converted to ``StringDtype()``.
convert_integer : bool, default True
Whether, if possible, conversion can be done to integer extension types.
convert_boolean : bool, defaults True
Whether object dtypes should be converted to ``BooleanDtypes()``.
convert_floating : bool, defaults True
Whether, if possible, conversion can be done to floating extension types.
If `convert_integer` is also True, preference will be give to integer
dtypes if the floats can be faithfully casted to integers.
.. versionadded:: 1.2.0
dtype_backend : {"numpy_nullable", "pyarrow"}, default "numpy_nullable"
Which dtype_backend to use, e.g. whether a DataFrame should use nullable
dtypes for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
Returns
-------
Series or DataFrame
Copy of input object with new dtype.
See Also
--------
infer_objects : Infer dtypes of objects.
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to a numeric type.
Notes
-----
By default, ``convert_dtypes`` will attempt to convert a Series (or each
Series in a DataFrame) to dtypes that support ``pd.NA``. By using the options
``convert_string``, ``convert_integer``, ``convert_boolean`` and
``convert_floating``, it is possible to turn off individual conversions
to ``StringDtype``, the integer extension types, ``BooleanDtype``
or floating extension types, respectively.
For object-dtyped columns, if ``infer_objects`` is ``True``, use the inference
rules as during normal Series/DataFrame construction. Then, if possible,
convert to ``StringDtype``, ``BooleanDtype`` or an appropriate integer
or floating extension type, otherwise leave as ``object``.
If the dtype is integer, convert to an appropriate integer extension type.
If the dtype is numeric, and consists of all integers, convert to an
appropriate integer extension type. Otherwise, convert to an
appropriate floating extension type.
.. versionchanged:: 1.2
Starting with pandas 1.2, this method also converts float columns
to the nullable floating extension type.
In the future, as new dtypes are added that support ``pd.NA``, the results
of this method will change to support those new dtypes.
.. versionadded:: 2.0
The nullable dtype implementation can be configured by calling
``pd.set_option("mode.dtype_backend", "pandas")`` to use
numpy-backed nullable dtypes or
``pd.set_option("mode.dtype_backend", "pyarrow")`` to use
pyarrow-backed nullable dtypes (using ``pd.ArrowDtype``).
Examples
--------
>>> df = pd.DataFrame(
... {
... "a": pd.Series([1, 2, 3], dtype=np.dtype("int32")),
... "b": pd.Series(["x", "y", "z"], dtype=np.dtype("O")),
... "c": pd.Series([True, False, np.nan], dtype=np.dtype("O")),
... "d": pd.Series(["h", "i", np.nan], dtype=np.dtype("O")),
... "e": pd.Series([10, np.nan, 20], dtype=np.dtype("float")),
... "f": pd.Series([np.nan, 100.5, 200], dtype=np.dtype("float")),
... }
... )
Start with a DataFrame with default dtypes.
>>> df
a b c d e f
0 1 x True h 10.0 NaN
1 2 y False i NaN 100.5
2 3 z NaN NaN 20.0 200.0
>>> df.dtypes
a int32
b object
c object
d object
e float64
f float64
dtype: object
Convert the DataFrame to use best possible dtypes.
>>> dfn = df.convert_dtypes()
>>> dfn
a b c d e f
0 1 x True h 10 <NA>
1 2 y False i <NA> 100.5
2 3 z <NA> <NA> 20 200.0
>>> dfn.dtypes
a Int32
b string[python]
c boolean
d string[python]
e Int64
f Float64
dtype: object
Start with a Series of strings and missing data represented by ``np.nan``.
>>> s = pd.Series(["a", "b", np.nan])
>>> s
0 a
1 b
2 NaN
dtype: object
Obtain a Series with dtype ``StringDtype``.
>>> s.convert_dtypes()
0 a
1 b
2 <NA>
dtype: string
"""
check_dtype_backend(dtype_backend)
if self.ndim == 1:
return self._convert_dtypes(
infer_objects,
convert_string,
convert_integer,
convert_boolean,
convert_floating,
dtype_backend=dtype_backend,
)
else:
results = [
col._convert_dtypes(
infer_objects,
convert_string,
convert_integer,
convert_boolean,
convert_floating,
dtype_backend=dtype_backend,
)
for col_name, col in self.items()
]
if len(results) > 0:
result = concat(results, axis=1, copy=False, keys=self.columns)
cons = cast(Type["DataFrame"], self._constructor)
result = cons(result)
result = result.__finalize__(self, method="convert_dtypes")
# https://github.com/python/mypy/issues/8354
return cast(NDFrameT, result)
else:
return self.copy(deep=None)
# ----------------------------------------------------------------------
# Filling NA's
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: Literal[False] = ...,
limit: int | None = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def fillna(
self,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: Literal[True],
limit: int | None = ...,
downcast: dict | None = ...,
) -> None:
...
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: bool_t = ...,
limit: int | None = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = None,
*,
method: FillnaOptions | None = None,
axis: Axis | None = None,
inplace: bool_t = False,
limit: int | None = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Fill NA/NaN values using the specified method.
Parameters
----------
value : scalar, dict, Series, or DataFrame
Value to use to fill holes (e.g. 0), alternately a
dict/Series/DataFrame of values specifying which value to use for
each index (for a Series) or column (for a DataFrame). Values not
in the dict/Series/DataFrame will not be filled. This value cannot
be a list.
method : {{'backfill', 'bfill', 'ffill', None}}, default None
Method to use for filling holes in reindexed Series:
* ffill: propagate last valid observation forward to next valid.
* backfill / bfill: use next valid observation to fill gap.
axis : {axes_single_arg}
Axis along which to fill missing values. For `Series`
this parameter is unused and defaults to 0.
inplace : bool, default False
If True, fill in-place. Note: this will modify any
other views on this object (e.g., a no-copy slice for a column in a
DataFrame).
limit : int, default None
If method is specified, this is the maximum number of consecutive
NaN values to forward/backward fill. In other words, if there is
a gap with more than this number of consecutive NaNs, it will only
be partially filled. If method is not specified, this is the
maximum number of entries along the entire axis where NaNs will be
filled. Must be greater than 0 if not None.
downcast : dict, default is None
A dict of item->dtype of what to downcast if possible,
or the string 'infer' which will try to downcast to an appropriate
equal type (e.g. float64 to int64 if possible).
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
See Also
--------
interpolate : Fill NaN values using interpolation.
reindex : Conform object to new index.
asfreq : Convert TimeSeries to specified frequency.
Examples
--------
>>> df = pd.DataFrame([[np.nan, 2, np.nan, 0],
... [3, 4, np.nan, 1],
... [np.nan, np.nan, np.nan, np.nan],
... [np.nan, 3, np.nan, 4]],
... columns=list("ABCD"))
>>> df
A B C D
0 NaN 2.0 NaN 0.0
1 3.0 4.0 NaN 1.0
2 NaN NaN NaN NaN
3 NaN 3.0 NaN 4.0
Replace all NaN elements with 0s.
>>> df.fillna(0)
A B C D
0 0.0 2.0 0.0 0.0
1 3.0 4.0 0.0 1.0
2 0.0 0.0 0.0 0.0
3 0.0 3.0 0.0 4.0
We can also propagate non-null values forward or backward.
>>> df.fillna(method="ffill")
A B C D
0 NaN 2.0 NaN 0.0
1 3.0 4.0 NaN 1.0
2 3.0 4.0 NaN 1.0
3 3.0 3.0 NaN 4.0
Replace all NaN elements in column 'A', 'B', 'C', and 'D', with 0, 1,
2, and 3 respectively.
>>> values = {{"A": 0, "B": 1, "C": 2, "D": 3}}
>>> df.fillna(value=values)
A B C D
0 0.0 2.0 2.0 0.0
1 3.0 4.0 2.0 1.0
2 0.0 1.0 2.0 3.0
3 0.0 3.0 2.0 4.0
Only replace the first NaN element.
>>> df.fillna(value=values, limit=1)
A B C D
0 0.0 2.0 2.0 0.0
1 3.0 4.0 NaN 1.0
2 NaN 1.0 NaN 3.0
3 NaN 3.0 NaN 4.0
When filling using a DataFrame, replacement happens along
the same column names and same indices
>>> df2 = pd.DataFrame(np.zeros((4, 4)), columns=list("ABCE"))
>>> df.fillna(df2)
A B C D
0 0.0 2.0 0.0 0.0
1 3.0 4.0 0.0 1.0
2 0.0 0.0 0.0 NaN
3 0.0 3.0 0.0 4.0
Note that column D is not affected since it is not present in df2.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
value, method = validate_fillna_kwargs(value, method)
# set the default here, so functions examining the signaure
# can detect if something was set (e.g. in groupby) (GH9221)
if axis is None:
axis = 0
axis = self._get_axis_number(axis)
if value is None:
if not self._mgr.is_single_block and axis == 1:
if inplace:
raise NotImplementedError()
result = self.T.fillna(method=method, limit=limit).T
return result
new_data = self._mgr.interpolate(
method=method,
axis=axis,
limit=limit,
inplace=inplace,
downcast=downcast,
)
else:
if self.ndim == 1:
if isinstance(value, (dict, ABCSeries)):
if not len(value):
# test_fillna_nonscalar
if inplace:
return None
return self.copy(deep=None)
from pandas import Series
value = Series(value)
value = value.reindex(self.index, copy=False)
value = value._values
elif not is_list_like(value):
pass
else:
raise TypeError(
'"value" parameter must be a scalar, dict '
"or Series, but you passed a "
f'"{type(value).__name__}"'
)
new_data = self._mgr.fillna(
value=value, limit=limit, inplace=inplace, downcast=downcast
)
elif isinstance(value, (dict, ABCSeries)):
if axis == 1:
raise NotImplementedError(
"Currently only can fill "
"with dict/Series column "
"by column"
)
if using_copy_on_write():
result = self.copy(deep=None)
else:
result = self if inplace else self.copy()
is_dict = isinstance(downcast, dict)
for k, v in value.items():
if k not in result:
continue
# error: Item "None" of "Optional[Dict[Any, Any]]" has no
# attribute "get"
downcast_k = (
downcast
if not is_dict
else downcast.get(k) # type: ignore[union-attr]
)
res_k = result[k].fillna(v, limit=limit, downcast=downcast_k)
if not inplace:
result[k] = res_k
else:
# We can write into our existing column(s) iff dtype
# was preserved.
if isinstance(res_k, ABCSeries):
# i.e. 'k' only shows up once in self.columns
if res_k.dtype == result[k].dtype:
result.loc[:, k] = res_k
else:
# Different dtype -> no way to do inplace.
result[k] = res_k
else:
# see test_fillna_dict_inplace_nonunique_columns
locs = result.columns.get_loc(k)
if isinstance(locs, slice):
locs = np.arange(self.shape[1])[locs]
elif (
isinstance(locs, np.ndarray) and locs.dtype.kind == "b"
):
locs = locs.nonzero()[0]
elif not (
isinstance(locs, np.ndarray) and locs.dtype.kind == "i"
):
# Should never be reached, but let's cover our bases
raise NotImplementedError(
"Unexpected get_loc result, please report a bug at "
"https://github.com/pandas-dev/pandas"
)
for i, loc in enumerate(locs):
res_loc = res_k.iloc[:, i]
target = self.iloc[:, loc]
if res_loc.dtype == target.dtype:
result.iloc[:, loc] = res_loc
else:
result.isetitem(loc, res_loc)
if inplace:
return self._update_inplace(result)
else:
return result
elif not is_list_like(value):
if axis == 1:
result = self.T.fillna(value=value, limit=limit).T
new_data = result
else:
new_data = self._mgr.fillna(
value=value, limit=limit, inplace=inplace, downcast=downcast
)
elif isinstance(value, ABCDataFrame) and self.ndim == 2:
new_data = self.where(self.notna(), value)._mgr
else:
raise ValueError(f"invalid fill value with a {type(value)}")
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="fillna")
def ffill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: Literal[False] = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def ffill(
self,
*,
axis: None | Axis = ...,
inplace: Literal[True],
limit: None | int = ...,
downcast: dict | None = ...,
) -> None:
...
def ffill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: bool_t = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def ffill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='ffill'``.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
return self.fillna(
method="ffill", axis=axis, inplace=inplace, limit=limit, downcast=downcast
)
def pad(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='ffill'``.
.. deprecated:: 2.0
{klass}.pad is deprecated. Use {klass}.ffill instead.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
warnings.warn(
"DataFrame.pad/Series.pad is deprecated. Use "
"DataFrame.ffill/Series.ffill instead",
FutureWarning,
stacklevel=find_stack_level(),
)
return self.ffill(axis=axis, inplace=inplace, limit=limit, downcast=downcast)
def bfill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: Literal[False] = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def bfill(
self,
*,
axis: None | Axis = ...,
inplace: Literal[True],
limit: None | int = ...,
downcast: dict | None = ...,
) -> None:
...
def bfill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: bool_t = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def bfill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='bfill'``.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
return self.fillna(
method="bfill", axis=axis, inplace=inplace, limit=limit, downcast=downcast
)
def backfill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='bfill'``.
.. deprecated:: 2.0
{klass}.backfill is deprecated. Use {klass}.bfill instead.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
warnings.warn(
"DataFrame.backfill/Series.backfill is deprecated. Use "
"DataFrame.bfill/Series.bfill instead",
FutureWarning,
stacklevel=find_stack_level(),
)
return self.bfill(axis=axis, inplace=inplace, limit=limit, downcast=downcast)
def replace(
self: NDFrameT,
to_replace=...,
value=...,
*,
inplace: Literal[False] = ...,
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> NDFrameT:
...
def replace(
self,
to_replace=...,
value=...,
*,
inplace: Literal[True],
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> None:
...
def replace(
self: NDFrameT,
to_replace=...,
value=...,
*,
inplace: bool_t = ...,
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> NDFrameT | None:
...
_shared_docs["replace"],
klass=_shared_doc_kwargs["klass"],
inplace=_shared_doc_kwargs["inplace"],
replace_iloc=_shared_doc_kwargs["replace_iloc"],
)
def replace(
self: NDFrameT,
to_replace=None,
value=lib.no_default,
*,
inplace: bool_t = False,
limit: int | None = None,
regex: bool_t = False,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = lib.no_default,
) -> NDFrameT | None:
if not (
is_scalar(to_replace)
or is_re_compilable(to_replace)
or is_list_like(to_replace)
):
raise TypeError(
"Expecting 'to_replace' to be either a scalar, array-like, "
"dict or None, got invalid type "
f"{repr(type(to_replace).__name__)}"
)
inplace = validate_bool_kwarg(inplace, "inplace")
if not is_bool(regex) and to_replace is not None:
raise ValueError("'to_replace' must be 'None' if 'regex' is not a bool")
if value is lib.no_default or method is not lib.no_default:
# GH#36984 if the user explicitly passes value=None we want to
# respect that. We have the corner case where the user explicitly
# passes value=None *and* a method, which we interpret as meaning
# they want the (documented) default behavior.
if method is lib.no_default:
# TODO: get this to show up as the default in the docs?
method = "pad"
# passing a single value that is scalar like
# when value is None (GH5319), for compat
if not is_dict_like(to_replace) and not is_dict_like(regex):
to_replace = [to_replace]
if isinstance(to_replace, (tuple, list)):
# TODO: Consider copy-on-write for non-replaced columns's here
if isinstance(self, ABCDataFrame):
from pandas import Series
result = self.apply(
Series._replace_single,
args=(to_replace, method, inplace, limit),
)
if inplace:
return None
return result
return self._replace_single(to_replace, method, inplace, limit)
if not is_dict_like(to_replace):
if not is_dict_like(regex):
raise TypeError(
'If "to_replace" and "value" are both None '
'and "to_replace" is not a list, then '
"regex must be a mapping"
)
to_replace = regex
regex = True
items = list(to_replace.items())
if items:
keys, values = zip(*items)
else:
keys, values = ([], [])
are_mappings = [is_dict_like(v) for v in values]
if any(are_mappings):
if not all(are_mappings):
raise TypeError(
"If a nested mapping is passed, all values "
"of the top level mapping must be mappings"
)
# passed a nested dict/Series
to_rep_dict = {}
value_dict = {}
for k, v in items:
keys, values = list(zip(*v.items())) or ([], [])
to_rep_dict[k] = list(keys)
value_dict[k] = list(values)
to_replace, value = to_rep_dict, value_dict
else:
to_replace, value = keys, values
return self.replace(
to_replace, value, inplace=inplace, limit=limit, regex=regex
)
else:
# need a non-zero len on all axes
if not self.size:
if inplace:
return None
return self.copy(deep=None)
if is_dict_like(to_replace):
if is_dict_like(value): # {'A' : NA} -> {'A' : 0}
# Note: Checking below for `in foo.keys()` instead of
# `in foo` is needed for when we have a Series and not dict
mapping = {
col: (to_replace[col], value[col])
for col in to_replace.keys()
if col in value.keys() and col in self
}
return self._replace_columnwise(mapping, inplace, regex)
# {'A': NA} -> 0
elif not is_list_like(value):
# Operate column-wise
if self.ndim == 1:
raise ValueError(
"Series.replace cannot use dict-like to_replace "
"and non-None value"
)
mapping = {
col: (to_rep, value) for col, to_rep in to_replace.items()
}
return self._replace_columnwise(mapping, inplace, regex)
else:
raise TypeError("value argument must be scalar, dict, or Series")
elif is_list_like(to_replace):
if not is_list_like(value):
# e.g. to_replace = [NA, ''] and value is 0,
# so we replace NA with 0 and then replace '' with 0
value = [value] * len(to_replace)
# e.g. we have to_replace = [NA, ''] and value = [0, 'missing']
if len(to_replace) != len(value):
raise ValueError(
f"Replacement lists must match in length. "
f"Expecting {len(to_replace)} got {len(value)} "
)
new_data = self._mgr.replace_list(
src_list=to_replace,
dest_list=value,
inplace=inplace,
regex=regex,
)
elif to_replace is None:
if not (
is_re_compilable(regex)
or is_list_like(regex)
or is_dict_like(regex)
):
raise TypeError(
f"'regex' must be a string or a compiled regular expression "
f"or a list or dict of strings or regular expressions, "
f"you passed a {repr(type(regex).__name__)}"
)
return self.replace(
regex, value, inplace=inplace, limit=limit, regex=True
)
else:
# dest iterable dict-like
if is_dict_like(value): # NA -> {'A' : 0, 'B' : -1}
# Operate column-wise
if self.ndim == 1:
raise ValueError(
"Series.replace cannot use dict-value and "
"non-None to_replace"
)
mapping = {col: (to_replace, val) for col, val in value.items()}
return self._replace_columnwise(mapping, inplace, regex)
elif not is_list_like(value): # NA -> 0
regex = should_use_regex(regex, to_replace)
if regex:
new_data = self._mgr.replace_regex(
to_replace=to_replace,
value=value,
inplace=inplace,
)
else:
new_data = self._mgr.replace(
to_replace=to_replace, value=value, inplace=inplace
)
else:
raise TypeError(
f'Invalid "to_replace" type: {repr(type(to_replace).__name__)}'
)
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="replace")
def interpolate(
self: NDFrameT,
method: str = "linear",
*,
axis: Axis = 0,
limit: int | None = None,
inplace: bool_t = False,
limit_direction: str | None = None,
limit_area: str | None = None,
downcast: str | None = None,
**kwargs,
) -> NDFrameT | None:
"""
Fill NaN values using an interpolation method.
Please note that only ``method='linear'`` is supported for
DataFrame/Series with a MultiIndex.
Parameters
----------
method : str, default 'linear'
Interpolation technique to use. One of:
* 'linear': Ignore the index and treat the values as equally
spaced. This is the only method supported on MultiIndexes.
* 'time': Works on daily and higher resolution data to interpolate
given length of interval.
* 'index', 'values': use the actual numerical values of the index.
* 'pad': Fill in NaNs using existing values.
* 'nearest', 'zero', 'slinear', 'quadratic', 'cubic',
'barycentric', 'polynomial': Passed to
`scipy.interpolate.interp1d`, whereas 'spline' is passed to
`scipy.interpolate.UnivariateSpline`. These methods use the numerical
values of the index. Both 'polynomial' and 'spline' require that
you also specify an `order` (int), e.g.
``df.interpolate(method='polynomial', order=5)``. Note that,
`slinear` method in Pandas refers to the Scipy first order `spline`
instead of Pandas first order `spline`.
* 'krogh', 'piecewise_polynomial', 'spline', 'pchip', 'akima',
'cubicspline': Wrappers around the SciPy interpolation methods of
similar names. See `Notes`.
* 'from_derivatives': Refers to
`scipy.interpolate.BPoly.from_derivatives` which
replaces 'piecewise_polynomial' interpolation method in
scipy 0.18.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to interpolate along. For `Series` this parameter is unused
and defaults to 0.
limit : int, optional
Maximum number of consecutive NaNs to fill. Must be greater than
0.
inplace : bool, default False
Update the data in place if possible.
limit_direction : {{'forward', 'backward', 'both'}}, Optional
Consecutive NaNs will be filled in this direction.
If limit is specified:
* If 'method' is 'pad' or 'ffill', 'limit_direction' must be 'forward'.
* If 'method' is 'backfill' or 'bfill', 'limit_direction' must be
'backwards'.
If 'limit' is not specified:
* If 'method' is 'backfill' or 'bfill', the default is 'backward'
* else the default is 'forward'
.. versionchanged:: 1.1.0
raises ValueError if `limit_direction` is 'forward' or 'both' and
method is 'backfill' or 'bfill'.
raises ValueError if `limit_direction` is 'backward' or 'both' and
method is 'pad' or 'ffill'.
limit_area : {{`None`, 'inside', 'outside'}}, default None
If limit is specified, consecutive NaNs will be filled with this
restriction.
* ``None``: No fill restriction.
* 'inside': Only fill NaNs surrounded by valid values
(interpolate).
* 'outside': Only fill NaNs outside valid values (extrapolate).
downcast : optional, 'infer' or None, defaults to None
Downcast dtypes if possible.
``**kwargs`` : optional
Keyword arguments to pass on to the interpolating function.
Returns
-------
Series or DataFrame or None
Returns the same object type as the caller, interpolated at
some or all ``NaN`` values or None if ``inplace=True``.
See Also
--------
fillna : Fill missing values using different methods.
scipy.interpolate.Akima1DInterpolator : Piecewise cubic polynomials
(Akima interpolator).
scipy.interpolate.BPoly.from_derivatives : Piecewise polynomial in the
Bernstein basis.
scipy.interpolate.interp1d : Interpolate a 1-D function.
scipy.interpolate.KroghInterpolator : Interpolate polynomial (Krogh
interpolator).
scipy.interpolate.PchipInterpolator : PCHIP 1-d monotonic cubic
interpolation.
scipy.interpolate.CubicSpline : Cubic spline data interpolator.
Notes
-----
The 'krogh', 'piecewise_polynomial', 'spline', 'pchip' and 'akima'
methods are wrappers around the respective SciPy implementations of
similar names. These use the actual numerical values of the index.
For more information on their behavior, see the
`SciPy documentation
<https://docs.scipy.org/doc/scipy/reference/interpolate.html#univariate-interpolation>`__.
Examples
--------
Filling in ``NaN`` in a :class:`~pandas.Series` via linear
interpolation.
>>> s = pd.Series([0, 1, np.nan, 3])
>>> s
0 0.0
1 1.0
2 NaN
3 3.0
dtype: float64
>>> s.interpolate()
0 0.0
1 1.0
2 2.0
3 3.0
dtype: float64
Filling in ``NaN`` in a Series by padding, but filling at most two
consecutive ``NaN`` at a time.
>>> s = pd.Series([np.nan, "single_one", np.nan,
... "fill_two_more", np.nan, np.nan, np.nan,
... 4.71, np.nan])
>>> s
0 NaN
1 single_one
2 NaN
3 fill_two_more
4 NaN
5 NaN
6 NaN
7 4.71
8 NaN
dtype: object
>>> s.interpolate(method='pad', limit=2)
0 NaN
1 single_one
2 single_one
3 fill_two_more
4 fill_two_more
5 fill_two_more
6 NaN
7 4.71
8 4.71
dtype: object
Filling in ``NaN`` in a Series via polynomial interpolation or splines:
Both 'polynomial' and 'spline' methods require that you also specify
an ``order`` (int).
>>> s = pd.Series([0, 2, np.nan, 8])
>>> s.interpolate(method='polynomial', order=2)
0 0.000000
1 2.000000
2 4.666667
3 8.000000
dtype: float64
Fill the DataFrame forward (that is, going down) along each column
using linear interpolation.
Note how the last entry in column 'a' is interpolated differently,
because there is no entry after it to use for interpolation.
Note how the first entry in column 'b' remains ``NaN``, because there
is no entry before it to use for interpolation.
>>> df = pd.DataFrame([(0.0, np.nan, -1.0, 1.0),
... (np.nan, 2.0, np.nan, np.nan),
... (2.0, 3.0, np.nan, 9.0),
... (np.nan, 4.0, -4.0, 16.0)],
... columns=list('abcd'))
>>> df
a b c d
0 0.0 NaN -1.0 1.0
1 NaN 2.0 NaN NaN
2 2.0 3.0 NaN 9.0
3 NaN 4.0 -4.0 16.0
>>> df.interpolate(method='linear', limit_direction='forward', axis=0)
a b c d
0 0.0 NaN -1.0 1.0
1 1.0 2.0 -2.0 5.0
2 2.0 3.0 -3.0 9.0
3 2.0 4.0 -4.0 16.0
Using polynomial interpolation.
>>> df['d'].interpolate(method='polynomial', order=2)
0 1.0
1 4.0
2 9.0
3 16.0
Name: d, dtype: float64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
axis = self._get_axis_number(axis)
fillna_methods = ["ffill", "bfill", "pad", "backfill"]
should_transpose = axis == 1 and method not in fillna_methods
obj = self.T if should_transpose else self
if obj.empty:
return self.copy()
if method not in fillna_methods:
axis = self._info_axis_number
if isinstance(obj.index, MultiIndex) and method != "linear":
raise ValueError(
"Only `method=linear` interpolation is supported on MultiIndexes."
)
# Set `limit_direction` depending on `method`
if limit_direction is None:
limit_direction = (
"backward" if method in ("backfill", "bfill") else "forward"
)
else:
if method in ("pad", "ffill") and limit_direction != "forward":
raise ValueError(
f"`limit_direction` must be 'forward' for method `{method}`"
)
if method in ("backfill", "bfill") and limit_direction != "backward":
raise ValueError(
f"`limit_direction` must be 'backward' for method `{method}`"
)
if obj.ndim == 2 and np.all(obj.dtypes == np.dtype("object")):
raise TypeError(
"Cannot interpolate with all object-dtype columns "
"in the DataFrame. Try setting at least one "
"column to a numeric dtype."
)
# create/use the index
if method == "linear":
# prior default
index = Index(np.arange(len(obj.index)))
else:
index = obj.index
methods = {"index", "values", "nearest", "time"}
is_numeric_or_datetime = (
is_numeric_dtype(index.dtype)
or is_datetime64_any_dtype(index.dtype)
or is_timedelta64_dtype(index.dtype)
)
if method not in methods and not is_numeric_or_datetime:
raise ValueError(
"Index column must be numeric or datetime type when "
f"using {method} method other than linear. "
"Try setting a numeric or datetime index column before "
"interpolating."
)
if isna(index).any():
raise NotImplementedError(
"Interpolation with NaNs in the index "
"has not been implemented. Try filling "
"those NaNs before interpolating."
)
new_data = obj._mgr.interpolate(
method=method,
axis=axis,
index=index,
limit=limit,
limit_direction=limit_direction,
limit_area=limit_area,
inplace=inplace,
downcast=downcast,
**kwargs,
)
result = self._constructor(new_data)
if should_transpose:
result = result.T
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="interpolate")
# ----------------------------------------------------------------------
# Timeseries methods Methods
def asof(self, where, subset=None):
"""
Return the last row(s) without any NaNs before `where`.
The last row (for each element in `where`, if list) without any
NaN is taken.
In case of a :class:`~pandas.DataFrame`, the last row without NaN
considering only the subset of columns (if not `None`)
If there is no good value, NaN is returned for a Series or
a Series of NaN values for a DataFrame
Parameters
----------
where : date or array-like of dates
Date(s) before which the last row(s) are returned.
subset : str or array-like of str, default `None`
For DataFrame, if not `None`, only use these columns to
check for NaNs.
Returns
-------
scalar, Series, or DataFrame
The return can be:
* scalar : when `self` is a Series and `where` is a scalar
* Series: when `self` is a Series and `where` is an array-like,
or when `self` is a DataFrame and `where` is a scalar
* DataFrame : when `self` is a DataFrame and `where` is an
array-like
Return scalar, Series, or DataFrame.
See Also
--------
merge_asof : Perform an asof merge. Similar to left join.
Notes
-----
Dates are assumed to be sorted. Raises if this is not the case.
Examples
--------
A Series and a scalar `where`.
>>> s = pd.Series([1, 2, np.nan, 4], index=[10, 20, 30, 40])
>>> s
10 1.0
20 2.0
30 NaN
40 4.0
dtype: float64
>>> s.asof(20)
2.0
For a sequence `where`, a Series is returned. The first value is
NaN, because the first element of `where` is before the first
index value.
>>> s.asof([5, 20])
5 NaN
20 2.0
dtype: float64
Missing values are not considered. The following is ``2.0``, not
NaN, even though NaN is at the index location for ``30``.
>>> s.asof(30)
2.0
Take all columns into consideration
>>> df = pd.DataFrame({'a': [10, 20, 30, 40, 50],
... 'b': [None, None, None, None, 500]},
... index=pd.DatetimeIndex(['2018-02-27 09:01:00',
... '2018-02-27 09:02:00',
... '2018-02-27 09:03:00',
... '2018-02-27 09:04:00',
... '2018-02-27 09:05:00']))
>>> df.asof(pd.DatetimeIndex(['2018-02-27 09:03:30',
... '2018-02-27 09:04:30']))
a b
2018-02-27 09:03:30 NaN NaN
2018-02-27 09:04:30 NaN NaN
Take a single column into consideration
>>> df.asof(pd.DatetimeIndex(['2018-02-27 09:03:30',
... '2018-02-27 09:04:30']),
... subset=['a'])
a b
2018-02-27 09:03:30 30 NaN
2018-02-27 09:04:30 40 NaN
"""
if isinstance(where, str):
where = Timestamp(where)
if not self.index.is_monotonic_increasing:
raise ValueError("asof requires a sorted index")
is_series = isinstance(self, ABCSeries)
if is_series:
if subset is not None:
raise ValueError("subset is not valid for Series")
else:
if subset is None:
subset = self.columns
if not is_list_like(subset):
subset = [subset]
is_list = is_list_like(where)
if not is_list:
start = self.index[0]
if isinstance(self.index, PeriodIndex):
where = Period(where, freq=self.index.freq)
if where < start:
if not is_series:
return self._constructor_sliced(
index=self.columns, name=where, dtype=np.float64
)
return np.nan
# It's always much faster to use a *while* loop here for
# Series than pre-computing all the NAs. However a
# *while* loop is extremely expensive for DataFrame
# so we later pre-compute all the NAs and use the same
# code path whether *where* is a scalar or list.
# See PR: https://github.com/pandas-dev/pandas/pull/14476
if is_series:
loc = self.index.searchsorted(where, side="right")
if loc > 0:
loc -= 1
values = self._values
while loc > 0 and isna(values[loc]):
loc -= 1
return values[loc]
if not isinstance(where, Index):
where = Index(where) if is_list else Index([where])
nulls = self.isna() if is_series else self[subset].isna().any(axis=1)
if nulls.all():
if is_series:
self = cast("Series", self)
return self._constructor(np.nan, index=where, name=self.name)
elif is_list:
self = cast("DataFrame", self)
return self._constructor(np.nan, index=where, columns=self.columns)
else:
self = cast("DataFrame", self)
return self._constructor_sliced(
np.nan, index=self.columns, name=where[0]
)
locs = self.index.asof_locs(where, ~(nulls._values))
# mask the missing
missing = locs == -1
data = self.take(locs)
data.index = where
if missing.any():
# GH#16063 only do this setting when necessary, otherwise
# we'd cast e.g. bools to floats
data.loc[missing] = np.nan
return data if is_list else data.iloc[-1]
# ----------------------------------------------------------------------
# Action Methods
def isna(self: NDFrameT) -> NDFrameT:
"""
Detect missing values.
Return a boolean same-sized object indicating if the values are NA.
NA values, such as None or :attr:`numpy.NaN`, gets mapped to True
values.
Everything else gets mapped to False values. Characters such as empty
strings ``''`` or :attr:`numpy.inf` are not considered NA values
(unless you set ``pandas.options.mode.use_inf_as_na = True``).
Returns
-------
{klass}
Mask of bool values for each element in {klass} that
indicates whether an element is an NA value.
See Also
--------
{klass}.isnull : Alias of isna.
{klass}.notna : Boolean inverse of isna.
{klass}.dropna : Omit axes labels with missing values.
isna : Top-level isna.
Examples
--------
Show which entries in a DataFrame are NA.
>>> df = pd.DataFrame(dict(age=[5, 6, np.NaN],
... born=[pd.NaT, pd.Timestamp('1939-05-27'),
... pd.Timestamp('1940-04-25')],
... name=['Alfred', 'Batman', ''],
... toy=[None, 'Batmobile', 'Joker']))
>>> df
age born name toy
0 5.0 NaT Alfred None
1 6.0 1939-05-27 Batman Batmobile
2 NaN 1940-04-25 Joker
>>> df.isna()
age born name toy
0 False True False True
1 False False False False
2 True False False False
Show which entries in a Series are NA.
>>> ser = pd.Series([5, 6, np.NaN])
>>> ser
0 5.0
1 6.0
2 NaN
dtype: float64
>>> ser.isna()
0 False
1 False
2 True
dtype: bool
"""
return isna(self).__finalize__(self, method="isna")
def isnull(self: NDFrameT) -> NDFrameT:
return isna(self).__finalize__(self, method="isnull")
def notna(self: NDFrameT) -> NDFrameT:
"""
Detect existing (non-missing) values.
Return a boolean same-sized object indicating if the values are not NA.
Non-missing values get mapped to True. Characters such as empty
strings ``''`` or :attr:`numpy.inf` are not considered NA values
(unless you set ``pandas.options.mode.use_inf_as_na = True``).
NA values, such as None or :attr:`numpy.NaN`, get mapped to False
values.
Returns
-------
{klass}
Mask of bool values for each element in {klass} that
indicates whether an element is not an NA value.
See Also
--------
{klass}.notnull : Alias of notna.
{klass}.isna : Boolean inverse of notna.
{klass}.dropna : Omit axes labels with missing values.
notna : Top-level notna.
Examples
--------
Show which entries in a DataFrame are not NA.
>>> df = pd.DataFrame(dict(age=[5, 6, np.NaN],
... born=[pd.NaT, pd.Timestamp('1939-05-27'),
... pd.Timestamp('1940-04-25')],
... name=['Alfred', 'Batman', ''],
... toy=[None, 'Batmobile', 'Joker']))
>>> df
age born name toy
0 5.0 NaT Alfred None
1 6.0 1939-05-27 Batman Batmobile
2 NaN 1940-04-25 Joker
>>> df.notna()
age born name toy
0 True False True False
1 True True True True
2 False True True True
Show which entries in a Series are not NA.
>>> ser = pd.Series([5, 6, np.NaN])
>>> ser
0 5.0
1 6.0
2 NaN
dtype: float64
>>> ser.notna()
0 True
1 True
2 False
dtype: bool
"""
return notna(self).__finalize__(self, method="notna")
def notnull(self: NDFrameT) -> NDFrameT:
return notna(self).__finalize__(self, method="notnull")
def _clip_with_scalar(self, lower, upper, inplace: bool_t = False):
if (lower is not None and np.any(isna(lower))) or (
upper is not None and np.any(isna(upper))
):
raise ValueError("Cannot use an NA value as a clip threshold")
result = self
mask = isna(self._values)
with np.errstate(all="ignore"):
if upper is not None:
subset = self <= upper
result = result.where(subset, upper, axis=None, inplace=False)
if lower is not None:
subset = self >= lower
result = result.where(subset, lower, axis=None, inplace=False)
if np.any(mask):
result[mask] = np.nan
if inplace:
return self._update_inplace(result)
else:
return result
def _clip_with_one_bound(self, threshold, method, axis, inplace):
if axis is not None:
axis = self._get_axis_number(axis)
# method is self.le for upper bound and self.ge for lower bound
if is_scalar(threshold) and is_number(threshold):
if method.__name__ == "le":
return self._clip_with_scalar(None, threshold, inplace=inplace)
return self._clip_with_scalar(threshold, None, inplace=inplace)
# GH #15390
# In order for where method to work, the threshold must
# be transformed to NDFrame from other array like structure.
if (not isinstance(threshold, ABCSeries)) and is_list_like(threshold):
if isinstance(self, ABCSeries):
threshold = self._constructor(threshold, index=self.index)
else:
threshold = align_method_FRAME(self, threshold, axis, flex=None)[1]
# GH 40420
# Treat missing thresholds as no bounds, not clipping the values
if is_list_like(threshold):
fill_value = np.inf if method.__name__ == "le" else -np.inf
threshold_inf = threshold.fillna(fill_value)
else:
threshold_inf = threshold
subset = method(threshold_inf, axis=axis) | isna(self)
# GH 40420
return self.where(subset, threshold, axis=axis, inplace=inplace)
def clip(
self: NDFrameT,
lower=None,
upper=None,
*,
axis: Axis | None = None,
inplace: bool_t = False,
**kwargs,
) -> NDFrameT | None:
"""
Trim values at input threshold(s).
Assigns values outside boundary to boundary values. Thresholds
can be singular values or array like, and in the latter case
the clipping is performed element-wise in the specified axis.
Parameters
----------
lower : float or array-like, default None
Minimum threshold value. All values below this
threshold will be set to it. A missing
threshold (e.g `NA`) will not clip the value.
upper : float or array-like, default None
Maximum threshold value. All values above this
threshold will be set to it. A missing
threshold (e.g `NA`) will not clip the value.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Align object with lower and upper along the given axis.
For `Series` this parameter is unused and defaults to `None`.
inplace : bool, default False
Whether to perform the operation in place on the data.
*args, **kwargs
Additional keywords have no effect but might be accepted
for compatibility with numpy.
Returns
-------
Series or DataFrame or None
Same type as calling object with the values outside the
clip boundaries replaced or None if ``inplace=True``.
See Also
--------
Series.clip : Trim values at input threshold in series.
DataFrame.clip : Trim values at input threshold in dataframe.
numpy.clip : Clip (limit) the values in an array.
Examples
--------
>>> data = {'col_0': [9, -3, 0, -1, 5], 'col_1': [-2, -7, 6, 8, -5]}
>>> df = pd.DataFrame(data)
>>> df
col_0 col_1
0 9 -2
1 -3 -7
2 0 6
3 -1 8
4 5 -5
Clips per column using lower and upper thresholds:
>>> df.clip(-4, 6)
col_0 col_1
0 6 -2
1 -3 -4
2 0 6
3 -1 6
4 5 -4
Clips using specific lower and upper thresholds per column element:
>>> t = pd.Series([2, -4, -1, 6, 3])
>>> t
0 2
1 -4
2 -1
3 6
4 3
dtype: int64
>>> df.clip(t, t + 4, axis=0)
col_0 col_1
0 6 2
1 -3 -4
2 0 3
3 6 8
4 5 3
Clips using specific lower threshold per column element, with missing values:
>>> t = pd.Series([2, -4, np.NaN, 6, 3])
>>> t
0 2.0
1 -4.0
2 NaN
3 6.0
4 3.0
dtype: float64
>>> df.clip(t, axis=0)
col_0 col_1
0 9 2
1 -3 -4
2 0 6
3 6 8
4 5 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
axis = nv.validate_clip_with_axis(axis, (), kwargs)
if axis is not None:
axis = self._get_axis_number(axis)
# GH 17276
# numpy doesn't like NaN as a clip value
# so ignore
# GH 19992
# numpy doesn't drop a list-like bound containing NaN
isna_lower = isna(lower)
if not is_list_like(lower):
if np.any(isna_lower):
lower = None
elif np.all(isna_lower):
lower = None
isna_upper = isna(upper)
if not is_list_like(upper):
if np.any(isna_upper):
upper = None
elif np.all(isna_upper):
upper = None
# GH 2747 (arguments were reversed)
if (
lower is not None
and upper is not None
and is_scalar(lower)
and is_scalar(upper)
):
lower, upper = min(lower, upper), max(lower, upper)
# fast-path for scalars
if (lower is None or (is_scalar(lower) and is_number(lower))) and (
upper is None or (is_scalar(upper) and is_number(upper))
):
return self._clip_with_scalar(lower, upper, inplace=inplace)
result = self
if lower is not None:
result = result._clip_with_one_bound(
lower, method=self.ge, axis=axis, inplace=inplace
)
if upper is not None:
if inplace:
result = self
result = result._clip_with_one_bound(
upper, method=self.le, axis=axis, inplace=inplace
)
return result
def asfreq(
self: NDFrameT,
freq: Frequency,
method: FillnaOptions | None = None,
how: str | None = None,
normalize: bool_t = False,
fill_value: Hashable = None,
) -> NDFrameT:
"""
Convert time series to specified frequency.
Returns the original data conformed to a new index with the specified
frequency.
If the index of this {klass} is a :class:`~pandas.PeriodIndex`, the new index
is the result of transforming the original index with
:meth:`PeriodIndex.asfreq <pandas.PeriodIndex.asfreq>` (so the original index
will map one-to-one to the new index).
Otherwise, the new index will be equivalent to ``pd.date_range(start, end,
freq=freq)`` where ``start`` and ``end`` are, respectively, the first and
last entries in the original index (see :func:`pandas.date_range`). The
values corresponding to any timesteps in the new index which were not present
in the original index will be null (``NaN``), unless a method for filling
such unknowns is provided (see the ``method`` parameter below).
The :meth:`resample` method is more appropriate if an operation on each group of
timesteps (such as an aggregate) is necessary to represent the data at the new
frequency.
Parameters
----------
freq : DateOffset or str
Frequency DateOffset or string.
method : {{'backfill'/'bfill', 'pad'/'ffill'}}, default None
Method to use for filling holes in reindexed Series (note this
does not fill NaNs that already were present):
* 'pad' / 'ffill': propagate last valid observation forward to next
valid
* 'backfill' / 'bfill': use NEXT valid observation to fill.
how : {{'start', 'end'}}, default end
For PeriodIndex only (see PeriodIndex.asfreq).
normalize : bool, default False
Whether to reset output index to midnight.
fill_value : scalar, optional
Value to use for missing values, applied during upsampling (note
this does not fill NaNs that already were present).
Returns
-------
{klass}
{klass} object reindexed to the specified frequency.
See Also
--------
reindex : Conform DataFrame to new index with optional filling logic.
Notes
-----
To learn more about the frequency strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__.
Examples
--------
Start by creating a series with 4 one minute timestamps.
>>> index = pd.date_range('1/1/2000', periods=4, freq='T')
>>> series = pd.Series([0.0, None, 2.0, 3.0], index=index)
>>> df = pd.DataFrame({{'s': series}})
>>> df
s
2000-01-01 00:00:00 0.0
2000-01-01 00:01:00 NaN
2000-01-01 00:02:00 2.0
2000-01-01 00:03:00 3.0
Upsample the series into 30 second bins.
>>> df.asfreq(freq='30S')
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 NaN
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 NaN
2000-01-01 00:03:00 3.0
Upsample again, providing a ``fill value``.
>>> df.asfreq(freq='30S', fill_value=9.0)
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 9.0
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 9.0
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 9.0
2000-01-01 00:03:00 3.0
Upsample again, providing a ``method``.
>>> df.asfreq(freq='30S', method='bfill')
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 2.0
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 3.0
2000-01-01 00:03:00 3.0
"""
from pandas.core.resample import asfreq
return asfreq(
self,
freq,
method=method,
how=how,
normalize=normalize,
fill_value=fill_value,
)
def at_time(
self: NDFrameT, time, asof: bool_t = False, axis: Axis | None = None
) -> NDFrameT:
"""
Select values at particular time of day (e.g., 9:30AM).
Parameters
----------
time : datetime.time or str
The values to select.
axis : {0 or 'index', 1 or 'columns'}, default 0
For `Series` this parameter is unused and defaults to 0.
Returns
-------
Series or DataFrame
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
between_time : Select values between particular times of the day.
first : Select initial periods of time series based on a date offset.
last : Select final periods of time series based on a date offset.
DatetimeIndex.indexer_at_time : Get just the index locations for
values at particular time of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='12H')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 00:00:00 1
2018-04-09 12:00:00 2
2018-04-10 00:00:00 3
2018-04-10 12:00:00 4
>>> ts.at_time('12:00')
A
2018-04-09 12:00:00 2
2018-04-10 12:00:00 4
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
index = self._get_axis(axis)
if not isinstance(index, DatetimeIndex):
raise TypeError("Index must be DatetimeIndex")
indexer = index.indexer_at_time(time, asof=asof)
return self._take_with_is_copy(indexer, axis=axis)
def between_time(
self: NDFrameT,
start_time,
end_time,
inclusive: IntervalClosedType = "both",
axis: Axis | None = None,
) -> NDFrameT:
"""
Select values between particular times of the day (e.g., 9:00-9:30 AM).
By setting ``start_time`` to be later than ``end_time``,
you can get the times that are *not* between the two times.
Parameters
----------
start_time : datetime.time or str
Initial time as a time filter limit.
end_time : datetime.time or str
End time as a time filter limit.
inclusive : {"both", "neither", "left", "right"}, default "both"
Include boundaries; whether to set each bound as closed or open.
axis : {0 or 'index', 1 or 'columns'}, default 0
Determine range time on index or columns value.
For `Series` this parameter is unused and defaults to 0.
Returns
-------
Series or DataFrame
Data from the original object filtered to the specified dates range.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
at_time : Select values at a particular time of the day.
first : Select initial periods of time series based on a date offset.
last : Select final periods of time series based on a date offset.
DatetimeIndex.indexer_between_time : Get just the index locations for
values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='1D20min')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 00:00:00 1
2018-04-10 00:20:00 2
2018-04-11 00:40:00 3
2018-04-12 01:00:00 4
>>> ts.between_time('0:15', '0:45')
A
2018-04-10 00:20:00 2
2018-04-11 00:40:00 3
You get the times that are *not* between two times by setting
``start_time`` later than ``end_time``:
>>> ts.between_time('0:45', '0:15')
A
2018-04-09 00:00:00 1
2018-04-12 01:00:00 4
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
index = self._get_axis(axis)
if not isinstance(index, DatetimeIndex):
raise TypeError("Index must be DatetimeIndex")
left_inclusive, right_inclusive = validate_inclusive(inclusive)
indexer = index.indexer_between_time(
start_time,
end_time,
include_start=left_inclusive,
include_end=right_inclusive,
)
return self._take_with_is_copy(indexer, axis=axis)
def resample(
self,
rule,
axis: Axis = 0,
closed: str | None = None,
label: str | None = None,
convention: str = "start",
kind: str | None = None,
on: Level = None,
level: Level = None,
origin: str | TimestampConvertibleTypes = "start_day",
offset: TimedeltaConvertibleTypes | None = None,
group_keys: bool_t = False,
) -> Resampler:
"""
Resample time-series data.
Convenience method for frequency conversion and resampling of time series.
The object must have a datetime-like index (`DatetimeIndex`, `PeriodIndex`,
or `TimedeltaIndex`), or the caller must pass the label of a datetime-like
series/index to the ``on``/``level`` keyword parameter.
Parameters
----------
rule : DateOffset, Timedelta or str
The offset string or object representing target conversion.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
Which axis to use for up- or down-sampling. For `Series` this parameter
is unused and defaults to 0. Must be
`DatetimeIndex`, `TimedeltaIndex` or `PeriodIndex`.
closed : {{'right', 'left'}}, default None
Which side of bin interval is closed. The default is 'left'
for all frequency offsets except for 'M', 'A', 'Q', 'BM',
'BA', 'BQ', and 'W' which all have a default of 'right'.
label : {{'right', 'left'}}, default None
Which bin edge label to label bucket with. The default is 'left'
for all frequency offsets except for 'M', 'A', 'Q', 'BM',
'BA', 'BQ', and 'W' which all have a default of 'right'.
convention : {{'start', 'end', 's', 'e'}}, default 'start'
For `PeriodIndex` only, controls whether to use the start or
end of `rule`.
kind : {{'timestamp', 'period'}}, optional, default None
Pass 'timestamp' to convert the resulting index to a
`DateTimeIndex` or 'period' to convert it to a `PeriodIndex`.
By default the input representation is retained.
on : str, optional
For a DataFrame, column to use instead of index for resampling.
Column must be datetime-like.
level : str or int, optional
For a MultiIndex, level (name or number) to use for
resampling. `level` must be datetime-like.
origin : Timestamp or str, default 'start_day'
The timestamp on which to adjust the grouping. The timezone of origin
must match the timezone of the index.
If string, must be one of the following:
- 'epoch': `origin` is 1970-01-01
- 'start': `origin` is the first value of the timeseries
- 'start_day': `origin` is the first day at midnight of the timeseries
.. versionadded:: 1.1.0
- 'end': `origin` is the last value of the timeseries
- 'end_day': `origin` is the ceiling midnight of the last day
.. versionadded:: 1.3.0
offset : Timedelta or str, default is None
An offset timedelta added to the origin.
.. versionadded:: 1.1.0
group_keys : bool, default False
Whether to include the group keys in the result index when using
``.apply()`` on the resampled object.
.. versionadded:: 1.5.0
Not specifying ``group_keys`` will retain values-dependent behavior
from pandas 1.4 and earlier (see :ref:`pandas 1.5.0 Release notes
<whatsnew_150.enhancements.resample_group_keys>` for examples).
.. versionchanged:: 2.0.0
``group_keys`` now defaults to ``False``.
Returns
-------
pandas.core.Resampler
:class:`~pandas.core.Resampler` object.
See Also
--------
Series.resample : Resample a Series.
DataFrame.resample : Resample a DataFrame.
groupby : Group {klass} by mapping, function, label, or list of labels.
asfreq : Reindex a {klass} with the given frequency without grouping.
Notes
-----
See the `user guide
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#resampling>`__
for more.
To learn more about the offset strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#dateoffset-objects>`__.
Examples
--------
Start by creating a series with 9 one minute timestamps.
>>> index = pd.date_range('1/1/2000', periods=9, freq='T')
>>> series = pd.Series(range(9), index=index)
>>> series
2000-01-01 00:00:00 0
2000-01-01 00:01:00 1
2000-01-01 00:02:00 2
2000-01-01 00:03:00 3
2000-01-01 00:04:00 4
2000-01-01 00:05:00 5
2000-01-01 00:06:00 6
2000-01-01 00:07:00 7
2000-01-01 00:08:00 8
Freq: T, dtype: int64
Downsample the series into 3 minute bins and sum the values
of the timestamps falling into a bin.
>>> series.resample('3T').sum()
2000-01-01 00:00:00 3
2000-01-01 00:03:00 12
2000-01-01 00:06:00 21
Freq: 3T, dtype: int64
Downsample the series into 3 minute bins as above, but label each
bin using the right edge instead of the left. Please note that the
value in the bucket used as the label is not included in the bucket,
which it labels. For example, in the original series the
bucket ``2000-01-01 00:03:00`` contains the value 3, but the summed
value in the resampled bucket with the label ``2000-01-01 00:03:00``
does not include 3 (if it did, the summed value would be 6, not 3).
To include this value close the right side of the bin interval as
illustrated in the example below this one.
>>> series.resample('3T', label='right').sum()
2000-01-01 00:03:00 3
2000-01-01 00:06:00 12
2000-01-01 00:09:00 21
Freq: 3T, dtype: int64
Downsample the series into 3 minute bins as above, but close the right
side of the bin interval.
>>> series.resample('3T', label='right', closed='right').sum()
2000-01-01 00:00:00 0
2000-01-01 00:03:00 6
2000-01-01 00:06:00 15
2000-01-01 00:09:00 15
Freq: 3T, dtype: int64
Upsample the series into 30 second bins.
>>> series.resample('30S').asfreq()[0:5] # Select first 5 rows
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 1.0
2000-01-01 00:01:30 NaN
2000-01-01 00:02:00 2.0
Freq: 30S, dtype: float64
Upsample the series into 30 second bins and fill the ``NaN``
values using the ``ffill`` method.
>>> series.resample('30S').ffill()[0:5]
2000-01-01 00:00:00 0
2000-01-01 00:00:30 0
2000-01-01 00:01:00 1
2000-01-01 00:01:30 1
2000-01-01 00:02:00 2
Freq: 30S, dtype: int64
Upsample the series into 30 second bins and fill the
``NaN`` values using the ``bfill`` method.
>>> series.resample('30S').bfill()[0:5]
2000-01-01 00:00:00 0
2000-01-01 00:00:30 1
2000-01-01 00:01:00 1
2000-01-01 00:01:30 2
2000-01-01 00:02:00 2
Freq: 30S, dtype: int64
Pass a custom function via ``apply``
>>> def custom_resampler(arraylike):
... return np.sum(arraylike) + 5
...
>>> series.resample('3T').apply(custom_resampler)
2000-01-01 00:00:00 8
2000-01-01 00:03:00 17
2000-01-01 00:06:00 26
Freq: 3T, dtype: int64
For a Series with a PeriodIndex, the keyword `convention` can be
used to control whether to use the start or end of `rule`.
Resample a year by quarter using 'start' `convention`. Values are
assigned to the first quarter of the period.
>>> s = pd.Series([1, 2], index=pd.period_range('2012-01-01',
... freq='A',
... periods=2))
>>> s
2012 1
2013 2
Freq: A-DEC, dtype: int64
>>> s.resample('Q', convention='start').asfreq()
2012Q1 1.0
2012Q2 NaN
2012Q3 NaN
2012Q4 NaN
2013Q1 2.0
2013Q2 NaN
2013Q3 NaN
2013Q4 NaN
Freq: Q-DEC, dtype: float64
Resample quarters by month using 'end' `convention`. Values are
assigned to the last month of the period.
>>> q = pd.Series([1, 2, 3, 4], index=pd.period_range('2018-01-01',
... freq='Q',
... periods=4))
>>> q
2018Q1 1
2018Q2 2
2018Q3 3
2018Q4 4
Freq: Q-DEC, dtype: int64
>>> q.resample('M', convention='end').asfreq()
2018-03 1.0
2018-04 NaN
2018-05 NaN
2018-06 2.0
2018-07 NaN
2018-08 NaN
2018-09 3.0
2018-10 NaN
2018-11 NaN
2018-12 4.0
Freq: M, dtype: float64
For DataFrame objects, the keyword `on` can be used to specify the
column instead of the index for resampling.
>>> d = {{'price': [10, 11, 9, 13, 14, 18, 17, 19],
... 'volume': [50, 60, 40, 100, 50, 100, 40, 50]}}
>>> df = pd.DataFrame(d)
>>> df['week_starting'] = pd.date_range('01/01/2018',
... periods=8,
... freq='W')
>>> df
price volume week_starting
0 10 50 2018-01-07
1 11 60 2018-01-14
2 9 40 2018-01-21
3 13 100 2018-01-28
4 14 50 2018-02-04
5 18 100 2018-02-11
6 17 40 2018-02-18
7 19 50 2018-02-25
>>> df.resample('M', on='week_starting').mean()
price volume
week_starting
2018-01-31 10.75 62.5
2018-02-28 17.00 60.0
For a DataFrame with MultiIndex, the keyword `level` can be used to
specify on which level the resampling needs to take place.
>>> days = pd.date_range('1/1/2000', periods=4, freq='D')
>>> d2 = {{'price': [10, 11, 9, 13, 14, 18, 17, 19],
... 'volume': [50, 60, 40, 100, 50, 100, 40, 50]}}
>>> df2 = pd.DataFrame(
... d2,
... index=pd.MultiIndex.from_product(
... [days, ['morning', 'afternoon']]
... )
... )
>>> df2
price volume
2000-01-01 morning 10 50
afternoon 11 60
2000-01-02 morning 9 40
afternoon 13 100
2000-01-03 morning 14 50
afternoon 18 100
2000-01-04 morning 17 40
afternoon 19 50
>>> df2.resample('D', level=0).sum()
price volume
2000-01-01 21 110
2000-01-02 22 140
2000-01-03 32 150
2000-01-04 36 90
If you want to adjust the start of the bins based on a fixed timestamp:
>>> start, end = '2000-10-01 23:30:00', '2000-10-02 00:30:00'
>>> rng = pd.date_range(start, end, freq='7min')
>>> ts = pd.Series(np.arange(len(rng)) * 3, index=rng)
>>> ts
2000-10-01 23:30:00 0
2000-10-01 23:37:00 3
2000-10-01 23:44:00 6
2000-10-01 23:51:00 9
2000-10-01 23:58:00 12
2000-10-02 00:05:00 15
2000-10-02 00:12:00 18
2000-10-02 00:19:00 21
2000-10-02 00:26:00 24
Freq: 7T, dtype: int64
>>> ts.resample('17min').sum()
2000-10-01 23:14:00 0
2000-10-01 23:31:00 9
2000-10-01 23:48:00 21
2000-10-02 00:05:00 54
2000-10-02 00:22:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', origin='epoch').sum()
2000-10-01 23:18:00 0
2000-10-01 23:35:00 18
2000-10-01 23:52:00 27
2000-10-02 00:09:00 39
2000-10-02 00:26:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', origin='2000-01-01').sum()
2000-10-01 23:24:00 3
2000-10-01 23:41:00 15
2000-10-01 23:58:00 45
2000-10-02 00:15:00 45
Freq: 17T, dtype: int64
If you want to adjust the start of the bins with an `offset` Timedelta, the two
following lines are equivalent:
>>> ts.resample('17min', origin='start').sum()
2000-10-01 23:30:00 9
2000-10-01 23:47:00 21
2000-10-02 00:04:00 54
2000-10-02 00:21:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', offset='23h30min').sum()
2000-10-01 23:30:00 9
2000-10-01 23:47:00 21
2000-10-02 00:04:00 54
2000-10-02 00:21:00 24
Freq: 17T, dtype: int64
If you want to take the largest Timestamp as the end of the bins:
>>> ts.resample('17min', origin='end').sum()
2000-10-01 23:35:00 0
2000-10-01 23:52:00 18
2000-10-02 00:09:00 27
2000-10-02 00:26:00 63
Freq: 17T, dtype: int64
In contrast with the `start_day`, you can use `end_day` to take the ceiling
midnight of the largest Timestamp as the end of the bins and drop the bins
not containing data:
>>> ts.resample('17min', origin='end_day').sum()
2000-10-01 23:38:00 3
2000-10-01 23:55:00 15
2000-10-02 00:12:00 45
2000-10-02 00:29:00 45
Freq: 17T, dtype: int64
"""
from pandas.core.resample import get_resampler
axis = self._get_axis_number(axis)
return get_resampler(
cast("Series | DataFrame", self),
freq=rule,
label=label,
closed=closed,
axis=axis,
kind=kind,
convention=convention,
key=on,
level=level,
origin=origin,
offset=offset,
group_keys=group_keys,
)
def first(self: NDFrameT, offset) -> NDFrameT:
"""
Select initial periods of time series data based on a date offset.
When having a DataFrame with dates as index, this function can
select the first few rows based on a date offset.
Parameters
----------
offset : str, DateOffset or dateutil.relativedelta
The offset length of the data that will be selected. For instance,
'1M' will display all the rows having their index within the first month.
Returns
-------
Series or DataFrame
A subset of the caller.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
last : Select final periods of time series based on a date offset.
at_time : Select values at a particular time of the day.
between_time : Select values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='2D')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 1
2018-04-11 2
2018-04-13 3
2018-04-15 4
Get the rows for the first 3 days:
>>> ts.first('3D')
A
2018-04-09 1
2018-04-11 2
Notice the data for 3 first calendar days were returned, not the first
3 days observed in the dataset, and therefore data for 2018-04-13 was
not returned.
"""
if not isinstance(self.index, DatetimeIndex):
raise TypeError("'first' only supports a DatetimeIndex index")
if len(self.index) == 0:
return self.copy(deep=False)
offset = to_offset(offset)
if not isinstance(offset, Tick) and offset.is_on_offset(self.index[0]):
# GH#29623 if first value is end of period, remove offset with n = 1
# before adding the real offset
end_date = end = self.index[0] - offset.base + offset
else:
end_date = end = self.index[0] + offset
# Tick-like, e.g. 3 weeks
if isinstance(offset, Tick) and end_date in self.index:
end = self.index.searchsorted(end_date, side="left")
return self.iloc[:end]
return self.loc[:end]
def last(self: NDFrameT, offset) -> NDFrameT:
"""
Select final periods of time series data based on a date offset.
For a DataFrame with a sorted DatetimeIndex, this function
selects the last few rows based on a date offset.
Parameters
----------
offset : str, DateOffset, dateutil.relativedelta
The offset length of the data that will be selected. For instance,
'3D' will display all the rows having their index within the last 3 days.
Returns
-------
Series or DataFrame
A subset of the caller.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
first : Select initial periods of time series based on a date offset.
at_time : Select values at a particular time of the day.
between_time : Select values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='2D')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 1
2018-04-11 2
2018-04-13 3
2018-04-15 4
Get the rows for the last 3 days:
>>> ts.last('3D')
A
2018-04-13 3
2018-04-15 4
Notice the data for 3 last calendar days were returned, not the last
3 observed days in the dataset, and therefore data for 2018-04-11 was
not returned.
"""
if not isinstance(self.index, DatetimeIndex):
raise TypeError("'last' only supports a DatetimeIndex index")
if len(self.index) == 0:
return self.copy(deep=False)
offset = to_offset(offset)
start_date = self.index[-1] - offset
start = self.index.searchsorted(start_date, side="right")
return self.iloc[start:]
def rank(
self: NDFrameT,
axis: Axis = 0,
method: str = "average",
numeric_only: bool_t = False,
na_option: str = "keep",
ascending: bool_t = True,
pct: bool_t = False,
) -> NDFrameT:
"""
Compute numerical data ranks (1 through n) along axis.
By default, equal values are assigned a rank that is the average of the
ranks of those values.
Parameters
----------
axis : {0 or 'index', 1 or 'columns'}, default 0
Index to direct ranking.
For `Series` this parameter is unused and defaults to 0.
method : {'average', 'min', 'max', 'first', 'dense'}, default 'average'
How to rank the group of records that have the same value (i.e. ties):
* average: average rank of the group
* min: lowest rank in the group
* max: highest rank in the group
* first: ranks assigned in order they appear in the array
* dense: like 'min', but rank always increases by 1 between groups.
numeric_only : bool, default False
For DataFrame objects, rank only numeric columns if set to True.
.. versionchanged:: 2.0.0
The default value of ``numeric_only`` is now ``False``.
na_option : {'keep', 'top', 'bottom'}, default 'keep'
How to rank NaN values:
* keep: assign NaN rank to NaN values
* top: assign lowest rank to NaN values
* bottom: assign highest rank to NaN values
ascending : bool, default True
Whether or not the elements should be ranked in ascending order.
pct : bool, default False
Whether or not to display the returned rankings in percentile
form.
Returns
-------
same type as caller
Return a Series or DataFrame with data ranks as values.
See Also
--------
core.groupby.DataFrameGroupBy.rank : Rank of values within each group.
core.groupby.SeriesGroupBy.rank : Rank of values within each group.
Examples
--------
>>> df = pd.DataFrame(data={'Animal': ['cat', 'penguin', 'dog',
... 'spider', 'snake'],
... 'Number_legs': [4, 2, 4, 8, np.nan]})
>>> df
Animal Number_legs
0 cat 4.0
1 penguin 2.0
2 dog 4.0
3 spider 8.0
4 snake NaN
Ties are assigned the mean of the ranks (by default) for the group.
>>> s = pd.Series(range(5), index=list("abcde"))
>>> s["d"] = s["b"]
>>> s.rank()
a 1.0
b 2.5
c 4.0
d 2.5
e 5.0
dtype: float64
The following example shows how the method behaves with the above
parameters:
* default_rank: this is the default behaviour obtained without using
any parameter.
* max_rank: setting ``method = 'max'`` the records that have the
same values are ranked using the highest rank (e.g.: since 'cat'
and 'dog' are both in the 2nd and 3rd position, rank 3 is assigned.)
* NA_bottom: choosing ``na_option = 'bottom'``, if there are records
with NaN values they are placed at the bottom of the ranking.
* pct_rank: when setting ``pct = True``, the ranking is expressed as
percentile rank.
>>> df['default_rank'] = df['Number_legs'].rank()
>>> df['max_rank'] = df['Number_legs'].rank(method='max')
>>> df['NA_bottom'] = df['Number_legs'].rank(na_option='bottom')
>>> df['pct_rank'] = df['Number_legs'].rank(pct=True)
>>> df
Animal Number_legs default_rank max_rank NA_bottom pct_rank
0 cat 4.0 2.5 3.0 2.5 0.625
1 penguin 2.0 1.0 1.0 1.0 0.250
2 dog 4.0 2.5 3.0 2.5 0.625
3 spider 8.0 4.0 4.0 4.0 1.000
4 snake NaN NaN NaN 5.0 NaN
"""
axis_int = self._get_axis_number(axis)
if na_option not in {"keep", "top", "bottom"}:
msg = "na_option must be one of 'keep', 'top', or 'bottom'"
raise ValueError(msg)
def ranker(data):
if data.ndim == 2:
# i.e. DataFrame, we cast to ndarray
values = data.values
else:
# i.e. Series, can dispatch to EA
values = data._values
if isinstance(values, ExtensionArray):
ranks = values._rank(
axis=axis_int,
method=method,
ascending=ascending,
na_option=na_option,
pct=pct,
)
else:
ranks = algos.rank(
values,
axis=axis_int,
method=method,
ascending=ascending,
na_option=na_option,
pct=pct,
)
ranks_obj = self._constructor(ranks, **data._construct_axes_dict())
return ranks_obj.__finalize__(self, method="rank")
if numeric_only:
if self.ndim == 1 and not is_numeric_dtype(self.dtype):
# GH#47500
raise TypeError(
"Series.rank does not allow numeric_only=True with "
"non-numeric dtype."
)
data = self._get_numeric_data()
else:
data = self
return ranker(data)
def compare(
self,
other,
align_axis: Axis = 1,
keep_shape: bool_t = False,
keep_equal: bool_t = False,
result_names: Suffixes = ("self", "other"),
):
if type(self) is not type(other):
cls_self, cls_other = type(self).__name__, type(other).__name__
raise TypeError(
f"can only compare '{cls_self}' (not '{cls_other}') with '{cls_self}'"
)
mask = ~((self == other) | (self.isna() & other.isna()))
mask.fillna(True, inplace=True)
if not keep_equal:
self = self.where(mask)
other = other.where(mask)
if not keep_shape:
if isinstance(self, ABCDataFrame):
cmask = mask.any()
rmask = mask.any(axis=1)
self = self.loc[rmask, cmask]
other = other.loc[rmask, cmask]
else:
self = self[mask]
other = other[mask]
if not isinstance(result_names, tuple):
raise TypeError(
f"Passing 'result_names' as a {type(result_names)} is not "
"supported. Provide 'result_names' as a tuple instead."
)
if align_axis in (1, "columns"): # This is needed for Series
axis = 1
else:
axis = self._get_axis_number(align_axis)
diff = concat([self, other], axis=axis, keys=result_names)
if axis >= self.ndim:
# No need to reorganize data if stacking on new axis
# This currently applies for stacking two Series on columns
return diff
ax = diff._get_axis(axis)
ax_names = np.array(ax.names)
# set index names to positions to avoid confusion
ax.names = np.arange(len(ax_names))
# bring self-other to inner level
order = list(range(1, ax.nlevels)) + [0]
if isinstance(diff, ABCDataFrame):
diff = diff.reorder_levels(order, axis=axis)
else:
diff = diff.reorder_levels(order)
# restore the index names in order
diff._get_axis(axis=axis).names = ax_names[order]
# reorder axis to keep things organized
indices = (
np.arange(diff.shape[axis]).reshape([2, diff.shape[axis] // 2]).T.flatten()
)
diff = diff.take(indices, axis=axis)
return diff
def align(
self: NDFrameT,
other: NDFrameT,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool_t | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> NDFrameT:
"""
Align two objects on their axes with the specified join method.
Join method is specified for each axis Index.
Parameters
----------
other : DataFrame or Series
join : {{'outer', 'inner', 'left', 'right'}}, default 'outer'
axis : allowed axis of the other object, default None
Align on index (0), columns (1), or both (None).
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
copy : bool, default True
Always returns new objects. If copy=False and no reindexing is
required then original objects are returned.
fill_value : scalar, default np.NaN
Value to use for missing values. Defaults to NaN, but can be any
"compatible" value.
method : {{'backfill', 'bfill', 'pad', 'ffill', None}}, default None
Method to use for filling holes in reindexed Series:
- pad / ffill: propagate last valid observation forward to next valid.
- backfill / bfill: use NEXT valid observation to fill gap.
limit : int, default None
If method is specified, this is the maximum number of consecutive
NaN values to forward/backward fill. In other words, if there is
a gap with more than this number of consecutive NaNs, it will only
be partially filled. If method is not specified, this is the
maximum number of entries along the entire axis where NaNs will be
filled. Must be greater than 0 if not None.
fill_axis : {axes_single_arg}, default 0
Filling axis, method and limit.
broadcast_axis : {axes_single_arg}, default None
Broadcast values along this axis, if aligning two objects of
different dimensions.
Returns
-------
tuple of ({klass}, type of other)
Aligned objects.
Examples
--------
>>> df = pd.DataFrame(
... [[1, 2, 3, 4], [6, 7, 8, 9]], columns=["D", "B", "E", "A"], index=[1, 2]
... )
>>> other = pd.DataFrame(
... [[10, 20, 30, 40], [60, 70, 80, 90], [600, 700, 800, 900]],
... columns=["A", "B", "C", "D"],
... index=[2, 3, 4],
... )
>>> df
D B E A
1 1 2 3 4
2 6 7 8 9
>>> other
A B C D
2 10 20 30 40
3 60 70 80 90
4 600 700 800 900
Align on columns:
>>> left, right = df.align(other, join="outer", axis=1)
>>> left
A B C D E
1 4 2 NaN 1 3
2 9 7 NaN 6 8
>>> right
A B C D E
2 10 20 30 40 NaN
3 60 70 80 90 NaN
4 600 700 800 900 NaN
We can also align on the index:
>>> left, right = df.align(other, join="outer", axis=0)
>>> left
D B E A
1 1.0 2.0 3.0 4.0
2 6.0 7.0 8.0 9.0
3 NaN NaN NaN NaN
4 NaN NaN NaN NaN
>>> right
A B C D
1 NaN NaN NaN NaN
2 10.0 20.0 30.0 40.0
3 60.0 70.0 80.0 90.0
4 600.0 700.0 800.0 900.0
Finally, the default `axis=None` will align on both index and columns:
>>> left, right = df.align(other, join="outer", axis=None)
>>> left
A B C D E
1 4.0 2.0 NaN 1.0 3.0
2 9.0 7.0 NaN 6.0 8.0
3 NaN NaN NaN NaN NaN
4 NaN NaN NaN NaN NaN
>>> right
A B C D E
1 NaN NaN NaN NaN NaN
2 10.0 20.0 30.0 40.0 NaN
3 60.0 70.0 80.0 90.0 NaN
4 600.0 700.0 800.0 900.0 NaN
"""
method = clean_fill_method(method)
if broadcast_axis == 1 and self.ndim != other.ndim:
if isinstance(self, ABCSeries):
# this means other is a DataFrame, and we need to broadcast
# self
cons = self._constructor_expanddim
df = cons(
{c: self for c in other.columns}, **other._construct_axes_dict()
)
return df._align_frame(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
elif isinstance(other, ABCSeries):
# this means self is a DataFrame, and we need to broadcast
# other
cons = other._constructor_expanddim
df = cons(
{c: other for c in self.columns}, **self._construct_axes_dict()
)
return self._align_frame(
df,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
if axis is not None:
axis = self._get_axis_number(axis)
if isinstance(other, ABCDataFrame):
return self._align_frame(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
elif isinstance(other, ABCSeries):
return self._align_series(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def _align_frame(
self,
other,
join: AlignJoin = "outer",
axis: Axis | None = None,
level=None,
copy: bool_t | None = None,
fill_value=None,
method=None,
limit=None,
fill_axis: Axis = 0,
):
# defaults
join_index, join_columns = None, None
ilidx, iridx = None, None
clidx, cridx = None, None
is_series = isinstance(self, ABCSeries)
if (axis is None or axis == 0) and not self.index.equals(other.index):
join_index, ilidx, iridx = self.index.join(
other.index, how=join, level=level, return_indexers=True
)
if (
(axis is None or axis == 1)
and not is_series
and not self.columns.equals(other.columns)
):
join_columns, clidx, cridx = self.columns.join(
other.columns, how=join, level=level, return_indexers=True
)
if is_series:
reindexers = {0: [join_index, ilidx]}
else:
reindexers = {0: [join_index, ilidx], 1: [join_columns, clidx]}
left = self._reindex_with_indexers(
reindexers, copy=copy, fill_value=fill_value, allow_dups=True
)
# other must be always DataFrame
right = other._reindex_with_indexers(
{0: [join_index, iridx], 1: [join_columns, cridx]},
copy=copy,
fill_value=fill_value,
allow_dups=True,
)
if method is not None:
_left = left.fillna(method=method, axis=fill_axis, limit=limit)
assert _left is not None # needed for mypy
left = _left
right = right.fillna(method=method, axis=fill_axis, limit=limit)
# if DatetimeIndex have different tz, convert to UTC
left, right = _align_as_utc(left, right, join_index)
return (
left.__finalize__(self),
right.__finalize__(other),
)
def _align_series(
self,
other,
join: AlignJoin = "outer",
axis: Axis | None = None,
level=None,
copy: bool_t | None = None,
fill_value=None,
method=None,
limit=None,
fill_axis: Axis = 0,
):
is_series = isinstance(self, ABCSeries)
if copy and using_copy_on_write():
copy = False
if (not is_series and axis is None) or axis not in [None, 0, 1]:
raise ValueError("Must specify axis=0 or 1")
if is_series and axis == 1:
raise ValueError("cannot align series to a series other than axis 0")
# series/series compat, other must always be a Series
if not axis:
# equal
if self.index.equals(other.index):
join_index, lidx, ridx = None, None, None
else:
join_index, lidx, ridx = self.index.join(
other.index, how=join, level=level, return_indexers=True
)
if is_series:
left = self._reindex_indexer(join_index, lidx, copy)
elif lidx is None or join_index is None:
left = self.copy(deep=copy)
else:
left = self._constructor(
self._mgr.reindex_indexer(join_index, lidx, axis=1, copy=copy)
)
right = other._reindex_indexer(join_index, ridx, copy)
else:
# one has > 1 ndim
fdata = self._mgr
join_index = self.axes[1]
lidx, ridx = None, None
if not join_index.equals(other.index):
join_index, lidx, ridx = join_index.join(
other.index, how=join, level=level, return_indexers=True
)
if lidx is not None:
bm_axis = self._get_block_manager_axis(1)
fdata = fdata.reindex_indexer(join_index, lidx, axis=bm_axis)
if copy and fdata is self._mgr:
fdata = fdata.copy()
left = self._constructor(fdata)
if ridx is None:
right = other.copy(deep=copy)
else:
right = other.reindex(join_index, level=level)
# fill
fill_na = notna(fill_value) or (method is not None)
if fill_na:
left = left.fillna(fill_value, method=method, limit=limit, axis=fill_axis)
right = right.fillna(fill_value, method=method, limit=limit)
# if DatetimeIndex have different tz, convert to UTC
if is_series or (not is_series and axis == 0):
left, right = _align_as_utc(left, right, join_index)
return (
left.__finalize__(self),
right.__finalize__(other),
)
def _where(
self,
cond,
other=lib.no_default,
inplace: bool_t = False,
axis: Axis | None = None,
level=None,
):
"""
Equivalent to public method `where`, except that `other` is not
applied as a function even if callable. Used in __setitem__.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if axis is not None:
axis = self._get_axis_number(axis)
# align the cond to same shape as myself
cond = common.apply_if_callable(cond, self)
if isinstance(cond, NDFrame):
# CoW: Make sure reference is not kept alive
cond = cond.align(self, join="right", broadcast_axis=1, copy=False)[0]
else:
if not hasattr(cond, "shape"):
cond = np.asanyarray(cond)
if cond.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
cond = self._constructor(cond, **self._construct_axes_dict(), copy=False)
# make sure we are boolean
fill_value = bool(inplace)
cond = cond.fillna(fill_value)
msg = "Boolean array expected for the condition, not {dtype}"
if not cond.empty:
if not isinstance(cond, ABCDataFrame):
# This is a single-dimensional object.
if not is_bool_dtype(cond):
raise ValueError(msg.format(dtype=cond.dtype))
else:
for _dt in cond.dtypes:
if not is_bool_dtype(_dt):
raise ValueError(msg.format(dtype=_dt))
else:
# GH#21947 we have an empty DataFrame/Series, could be object-dtype
cond = cond.astype(bool)
cond = -cond if inplace else cond
cond = cond.reindex(self._info_axis, axis=self._info_axis_number, copy=False)
# try to align with other
if isinstance(other, NDFrame):
# align with me
if other.ndim <= self.ndim:
# CoW: Make sure reference is not kept alive
other = self.align(
other,
join="left",
axis=axis,
level=level,
fill_value=None,
copy=False,
)[1]
# if we are NOT aligned, raise as we cannot where index
if axis is None and not other._indexed_same(self):
raise InvalidIndexError
if other.ndim < self.ndim:
# TODO(EA2D): avoid object-dtype cast in EA case GH#38729
other = other._values
if axis == 0:
other = np.reshape(other, (-1, 1))
elif axis == 1:
other = np.reshape(other, (1, -1))
other = np.broadcast_to(other, self.shape)
# slice me out of the other
else:
raise NotImplementedError(
"cannot align with a higher dimensional NDFrame"
)
elif not isinstance(other, (MultiIndex, NDFrame)):
# mainly just catching Index here
other = extract_array(other, extract_numpy=True)
if isinstance(other, (np.ndarray, ExtensionArray)):
if other.shape != self.shape:
if self.ndim != 1:
# In the ndim == 1 case we may have
# other length 1, which we treat as scalar (GH#2745, GH#4192)
# or len(other) == icond.sum(), which we treat like
# __setitem__ (GH#3235)
raise ValueError(
"other must be the same shape as self when an ndarray"
)
# we are the same shape, so create an actual object for alignment
else:
other = self._constructor(
other, **self._construct_axes_dict(), copy=False
)
if axis is None:
axis = 0
if self.ndim == getattr(other, "ndim", 0):
align = True
else:
align = self._get_axis_number(axis) == 1
if inplace:
# we may have different type blocks come out of putmask, so
# reconstruct the block manager
self._check_inplace_setting(other)
new_data = self._mgr.putmask(mask=cond, new=other, align=align)
result = self._constructor(new_data)
return self._update_inplace(result)
else:
new_data = self._mgr.where(
other=other,
cond=cond,
align=align,
)
result = self._constructor(new_data)
return result.__finalize__(self)
def where(
self: NDFrameT,
cond,
other=...,
*,
inplace: Literal[False] = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT:
...
def where(
self,
cond,
other=...,
*,
inplace: Literal[True],
axis: Axis | None = ...,
level: Level = ...,
) -> None:
...
def where(
self: NDFrameT,
cond,
other=...,
*,
inplace: bool_t = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT | None:
...
klass=_shared_doc_kwargs["klass"],
cond="True",
cond_rev="False",
name="where",
name_other="mask",
)
def where(
self: NDFrameT,
cond,
other=np.nan,
*,
inplace: bool_t = False,
axis: Axis | None = None,
level: Level = None,
) -> NDFrameT | None:
"""
Replace values where the condition is {cond_rev}.
Parameters
----------
cond : bool {klass}, array-like, or callable
Where `cond` is {cond}, keep the original value. Where
{cond_rev}, replace with corresponding value from `other`.
If `cond` is callable, it is computed on the {klass} and
should return boolean {klass} or array. The callable must
not change input {klass} (though pandas doesn't check it).
other : scalar, {klass}, or callable
Entries where `cond` is {cond_rev} are replaced with
corresponding value from `other`.
If other is callable, it is computed on the {klass} and
should return scalar or {klass}. The callable must not
change input {klass} (though pandas doesn't check it).
If not specified, entries will be filled with the corresponding
NULL value (``np.nan`` for numpy dtypes, ``pd.NA`` for extension
dtypes).
inplace : bool, default False
Whether to perform the operation in place on the data.
axis : int, default None
Alignment axis if needed. For `Series` this parameter is
unused and defaults to 0.
level : int, default None
Alignment level if needed.
Returns
-------
Same type as caller or None if ``inplace=True``.
See Also
--------
:func:`DataFrame.{name_other}` : Return an object of same shape as
self.
Notes
-----
The {name} method is an application of the if-then idiom. For each
element in the calling DataFrame, if ``cond`` is ``{cond}`` the
element is used; otherwise the corresponding element from the DataFrame
``other`` is used. If the axis of ``other`` does not align with axis of
``cond`` {klass}, the misaligned index positions will be filled with
{cond_rev}.
The signature for :func:`DataFrame.where` differs from
:func:`numpy.where`. Roughly ``df1.where(m, df2)`` is equivalent to
``np.where(m, df1, df2)``.
For further details and examples see the ``{name}`` documentation in
:ref:`indexing <indexing.where_mask>`.
The dtype of the object takes precedence. The fill value is casted to
the object's dtype, if this can be done losslessly.
Examples
--------
>>> s = pd.Series(range(5))
>>> s.where(s > 0)
0 NaN
1 1.0
2 2.0
3 3.0
4 4.0
dtype: float64
>>> s.mask(s > 0)
0 0.0
1 NaN
2 NaN
3 NaN
4 NaN
dtype: float64
>>> s = pd.Series(range(5))
>>> t = pd.Series([True, False])
>>> s.where(t, 99)
0 0
1 99
2 99
3 99
4 99
dtype: int64
>>> s.mask(t, 99)
0 99
1 1
2 99
3 99
4 99
dtype: int64
>>> s.where(s > 1, 10)
0 10
1 10
2 2
3 3
4 4
dtype: int64
>>> s.mask(s > 1, 10)
0 0
1 1
2 10
3 10
4 10
dtype: int64
>>> df = pd.DataFrame(np.arange(10).reshape(-1, 2), columns=['A', 'B'])
>>> df
A B
0 0 1
1 2 3
2 4 5
3 6 7
4 8 9
>>> m = df % 3 == 0
>>> df.where(m, -df)
A B
0 0 -1
1 -2 3
2 -4 -5
3 6 -7
4 -8 9
>>> df.where(m, -df) == np.where(m, df, -df)
A B
0 True True
1 True True
2 True True
3 True True
4 True True
>>> df.where(m, -df) == df.mask(~m, -df)
A B
0 True True
1 True True
2 True True
3 True True
4 True True
"""
other = common.apply_if_callable(other, self)
return self._where(cond, other, inplace, axis, level)
def mask(
self: NDFrameT,
cond,
other=...,
*,
inplace: Literal[False] = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT:
...
def mask(
self,
cond,
other=...,
*,
inplace: Literal[True],
axis: Axis | None = ...,
level: Level = ...,
) -> None:
...
def mask(
self: NDFrameT,
cond,
other=...,
*,
inplace: bool_t = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT | None:
...
where,
klass=_shared_doc_kwargs["klass"],
cond="False",
cond_rev="True",
name="mask",
name_other="where",
)
def mask(
self: NDFrameT,
cond,
other=lib.no_default,
*,
inplace: bool_t = False,
axis: Axis | None = None,
level: Level = None,
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
cond = common.apply_if_callable(cond, self)
# see gh-21891
if not hasattr(cond, "__invert__"):
cond = np.array(cond)
return self.where(
~cond,
other=other,
inplace=inplace,
axis=axis,
level=level,
)
def shift(
self: NDFrameT,
periods: int = 1,
freq=None,
axis: Axis = 0,
fill_value: Hashable = None,
) -> NDFrameT:
"""
Shift index by desired number of periods with an optional time `freq`.
When `freq` is not passed, shift the index without realigning the data.
If `freq` is passed (in this case, the index must be date or datetime,
or it will raise a `NotImplementedError`), the index will be
increased using the periods and the `freq`. `freq` can be inferred
when specified as "infer" as long as either freq or inferred_freq
attribute is set in the index.
Parameters
----------
periods : int
Number of periods to shift. Can be positive or negative.
freq : DateOffset, tseries.offsets, timedelta, or str, optional
Offset to use from the tseries module or time rule (e.g. 'EOM').
If `freq` is specified then the index values are shifted but the
data is not realigned. That is, use `freq` if you would like to
extend the index when shifting and preserve the original data.
If `freq` is specified as "infer" then it will be inferred from
the freq or inferred_freq attributes of the index. If neither of
those attributes exist, a ValueError is thrown.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Shift direction. For `Series` this parameter is unused and defaults to 0.
fill_value : object, optional
The scalar value to use for newly introduced missing values.
the default depends on the dtype of `self`.
For numeric data, ``np.nan`` is used.
For datetime, timedelta, or period data, etc. :attr:`NaT` is used.
For extension dtypes, ``self.dtype.na_value`` is used.
.. versionchanged:: 1.1.0
Returns
-------
{klass}
Copy of input object, shifted.
See Also
--------
Index.shift : Shift values of Index.
DatetimeIndex.shift : Shift values of DatetimeIndex.
PeriodIndex.shift : Shift values of PeriodIndex.
Examples
--------
>>> df = pd.DataFrame({{"Col1": [10, 20, 15, 30, 45],
... "Col2": [13, 23, 18, 33, 48],
... "Col3": [17, 27, 22, 37, 52]}},
... index=pd.date_range("2020-01-01", "2020-01-05"))
>>> df
Col1 Col2 Col3
2020-01-01 10 13 17
2020-01-02 20 23 27
2020-01-03 15 18 22
2020-01-04 30 33 37
2020-01-05 45 48 52
>>> df.shift(periods=3)
Col1 Col2 Col3
2020-01-01 NaN NaN NaN
2020-01-02 NaN NaN NaN
2020-01-03 NaN NaN NaN
2020-01-04 10.0 13.0 17.0
2020-01-05 20.0 23.0 27.0
>>> df.shift(periods=1, axis="columns")
Col1 Col2 Col3
2020-01-01 NaN 10 13
2020-01-02 NaN 20 23
2020-01-03 NaN 15 18
2020-01-04 NaN 30 33
2020-01-05 NaN 45 48
>>> df.shift(periods=3, fill_value=0)
Col1 Col2 Col3
2020-01-01 0 0 0
2020-01-02 0 0 0
2020-01-03 0 0 0
2020-01-04 10 13 17
2020-01-05 20 23 27
>>> df.shift(periods=3, freq="D")
Col1 Col2 Col3
2020-01-04 10 13 17
2020-01-05 20 23 27
2020-01-06 15 18 22
2020-01-07 30 33 37
2020-01-08 45 48 52
>>> df.shift(periods=3, freq="infer")
Col1 Col2 Col3
2020-01-04 10 13 17
2020-01-05 20 23 27
2020-01-06 15 18 22
2020-01-07 30 33 37
2020-01-08 45 48 52
"""
if periods == 0:
return self.copy(deep=None)
if freq is None:
# when freq is None, data is shifted, index is not
axis = self._get_axis_number(axis)
new_data = self._mgr.shift(
periods=periods, axis=axis, fill_value=fill_value
)
return self._constructor(new_data).__finalize__(self, method="shift")
# when freq is given, index is shifted, data is not
index = self._get_axis(axis)
if freq == "infer":
freq = getattr(index, "freq", None)
if freq is None:
freq = getattr(index, "inferred_freq", None)
if freq is None:
msg = "Freq was not set in the index hence cannot be inferred"
raise ValueError(msg)
elif isinstance(freq, str):
freq = to_offset(freq)
if isinstance(index, PeriodIndex):
orig_freq = to_offset(index.freq)
if freq != orig_freq:
assert orig_freq is not None # for mypy
raise ValueError(
f"Given freq {freq.rule_code} does not match "
f"PeriodIndex freq {orig_freq.rule_code}"
)
new_ax = index.shift(periods)
else:
new_ax = index.shift(periods, freq)
result = self.set_axis(new_ax, axis=axis)
return result.__finalize__(self, method="shift")
def truncate(
self: NDFrameT,
before=None,
after=None,
axis: Axis | None = None,
copy: bool_t | None = None,
) -> NDFrameT:
"""
Truncate a Series or DataFrame before and after some index value.
This is a useful shorthand for boolean indexing based on index
values above or below certain thresholds.
Parameters
----------
before : date, str, int
Truncate all rows before this index value.
after : date, str, int
Truncate all rows after this index value.
axis : {0 or 'index', 1 or 'columns'}, optional
Axis to truncate. Truncates the index (rows) by default.
For `Series` this parameter is unused and defaults to 0.
copy : bool, default is True,
Return a copy of the truncated section.
Returns
-------
type of caller
The truncated Series or DataFrame.
See Also
--------
DataFrame.loc : Select a subset of a DataFrame by label.
DataFrame.iloc : Select a subset of a DataFrame by position.
Notes
-----
If the index being truncated contains only datetime values,
`before` and `after` may be specified as strings instead of
Timestamps.
Examples
--------
>>> df = pd.DataFrame({'A': ['a', 'b', 'c', 'd', 'e'],
... 'B': ['f', 'g', 'h', 'i', 'j'],
... 'C': ['k', 'l', 'm', 'n', 'o']},
... index=[1, 2, 3, 4, 5])
>>> df
A B C
1 a f k
2 b g l
3 c h m
4 d i n
5 e j o
>>> df.truncate(before=2, after=4)
A B C
2 b g l
3 c h m
4 d i n
The columns of a DataFrame can be truncated.
>>> df.truncate(before="A", after="B", axis="columns")
A B
1 a f
2 b g
3 c h
4 d i
5 e j
For Series, only rows can be truncated.
>>> df['A'].truncate(before=2, after=4)
2 b
3 c
4 d
Name: A, dtype: object
The index values in ``truncate`` can be datetimes or string
dates.
>>> dates = pd.date_range('2016-01-01', '2016-02-01', freq='s')
>>> df = pd.DataFrame(index=dates, data={'A': 1})
>>> df.tail()
A
2016-01-31 23:59:56 1
2016-01-31 23:59:57 1
2016-01-31 23:59:58 1
2016-01-31 23:59:59 1
2016-02-01 00:00:00 1
>>> df.truncate(before=pd.Timestamp('2016-01-05'),
... after=pd.Timestamp('2016-01-10')).tail()
A
2016-01-09 23:59:56 1
2016-01-09 23:59:57 1
2016-01-09 23:59:58 1
2016-01-09 23:59:59 1
2016-01-10 00:00:00 1
Because the index is a DatetimeIndex containing only dates, we can
specify `before` and `after` as strings. They will be coerced to
Timestamps before truncation.
>>> df.truncate('2016-01-05', '2016-01-10').tail()
A
2016-01-09 23:59:56 1
2016-01-09 23:59:57 1
2016-01-09 23:59:58 1
2016-01-09 23:59:59 1
2016-01-10 00:00:00 1
Note that ``truncate`` assumes a 0 value for any unspecified time
component (midnight). This differs from partial string slicing, which
returns any partially matching dates.
>>> df.loc['2016-01-05':'2016-01-10', :].tail()
A
2016-01-10 23:59:55 1
2016-01-10 23:59:56 1
2016-01-10 23:59:57 1
2016-01-10 23:59:58 1
2016-01-10 23:59:59 1
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
# GH 17935
# Check that index is sorted
if not ax.is_monotonic_increasing and not ax.is_monotonic_decreasing:
raise ValueError("truncate requires a sorted index")
# if we have a date index, convert to dates, otherwise
# treat like a slice
if ax._is_all_dates:
from pandas.core.tools.datetimes import to_datetime
before = to_datetime(before)
after = to_datetime(after)
if before is not None and after is not None and before > after:
raise ValueError(f"Truncate: {after} must be after {before}")
if len(ax) > 1 and ax.is_monotonic_decreasing and ax.nunique() > 1:
before, after = after, before
slicer = [slice(None, None)] * self._AXIS_LEN
slicer[axis] = slice(before, after)
result = self.loc[tuple(slicer)]
if isinstance(ax, MultiIndex):
setattr(result, self._get_axis_name(axis), ax.truncate(before, after))
result = result.copy(deep=copy and not using_copy_on_write())
return result
def tz_convert(
self: NDFrameT, tz, axis: Axis = 0, level=None, copy: bool_t | None = None
) -> NDFrameT:
"""
Convert tz-aware axis to target time zone.
Parameters
----------
tz : str or tzinfo object or None
Target time zone. Passing ``None`` will convert to
UTC and remove the timezone information.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
The axis to convert
level : int, str, default None
If axis is a MultiIndex, convert a specific level. Otherwise
must be None.
copy : bool, default True
Also make a copy of the underlying data.
Returns
-------
{klass}
Object with time zone converted axis.
Raises
------
TypeError
If the axis is tz-naive.
Examples
--------
Change to another time zone:
>>> s = pd.Series(
... [1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']),
... )
>>> s.tz_convert('Asia/Shanghai')
2018-09-15 07:30:00+08:00 1
dtype: int64
Pass None to convert to UTC and get a tz-naive index:
>>> s = pd.Series([1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']))
>>> s.tz_convert(None)
2018-09-14 23:30:00 1
dtype: int64
"""
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
def _tz_convert(ax, tz):
if not hasattr(ax, "tz_convert"):
if len(ax) > 0:
ax_name = self._get_axis_name(axis)
raise TypeError(
f"{ax_name} is not a valid DatetimeIndex or PeriodIndex"
)
ax = DatetimeIndex([], tz=tz)
else:
ax = ax.tz_convert(tz)
return ax
# if a level is given it must be a MultiIndex level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
new_level = _tz_convert(ax.levels[level], tz)
ax = ax.set_levels(new_level, level=level)
else:
if level not in (None, 0, ax.name):
raise ValueError(f"The level {level} is not valid")
ax = _tz_convert(ax, tz)
result = self.copy(deep=copy and not using_copy_on_write())
result = result.set_axis(ax, axis=axis, copy=False)
return result.__finalize__(self, method="tz_convert")
def tz_localize(
self: NDFrameT,
tz,
axis: Axis = 0,
level=None,
copy: bool_t | None = None,
ambiguous: TimeAmbiguous = "raise",
nonexistent: TimeNonexistent = "raise",
) -> NDFrameT:
"""
Localize tz-naive index of a Series or DataFrame to target time zone.
This operation localizes the Index. To localize the values in a
timezone-naive Series, use :meth:`Series.dt.tz_localize`.
Parameters
----------
tz : str or tzinfo or None
Time zone to localize. Passing ``None`` will remove the
time zone information and preserve local time.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
The axis to localize
level : int, str, default None
If axis ia a MultiIndex, localize a specific level. Otherwise
must be None.
copy : bool, default True
Also make a copy of the underlying data.
ambiguous : 'infer', bool-ndarray, 'NaT', default 'raise'
When clocks moved backward due to DST, ambiguous times may arise.
For example in Central European Time (UTC+01), when going from
03:00 DST to 02:00 non-DST, 02:30:00 local time occurs both at
00:30:00 UTC and at 01:30:00 UTC. In such a situation, the
`ambiguous` parameter dictates how ambiguous times should be
handled.
- 'infer' will attempt to infer fall dst-transition hours based on
order
- bool-ndarray where True signifies a DST time, False designates
a non-DST time (note that this flag is only applicable for
ambiguous times)
- 'NaT' will return NaT where there are ambiguous times
- 'raise' will raise an AmbiguousTimeError if there are ambiguous
times.
nonexistent : str, default 'raise'
A nonexistent time does not exist in a particular timezone
where clocks moved forward due to DST. Valid values are:
- 'shift_forward' will shift the nonexistent time forward to the
closest existing time
- 'shift_backward' will shift the nonexistent time backward to the
closest existing time
- 'NaT' will return NaT where there are nonexistent times
- timedelta objects will shift nonexistent times by the timedelta
- 'raise' will raise an NonExistentTimeError if there are
nonexistent times.
Returns
-------
{klass}
Same type as the input.
Raises
------
TypeError
If the TimeSeries is tz-aware and tz is not None.
Examples
--------
Localize local times:
>>> s = pd.Series(
... [1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00']),
... )
>>> s.tz_localize('CET')
2018-09-15 01:30:00+02:00 1
dtype: int64
Pass None to convert to tz-naive index and preserve local time:
>>> s = pd.Series([1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']))
>>> s.tz_localize(None)
2018-09-15 01:30:00 1
dtype: int64
Be careful with DST changes. When there is sequential data, pandas
can infer the DST time:
>>> s = pd.Series(range(7),
... index=pd.DatetimeIndex(['2018-10-28 01:30:00',
... '2018-10-28 02:00:00',
... '2018-10-28 02:30:00',
... '2018-10-28 02:00:00',
... '2018-10-28 02:30:00',
... '2018-10-28 03:00:00',
... '2018-10-28 03:30:00']))
>>> s.tz_localize('CET', ambiguous='infer')
2018-10-28 01:30:00+02:00 0
2018-10-28 02:00:00+02:00 1
2018-10-28 02:30:00+02:00 2
2018-10-28 02:00:00+01:00 3
2018-10-28 02:30:00+01:00 4
2018-10-28 03:00:00+01:00 5
2018-10-28 03:30:00+01:00 6
dtype: int64
In some cases, inferring the DST is impossible. In such cases, you can
pass an ndarray to the ambiguous parameter to set the DST explicitly
>>> s = pd.Series(range(3),
... index=pd.DatetimeIndex(['2018-10-28 01:20:00',
... '2018-10-28 02:36:00',
... '2018-10-28 03:46:00']))
>>> s.tz_localize('CET', ambiguous=np.array([True, True, False]))
2018-10-28 01:20:00+02:00 0
2018-10-28 02:36:00+02:00 1
2018-10-28 03:46:00+01:00 2
dtype: int64
If the DST transition causes nonexistent times, you can shift these
dates forward or backward with a timedelta object or `'shift_forward'`
or `'shift_backward'`.
>>> s = pd.Series(range(2),
... index=pd.DatetimeIndex(['2015-03-29 02:30:00',
... '2015-03-29 03:30:00']))
>>> s.tz_localize('Europe/Warsaw', nonexistent='shift_forward')
2015-03-29 03:00:00+02:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
>>> s.tz_localize('Europe/Warsaw', nonexistent='shift_backward')
2015-03-29 01:59:59.999999999+01:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
>>> s.tz_localize('Europe/Warsaw', nonexistent=pd.Timedelta('1H'))
2015-03-29 03:30:00+02:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
"""
nonexistent_options = ("raise", "NaT", "shift_forward", "shift_backward")
if nonexistent not in nonexistent_options and not isinstance(
nonexistent, dt.timedelta
):
raise ValueError(
"The nonexistent argument must be one of 'raise', "
"'NaT', 'shift_forward', 'shift_backward' or "
"a timedelta object"
)
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
def _tz_localize(ax, tz, ambiguous, nonexistent):
if not hasattr(ax, "tz_localize"):
if len(ax) > 0:
ax_name = self._get_axis_name(axis)
raise TypeError(
f"{ax_name} is not a valid DatetimeIndex or PeriodIndex"
)
ax = DatetimeIndex([], tz=tz)
else:
ax = ax.tz_localize(tz, ambiguous=ambiguous, nonexistent=nonexistent)
return ax
# if a level is given it must be a MultiIndex level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
new_level = _tz_localize(ax.levels[level], tz, ambiguous, nonexistent)
ax = ax.set_levels(new_level, level=level)
else:
if level not in (None, 0, ax.name):
raise ValueError(f"The level {level} is not valid")
ax = _tz_localize(ax, tz, ambiguous, nonexistent)
result = self.copy(deep=copy and not using_copy_on_write())
result = result.set_axis(ax, axis=axis, copy=False)
return result.__finalize__(self, method="tz_localize")
# ----------------------------------------------------------------------
# Numeric Methods
def describe(
self: NDFrameT,
percentiles=None,
include=None,
exclude=None,
) -> NDFrameT:
"""
Generate descriptive statistics.
Descriptive statistics include those that summarize the central
tendency, dispersion and shape of a
dataset's distribution, excluding ``NaN`` values.
Analyzes both numeric and object series, as well
as ``DataFrame`` column sets of mixed data types. The output
will vary depending on what is provided. Refer to the notes
below for more detail.
Parameters
----------
percentiles : list-like of numbers, optional
The percentiles to include in the output. All should
fall between 0 and 1. The default is
``[.25, .5, .75]``, which returns the 25th, 50th, and
75th percentiles.
include : 'all', list-like of dtypes or None (default), optional
A white list of data types to include in the result. Ignored
for ``Series``. Here are the options:
- 'all' : All columns of the input will be included in the output.
- A list-like of dtypes : Limits the results to the
provided data types.
To limit the result to numeric types submit
``numpy.number``. To limit it instead to object columns submit
the ``numpy.object`` data type. Strings
can also be used in the style of
``select_dtypes`` (e.g. ``df.describe(include=['O'])``). To
select pandas categorical columns, use ``'category'``
- None (default) : The result will include all numeric columns.
exclude : list-like of dtypes or None (default), optional,
A black list of data types to omit from the result. Ignored
for ``Series``. Here are the options:
- A list-like of dtypes : Excludes the provided data types
from the result. To exclude numeric types submit
``numpy.number``. To exclude object columns submit the data
type ``numpy.object``. Strings can also be used in the style of
``select_dtypes`` (e.g. ``df.describe(exclude=['O'])``). To
exclude pandas categorical columns, use ``'category'``
- None (default) : The result will exclude nothing.
Returns
-------
Series or DataFrame
Summary statistics of the Series or Dataframe provided.
See Also
--------
DataFrame.count: Count number of non-NA/null observations.
DataFrame.max: Maximum of the values in the object.
DataFrame.min: Minimum of the values in the object.
DataFrame.mean: Mean of the values.
DataFrame.std: Standard deviation of the observations.
DataFrame.select_dtypes: Subset of a DataFrame including/excluding
columns based on their dtype.
Notes
-----
For numeric data, the result's index will include ``count``,
``mean``, ``std``, ``min``, ``max`` as well as lower, ``50`` and
upper percentiles. By default the lower percentile is ``25`` and the
upper percentile is ``75``. The ``50`` percentile is the
same as the median.
For object data (e.g. strings or timestamps), the result's index
will include ``count``, ``unique``, ``top``, and ``freq``. The ``top``
is the most common value. The ``freq`` is the most common value's
frequency. Timestamps also include the ``first`` and ``last`` items.
If multiple object values have the highest count, then the
``count`` and ``top`` results will be arbitrarily chosen from
among those with the highest count.
For mixed data types provided via a ``DataFrame``, the default is to
return only an analysis of numeric columns. If the dataframe consists
only of object and categorical data without any numeric columns, the
default is to return an analysis of both the object and categorical
columns. If ``include='all'`` is provided as an option, the result
will include a union of attributes of each type.
The `include` and `exclude` parameters can be used to limit
which columns in a ``DataFrame`` are analyzed for the output.
The parameters are ignored when analyzing a ``Series``.
Examples
--------
Describing a numeric ``Series``.
>>> s = pd.Series([1, 2, 3])
>>> s.describe()
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
dtype: float64
Describing a categorical ``Series``.
>>> s = pd.Series(['a', 'a', 'b', 'c'])
>>> s.describe()
count 4
unique 3
top a
freq 2
dtype: object
Describing a timestamp ``Series``.
>>> s = pd.Series([
... np.datetime64("2000-01-01"),
... np.datetime64("2010-01-01"),
... np.datetime64("2010-01-01")
... ])
>>> s.describe()
count 3
mean 2006-09-01 08:00:00
min 2000-01-01 00:00:00
25% 2004-12-31 12:00:00
50% 2010-01-01 00:00:00
75% 2010-01-01 00:00:00
max 2010-01-01 00:00:00
dtype: object
Describing a ``DataFrame``. By default only numeric fields
are returned.
>>> df = pd.DataFrame({'categorical': pd.Categorical(['d','e','f']),
... 'numeric': [1, 2, 3],
... 'object': ['a', 'b', 'c']
... })
>>> df.describe()
numeric
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Describing all columns of a ``DataFrame`` regardless of data type.
>>> df.describe(include='all') # doctest: +SKIP
categorical numeric object
count 3 3.0 3
unique 3 NaN 3
top f NaN a
freq 1 NaN 1
mean NaN 2.0 NaN
std NaN 1.0 NaN
min NaN 1.0 NaN
25% NaN 1.5 NaN
50% NaN 2.0 NaN
75% NaN 2.5 NaN
max NaN 3.0 NaN
Describing a column from a ``DataFrame`` by accessing it as
an attribute.
>>> df.numeric.describe()
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Name: numeric, dtype: float64
Including only numeric columns in a ``DataFrame`` description.
>>> df.describe(include=[np.number])
numeric
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Including only string columns in a ``DataFrame`` description.
>>> df.describe(include=[object]) # doctest: +SKIP
object
count 3
unique 3
top a
freq 1
Including only categorical columns from a ``DataFrame`` description.
>>> df.describe(include=['category'])
categorical
count 3
unique 3
top d
freq 1
Excluding numeric columns from a ``DataFrame`` description.
>>> df.describe(exclude=[np.number]) # doctest: +SKIP
categorical object
count 3 3
unique 3 3
top f a
freq 1 1
Excluding object columns from a ``DataFrame`` description.
>>> df.describe(exclude=[object]) # doctest: +SKIP
categorical numeric
count 3 3.0
unique 3 NaN
top f NaN
freq 1 NaN
mean NaN 2.0
std NaN 1.0
min NaN 1.0
25% NaN 1.5
50% NaN 2.0
75% NaN 2.5
max NaN 3.0
"""
return describe_ndframe(
obj=self,
include=include,
exclude=exclude,
percentiles=percentiles,
)
def pct_change(
self: NDFrameT,
periods: int = 1,
fill_method: Literal["backfill", "bfill", "pad", "ffill"] | None = "pad",
limit=None,
freq=None,
**kwargs,
) -> NDFrameT:
"""
Percentage change between the current and a prior element.
Computes the percentage change from the immediately previous row by
default. This is useful in comparing the percentage of change in a time
series of elements.
Parameters
----------
periods : int, default 1
Periods to shift for forming percent change.
fill_method : {'backfill', 'bfill', 'pad', 'ffill', None}, default 'pad'
How to handle NAs **before** computing percent changes.
limit : int, default None
The number of consecutive NAs to fill before stopping.
freq : DateOffset, timedelta, or str, optional
Increment to use from time series API (e.g. 'M' or BDay()).
**kwargs
Additional keyword arguments are passed into
`DataFrame.shift` or `Series.shift`.
Returns
-------
Series or DataFrame
The same type as the calling object.
See Also
--------
Series.diff : Compute the difference of two elements in a Series.
DataFrame.diff : Compute the difference of two elements in a DataFrame.
Series.shift : Shift the index by some number of periods.
DataFrame.shift : Shift the index by some number of periods.
Examples
--------
**Series**
>>> s = pd.Series([90, 91, 85])
>>> s
0 90
1 91
2 85
dtype: int64
>>> s.pct_change()
0 NaN
1 0.011111
2 -0.065934
dtype: float64
>>> s.pct_change(periods=2)
0 NaN
1 NaN
2 -0.055556
dtype: float64
See the percentage change in a Series where filling NAs with last
valid observation forward to next valid.
>>> s = pd.Series([90, 91, None, 85])
>>> s
0 90.0
1 91.0
2 NaN
3 85.0
dtype: float64
>>> s.pct_change(fill_method='ffill')
0 NaN
1 0.011111
2 0.000000
3 -0.065934
dtype: float64
**DataFrame**
Percentage change in French franc, Deutsche Mark, and Italian lira from
1980-01-01 to 1980-03-01.
>>> df = pd.DataFrame({
... 'FR': [4.0405, 4.0963, 4.3149],
... 'GR': [1.7246, 1.7482, 1.8519],
... 'IT': [804.74, 810.01, 860.13]},
... index=['1980-01-01', '1980-02-01', '1980-03-01'])
>>> df
FR GR IT
1980-01-01 4.0405 1.7246 804.74
1980-02-01 4.0963 1.7482 810.01
1980-03-01 4.3149 1.8519 860.13
>>> df.pct_change()
FR GR IT
1980-01-01 NaN NaN NaN
1980-02-01 0.013810 0.013684 0.006549
1980-03-01 0.053365 0.059318 0.061876
Percentage of change in GOOG and APPL stock volume. Shows computing
the percentage change between columns.
>>> df = pd.DataFrame({
... '2016': [1769950, 30586265],
... '2015': [1500923, 40912316],
... '2014': [1371819, 41403351]},
... index=['GOOG', 'APPL'])
>>> df
2016 2015 2014
GOOG 1769950 1500923 1371819
APPL 30586265 40912316 41403351
>>> df.pct_change(axis='columns', periods=-1)
2016 2015 2014
GOOG 0.179241 0.094112 NaN
APPL -0.252395 -0.011860 NaN
"""
axis = self._get_axis_number(kwargs.pop("axis", self._stat_axis_name))
if fill_method is None:
data = self
else:
_data = self.fillna(method=fill_method, axis=axis, limit=limit)
assert _data is not None # needed for mypy
data = _data
shifted = data.shift(periods=periods, freq=freq, axis=axis, **kwargs)
# Unsupported left operand type for / ("NDFrameT")
rs = data / shifted - 1 # type: ignore[operator]
if freq is not None:
# Shift method is implemented differently when freq is not None
# We want to restore the original index
rs = rs.loc[~rs.index.duplicated()]
rs = rs.reindex_like(data)
return rs.__finalize__(self, method="pct_change")
def _logical_func(
self,
name: str,
func,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> Series | bool_t:
nv.validate_logical_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if self.ndim > 1 and axis is None:
# Reduce along one dimension then the other, to simplify DataFrame._reduce
res = self._logical_func(
name, func, axis=0, bool_only=bool_only, skipna=skipna, **kwargs
)
return res._logical_func(name, func, skipna=skipna, **kwargs)
if (
self.ndim > 1
and axis == 1
and len(self._mgr.arrays) > 1
# TODO(EA2D): special-case not needed
and all(x.ndim == 2 for x in self._mgr.arrays)
and not kwargs
):
# Fastpath avoiding potentially expensive transpose
obj = self
if bool_only:
obj = self._get_bool_data()
return obj._reduce_axis1(name, func, skipna=skipna)
return self._reduce(
func,
name=name,
axis=axis,
skipna=skipna,
numeric_only=bool_only,
filter_type="bool",
)
def any(
self,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> DataFrame | Series | bool_t:
return self._logical_func(
"any", nanops.nanany, axis, bool_only, skipna, **kwargs
)
def all(
self,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> Series | bool_t:
return self._logical_func(
"all", nanops.nanall, axis, bool_only, skipna, **kwargs
)
def _accum_func(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
*args,
**kwargs,
):
skipna = nv.validate_cum_func_with_skipna(skipna, args, kwargs, name)
if axis is None:
axis = self._stat_axis_number
else:
axis = self._get_axis_number(axis)
if axis == 1:
return self.T._accum_func(
name, func, axis=0, skipna=skipna, *args, **kwargs # noqa: B026
).T
def block_accum_func(blk_values):
values = blk_values.T if hasattr(blk_values, "T") else blk_values
result: np.ndarray | ExtensionArray
if isinstance(values, ExtensionArray):
result = values._accumulate(name, skipna=skipna, **kwargs)
else:
result = nanops.na_accum_func(values, func, skipna=skipna)
result = result.T if hasattr(result, "T") else result
return result
result = self._mgr.apply(block_accum_func)
return self._constructor(result).__finalize__(self, method=name)
def cummax(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func(
"cummax", np.maximum.accumulate, axis, skipna, *args, **kwargs
)
def cummin(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func(
"cummin", np.minimum.accumulate, axis, skipna, *args, **kwargs
)
def cumsum(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func("cumsum", np.cumsum, axis, skipna, *args, **kwargs)
def cumprod(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func("cumprod", np.cumprod, axis, skipna, *args, **kwargs)
def _stat_function_ddof(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
nv.validate_stat_ddof_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if axis is None:
axis = self._stat_axis_number
return self._reduce(
func, name, axis=axis, numeric_only=numeric_only, skipna=skipna, ddof=ddof
)
def sem(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"sem", nanops.nansem, axis, skipna, ddof, numeric_only, **kwargs
)
def var(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"var", nanops.nanvar, axis, skipna, ddof, numeric_only, **kwargs
)
def std(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"std", nanops.nanstd, axis, skipna, ddof, numeric_only, **kwargs
)
def _stat_function(
self,
name: str,
func,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
if name == "median":
nv.validate_median((), kwargs)
else:
nv.validate_stat_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
return self._reduce(
func, name=name, axis=axis, skipna=skipna, numeric_only=numeric_only
)
def min(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return self._stat_function(
"min",
nanops.nanmin,
axis,
skipna,
numeric_only,
**kwargs,
)
def max(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return self._stat_function(
"max",
nanops.nanmax,
axis,
skipna,
numeric_only,
**kwargs,
)
def mean(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"mean", nanops.nanmean, axis, skipna, numeric_only, **kwargs
)
def median(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"median", nanops.nanmedian, axis, skipna, numeric_only, **kwargs
)
def skew(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"skew", nanops.nanskew, axis, skipna, numeric_only, **kwargs
)
def kurt(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"kurt", nanops.nankurt, axis, skipna, numeric_only, **kwargs
)
kurtosis = kurt
def _min_count_stat_function(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
if name == "sum":
nv.validate_sum((), kwargs)
elif name == "prod":
nv.validate_prod((), kwargs)
else:
nv.validate_stat_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if axis is None:
axis = self._stat_axis_number
return self._reduce(
func,
name=name,
axis=axis,
skipna=skipna,
numeric_only=numeric_only,
min_count=min_count,
)
def sum(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return self._min_count_stat_function(
"sum", nanops.nansum, axis, skipna, numeric_only, min_count, **kwargs
)
def prod(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return self._min_count_stat_function(
"prod",
nanops.nanprod,
axis,
skipna,
numeric_only,
min_count,
**kwargs,
)
product = prod
def _add_numeric_operations(cls) -> None:
"""
Add the operations to the cls; evaluate the doc strings again
"""
axis_descr, name1, name2 = _doc_params(cls)
_bool_doc,
desc=_any_desc,
name1=name1,
name2=name2,
axis_descr=axis_descr,
see_also=_any_see_also,
examples=_any_examples,
empty_value=False,
)
def any(
self,
*,
axis: Axis = 0,
bool_only=None,
skipna: bool_t = True,
**kwargs,
):
return NDFrame.any(
self,
axis=axis,
bool_only=bool_only,
skipna=skipna,
**kwargs,
)
setattr(cls, "any", any)
_bool_doc,
desc=_all_desc,
name1=name1,
name2=name2,
axis_descr=axis_descr,
see_also=_all_see_also,
examples=_all_examples,
empty_value=True,
)
def all(
self,
axis: Axis = 0,
bool_only=None,
skipna: bool_t = True,
**kwargs,
):
return NDFrame.all(self, axis, bool_only, skipna, **kwargs)
setattr(cls, "all", all)
_num_ddof_doc,
desc="Return unbiased standard error of the mean over requested "
"axis.\n\nNormalized by N-1 by default. This can be changed "
"using the ddof argument",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes="",
examples="",
)
def sem(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.sem(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "sem", sem)
_num_ddof_doc,
desc="Return unbiased variance over requested axis.\n\nNormalized by "
"N-1 by default. This can be changed using the ddof argument.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes="",
examples=_var_examples,
)
def var(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.var(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "var", var)
_num_ddof_doc,
desc="Return sample standard deviation over requested axis."
"\n\nNormalized by N-1 by default. This can be changed using the "
"ddof argument.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes=_std_notes,
examples=_std_examples,
)
def std(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.std(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "std", std)
_cnum_doc,
desc="minimum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="min",
examples=_cummin_examples,
)
def cummin(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cummin(self, axis, skipna, *args, **kwargs)
setattr(cls, "cummin", cummin)
_cnum_doc,
desc="maximum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="max",
examples=_cummax_examples,
)
def cummax(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cummax(self, axis, skipna, *args, **kwargs)
setattr(cls, "cummax", cummax)
_cnum_doc,
desc="sum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="sum",
examples=_cumsum_examples,
)
def cumsum(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cumsum(self, axis, skipna, *args, **kwargs)
setattr(cls, "cumsum", cumsum)
_cnum_doc,
desc="product",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="prod",
examples=_cumprod_examples,
)
def cumprod(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cumprod(self, axis, skipna, *args, **kwargs)
setattr(cls, "cumprod", cumprod)
# error: Untyped decorator makes function "sum" untyped
_num_doc,
desc="Return the sum of the values over the requested axis.\n\n"
"This is equivalent to the method ``numpy.sum``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count=_min_count_stub,
see_also=_stat_func_see_also,
examples=_sum_examples,
)
def sum(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return NDFrame.sum(self, axis, skipna, numeric_only, min_count, **kwargs)
setattr(cls, "sum", sum)
_num_doc,
desc="Return the product of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count=_min_count_stub,
see_also=_stat_func_see_also,
examples=_prod_examples,
)
def prod(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return NDFrame.prod(self, axis, skipna, numeric_only, min_count, **kwargs)
setattr(cls, "prod", prod)
cls.product = prod
_num_doc,
desc="Return the mean of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def mean(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.mean(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "mean", mean)
_num_doc,
desc="Return unbiased skew over requested axis.\n\nNormalized by N-1.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def skew(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.skew(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "skew", skew)
_num_doc,
desc="Return unbiased kurtosis over requested axis.\n\n"
"Kurtosis obtained using Fisher's definition of\n"
"kurtosis (kurtosis of normal == 0.0). Normalized "
"by N-1.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def kurt(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.kurt(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "kurt", kurt)
cls.kurtosis = kurt
_num_doc,
desc="Return the median of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def median(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.median(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "median", median)
_num_doc,
desc="Return the maximum of the values over the requested axis.\n\n"
"If you want the *index* of the maximum, use ``idxmax``. This is "
"the equivalent of the ``numpy.ndarray`` method ``argmax``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also=_stat_func_see_also,
examples=_max_examples,
)
def max(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.max(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "max", max)
_num_doc,
desc="Return the minimum of the values over the requested axis.\n\n"
"If you want the *index* of the minimum, use ``idxmin``. This is "
"the equivalent of the ``numpy.ndarray`` method ``argmin``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also=_stat_func_see_also,
examples=_min_examples,
)
def min(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.min(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "min", min)
def rolling(
self,
window: int | dt.timedelta | str | BaseOffset | BaseIndexer,
min_periods: int | None = None,
center: bool_t = False,
win_type: str | None = None,
on: str | None = None,
axis: Axis = 0,
closed: str | None = None,
step: int | None = None,
method: str = "single",
) -> Window | Rolling:
axis = self._get_axis_number(axis)
if win_type is not None:
return Window(
self,
window=window,
min_periods=min_periods,
center=center,
win_type=win_type,
on=on,
axis=axis,
closed=closed,
step=step,
method=method,
)
return Rolling(
self,
window=window,
min_periods=min_periods,
center=center,
win_type=win_type,
on=on,
axis=axis,
closed=closed,
step=step,
method=method,
)
def expanding(
self,
min_periods: int = 1,
axis: Axis = 0,
method: str = "single",
) -> Expanding:
axis = self._get_axis_number(axis)
return Expanding(self, min_periods=min_periods, axis=axis, method=method)
def ewm(
self,
com: float | None = None,
span: float | None = None,
halflife: float | TimedeltaConvertibleTypes | None = None,
alpha: float | None = None,
min_periods: int | None = 0,
adjust: bool_t = True,
ignore_na: bool_t = False,
axis: Axis = 0,
times: np.ndarray | DataFrame | Series | None = None,
method: str = "single",
) -> ExponentialMovingWindow:
axis = self._get_axis_number(axis)
return ExponentialMovingWindow(
self,
com=com,
span=span,
halflife=halflife,
alpha=alpha,
min_periods=min_periods,
adjust=adjust,
ignore_na=ignore_na,
axis=axis,
times=times,
method=method,
)
# ----------------------------------------------------------------------
# Arithmetic Methods
def _inplace_method(self, other, op):
"""
Wrap arithmetic method to operate inplace.
"""
result = op(self, other)
if (
self.ndim == 1
and result._indexed_same(self)
and is_dtype_equal(result.dtype, self.dtype)
):
# GH#36498 this inplace op can _actually_ be inplace.
# Item "ArrayManager" of "Union[ArrayManager, SingleArrayManager,
# BlockManager, SingleBlockManager]" has no attribute "setitem_inplace"
self._mgr.setitem_inplace( # type: ignore[union-attr]
slice(None), result._values
)
return self
# Delete cacher
self._reset_cacher()
# this makes sure that we are aligned like the input
# we are updating inplace so we want to ignore is_copy
self._update_inplace(
result.reindex_like(self, copy=False), verify_is_copy=False
)
return self
def __iadd__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for + ("Type[NDFrame]")
return self._inplace_method(other, type(self).__add__) # type: ignore[operator]
def __isub__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for - ("Type[NDFrame]")
return self._inplace_method(other, type(self).__sub__) # type: ignore[operator]
def __imul__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for * ("Type[NDFrame]")
return self._inplace_method(other, type(self).__mul__) # type: ignore[operator]
def __itruediv__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for / ("Type[NDFrame]")
return self._inplace_method(
other, type(self).__truediv__ # type: ignore[operator]
)
def __ifloordiv__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for // ("Type[NDFrame]")
return self._inplace_method(
other, type(self).__floordiv__ # type: ignore[operator]
)
def __imod__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for % ("Type[NDFrame]")
return self._inplace_method(other, type(self).__mod__) # type: ignore[operator]
def __ipow__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for ** ("Type[NDFrame]")
return self._inplace_method(other, type(self).__pow__) # type: ignore[operator]
def __iand__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for & ("Type[NDFrame]")
return self._inplace_method(other, type(self).__and__) # type: ignore[operator]
def __ior__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for | ("Type[NDFrame]")
return self._inplace_method(other, type(self).__or__) # type: ignore[operator]
def __ixor__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for ^ ("Type[NDFrame]")
return self._inplace_method(other, type(self).__xor__) # type: ignore[operator]
# ----------------------------------------------------------------------
# Misc methods
def _find_valid_index(self, *, how: str) -> Hashable | None:
"""
Retrieves the index of the first valid value.
Parameters
----------
how : {'first', 'last'}
Use this parameter to change between the first or last valid index.
Returns
-------
idx_first_valid : type of index
"""
idxpos = find_valid_index(self._values, how=how, is_valid=~isna(self._values))
if idxpos is None:
return None
return self.index[idxpos]
def first_valid_index(self) -> Hashable | None:
"""
Return index for {position} non-NA value or None, if no non-NA value is found.
Returns
-------
type of index
Notes
-----
If all elements are non-NA/null, returns None.
Also returns None for empty {klass}.
"""
return self._find_valid_index(how="first")
def last_valid_index(self) -> Hashable | None:
return self._find_valid_index(how="last")
def to_json(
path_or_buf: None,
obj: NDFrame,
orient: str | None = ...,
date_format: str = ...,
double_precision: int = ...,
force_ascii: bool = ...,
date_unit: str = ...,
default_handler: Callable[[Any], JSONSerializable] | None = ...,
lines: bool = ...,
compression: CompressionOptions = ...,
index: bool = ...,
indent: int = ...,
storage_options: StorageOptions = ...,
mode: Literal["a", "w"] = ...,
) -> str:
... | null |
173,501 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
class Writer(ABC):
_default_orient: str
def __init__(
self,
obj: NDFrame,
orient: str | None,
date_format: str,
double_precision: int,
ensure_ascii: bool,
date_unit: str,
index: bool,
default_handler: Callable[[Any], JSONSerializable] | None = None,
indent: int = 0,
) -> None:
self.obj = obj
if orient is None:
orient = self._default_orient
self.orient = orient
self.date_format = date_format
self.double_precision = double_precision
self.ensure_ascii = ensure_ascii
self.date_unit = date_unit
self.default_handler = default_handler
self.index = index
self.indent = indent
self.is_copy = None
self._format_axes()
def _format_axes(self):
raise AbstractMethodError(self)
def write(self) -> str:
iso_dates = self.date_format == "iso"
return dumps(
self.obj_to_write,
orient=self.orient,
double_precision=self.double_precision,
ensure_ascii=self.ensure_ascii,
date_unit=self.date_unit,
iso_dates=iso_dates,
default_handler=self.default_handler,
indent=self.indent,
)
def obj_to_write(self) -> NDFrame | Mapping[IndexLabel, Any]:
"""Object to write in JSON format."""
class SeriesWriter(Writer):
_default_orient = "index"
def obj_to_write(self) -> NDFrame | Mapping[IndexLabel, Any]:
if not self.index and self.orient == "split":
return {"name": self.obj.name, "data": self.obj.values}
else:
return self.obj
def _format_axes(self):
if not self.obj.index.is_unique and self.orient == "index":
raise ValueError(f"Series index must be unique for orient='{self.orient}'")
class FrameWriter(Writer):
_default_orient = "columns"
def obj_to_write(self) -> NDFrame | Mapping[IndexLabel, Any]:
if not self.index and self.orient == "split":
obj_to_write = self.obj.to_dict(orient="split")
del obj_to_write["index"]
else:
obj_to_write = self.obj
return obj_to_write
def _format_axes(self):
"""
Try to format axes if they are datelike.
"""
if not self.obj.index.is_unique and self.orient in ("index", "columns"):
raise ValueError(
f"DataFrame index must be unique for orient='{self.orient}'."
)
if not self.obj.columns.is_unique and self.orient in (
"index",
"columns",
"records",
):
raise ValueError(
f"DataFrame columns must be unique for orient='{self.orient}'."
)
class JSONTableWriter(FrameWriter):
_default_orient = "records"
def __init__(
self,
obj,
orient: str | None,
date_format: str,
double_precision: int,
ensure_ascii: bool,
date_unit: str,
index: bool,
default_handler: Callable[[Any], JSONSerializable] | None = None,
indent: int = 0,
) -> None:
"""
Adds a `schema` attribute with the Table Schema, resets
the index (can't do in caller, because the schema inference needs
to know what the index is, forces orient to records, and forces
date_format to 'iso'.
"""
super().__init__(
obj,
orient,
date_format,
double_precision,
ensure_ascii,
date_unit,
index,
default_handler=default_handler,
indent=indent,
)
if date_format != "iso":
msg = (
"Trying to write with `orient='table'` and "
f"`date_format='{date_format}'`. Table Schema requires dates "
"to be formatted with `date_format='iso'`"
)
raise ValueError(msg)
self.schema = build_table_schema(obj, index=self.index)
# NotImplemented on a column MultiIndex
if obj.ndim == 2 and isinstance(obj.columns, MultiIndex):
raise NotImplementedError(
"orient='table' is not supported for MultiIndex columns"
)
# TODO: Do this timedelta properly in objToJSON.c See GH #15137
if (
(obj.ndim == 1)
and (obj.name in set(obj.index.names))
or len(obj.columns.intersection(obj.index.names))
):
msg = "Overlapping names between the index and columns"
raise ValueError(msg)
obj = obj.copy()
timedeltas = obj.select_dtypes(include=["timedelta"]).columns
if len(timedeltas):
obj[timedeltas] = obj[timedeltas].applymap(lambda x: x.isoformat())
# Convert PeriodIndex to datetimes before serializing
if is_period_dtype(obj.index.dtype):
obj.index = obj.index.to_timestamp()
# exclude index from obj if index=False
if not self.index:
self.obj = obj.reset_index(drop=True)
else:
self.obj = obj.reset_index(drop=False)
self.date_format = "iso"
self.orient = "records"
self.index = index
def obj_to_write(self) -> NDFrame | Mapping[IndexLabel, Any]:
return {"schema": self.schema, "data": self.obj}
Any = object()
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
Literal: _SpecialForm = ...
JSONSerializable = Optional[Union[PythonScalar, List, Dict]]
class WriteBuffer(BaseBuffer, Protocol[AnyStr_contra]):
def write(self, __b: AnyStr_contra) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
def flush(self) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
)
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[False],
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[True] = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: bool = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str] | IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = None,
compression: CompressionOptions = None,
memory_map: bool = False,
is_text: bool = True,
errors: str | None = None,
storage_options: StorageOptions = None,
) -> IOHandles[str] | IOHandles[bytes]:
"""
Get file handle for given path/buffer and mode.
Parameters
----------
path_or_buf : str or file handle
File path or object.
mode : str
Mode to open path_or_buf with.
encoding : str or None
Encoding to use.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other keys as compression options if compression
mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is now
supported for compression modes 'gzip', 'bz2', 'zstd' and 'zip'.
.. versionchanged:: 1.4.0 Zstandard support.
memory_map : bool, default False
See parsers._parser_params for more information. Only used by read_csv.
is_text : bool, default True
Whether the type of the content passed to the file/buffer is string or
bytes. This is not the same as `"b" not in mode`. If a string content is
passed to a binary file/buffer, a wrapper is inserted.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
storage_options: StorageOptions = None
Passed to _get_filepath_or_buffer
.. versionchanged:: 1.2.0
Returns the dataclass IOHandles
"""
# Windows does not default to utf-8. Set to utf-8 for a consistent behavior
encoding = encoding or "utf-8"
errors = errors or "strict"
# read_csv does not know whether the buffer is opened in binary/text mode
if _is_binary_mode(path_or_buf, mode) and "b" not in mode:
mode += "b"
# validate encoding and errors
codecs.lookup(encoding)
if isinstance(errors, str):
codecs.lookup_error(errors)
# open URLs
ioargs = _get_filepath_or_buffer(
path_or_buf,
encoding=encoding,
compression=compression,
mode=mode,
storage_options=storage_options,
)
handle = ioargs.filepath_or_buffer
handles: list[BaseBuffer]
# memory mapping needs to be the first step
# only used for read_csv
handle, memory_map, handles = _maybe_memory_map(handle, memory_map)
is_path = isinstance(handle, str)
compression_args = dict(ioargs.compression)
compression = compression_args.pop("method")
# Only for write methods
if "r" not in mode and is_path:
check_parent_directory(str(handle))
if compression:
if compression != "zstd":
# compression libraries do not like an explicit text-mode
ioargs.mode = ioargs.mode.replace("t", "")
elif compression == "zstd" and "b" not in ioargs.mode:
# python-zstandard defaults to text mode, but we always expect
# compression libraries to use binary mode.
ioargs.mode += "b"
# GZ Compression
if compression == "gzip":
if isinstance(handle, str):
# error: Incompatible types in assignment (expression has type
# "GzipFile", variable has type "Union[str, BaseBuffer]")
handle = gzip.GzipFile( # type: ignore[assignment]
filename=handle,
mode=ioargs.mode,
**compression_args,
)
else:
handle = gzip.GzipFile(
# No overload variant of "GzipFile" matches argument types
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
fileobj=handle, # type: ignore[call-overload]
mode=ioargs.mode,
**compression_args,
)
# BZ Compression
elif compression == "bz2":
# Overload of "BZ2File" to handle pickle protocol 5
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
handle = _BZ2File( # type: ignore[call-overload]
handle,
mode=ioargs.mode,
**compression_args,
)
# ZIP Compression
elif compression == "zip":
# error: Argument 1 to "_BytesZipFile" has incompatible type
# "Union[str, BaseBuffer]"; expected "Union[Union[str, PathLike[str]],
# ReadBuffer[bytes], WriteBuffer[bytes]]"
handle = _BytesZipFile(
handle, ioargs.mode, **compression_args # type: ignore[arg-type]
)
if handle.buffer.mode == "r":
handles.append(handle)
zip_names = handle.buffer.namelist()
if len(zip_names) == 1:
handle = handle.buffer.open(zip_names.pop())
elif not zip_names:
raise ValueError(f"Zero files found in ZIP file {path_or_buf}")
else:
raise ValueError(
"Multiple files found in ZIP file. "
f"Only one file per ZIP: {zip_names}"
)
# TAR Encoding
elif compression == "tar":
compression_args.setdefault("mode", ioargs.mode)
if isinstance(handle, str):
handle = _BytesTarFile(name=handle, **compression_args)
else:
# error: Argument "fileobj" to "_BytesTarFile" has incompatible
# type "BaseBuffer"; expected "Union[ReadBuffer[bytes],
# WriteBuffer[bytes], None]"
handle = _BytesTarFile(
fileobj=handle, **compression_args # type: ignore[arg-type]
)
assert isinstance(handle, _BytesTarFile)
if "r" in handle.buffer.mode:
handles.append(handle)
files = handle.buffer.getnames()
if len(files) == 1:
file = handle.buffer.extractfile(files[0])
assert file is not None
handle = file
elif not files:
raise ValueError(f"Zero files found in TAR archive {path_or_buf}")
else:
raise ValueError(
"Multiple files found in TAR archive. "
f"Only one file per TAR archive: {files}"
)
# XZ Compression
elif compression == "xz":
# error: Argument 1 to "LZMAFile" has incompatible type "Union[str,
# BaseBuffer]"; expected "Optional[Union[Union[str, bytes, PathLike[str],
# PathLike[bytes]], IO[bytes]]]"
handle = get_lzma_file()(handle, ioargs.mode) # type: ignore[arg-type]
# Zstd Compression
elif compression == "zstd":
zstd = import_optional_dependency("zstandard")
if "r" in ioargs.mode:
open_args = {"dctx": zstd.ZstdDecompressor(**compression_args)}
else:
open_args = {"cctx": zstd.ZstdCompressor(**compression_args)}
handle = zstd.open(
handle,
mode=ioargs.mode,
**open_args,
)
# Unrecognized Compression
else:
msg = f"Unrecognized compression type: {compression}"
raise ValueError(msg)
assert not isinstance(handle, str)
handles.append(handle)
elif isinstance(handle, str):
# Check whether the filename is to be opened in binary mode.
# Binary mode does not support 'encoding' and 'newline'.
if ioargs.encoding and "b" not in ioargs.mode:
# Encoding
handle = open(
handle,
ioargs.mode,
encoding=ioargs.encoding,
errors=errors,
newline="",
)
else:
# Binary mode
handle = open(handle, ioargs.mode)
handles.append(handle)
# Convert BytesIO or file objects passed with an encoding
is_wrapped = False
if not is_text and ioargs.mode == "rb" and isinstance(handle, TextIOBase):
# not added to handles as it does not open/buffer resources
handle = _BytesIOWrapper(
handle,
encoding=ioargs.encoding,
)
elif is_text and (
compression or memory_map or _is_binary_mode(handle, ioargs.mode)
):
if (
not hasattr(handle, "readable")
or not hasattr(handle, "writable")
or not hasattr(handle, "seekable")
):
handle = _IOWrapper(handle)
# error: Argument 1 to "TextIOWrapper" has incompatible type
# "_IOWrapper"; expected "IO[bytes]"
handle = TextIOWrapper(
handle, # type: ignore[arg-type]
encoding=ioargs.encoding,
errors=errors,
newline="",
)
handles.append(handle)
# only marked as wrapped when the caller provided a handle
is_wrapped = not (
isinstance(ioargs.filepath_or_buffer, str) or ioargs.should_close
)
if "r" in ioargs.mode and not hasattr(handle, "read"):
raise TypeError(
"Expected file path name or file-like object, "
f"got {type(ioargs.filepath_or_buffer)} type"
)
handles.reverse() # close the most recently added buffer first
if ioargs.should_close:
assert not isinstance(ioargs.filepath_or_buffer, str)
handles.append(ioargs.filepath_or_buffer)
return IOHandles(
# error: Argument "handle" to "IOHandles" has incompatible type
# "Union[TextIOWrapper, GzipFile, BaseBuffer, typing.IO[bytes],
# typing.IO[Any]]"; expected "pandas._typing.IO[Any]"
handle=handle, # type: ignore[arg-type]
# error: Argument "created_handles" to "IOHandles" has incompatible type
# "List[BaseBuffer]"; expected "List[Union[IO[bytes], IO[str]]]"
created_handles=handles, # type: ignore[arg-type]
is_wrapped=is_wrapped,
compression=ioargs.compression,
)
def convert_to_line_delimits(s: str) -> str:
"""
Helper function that converts JSON lists to line delimited JSON.
"""
# Determine we have a JSON list to turn to lines otherwise just return the
# json object, only lists can
if not s[0] == "[" and s[-1] == "]":
return s
s = s[1:-1]
return convert_json_to_lines(s)
class NDFrame(PandasObject, indexing.IndexingMixin):
"""
N-dimensional analogue of DataFrame. Store multi-dimensional in a
size-mutable, labeled data structure
Parameters
----------
data : BlockManager
axes : list
copy : bool, default False
"""
_internal_names: list[str] = [
"_mgr",
"_cacher",
"_item_cache",
"_cache",
"_is_copy",
"_subtyp",
"_name",
"_default_kind",
"_default_fill_value",
"_metadata",
"__array_struct__",
"__array_interface__",
"_flags",
]
_internal_names_set: set[str] = set(_internal_names)
_accessors: set[str] = set()
_hidden_attrs: frozenset[str] = frozenset([])
_metadata: list[str] = []
_is_copy: weakref.ReferenceType[NDFrame] | None = None
_mgr: Manager
_attrs: dict[Hashable, Any]
_typ: str
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data: Manager,
copy: bool_t = False,
attrs: Mapping[Hashable, Any] | None = None,
) -> None:
# copy kwarg is retained for mypy compat, is not used
object.__setattr__(self, "_is_copy", None)
object.__setattr__(self, "_mgr", data)
object.__setattr__(self, "_item_cache", {})
if attrs is None:
attrs = {}
else:
attrs = dict(attrs)
object.__setattr__(self, "_attrs", attrs)
object.__setattr__(self, "_flags", Flags(self, allows_duplicate_labels=True))
def _init_mgr(
cls,
mgr: Manager,
axes,
dtype: Dtype | None = None,
copy: bool_t = False,
) -> Manager:
"""passed a manager and a axes dict"""
for a, axe in axes.items():
if axe is not None:
axe = ensure_index(axe)
bm_axis = cls._get_block_manager_axis(a)
mgr = mgr.reindex_axis(axe, axis=bm_axis)
# make a copy if explicitly requested
if copy:
mgr = mgr.copy()
if dtype is not None:
# avoid further copies if we can
if (
isinstance(mgr, BlockManager)
and len(mgr.blocks) == 1
and is_dtype_equal(mgr.blocks[0].values.dtype, dtype)
):
pass
else:
mgr = mgr.astype(dtype=dtype)
return mgr
def _as_manager(self: NDFrameT, typ: str, copy: bool_t = True) -> NDFrameT:
"""
Private helper function to create a DataFrame with specific manager.
Parameters
----------
typ : {"block", "array"}
copy : bool, default True
Only controls whether the conversion from Block->ArrayManager
copies the 1D arrays (to ensure proper/contiguous memory layout).
Returns
-------
DataFrame
New DataFrame using specified manager type. Is not guaranteed
to be a copy or not.
"""
new_mgr: Manager
new_mgr = mgr_to_mgr(self._mgr, typ=typ, copy=copy)
# fastpath of passing a manager doesn't check the option/manager class
return self._constructor(new_mgr).__finalize__(self)
# ----------------------------------------------------------------------
# attrs and flags
def attrs(self) -> dict[Hashable, Any]:
"""
Dictionary of global attributes of this dataset.
.. warning::
attrs is experimental and may change without warning.
See Also
--------
DataFrame.flags : Global flags applying to this object.
"""
if self._attrs is None:
self._attrs = {}
return self._attrs
def attrs(self, value: Mapping[Hashable, Any]) -> None:
self._attrs = dict(value)
def flags(self) -> Flags:
"""
Get the properties associated with this pandas object.
The available flags are
* :attr:`Flags.allows_duplicate_labels`
See Also
--------
Flags : Flags that apply to pandas objects.
DataFrame.attrs : Global metadata applying to this dataset.
Notes
-----
"Flags" differ from "metadata". Flags reflect properties of the
pandas object (the Series or DataFrame). Metadata refer to properties
of the dataset, and should be stored in :attr:`DataFrame.attrs`.
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2]})
>>> df.flags
<Flags(allows_duplicate_labels=True)>
Flags can be get or set using ``.``
>>> df.flags.allows_duplicate_labels
True
>>> df.flags.allows_duplicate_labels = False
Or by slicing with a key
>>> df.flags["allows_duplicate_labels"]
False
>>> df.flags["allows_duplicate_labels"] = True
"""
return self._flags
def set_flags(
self: NDFrameT,
*,
copy: bool_t = False,
allows_duplicate_labels: bool_t | None = None,
) -> NDFrameT:
"""
Return a new object with updated flags.
Parameters
----------
copy : bool, default False
Specify if a copy of the object should be made.
allows_duplicate_labels : bool, optional
Whether the returned object allows duplicate labels.
Returns
-------
Series or DataFrame
The same type as the caller.
See Also
--------
DataFrame.attrs : Global metadata applying to this dataset.
DataFrame.flags : Global flags applying to this object.
Notes
-----
This method returns a new object that's a view on the same data
as the input. Mutating the input or the output values will be reflected
in the other.
This method is intended to be used in method chains.
"Flags" differ from "metadata". Flags reflect properties of the
pandas object (the Series or DataFrame). Metadata refer to properties
of the dataset, and should be stored in :attr:`DataFrame.attrs`.
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2]})
>>> df.flags.allows_duplicate_labels
True
>>> df2 = df.set_flags(allows_duplicate_labels=False)
>>> df2.flags.allows_duplicate_labels
False
"""
df = self.copy(deep=copy and not using_copy_on_write())
if allows_duplicate_labels is not None:
df.flags["allows_duplicate_labels"] = allows_duplicate_labels
return df
def _validate_dtype(cls, dtype) -> DtypeObj | None:
"""validate the passed dtype"""
if dtype is not None:
dtype = pandas_dtype(dtype)
# a compound dtype
if dtype.kind == "V":
raise NotImplementedError(
"compound dtypes are not implemented "
f"in the {cls.__name__} constructor"
)
return dtype
# ----------------------------------------------------------------------
# Construction
def _constructor(self: NDFrameT) -> Callable[..., NDFrameT]:
"""
Used when a manipulation result has the same dimensions as the
original.
"""
raise AbstractMethodError(self)
# ----------------------------------------------------------------------
# Internals
def _data(self):
# GH#33054 retained because some downstream packages uses this,
# e.g. fastparquet
return self._mgr
# ----------------------------------------------------------------------
# Axis
_stat_axis_number = 0
_stat_axis_name = "index"
_AXIS_ORDERS: list[Literal["index", "columns"]]
_AXIS_TO_AXIS_NUMBER: dict[Axis, AxisInt] = {0: 0, "index": 0, "rows": 0}
_info_axis_number: int
_info_axis_name: Literal["index", "columns"]
_AXIS_LEN: int
def _construct_axes_dict(self, axes: Sequence[Axis] | None = None, **kwargs):
"""Return an axes dictionary for myself."""
d = {a: self._get_axis(a) for a in (axes or self._AXIS_ORDERS)}
# error: Argument 1 to "update" of "MutableMapping" has incompatible type
# "Dict[str, Any]"; expected "SupportsKeysAndGetItem[Union[int, str], Any]"
d.update(kwargs) # type: ignore[arg-type]
return d
def _get_axis_number(cls, axis: Axis) -> AxisInt:
try:
return cls._AXIS_TO_AXIS_NUMBER[axis]
except KeyError:
raise ValueError(f"No axis named {axis} for object type {cls.__name__}")
def _get_axis_name(cls, axis: Axis) -> Literal["index", "columns"]:
axis_number = cls._get_axis_number(axis)
return cls._AXIS_ORDERS[axis_number]
def _get_axis(self, axis: Axis) -> Index:
axis_number = self._get_axis_number(axis)
assert axis_number in {0, 1}
return self.index if axis_number == 0 else self.columns
def _get_block_manager_axis(cls, axis: Axis) -> AxisInt:
"""Map the axis to the block_manager axis."""
axis = cls._get_axis_number(axis)
ndim = cls._AXIS_LEN
if ndim == 2:
# i.e. DataFrame
return 1 - axis
return axis
def _get_axis_resolvers(self, axis: str) -> dict[str, Series | MultiIndex]:
# index or columns
axis_index = getattr(self, axis)
d = {}
prefix = axis[0]
for i, name in enumerate(axis_index.names):
if name is not None:
key = level = name
else:
# prefix with 'i' or 'c' depending on the input axis
# e.g., you must do ilevel_0 for the 0th level of an unnamed
# multiiindex
key = f"{prefix}level_{i}"
level = i
level_values = axis_index.get_level_values(level)
s = level_values.to_series()
s.index = axis_index
d[key] = s
# put the index/columns itself in the dict
if isinstance(axis_index, MultiIndex):
dindex = axis_index
else:
dindex = axis_index.to_series()
d[axis] = dindex
return d
def _get_index_resolvers(self) -> dict[Hashable, Series | MultiIndex]:
from pandas.core.computation.parsing import clean_column_name
d: dict[str, Series | MultiIndex] = {}
for axis_name in self._AXIS_ORDERS:
d.update(self._get_axis_resolvers(axis_name))
return {clean_column_name(k): v for k, v in d.items() if not isinstance(k, int)}
def _get_cleaned_column_resolvers(self) -> dict[Hashable, Series]:
"""
Return the special character free column resolvers of a dataframe.
Column names with special characters are 'cleaned up' so that they can
be referred to by backtick quoting.
Used in :meth:`DataFrame.eval`.
"""
from pandas.core.computation.parsing import clean_column_name
if isinstance(self, ABCSeries):
return {clean_column_name(self.name): self}
return {
clean_column_name(k): v for k, v in self.items() if not isinstance(k, int)
}
def _info_axis(self) -> Index:
return getattr(self, self._info_axis_name)
def _stat_axis(self) -> Index:
return getattr(self, self._stat_axis_name)
def shape(self) -> tuple[int, ...]:
"""
Return a tuple of axis dimensions
"""
return tuple(len(self._get_axis(a)) for a in self._AXIS_ORDERS)
def axes(self) -> list[Index]:
"""
Return index label(s) of the internal NDFrame
"""
# we do it this way because if we have reversed axes, then
# the block manager shows then reversed
return [self._get_axis(a) for a in self._AXIS_ORDERS]
def ndim(self) -> int:
"""
Return an int representing the number of axes / array dimensions.
Return 1 if Series. Otherwise return 2 if DataFrame.
See Also
--------
ndarray.ndim : Number of array dimensions.
Examples
--------
>>> s = pd.Series({'a': 1, 'b': 2, 'c': 3})
>>> s.ndim
1
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.ndim
2
"""
return self._mgr.ndim
def size(self) -> int:
"""
Return an int representing the number of elements in this object.
Return the number of rows if Series. Otherwise return the number of
rows times number of columns if DataFrame.
See Also
--------
ndarray.size : Number of elements in the array.
Examples
--------
>>> s = pd.Series({'a': 1, 'b': 2, 'c': 3})
>>> s.size
3
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.size
4
"""
# error: Incompatible return value type (got "signedinteger[_64Bit]",
# expected "int") [return-value]
return np.prod(self.shape) # type: ignore[return-value]
def set_axis(
self: NDFrameT,
labels,
*,
axis: Axis = 0,
copy: bool_t | None = None,
) -> NDFrameT:
"""
Assign desired index to given axis.
Indexes for%(extended_summary_sub)s row labels can be changed by assigning
a list-like or Index.
Parameters
----------
labels : list-like, Index
The values for the new index.
axis : %(axes_single_arg)s, default 0
The axis to update. The value 0 identifies the rows. For `Series`
this parameter is unused and defaults to 0.
copy : bool, default True
Whether to make a copy of the underlying data.
.. versionadded:: 1.5.0
Returns
-------
%(klass)s
An object of type %(klass)s.
See Also
--------
%(klass)s.rename_axis : Alter the name of the index%(see_also_sub)s.
"""
return self._set_axis_nocheck(labels, axis, inplace=False, copy=copy)
def _set_axis_nocheck(
self, labels, axis: Axis, inplace: bool_t, copy: bool_t | None
):
if inplace:
setattr(self, self._get_axis_name(axis), labels)
else:
# With copy=False, we create a new object but don't copy the
# underlying data.
obj = self.copy(deep=copy and not using_copy_on_write())
setattr(obj, obj._get_axis_name(axis), labels)
return obj
def _set_axis(self, axis: AxisInt, labels: AnyArrayLike | list) -> None:
"""
This is called from the cython code when we set the `index` attribute
directly, e.g. `series.index = [1, 2, 3]`.
"""
labels = ensure_index(labels)
self._mgr.set_axis(axis, labels)
self._clear_item_cache()
def swapaxes(
self: NDFrameT, axis1: Axis, axis2: Axis, copy: bool_t | None = None
) -> NDFrameT:
"""
Interchange axes and swap values axes appropriately.
Returns
-------
same as input
"""
i = self._get_axis_number(axis1)
j = self._get_axis_number(axis2)
if i == j:
return self.copy(deep=copy and not using_copy_on_write())
mapping = {i: j, j: i}
new_axes = [self._get_axis(mapping.get(k, k)) for k in range(self._AXIS_LEN)]
new_values = self._values.swapaxes(i, j) # type: ignore[union-attr]
if (
using_copy_on_write()
and self._mgr.is_single_block
and isinstance(self._mgr, BlockManager)
):
# This should only get hit in case of having a single block, otherwise a
# copy is made, we don't have to set up references.
new_mgr = ndarray_to_mgr(
new_values,
new_axes[0],
new_axes[1],
dtype=None,
copy=False,
typ="block",
)
assert isinstance(new_mgr, BlockManager)
assert isinstance(self._mgr, BlockManager)
new_mgr.blocks[0].refs = self._mgr.blocks[0].refs
new_mgr.blocks[0].refs.add_reference(
new_mgr.blocks[0] # type: ignore[arg-type]
)
return self._constructor(new_mgr).__finalize__(self, method="swapaxes")
elif (copy or copy is None) and self._mgr.is_single_block:
new_values = new_values.copy()
return self._constructor(
new_values,
*new_axes,
# The no-copy case for CoW is handled above
copy=False,
).__finalize__(self, method="swapaxes")
def droplevel(self: NDFrameT, level: IndexLabel, axis: Axis = 0) -> NDFrameT:
"""
Return {klass} with requested index / column level(s) removed.
Parameters
----------
level : int, str, or list-like
If a string is given, must be the name of a level
If list-like, elements must be names or positional indexes
of levels.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
Axis along which the level(s) is removed:
* 0 or 'index': remove level(s) in column.
* 1 or 'columns': remove level(s) in row.
For `Series` this parameter is unused and defaults to 0.
Returns
-------
{klass}
{klass} with requested index / column level(s) removed.
Examples
--------
>>> df = pd.DataFrame([
... [1, 2, 3, 4],
... [5, 6, 7, 8],
... [9, 10, 11, 12]
... ]).set_index([0, 1]).rename_axis(['a', 'b'])
>>> df.columns = pd.MultiIndex.from_tuples([
... ('c', 'e'), ('d', 'f')
... ], names=['level_1', 'level_2'])
>>> df
level_1 c d
level_2 e f
a b
1 2 3 4
5 6 7 8
9 10 11 12
>>> df.droplevel('a')
level_1 c d
level_2 e f
b
2 3 4
6 7 8
10 11 12
>>> df.droplevel('level_2', axis=1)
level_1 c d
a b
1 2 3 4
5 6 7 8
9 10 11 12
"""
labels = self._get_axis(axis)
new_labels = labels.droplevel(level)
return self.set_axis(new_labels, axis=axis, copy=None)
def pop(self, item: Hashable) -> Series | Any:
result = self[item]
del self[item]
return result
def squeeze(self, axis: Axis | None = None):
"""
Squeeze 1 dimensional axis objects into scalars.
Series or DataFrames with a single element are squeezed to a scalar.
DataFrames with a single column or a single row are squeezed to a
Series. Otherwise the object is unchanged.
This method is most useful when you don't know if your
object is a Series or DataFrame, but you do know it has just a single
column. In that case you can safely call `squeeze` to ensure you have a
Series.
Parameters
----------
axis : {0 or 'index', 1 or 'columns', None}, default None
A specific axis to squeeze. By default, all length-1 axes are
squeezed. For `Series` this parameter is unused and defaults to `None`.
Returns
-------
DataFrame, Series, or scalar
The projection after squeezing `axis` or all the axes.
See Also
--------
Series.iloc : Integer-location based indexing for selecting scalars.
DataFrame.iloc : Integer-location based indexing for selecting Series.
Series.to_frame : Inverse of DataFrame.squeeze for a
single-column DataFrame.
Examples
--------
>>> primes = pd.Series([2, 3, 5, 7])
Slicing might produce a Series with a single value:
>>> even_primes = primes[primes % 2 == 0]
>>> even_primes
0 2
dtype: int64
>>> even_primes.squeeze()
2
Squeezing objects with more than one value in every axis does nothing:
>>> odd_primes = primes[primes % 2 == 1]
>>> odd_primes
1 3
2 5
3 7
dtype: int64
>>> odd_primes.squeeze()
1 3
2 5
3 7
dtype: int64
Squeezing is even more effective when used with DataFrames.
>>> df = pd.DataFrame([[1, 2], [3, 4]], columns=['a', 'b'])
>>> df
a b
0 1 2
1 3 4
Slicing a single column will produce a DataFrame with the columns
having only one value:
>>> df_a = df[['a']]
>>> df_a
a
0 1
1 3
So the columns can be squeezed down, resulting in a Series:
>>> df_a.squeeze('columns')
0 1
1 3
Name: a, dtype: int64
Slicing a single row from a single column will produce a single
scalar DataFrame:
>>> df_0a = df.loc[df.index < 1, ['a']]
>>> df_0a
a
0 1
Squeezing the rows produces a single scalar Series:
>>> df_0a.squeeze('rows')
a 1
Name: 0, dtype: int64
Squeezing all axes will project directly into a scalar:
>>> df_0a.squeeze()
1
"""
axes = range(self._AXIS_LEN) if axis is None else (self._get_axis_number(axis),)
return self.iloc[
tuple(
0 if i in axes and len(a) == 1 else slice(None)
for i, a in enumerate(self.axes)
)
]
# ----------------------------------------------------------------------
# Rename
def _rename(
self: NDFrameT,
mapper: Renamer | None = None,
*,
index: Renamer | None = None,
columns: Renamer | None = None,
axis: Axis | None = None,
copy: bool_t | None = None,
inplace: bool_t = False,
level: Level | None = None,
errors: str = "ignore",
) -> NDFrameT | None:
# called by Series.rename and DataFrame.rename
if mapper is None and index is None and columns is None:
raise TypeError("must pass an index to rename")
if index is not None or columns is not None:
if axis is not None:
raise TypeError(
"Cannot specify both 'axis' and any of 'index' or 'columns'"
)
if mapper is not None:
raise TypeError(
"Cannot specify both 'mapper' and any of 'index' or 'columns'"
)
else:
# use the mapper argument
if axis and self._get_axis_number(axis) == 1:
columns = mapper
else:
index = mapper
self._check_inplace_and_allows_duplicate_labels(inplace)
result = self if inplace else self.copy(deep=copy and not using_copy_on_write())
for axis_no, replacements in enumerate((index, columns)):
if replacements is None:
continue
ax = self._get_axis(axis_no)
f = common.get_rename_function(replacements)
if level is not None:
level = ax._get_level_number(level)
# GH 13473
if not callable(replacements):
if ax._is_multi and level is not None:
indexer = ax.get_level_values(level).get_indexer_for(replacements)
else:
indexer = ax.get_indexer_for(replacements)
if errors == "raise" and len(indexer[indexer == -1]):
missing_labels = [
label
for index, label in enumerate(replacements)
if indexer[index] == -1
]
raise KeyError(f"{missing_labels} not found in axis")
new_index = ax._transform_index(f, level=level)
result._set_axis_nocheck(new_index, axis=axis_no, inplace=True, copy=False)
result._clear_item_cache()
if inplace:
self._update_inplace(result)
return None
else:
return result.__finalize__(self, method="rename")
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: Literal[False] = ...,
) -> NDFrameT:
...
def rename_axis(
self,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: Literal[True],
) -> None:
...
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = ...,
*,
index=...,
columns=...,
axis: Axis = ...,
copy: bool_t | None = ...,
inplace: bool_t = ...,
) -> NDFrameT | None:
...
def rename_axis(
self: NDFrameT,
mapper: IndexLabel | lib.NoDefault = lib.no_default,
*,
index=lib.no_default,
columns=lib.no_default,
axis: Axis = 0,
copy: bool_t | None = None,
inplace: bool_t = False,
) -> NDFrameT | None:
"""
Set the name of the axis for the index or columns.
Parameters
----------
mapper : scalar, list-like, optional
Value to set the axis name attribute.
index, columns : scalar, list-like, dict-like or function, optional
A scalar, list-like, dict-like or functions transformations to
apply to that axis' values.
Note that the ``columns`` parameter is not allowed if the
object is a Series. This parameter only apply for DataFrame
type objects.
Use either ``mapper`` and ``axis`` to
specify the axis to target with ``mapper``, or ``index``
and/or ``columns``.
axis : {0 or 'index', 1 or 'columns'}, default 0
The axis to rename. For `Series` this parameter is unused and defaults to 0.
copy : bool, default None
Also copy underlying data.
inplace : bool, default False
Modifies the object directly, instead of creating a new Series
or DataFrame.
Returns
-------
Series, DataFrame, or None
The same type as the caller or None if ``inplace=True``.
See Also
--------
Series.rename : Alter Series index labels or name.
DataFrame.rename : Alter DataFrame index labels or name.
Index.rename : Set new names on index.
Notes
-----
``DataFrame.rename_axis`` supports two calling conventions
* ``(index=index_mapper, columns=columns_mapper, ...)``
* ``(mapper, axis={'index', 'columns'}, ...)``
The first calling convention will only modify the names of
the index and/or the names of the Index object that is the columns.
In this case, the parameter ``copy`` is ignored.
The second calling convention will modify the names of the
corresponding index if mapper is a list or a scalar.
However, if mapper is dict-like or a function, it will use the
deprecated behavior of modifying the axis *labels*.
We *highly* recommend using keyword arguments to clarify your
intent.
Examples
--------
**Series**
>>> s = pd.Series(["dog", "cat", "monkey"])
>>> s
0 dog
1 cat
2 monkey
dtype: object
>>> s.rename_axis("animal")
animal
0 dog
1 cat
2 monkey
dtype: object
**DataFrame**
>>> df = pd.DataFrame({"num_legs": [4, 4, 2],
... "num_arms": [0, 0, 2]},
... ["dog", "cat", "monkey"])
>>> df
num_legs num_arms
dog 4 0
cat 4 0
monkey 2 2
>>> df = df.rename_axis("animal")
>>> df
num_legs num_arms
animal
dog 4 0
cat 4 0
monkey 2 2
>>> df = df.rename_axis("limbs", axis="columns")
>>> df
limbs num_legs num_arms
animal
dog 4 0
cat 4 0
monkey 2 2
**MultiIndex**
>>> df.index = pd.MultiIndex.from_product([['mammal'],
... ['dog', 'cat', 'monkey']],
... names=['type', 'name'])
>>> df
limbs num_legs num_arms
type name
mammal dog 4 0
cat 4 0
monkey 2 2
>>> df.rename_axis(index={'type': 'class'})
limbs num_legs num_arms
class name
mammal dog 4 0
cat 4 0
monkey 2 2
>>> df.rename_axis(columns=str.upper)
LIMBS num_legs num_arms
type name
mammal dog 4 0
cat 4 0
monkey 2 2
"""
axes = {"index": index, "columns": columns}
if axis is not None:
axis = self._get_axis_number(axis)
inplace = validate_bool_kwarg(inplace, "inplace")
if copy and using_copy_on_write():
copy = False
if mapper is not lib.no_default:
# Use v0.23 behavior if a scalar or list
non_mapper = is_scalar(mapper) or (
is_list_like(mapper) and not is_dict_like(mapper)
)
if non_mapper:
return self._set_axis_name(
mapper, axis=axis, inplace=inplace, copy=copy
)
else:
raise ValueError("Use `.rename` to alter labels with a mapper.")
else:
# Use new behavior. Means that index and/or columns
# is specified
result = self if inplace else self.copy(deep=copy)
for axis in range(self._AXIS_LEN):
v = axes.get(self._get_axis_name(axis))
if v is lib.no_default:
continue
non_mapper = is_scalar(v) or (is_list_like(v) and not is_dict_like(v))
if non_mapper:
newnames = v
else:
f = common.get_rename_function(v)
curnames = self._get_axis(axis).names
newnames = [f(name) for name in curnames]
result._set_axis_name(newnames, axis=axis, inplace=True, copy=copy)
if not inplace:
return result
return None
def _set_axis_name(
self, name, axis: Axis = 0, inplace: bool_t = False, copy: bool_t | None = True
):
"""
Set the name(s) of the axis.
Parameters
----------
name : str or list of str
Name(s) to set.
axis : {0 or 'index', 1 or 'columns'}, default 0
The axis to set the label. The value 0 or 'index' specifies index,
and the value 1 or 'columns' specifies columns.
inplace : bool, default False
If `True`, do operation inplace and return None.
copy:
Whether to make a copy of the result.
Returns
-------
Series, DataFrame, or None
The same type as the caller or `None` if `inplace` is `True`.
See Also
--------
DataFrame.rename : Alter the axis labels of :class:`DataFrame`.
Series.rename : Alter the index labels or set the index name
of :class:`Series`.
Index.rename : Set the name of :class:`Index` or :class:`MultiIndex`.
Examples
--------
>>> df = pd.DataFrame({"num_legs": [4, 4, 2]},
... ["dog", "cat", "monkey"])
>>> df
num_legs
dog 4
cat 4
monkey 2
>>> df._set_axis_name("animal")
num_legs
animal
dog 4
cat 4
monkey 2
>>> df.index = pd.MultiIndex.from_product(
... [["mammal"], ['dog', 'cat', 'monkey']])
>>> df._set_axis_name(["type", "name"])
num_legs
type name
mammal dog 4
cat 4
monkey 2
"""
axis = self._get_axis_number(axis)
idx = self._get_axis(axis).set_names(name)
inplace = validate_bool_kwarg(inplace, "inplace")
renamed = self if inplace else self.copy(deep=copy)
if axis == 0:
renamed.index = idx
else:
renamed.columns = idx
if not inplace:
return renamed
# ----------------------------------------------------------------------
# Comparison Methods
def _indexed_same(self, other) -> bool_t:
return all(
self._get_axis(a).equals(other._get_axis(a)) for a in self._AXIS_ORDERS
)
def equals(self, other: object) -> bool_t:
"""
Test whether two objects contain the same elements.
This function allows two Series or DataFrames to be compared against
each other to see if they have the same shape and elements. NaNs in
the same location are considered equal.
The row/column index do not need to have the same type, as long
as the values are considered equal. Corresponding columns must be of
the same dtype.
Parameters
----------
other : Series or DataFrame
The other Series or DataFrame to be compared with the first.
Returns
-------
bool
True if all elements are the same in both objects, False
otherwise.
See Also
--------
Series.eq : Compare two Series objects of the same length
and return a Series where each element is True if the element
in each Series is equal, False otherwise.
DataFrame.eq : Compare two DataFrame objects of the same shape and
return a DataFrame where each element is True if the respective
element in each DataFrame is equal, False otherwise.
testing.assert_series_equal : Raises an AssertionError if left and
right are not equal. Provides an easy interface to ignore
inequality in dtypes, indexes and precision among others.
testing.assert_frame_equal : Like assert_series_equal, but targets
DataFrames.
numpy.array_equal : Return True if two arrays have the same shape
and elements, False otherwise.
Examples
--------
>>> df = pd.DataFrame({1: [10], 2: [20]})
>>> df
1 2
0 10 20
DataFrames df and exactly_equal have the same types and values for
their elements and column labels, which will return True.
>>> exactly_equal = pd.DataFrame({1: [10], 2: [20]})
>>> exactly_equal
1 2
0 10 20
>>> df.equals(exactly_equal)
True
DataFrames df and different_column_type have the same element
types and values, but have different types for the column labels,
which will still return True.
>>> different_column_type = pd.DataFrame({1.0: [10], 2.0: [20]})
>>> different_column_type
1.0 2.0
0 10 20
>>> df.equals(different_column_type)
True
DataFrames df and different_data_type have different types for the
same values for their elements, and will return False even though
their column labels are the same values and types.
>>> different_data_type = pd.DataFrame({1: [10.0], 2: [20.0]})
>>> different_data_type
1 2
0 10.0 20.0
>>> df.equals(different_data_type)
False
"""
if not (isinstance(other, type(self)) or isinstance(self, type(other))):
return False
other = cast(NDFrame, other)
return self._mgr.equals(other._mgr)
# -------------------------------------------------------------------------
# Unary Methods
def __neg__(self: NDFrameT) -> NDFrameT:
def blk_func(values: ArrayLike):
if is_bool_dtype(values.dtype):
# error: Argument 1 to "inv" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsInversion[ndarray[Any, dtype[bool_]]]"
return operator.inv(values) # type: ignore[arg-type]
else:
# error: Argument 1 to "neg" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsNeg[ndarray[Any, dtype[Any]]]"
return operator.neg(values) # type: ignore[arg-type]
new_data = self._mgr.apply(blk_func)
res = self._constructor(new_data)
return res.__finalize__(self, method="__neg__")
def __pos__(self: NDFrameT) -> NDFrameT:
def blk_func(values: ArrayLike):
if is_bool_dtype(values.dtype):
return values.copy()
else:
# error: Argument 1 to "pos" has incompatible type "Union
# [ExtensionArray, ndarray[Any, Any]]"; expected
# "_SupportsPos[ndarray[Any, dtype[Any]]]"
return operator.pos(values) # type: ignore[arg-type]
new_data = self._mgr.apply(blk_func)
res = self._constructor(new_data)
return res.__finalize__(self, method="__pos__")
def __invert__(self: NDFrameT) -> NDFrameT:
if not self.size:
# inv fails with 0 len
return self.copy(deep=False)
new_data = self._mgr.apply(operator.invert)
return self._constructor(new_data).__finalize__(self, method="__invert__")
def __nonzero__(self) -> NoReturn:
raise ValueError(
f"The truth value of a {type(self).__name__} is ambiguous. "
"Use a.empty, a.bool(), a.item(), a.any() or a.all()."
)
__bool__ = __nonzero__
def bool(self) -> bool_t:
"""
Return the bool of a single element Series or DataFrame.
This must be a boolean scalar value, either True or False. It will raise a
ValueError if the Series or DataFrame does not have exactly 1 element, or that
element is not boolean (integer values 0 and 1 will also raise an exception).
Returns
-------
bool
The value in the Series or DataFrame.
See Also
--------
Series.astype : Change the data type of a Series, including to boolean.
DataFrame.astype : Change the data type of a DataFrame, including to boolean.
numpy.bool_ : NumPy boolean data type, used by pandas for boolean values.
Examples
--------
The method will only work for single element objects with a boolean value:
>>> pd.Series([True]).bool()
True
>>> pd.Series([False]).bool()
False
>>> pd.DataFrame({'col': [True]}).bool()
True
>>> pd.DataFrame({'col': [False]}).bool()
False
"""
v = self.squeeze()
if isinstance(v, (bool, np.bool_)):
return bool(v)
elif is_scalar(v):
raise ValueError(
"bool cannot act on a non-boolean single element "
f"{type(self).__name__}"
)
self.__nonzero__()
# for mypy (__nonzero__ raises)
return True
def abs(self: NDFrameT) -> NDFrameT:
"""
Return a Series/DataFrame with absolute numeric value of each element.
This function only applies to elements that are all numeric.
Returns
-------
abs
Series/DataFrame containing the absolute value of each element.
See Also
--------
numpy.absolute : Calculate the absolute value element-wise.
Notes
-----
For ``complex`` inputs, ``1.2 + 1j``, the absolute value is
:math:`\\sqrt{ a^2 + b^2 }`.
Examples
--------
Absolute numeric values in a Series.
>>> s = pd.Series([-1.10, 2, -3.33, 4])
>>> s.abs()
0 1.10
1 2.00
2 3.33
3 4.00
dtype: float64
Absolute numeric values in a Series with complex numbers.
>>> s = pd.Series([1.2 + 1j])
>>> s.abs()
0 1.56205
dtype: float64
Absolute numeric values in a Series with a Timedelta element.
>>> s = pd.Series([pd.Timedelta('1 days')])
>>> s.abs()
0 1 days
dtype: timedelta64[ns]
Select rows with data closest to certain value using argsort (from
`StackOverflow <https://stackoverflow.com/a/17758115>`__).
>>> df = pd.DataFrame({
... 'a': [4, 5, 6, 7],
... 'b': [10, 20, 30, 40],
... 'c': [100, 50, -30, -50]
... })
>>> df
a b c
0 4 10 100
1 5 20 50
2 6 30 -30
3 7 40 -50
>>> df.loc[(df.c - 43).abs().argsort()]
a b c
1 5 20 50
0 4 10 100
2 6 30 -30
3 7 40 -50
"""
res_mgr = self._mgr.apply(np.abs)
return self._constructor(res_mgr).__finalize__(self, name="abs")
def __abs__(self: NDFrameT) -> NDFrameT:
return self.abs()
def __round__(self: NDFrameT, decimals: int = 0) -> NDFrameT:
return self.round(decimals).__finalize__(self, method="__round__")
# -------------------------------------------------------------------------
# Label or Level Combination Helpers
#
# A collection of helper methods for DataFrame/Series operations that
# accept a combination of column/index labels and levels. All such
# operations should utilize/extend these methods when possible so that we
# have consistent precedence and validation logic throughout the library.
def _is_level_reference(self, key: Level, axis: Axis = 0) -> bool_t:
"""
Test whether a key is a level reference for a given axis.
To be considered a level reference, `key` must be a string that:
- (axis=0): Matches the name of an index level and does NOT match
a column label.
- (axis=1): Matches the name of a column level and does NOT match
an index label.
Parameters
----------
key : Hashable
Potential level name for the given axis
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
is_level : bool
"""
axis_int = self._get_axis_number(axis)
return (
key is not None
and is_hashable(key)
and key in self.axes[axis_int].names
and not self._is_label_reference(key, axis=axis_int)
)
def _is_label_reference(self, key: Level, axis: Axis = 0) -> bool_t:
"""
Test whether a key is a label reference for a given axis.
To be considered a label reference, `key` must be a string that:
- (axis=0): Matches a column label
- (axis=1): Matches an index label
Parameters
----------
key : Hashable
Potential label name, i.e. Index entry.
axis : int, default 0
Axis perpendicular to the axis that labels are associated with
(0 means search for column labels, 1 means search for index labels)
Returns
-------
is_label: bool
"""
axis_int = self._get_axis_number(axis)
other_axes = (ax for ax in range(self._AXIS_LEN) if ax != axis_int)
return (
key is not None
and is_hashable(key)
and any(key in self.axes[ax] for ax in other_axes)
)
def _is_label_or_level_reference(self, key: Level, axis: AxisInt = 0) -> bool_t:
"""
Test whether a key is a label or level reference for a given axis.
To be considered either a label or a level reference, `key` must be a
string that:
- (axis=0): Matches a column label or an index level
- (axis=1): Matches an index label or a column level
Parameters
----------
key : Hashable
Potential label or level name
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
bool
"""
return self._is_level_reference(key, axis=axis) or self._is_label_reference(
key, axis=axis
)
def _check_label_or_level_ambiguity(self, key: Level, axis: Axis = 0) -> None:
"""
Check whether `key` is ambiguous.
By ambiguous, we mean that it matches both a level of the input
`axis` and a label of the other axis.
Parameters
----------
key : Hashable
Label or level name.
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns).
Raises
------
ValueError: `key` is ambiguous
"""
axis_int = self._get_axis_number(axis)
other_axes = (ax for ax in range(self._AXIS_LEN) if ax != axis_int)
if (
key is not None
and is_hashable(key)
and key in self.axes[axis_int].names
and any(key in self.axes[ax] for ax in other_axes)
):
# Build an informative and grammatical warning
level_article, level_type = (
("an", "index") if axis_int == 0 else ("a", "column")
)
label_article, label_type = (
("a", "column") if axis_int == 0 else ("an", "index")
)
msg = (
f"'{key}' is both {level_article} {level_type} level and "
f"{label_article} {label_type} label, which is ambiguous."
)
raise ValueError(msg)
def _get_label_or_level_values(self, key: Level, axis: AxisInt = 0) -> ArrayLike:
"""
Return a 1-D array of values associated with `key`, a label or level
from the given `axis`.
Retrieval logic:
- (axis=0): Return column values if `key` matches a column label.
Otherwise return index level values if `key` matches an index
level.
- (axis=1): Return row values if `key` matches an index label.
Otherwise return column level values if 'key' matches a column
level
Parameters
----------
key : Hashable
Label or level name.
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
np.ndarray or ExtensionArray
Raises
------
KeyError
if `key` matches neither a label nor a level
ValueError
if `key` matches multiple labels
"""
axis = self._get_axis_number(axis)
other_axes = [ax for ax in range(self._AXIS_LEN) if ax != axis]
if self._is_label_reference(key, axis=axis):
self._check_label_or_level_ambiguity(key, axis=axis)
values = self.xs(key, axis=other_axes[0])._values
elif self._is_level_reference(key, axis=axis):
values = self.axes[axis].get_level_values(key)._values
else:
raise KeyError(key)
# Check for duplicates
if values.ndim > 1:
if other_axes and isinstance(self._get_axis(other_axes[0]), MultiIndex):
multi_message = (
"\n"
"For a multi-index, the label must be a "
"tuple with elements corresponding to each level."
)
else:
multi_message = ""
label_axis_name = "column" if axis == 0 else "index"
raise ValueError(
f"The {label_axis_name} label '{key}' is not unique.{multi_message}"
)
return values
def _drop_labels_or_levels(self, keys, axis: AxisInt = 0):
"""
Drop labels and/or levels for the given `axis`.
For each key in `keys`:
- (axis=0): If key matches a column label then drop the column.
Otherwise if key matches an index level then drop the level.
- (axis=1): If key matches an index label then drop the row.
Otherwise if key matches a column level then drop the level.
Parameters
----------
keys : str or list of str
labels or levels to drop
axis : int, default 0
Axis that levels are associated with (0 for index, 1 for columns)
Returns
-------
dropped: DataFrame
Raises
------
ValueError
if any `keys` match neither a label nor a level
"""
axis = self._get_axis_number(axis)
# Validate keys
keys = common.maybe_make_list(keys)
invalid_keys = [
k for k in keys if not self._is_label_or_level_reference(k, axis=axis)
]
if invalid_keys:
raise ValueError(
"The following keys are not valid labels or "
f"levels for axis {axis}: {invalid_keys}"
)
# Compute levels and labels to drop
levels_to_drop = [k for k in keys if self._is_level_reference(k, axis=axis)]
labels_to_drop = [k for k in keys if not self._is_level_reference(k, axis=axis)]
# Perform copy upfront and then use inplace operations below.
# This ensures that we always perform exactly one copy.
# ``copy`` and/or ``inplace`` options could be added in the future.
dropped = self.copy(deep=False)
if axis == 0:
# Handle dropping index levels
if levels_to_drop:
dropped.reset_index(levels_to_drop, drop=True, inplace=True)
# Handle dropping columns labels
if labels_to_drop:
dropped.drop(labels_to_drop, axis=1, inplace=True)
else:
# Handle dropping column levels
if levels_to_drop:
if isinstance(dropped.columns, MultiIndex):
# Drop the specified levels from the MultiIndex
dropped.columns = dropped.columns.droplevel(levels_to_drop)
else:
# Drop the last level of Index by replacing with
# a RangeIndex
dropped.columns = RangeIndex(dropped.columns.size)
# Handle dropping index labels
if labels_to_drop:
dropped.drop(labels_to_drop, axis=0, inplace=True)
return dropped
# ----------------------------------------------------------------------
# Iteration
# https://github.com/python/typeshed/issues/2148#issuecomment-520783318
# Incompatible types in assignment (expression has type "None", base class
# "object" defined the type as "Callable[[object], int]")
__hash__: ClassVar[None] # type: ignore[assignment]
def __iter__(self) -> Iterator:
"""
Iterate over info axis.
Returns
-------
iterator
Info axis as iterator.
"""
return iter(self._info_axis)
# can we get a better explanation of this?
def keys(self) -> Index:
"""
Get the 'info axis' (see Indexing for more).
This is index for Series, columns for DataFrame.
Returns
-------
Index
Info axis.
"""
return self._info_axis
def items(self):
"""
Iterate over (label, values) on info axis
This is index for Series and columns for DataFrame.
Returns
-------
Generator
"""
for h in self._info_axis:
yield h, self[h]
def __len__(self) -> int:
"""Returns length of info axis"""
return len(self._info_axis)
def __contains__(self, key) -> bool_t:
"""True if the key is in the info axis"""
return key in self._info_axis
def empty(self) -> bool_t:
"""
Indicator whether Series/DataFrame is empty.
True if Series/DataFrame is entirely empty (no items), meaning any of the
axes are of length 0.
Returns
-------
bool
If Series/DataFrame is empty, return True, if not return False.
See Also
--------
Series.dropna : Return series without null values.
DataFrame.dropna : Return DataFrame with labels on given axis omitted
where (all or any) data are missing.
Notes
-----
If Series/DataFrame contains only NaNs, it is still not considered empty. See
the example below.
Examples
--------
An example of an actual empty DataFrame. Notice the index is empty:
>>> df_empty = pd.DataFrame({'A' : []})
>>> df_empty
Empty DataFrame
Columns: [A]
Index: []
>>> df_empty.empty
True
If we only have NaNs in our DataFrame, it is not considered empty! We
will need to drop the NaNs to make the DataFrame empty:
>>> df = pd.DataFrame({'A' : [np.nan]})
>>> df
A
0 NaN
>>> df.empty
False
>>> df.dropna().empty
True
>>> ser_empty = pd.Series({'A' : []})
>>> ser_empty
A []
dtype: object
>>> ser_empty.empty
False
>>> ser_empty = pd.Series()
>>> ser_empty.empty
True
"""
return any(len(self._get_axis(a)) == 0 for a in self._AXIS_ORDERS)
# ----------------------------------------------------------------------
# Array Interface
# This is also set in IndexOpsMixin
# GH#23114 Ensure ndarray.__op__(DataFrame) returns NotImplemented
__array_priority__: int = 1000
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
values = self._values
arr = np.asarray(values, dtype=dtype)
if (
astype_is_view(values.dtype, arr.dtype)
and using_copy_on_write()
and self._mgr.is_single_block
):
# Check if both conversions can be done without a copy
if astype_is_view(self.dtypes.iloc[0], values.dtype) and astype_is_view(
values.dtype, arr.dtype
):
arr = arr.view()
arr.flags.writeable = False
return arr
def __array_ufunc__(
self, ufunc: np.ufunc, method: str, *inputs: Any, **kwargs: Any
):
return arraylike.array_ufunc(self, ufunc, method, *inputs, **kwargs)
# ----------------------------------------------------------------------
# Picklability
def __getstate__(self) -> dict[str, Any]:
meta = {k: getattr(self, k, None) for k in self._metadata}
return {
"_mgr": self._mgr,
"_typ": self._typ,
"_metadata": self._metadata,
"attrs": self.attrs,
"_flags": {k: self.flags[k] for k in self.flags._keys},
**meta,
}
def __setstate__(self, state) -> None:
if isinstance(state, BlockManager):
self._mgr = state
elif isinstance(state, dict):
if "_data" in state and "_mgr" not in state:
# compat for older pickles
state["_mgr"] = state.pop("_data")
typ = state.get("_typ")
if typ is not None:
attrs = state.get("_attrs", {})
object.__setattr__(self, "_attrs", attrs)
flags = state.get("_flags", {"allows_duplicate_labels": True})
object.__setattr__(self, "_flags", Flags(self, **flags))
# set in the order of internal names
# to avoid definitional recursion
# e.g. say fill_value needing _mgr to be
# defined
meta = set(self._internal_names + self._metadata)
for k in list(meta):
if k in state and k != "_flags":
v = state[k]
object.__setattr__(self, k, v)
for k, v in state.items():
if k not in meta:
object.__setattr__(self, k, v)
else:
raise NotImplementedError("Pre-0.12 pickles are no longer supported")
elif len(state) == 2:
raise NotImplementedError("Pre-0.12 pickles are no longer supported")
self._item_cache: dict[Hashable, Series] = {}
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
# string representation based upon iterating over self
# (since, by definition, `PandasContainers` are iterable)
prepr = f"[{','.join(map(pprint_thing, self))}]"
return f"{type(self).__name__}({prepr})"
def _repr_latex_(self):
"""
Returns a LaTeX representation for a particular object.
Mainly for use with nbconvert (jupyter notebook conversion to pdf).
"""
if config.get_option("styler.render.repr") == "latex":
return self.to_latex()
else:
return None
def _repr_data_resource_(self):
"""
Not a real Jupyter special repr method, but we use the same
naming convention.
"""
if config.get_option("display.html.table_schema"):
data = self.head(config.get_option("display.max_rows"))
as_json = data.to_json(orient="table")
as_json = cast(str, as_json)
return loads(as_json, object_pairs_hook=collections.OrderedDict)
# ----------------------------------------------------------------------
# I/O Methods
klass="object",
storage_options=_shared_docs["storage_options"],
storage_options_versionadded="1.2.0",
)
def to_excel(
self,
excel_writer,
sheet_name: str = "Sheet1",
na_rep: str = "",
float_format: str | None = None,
columns: Sequence[Hashable] | None = None,
header: Sequence[Hashable] | bool_t = True,
index: bool_t = True,
index_label: IndexLabel = None,
startrow: int = 0,
startcol: int = 0,
engine: str | None = None,
merge_cells: bool_t = True,
inf_rep: str = "inf",
freeze_panes: tuple[int, int] | None = None,
storage_options: StorageOptions = None,
) -> None:
"""
Write {klass} to an Excel sheet.
To write a single {klass} to an Excel .xlsx file it is only necessary to
specify a target file name. To write to multiple sheets it is necessary to
create an `ExcelWriter` object with a target file name, and specify a sheet
in the file to write to.
Multiple sheets may be written to by specifying unique `sheet_name`.
With all data written to the file it is necessary to save the changes.
Note that creating an `ExcelWriter` object with a file name that already
exists will result in the contents of the existing file being erased.
Parameters
----------
excel_writer : path-like, file-like, or ExcelWriter object
File path or existing ExcelWriter.
sheet_name : str, default 'Sheet1'
Name of sheet which will contain DataFrame.
na_rep : str, default ''
Missing data representation.
float_format : str, optional
Format string for floating point numbers. For example
``float_format="%.2f"`` will format 0.1234 to 0.12.
columns : sequence or list of str, optional
Columns to write.
header : bool or list of str, default True
Write out the column names. If a list of string is given it is
assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
index_label : str or sequence, optional
Column label for index column(s) if desired. If not specified, and
`header` and `index` are True, then the index names are used. A
sequence should be given if the DataFrame uses MultiIndex.
startrow : int, default 0
Upper left cell row to dump data frame.
startcol : int, default 0
Upper left cell column to dump data frame.
engine : str, optional
Write engine to use, 'openpyxl' or 'xlsxwriter'. You can also set this
via the options ``io.excel.xlsx.writer`` or
``io.excel.xlsm.writer``.
merge_cells : bool, default True
Write MultiIndex and Hierarchical Rows as merged cells.
inf_rep : str, default 'inf'
Representation for infinity (there is no native representation for
infinity in Excel).
freeze_panes : tuple of int (length 2), optional
Specifies the one-based bottommost row and rightmost column that
is to be frozen.
{storage_options}
.. versionadded:: {storage_options_versionadded}
See Also
--------
to_csv : Write DataFrame to a comma-separated values (csv) file.
ExcelWriter : Class for writing DataFrame objects into excel sheets.
read_excel : Read an Excel file into a pandas DataFrame.
read_csv : Read a comma-separated values (csv) file into DataFrame.
io.formats.style.Styler.to_excel : Add styles to Excel sheet.
Notes
-----
For compatibility with :meth:`~DataFrame.to_csv`,
to_excel serializes lists and dicts to strings before writing.
Once a workbook has been saved it is not possible to write further
data without rewriting the whole workbook.
Examples
--------
Create, write to and save a workbook:
>>> df1 = pd.DataFrame([['a', 'b'], ['c', 'd']],
... index=['row 1', 'row 2'],
... columns=['col 1', 'col 2'])
>>> df1.to_excel("output.xlsx") # doctest: +SKIP
To specify the sheet name:
>>> df1.to_excel("output.xlsx",
... sheet_name='Sheet_name_1') # doctest: +SKIP
If you wish to write to more than one sheet in the workbook, it is
necessary to specify an ExcelWriter object:
>>> df2 = df1.copy()
>>> with pd.ExcelWriter('output.xlsx') as writer: # doctest: +SKIP
... df1.to_excel(writer, sheet_name='Sheet_name_1')
... df2.to_excel(writer, sheet_name='Sheet_name_2')
ExcelWriter can also be used to append to an existing Excel file:
>>> with pd.ExcelWriter('output.xlsx',
... mode='a') as writer: # doctest: +SKIP
... df.to_excel(writer, sheet_name='Sheet_name_3')
To set the library that is used to write the Excel file,
you can pass the `engine` keyword (the default engine is
automatically chosen depending on the file extension):
>>> df1.to_excel('output1.xlsx', engine='xlsxwriter') # doctest: +SKIP
"""
df = self if isinstance(self, ABCDataFrame) else self.to_frame()
from pandas.io.formats.excel import ExcelFormatter
formatter = ExcelFormatter(
df,
na_rep=na_rep,
cols=columns,
header=header,
float_format=float_format,
index=index,
index_label=index_label,
merge_cells=merge_cells,
inf_rep=inf_rep,
)
formatter.write(
excel_writer,
sheet_name=sheet_name,
startrow=startrow,
startcol=startcol,
freeze_panes=freeze_panes,
engine=engine,
storage_options=storage_options,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buf",
)
def to_json(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
orient: str | None = None,
date_format: str | None = None,
double_precision: int = 10,
force_ascii: bool_t = True,
date_unit: str = "ms",
default_handler: Callable[[Any], JSONSerializable] | None = None,
lines: bool_t = False,
compression: CompressionOptions = "infer",
index: bool_t = True,
indent: int | None = None,
storage_options: StorageOptions = None,
mode: Literal["a", "w"] = "w",
) -> str | None:
"""
Convert the object to a JSON string.
Note NaN's and None will be converted to null and datetime objects
will be converted to UNIX timestamps.
Parameters
----------
path_or_buf : str, path object, file-like object, or None, default None
String, path object (implementing os.PathLike[str]), or file-like
object implementing a write() function. If None, the result is
returned as a string.
orient : str
Indication of expected JSON string format.
* Series:
- default is 'index'
- allowed values are: {{'split', 'records', 'index', 'table'}}.
* DataFrame:
- default is 'columns'
- allowed values are: {{'split', 'records', 'index', 'columns',
'values', 'table'}}.
* The format of the JSON string:
- 'split' : dict like {{'index' -> [index], 'columns' -> [columns],
'data' -> [values]}}
- 'records' : list like [{{column -> value}}, ... , {{column -> value}}]
- 'index' : dict like {{index -> {{column -> value}}}}
- 'columns' : dict like {{column -> {{index -> value}}}}
- 'values' : just the values array
- 'table' : dict like {{'schema': {{schema}}, 'data': {{data}}}}
Describing the data, where data component is like ``orient='records'``.
date_format : {{None, 'epoch', 'iso'}}
Type of date conversion. 'epoch' = epoch milliseconds,
'iso' = ISO8601. The default depends on the `orient`. For
``orient='table'``, the default is 'iso'. For all other orients,
the default is 'epoch'.
double_precision : int, default 10
The number of decimal places to use when encoding
floating point values.
force_ascii : bool, default True
Force encoded string to be ASCII.
date_unit : str, default 'ms' (milliseconds)
The time unit to encode to, governs timestamp and ISO8601
precision. One of 's', 'ms', 'us', 'ns' for second, millisecond,
microsecond, and nanosecond respectively.
default_handler : callable, default None
Handler to call if object cannot otherwise be converted to a
suitable format for JSON. Should receive a single argument which is
the object to convert and return a serialisable object.
lines : bool, default False
If 'orient' is 'records' write out line-delimited json format. Will
throw ValueError if incorrect 'orient' since others are not
list-like.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
index : bool, default True
Whether to include the index values in the JSON string. Not
including the index (``index=False``) is only supported when
orient is 'split' or 'table'.
indent : int, optional
Length of whitespace used to indent each record.
{storage_options}
.. versionadded:: 1.2.0
mode : str, default 'w' (writing)
Specify the IO mode for output when supplying a path_or_buf.
Accepted args are 'w' (writing) and 'a' (append) only.
mode='a' is only supported when lines is True and orient is 'records'.
Returns
-------
None or str
If path_or_buf is None, returns the resulting json format as a
string. Otherwise returns None.
See Also
--------
read_json : Convert a JSON string to pandas object.
Notes
-----
The behavior of ``indent=0`` varies from the stdlib, which does not
indent the output but does insert newlines. Currently, ``indent=0``
and the default ``indent=None`` are equivalent in pandas, though this
may change in a future release.
``orient='table'`` contains a 'pandas_version' field under 'schema'.
This stores the version of `pandas` used in the latest revision of the
schema.
Examples
--------
>>> from json import loads, dumps
>>> df = pd.DataFrame(
... [["a", "b"], ["c", "d"]],
... index=["row 1", "row 2"],
... columns=["col 1", "col 2"],
... )
>>> result = df.to_json(orient="split")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"columns": [
"col 1",
"col 2"
],
"index": [
"row 1",
"row 2"
],
"data": [
[
"a",
"b"
],
[
"c",
"d"
]
]
}}
Encoding/decoding a Dataframe using ``'records'`` formatted JSON.
Note that index labels are not preserved with this encoding.
>>> result = df.to_json(orient="records")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
[
{{
"col 1": "a",
"col 2": "b"
}},
{{
"col 1": "c",
"col 2": "d"
}}
]
Encoding/decoding a Dataframe using ``'index'`` formatted JSON:
>>> result = df.to_json(orient="index")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"row 1": {{
"col 1": "a",
"col 2": "b"
}},
"row 2": {{
"col 1": "c",
"col 2": "d"
}}
}}
Encoding/decoding a Dataframe using ``'columns'`` formatted JSON:
>>> result = df.to_json(orient="columns")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"col 1": {{
"row 1": "a",
"row 2": "c"
}},
"col 2": {{
"row 1": "b",
"row 2": "d"
}}
}}
Encoding/decoding a Dataframe using ``'values'`` formatted JSON:
>>> result = df.to_json(orient="values")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
[
[
"a",
"b"
],
[
"c",
"d"
]
]
Encoding with Table Schema:
>>> result = df.to_json(orient="table")
>>> parsed = loads(result)
>>> dumps(parsed, indent=4) # doctest: +SKIP
{{
"schema": {{
"fields": [
{{
"name": "index",
"type": "string"
}},
{{
"name": "col 1",
"type": "string"
}},
{{
"name": "col 2",
"type": "string"
}}
],
"primaryKey": [
"index"
],
"pandas_version": "1.4.0"
}},
"data": [
{{
"index": "row 1",
"col 1": "a",
"col 2": "b"
}},
{{
"index": "row 2",
"col 1": "c",
"col 2": "d"
}}
]
}}
"""
from pandas.io import json
if date_format is None and orient == "table":
date_format = "iso"
elif date_format is None:
date_format = "epoch"
config.is_nonnegative_int(indent)
indent = indent or 0
return json.to_json(
path_or_buf=path_or_buf,
obj=self,
orient=orient,
date_format=date_format,
double_precision=double_precision,
force_ascii=force_ascii,
date_unit=date_unit,
default_handler=default_handler,
lines=lines,
compression=compression,
index=index,
indent=indent,
storage_options=storage_options,
mode=mode,
)
def to_hdf(
self,
path_or_buf: FilePath | HDFStore,
key: str,
mode: str = "a",
complevel: int | None = None,
complib: str | None = None,
append: bool_t = False,
format: str | None = None,
index: bool_t = True,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
dropna: bool_t | None = None,
data_columns: Literal[True] | list[str] | None = None,
errors: str = "strict",
encoding: str = "UTF-8",
) -> None:
"""
Write the contained data to an HDF5 file using HDFStore.
Hierarchical Data Format (HDF) is self-describing, allowing an
application to interpret the structure and contents of a file with
no outside information. One HDF file can hold a mix of related objects
which can be accessed as a group or as individual objects.
In order to add another DataFrame or Series to an existing HDF file
please use append mode and a different a key.
.. warning::
One can store a subclass of ``DataFrame`` or ``Series`` to HDF5,
but the type of the subclass is lost upon storing.
For more information see the :ref:`user guide <io.hdf5>`.
Parameters
----------
path_or_buf : str or pandas.HDFStore
File path or HDFStore object.
key : str
Identifier for the group in the store.
mode : {'a', 'w', 'r+'}, default 'a'
Mode to open file:
- 'w': write, a new file is created (an existing file with
the same name would be deleted).
- 'a': append, an existing file is opened for reading and
writing, and if the file does not exist it is created.
- 'r+': similar to 'a', but the file must already exist.
complevel : {0-9}, default None
Specifies a compression level for data.
A value of 0 or None disables compression.
complib : {'zlib', 'lzo', 'bzip2', 'blosc'}, default 'zlib'
Specifies the compression library to be used.
As of v0.20.2 these additional compressors for Blosc are supported
(default if no compressor specified: 'blosc:blosclz'):
{'blosc:blosclz', 'blosc:lz4', 'blosc:lz4hc', 'blosc:snappy',
'blosc:zlib', 'blosc:zstd'}.
Specifying a compression library which is not available issues
a ValueError.
append : bool, default False
For Table formats, append the input data to the existing.
format : {'fixed', 'table', None}, default 'fixed'
Possible values:
- 'fixed': Fixed format. Fast writing/reading. Not-appendable,
nor searchable.
- 'table': Table format. Write as a PyTables Table structure
which may perform worse but allow more flexible operations
like searching / selecting subsets of the data.
- If None, pd.get_option('io.hdf.default_format') is checked,
followed by fallback to "fixed".
index : bool, default True
Write DataFrame index as a column.
min_itemsize : dict or int, optional
Map column names to minimum string sizes for columns.
nan_rep : Any, optional
How to represent null values as str.
Not allowed with append=True.
dropna : bool, default False, optional
Remove missing values.
data_columns : list of columns or True, optional
List of columns to create as indexed data columns for on-disk
queries, or True to use all columns. By default only the axes
of the object are indexed. See
:ref:`Query via data columns<io.hdf5-query-data-columns>`. for
more information.
Applicable only to format='table'.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
encoding : str, default "UTF-8"
See Also
--------
read_hdf : Read from HDF file.
DataFrame.to_orc : Write a DataFrame to the binary orc format.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
DataFrame.to_sql : Write to a SQL table.
DataFrame.to_feather : Write out feather-format for DataFrames.
DataFrame.to_csv : Write out to a csv file.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2, 3], 'B': [4, 5, 6]},
... index=['a', 'b', 'c']) # doctest: +SKIP
>>> df.to_hdf('data.h5', key='df', mode='w') # doctest: +SKIP
We can add another object to the same file:
>>> s = pd.Series([1, 2, 3, 4]) # doctest: +SKIP
>>> s.to_hdf('data.h5', key='s') # doctest: +SKIP
Reading from HDF file:
>>> pd.read_hdf('data.h5', 'df') # doctest: +SKIP
A B
a 1 4
b 2 5
c 3 6
>>> pd.read_hdf('data.h5', 's') # doctest: +SKIP
0 1
1 2
2 3
3 4
dtype: int64
"""
from pandas.io import pytables
# Argument 3 to "to_hdf" has incompatible type "NDFrame"; expected
# "Union[DataFrame, Series]" [arg-type]
pytables.to_hdf(
path_or_buf,
key,
self, # type: ignore[arg-type]
mode=mode,
complevel=complevel,
complib=complib,
append=append,
format=format,
index=index,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
dropna=dropna,
data_columns=data_columns,
errors=errors,
encoding=encoding,
)
def to_sql(
self,
name: str,
con,
schema: str | None = None,
if_exists: Literal["fail", "replace", "append"] = "fail",
index: bool_t = True,
index_label: IndexLabel = None,
chunksize: int | None = None,
dtype: DtypeArg | None = None,
method: str | None = None,
) -> int | None:
"""
Write records stored in a DataFrame to a SQL database.
Databases supported by SQLAlchemy [1]_ are supported. Tables can be
newly created, appended to, or overwritten.
Parameters
----------
name : str
Name of SQL table.
con : sqlalchemy.engine.(Engine or Connection) or sqlite3.Connection
Using SQLAlchemy makes it possible to use any DB supported by that
library. Legacy support is provided for sqlite3.Connection objects. The user
is responsible for engine disposal and connection closure for the SQLAlchemy
connectable. See `here \
<https://docs.sqlalchemy.org/en/20/core/connections.html>`_.
If passing a sqlalchemy.engine.Connection which is already in a transaction,
the transaction will not be committed. If passing a sqlite3.Connection,
it will not be possible to roll back the record insertion.
schema : str, optional
Specify the schema (if database flavor supports this). If None, use
default schema.
if_exists : {'fail', 'replace', 'append'}, default 'fail'
How to behave if the table already exists.
* fail: Raise a ValueError.
* replace: Drop the table before inserting new values.
* append: Insert new values to the existing table.
index : bool, default True
Write DataFrame index as a column. Uses `index_label` as the column
name in the table.
index_label : str or sequence, default None
Column label for index column(s). If None is given (default) and
`index` is True, then the index names are used.
A sequence should be given if the DataFrame uses MultiIndex.
chunksize : int, optional
Specify the number of rows in each batch to be written at a time.
By default, all rows will be written at once.
dtype : dict or scalar, optional
Specifying the datatype for columns. If a dictionary is used, the
keys should be the column names and the values should be the
SQLAlchemy types or strings for the sqlite3 legacy mode. If a
scalar is provided, it will be applied to all columns.
method : {None, 'multi', callable}, optional
Controls the SQL insertion clause used:
* None : Uses standard SQL ``INSERT`` clause (one per row).
* 'multi': Pass multiple values in a single ``INSERT`` clause.
* callable with signature ``(pd_table, conn, keys, data_iter)``.
Details and a sample callable implementation can be found in the
section :ref:`insert method <io.sql.method>`.
Returns
-------
None or int
Number of rows affected by to_sql. None is returned if the callable
passed into ``method`` does not return an integer number of rows.
The number of returned rows affected is the sum of the ``rowcount``
attribute of ``sqlite3.Cursor`` or SQLAlchemy connectable which may not
reflect the exact number of written rows as stipulated in the
`sqlite3 <https://docs.python.org/3/library/sqlite3.html#sqlite3.Cursor.rowcount>`__ or
`SQLAlchemy <https://docs.sqlalchemy.org/en/20/core/connections.html#sqlalchemy.engine.CursorResult.rowcount>`__.
.. versionadded:: 1.4.0
Raises
------
ValueError
When the table already exists and `if_exists` is 'fail' (the
default).
See Also
--------
read_sql : Read a DataFrame from a table.
Notes
-----
Timezone aware datetime columns will be written as
``Timestamp with timezone`` type with SQLAlchemy if supported by the
database. Otherwise, the datetimes will be stored as timezone unaware
timestamps local to the original timezone.
References
----------
.. [1] https://docs.sqlalchemy.org
.. [2] https://www.python.org/dev/peps/pep-0249/
Examples
--------
Create an in-memory SQLite database.
>>> from sqlalchemy import create_engine
>>> engine = create_engine('sqlite://', echo=False)
Create a table from scratch with 3 rows.
>>> df = pd.DataFrame({'name' : ['User 1', 'User 2', 'User 3']})
>>> df
name
0 User 1
1 User 2
2 User 3
>>> df.to_sql('users', con=engine)
3
>>> from sqlalchemy import text
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 1'), (1, 'User 2'), (2, 'User 3')]
An `sqlalchemy.engine.Connection` can also be passed to `con`:
>>> with engine.begin() as connection:
... df1 = pd.DataFrame({'name' : ['User 4', 'User 5']})
... df1.to_sql('users', con=connection, if_exists='append')
2
This is allowed to support operations that require that the same
DBAPI connection is used for the entire operation.
>>> df2 = pd.DataFrame({'name' : ['User 6', 'User 7']})
>>> df2.to_sql('users', con=engine, if_exists='append')
2
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 1'), (1, 'User 2'), (2, 'User 3'),
(0, 'User 4'), (1, 'User 5'), (0, 'User 6'),
(1, 'User 7')]
Overwrite the table with just ``df2``.
>>> df2.to_sql('users', con=engine, if_exists='replace',
... index_label='id')
2
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM users")).fetchall()
[(0, 'User 6'), (1, 'User 7')]
Specify the dtype (especially useful for integers with missing values).
Notice that while pandas is forced to store the data as floating point,
the database supports nullable integers. When fetching the data with
Python, we get back integer scalars.
>>> df = pd.DataFrame({"A": [1, None, 2]})
>>> df
A
0 1.0
1 NaN
2 2.0
>>> from sqlalchemy.types import Integer
>>> df.to_sql('integers', con=engine, index=False,
... dtype={"A": Integer()})
3
>>> with engine.connect() as conn:
... conn.execute(text("SELECT * FROM integers")).fetchall()
[(1,), (None,), (2,)]
""" # noqa:E501
from pandas.io import sql
return sql.to_sql(
self,
name,
con,
schema=schema,
if_exists=if_exists,
index=index,
index_label=index_label,
chunksize=chunksize,
dtype=dtype,
method=method,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_pickle(
self,
path: FilePath | WriteBuffer[bytes],
compression: CompressionOptions = "infer",
protocol: int = pickle.HIGHEST_PROTOCOL,
storage_options: StorageOptions = None,
) -> None:
"""
Pickle (serialize) object to file.
Parameters
----------
path : str, path object, or file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. File path where
the pickled object will be stored.
{compression_options}
protocol : int
Int which indicates which protocol should be used by the pickler,
default HIGHEST_PROTOCOL (see [1]_ paragraph 12.1.2). The possible
values are 0, 1, 2, 3, 4, 5. A negative value for the protocol
parameter is equivalent to setting its value to HIGHEST_PROTOCOL.
.. [1] https://docs.python.org/3/library/pickle.html.
{storage_options}
.. versionadded:: 1.2.0
See Also
--------
read_pickle : Load pickled pandas object (or any object) from file.
DataFrame.to_hdf : Write DataFrame to an HDF5 file.
DataFrame.to_sql : Write DataFrame to a SQL database.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
Examples
--------
>>> original_df = pd.DataFrame({{"foo": range(5), "bar": range(5, 10)}}) # doctest: +SKIP
>>> original_df # doctest: +SKIP
foo bar
0 0 5
1 1 6
2 2 7
3 3 8
4 4 9
>>> original_df.to_pickle("./dummy.pkl") # doctest: +SKIP
>>> unpickled_df = pd.read_pickle("./dummy.pkl") # doctest: +SKIP
>>> unpickled_df # doctest: +SKIP
foo bar
0 0 5
1 1 6
2 2 7
3 3 8
4 4 9
""" # noqa: E501
from pandas.io.pickle import to_pickle
to_pickle(
self,
path,
compression=compression,
protocol=protocol,
storage_options=storage_options,
)
def to_clipboard(
self, excel: bool_t = True, sep: str | None = None, **kwargs
) -> None:
r"""
Copy object to the system clipboard.
Write a text representation of object to the system clipboard.
This can be pasted into Excel, for example.
Parameters
----------
excel : bool, default True
Produce output in a csv format for easy pasting into excel.
- True, use the provided separator for csv pasting.
- False, write a string representation of the object to the clipboard.
sep : str, default ``'\t'``
Field delimiter.
**kwargs
These parameters will be passed to DataFrame.to_csv.
See Also
--------
DataFrame.to_csv : Write a DataFrame to a comma-separated values
(csv) file.
read_clipboard : Read text from clipboard and pass to read_csv.
Notes
-----
Requirements for your platform.
- Linux : `xclip`, or `xsel` (with `PyQt4` modules)
- Windows : none
- macOS : none
This method uses the processes developed for the package `pyperclip`. A
solution to render any output string format is given in the examples.
Examples
--------
Copy the contents of a DataFrame to the clipboard.
>>> df = pd.DataFrame([[1, 2, 3], [4, 5, 6]], columns=['A', 'B', 'C'])
>>> df.to_clipboard(sep=',') # doctest: +SKIP
... # Wrote the following to the system clipboard:
... # ,A,B,C
... # 0,1,2,3
... # 1,4,5,6
We can omit the index by passing the keyword `index` and setting
it to false.
>>> df.to_clipboard(sep=',', index=False) # doctest: +SKIP
... # Wrote the following to the system clipboard:
... # A,B,C
... # 1,2,3
... # 4,5,6
Using the original `pyperclip` package for any string output format.
.. code-block:: python
import pyperclip
html = df.style.to_html()
pyperclip.copy(html)
"""
from pandas.io import clipboards
clipboards.to_clipboard(self, excel=excel, sep=sep, **kwargs)
def to_xarray(self):
"""
Return an xarray object from the pandas object.
Returns
-------
xarray.DataArray or xarray.Dataset
Data in the pandas structure converted to Dataset if the object is
a DataFrame, or a DataArray if the object is a Series.
See Also
--------
DataFrame.to_hdf : Write DataFrame to an HDF5 file.
DataFrame.to_parquet : Write a DataFrame to the binary parquet format.
Notes
-----
See the `xarray docs <https://xarray.pydata.org/en/stable/>`__
Examples
--------
>>> df = pd.DataFrame([('falcon', 'bird', 389.0, 2),
... ('parrot', 'bird', 24.0, 2),
... ('lion', 'mammal', 80.5, 4),
... ('monkey', 'mammal', np.nan, 4)],
... columns=['name', 'class', 'max_speed',
... 'num_legs'])
>>> df
name class max_speed num_legs
0 falcon bird 389.0 2
1 parrot bird 24.0 2
2 lion mammal 80.5 4
3 monkey mammal NaN 4
>>> df.to_xarray()
<xarray.Dataset>
Dimensions: (index: 4)
Coordinates:
* index (index) int64 0 1 2 3
Data variables:
name (index) object 'falcon' 'parrot' 'lion' 'monkey'
class (index) object 'bird' 'bird' 'mammal' 'mammal'
max_speed (index) float64 389.0 24.0 80.5 nan
num_legs (index) int64 2 2 4 4
>>> df['max_speed'].to_xarray()
<xarray.DataArray 'max_speed' (index: 4)>
array([389. , 24. , 80.5, nan])
Coordinates:
* index (index) int64 0 1 2 3
>>> dates = pd.to_datetime(['2018-01-01', '2018-01-01',
... '2018-01-02', '2018-01-02'])
>>> df_multiindex = pd.DataFrame({'date': dates,
... 'animal': ['falcon', 'parrot',
... 'falcon', 'parrot'],
... 'speed': [350, 18, 361, 15]})
>>> df_multiindex = df_multiindex.set_index(['date', 'animal'])
>>> df_multiindex
speed
date animal
2018-01-01 falcon 350
parrot 18
2018-01-02 falcon 361
parrot 15
>>> df_multiindex.to_xarray()
<xarray.Dataset>
Dimensions: (date: 2, animal: 2)
Coordinates:
* date (date) datetime64[ns] 2018-01-01 2018-01-02
* animal (animal) object 'falcon' 'parrot'
Data variables:
speed (date, animal) int64 350 18 361 15
"""
xarray = import_optional_dependency("xarray")
if self.ndim == 1:
return xarray.DataArray.from_series(self)
else:
return xarray.Dataset.from_dataframe(self)
def to_latex(
self,
buf: None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | Sequence[str] = ...,
index: bool_t = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool_t | None = ...,
index_names: bool_t = ...,
bold_rows: bool_t = ...,
column_format: str | None = ...,
longtable: bool_t | None = ...,
escape: bool_t | None = ...,
encoding: str | None = ...,
decimal: str = ...,
multicolumn: bool_t | None = ...,
multicolumn_format: str | None = ...,
multirow: bool_t | None = ...,
caption: str | tuple[str, str] | None = ...,
label: str | None = ...,
position: str | None = ...,
) -> str:
...
def to_latex(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Hashable] | None = ...,
header: bool_t | Sequence[str] = ...,
index: bool_t = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool_t | None = ...,
index_names: bool_t = ...,
bold_rows: bool_t = ...,
column_format: str | None = ...,
longtable: bool_t | None = ...,
escape: bool_t | None = ...,
encoding: str | None = ...,
decimal: str = ...,
multicolumn: bool_t | None = ...,
multicolumn_format: str | None = ...,
multirow: bool_t | None = ...,
caption: str | tuple[str, str] | None = ...,
label: str | None = ...,
position: str | None = ...,
) -> None:
...
def to_latex(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Hashable] | None = None,
header: bool_t | Sequence[str] = True,
index: bool_t = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool_t | None = None,
index_names: bool_t = True,
bold_rows: bool_t = False,
column_format: str | None = None,
longtable: bool_t | None = None,
escape: bool_t | None = None,
encoding: str | None = None,
decimal: str = ".",
multicolumn: bool_t | None = None,
multicolumn_format: str | None = None,
multirow: bool_t | None = None,
caption: str | tuple[str, str] | None = None,
label: str | None = None,
position: str | None = None,
) -> str | None:
r"""
Render object to a LaTeX tabular, longtable, or nested table.
Requires ``\usepackage{{booktabs}}``. The output can be copy/pasted
into a main LaTeX document or read from an external file
with ``\input{{table.tex}}``.
.. versionchanged:: 1.2.0
Added position argument, changed meaning of caption argument.
.. versionchanged:: 2.0.0
Refactored to use the Styler implementation via jinja2 templating.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
columns : list of label, optional
The subset of columns to write. Writes all columns by default.
header : bool or list of str, default True
Write out the column names. If a list of strings is given,
it is assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
na_rep : str, default 'NaN'
Missing data representation.
formatters : list of functions or dict of {{str: function}}, optional
Formatter functions to apply to columns' elements by position or
name. The result of each function must be a unicode string.
List must be of length equal to the number of columns.
float_format : one-parameter function or str, optional, default None
Formatter for floating point numbers. For example
``float_format="%.2f"`` and ``float_format="{{:0.2f}}".format`` will
both result in 0.1234 being formatted as 0.12.
sparsify : bool, optional
Set to False for a DataFrame with a hierarchical index to print
every multiindex key at each row. By default, the value will be
read from the config module.
index_names : bool, default True
Prints the names of the indexes.
bold_rows : bool, default False
Make the row labels bold in the output.
column_format : str, optional
The columns format as specified in `LaTeX table format
<https://en.wikibooks.org/wiki/LaTeX/Tables>`__ e.g. 'rcl' for 3
columns. By default, 'l' will be used for all columns except
columns of numbers, which default to 'r'.
longtable : bool, optional
Use a longtable environment instead of tabular. Requires
adding a \usepackage{{longtable}} to your LaTeX preamble.
By default, the value will be read from the pandas config
module, and set to `True` if the option ``styler.latex.environment`` is
`"longtable"`.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed.
escape : bool, optional
By default, the value will be read from the pandas config
module and set to `True` if the option ``styler.format.escape`` is
`"latex"`. When set to False prevents from escaping latex special
characters in column names.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to `False`.
encoding : str, optional
A string representing the encoding to use in the output file,
defaults to 'utf-8'.
decimal : str, default '.'
Character recognized as decimal separator, e.g. ',' in Europe.
multicolumn : bool, default True
Use \multicolumn to enhance MultiIndex columns.
The default will be read from the config module, and is set
as the option ``styler.sparse.columns``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed.
multicolumn_format : str, default 'r'
The alignment for multicolumns, similar to `column_format`
The default will be read from the config module, and is set as the option
``styler.latex.multicol_align``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to "r".
multirow : bool, default True
Use \multirow to enhance MultiIndex rows. Requires adding a
\usepackage{{multirow}} to your LaTeX preamble. Will print
centered labels (instead of top-aligned) across the contained
rows, separating groups via clines. The default will be read
from the pandas config module, and is set as the option
``styler.sparse.index``.
.. versionchanged:: 2.0.0
The pandas option affecting this argument has changed, as has the
default value to `True`.
caption : str or tuple, optional
Tuple (full_caption, short_caption),
which results in ``\caption[short_caption]{{full_caption}}``;
if a single string is passed, no short caption will be set.
.. versionchanged:: 1.2.0
Optionally allow caption to be a tuple ``(full_caption, short_caption)``.
label : str, optional
The LaTeX label to be placed inside ``\label{{}}`` in the output.
This is used with ``\ref{{}}`` in the main ``.tex`` file.
position : str, optional
The LaTeX positional argument for tables, to be placed after
``\begin{{}}`` in the output.
.. versionadded:: 1.2.0
Returns
-------
str or None
If buf is None, returns the result as a string. Otherwise returns None.
See Also
--------
io.formats.style.Styler.to_latex : Render a DataFrame to LaTeX
with conditional formatting.
DataFrame.to_string : Render a DataFrame to a console-friendly
tabular output.
DataFrame.to_html : Render a DataFrame as an HTML table.
Notes
-----
As of v2.0.0 this method has changed to use the Styler implementation as
part of :meth:`.Styler.to_latex` via ``jinja2`` templating. This means
that ``jinja2`` is a requirement, and needs to be installed, for this method
to function. It is advised that users switch to using Styler, since that
implementation is more frequently updated and contains much more
flexibility with the output.
Examples
--------
Convert a general DataFrame to LaTeX with formatting:
>>> df = pd.DataFrame(dict(name=['Raphael', 'Donatello'],
... age=[26, 45],
... height=[181.23, 177.65]))
>>> print(df.to_latex(index=False,
... formatters={"name": str.upper},
... float_format="{:.1f}".format,
... )) # doctest: +SKIP
\begin{tabular}{lrr}
\toprule
name & age & height \\
\midrule
RAPHAEL & 26 & 181.2 \\
DONATELLO & 45 & 177.7 \\
\bottomrule
\end{tabular}
"""
# Get defaults from the pandas config
if self.ndim == 1:
self = self.to_frame()
if longtable is None:
longtable = config.get_option("styler.latex.environment") == "longtable"
if escape is None:
escape = config.get_option("styler.format.escape") == "latex"
if multicolumn is None:
multicolumn = config.get_option("styler.sparse.columns")
if multicolumn_format is None:
multicolumn_format = config.get_option("styler.latex.multicol_align")
if multirow is None:
multirow = config.get_option("styler.sparse.index")
if column_format is not None and not isinstance(column_format, str):
raise ValueError("`column_format` must be str or unicode")
length = len(self.columns) if columns is None else len(columns)
if isinstance(header, (list, tuple)) and len(header) != length:
raise ValueError(f"Writing {length} cols but got {len(header)} aliases")
# Refactor formatters/float_format/decimal/na_rep/escape to Styler structure
base_format_ = {
"na_rep": na_rep,
"escape": "latex" if escape else None,
"decimal": decimal,
}
index_format_: dict[str, Any] = {"axis": 0, **base_format_}
column_format_: dict[str, Any] = {"axis": 1, **base_format_}
if isinstance(float_format, str):
float_format_: Callable | None = lambda x: float_format % x
else:
float_format_ = float_format
def _wrap(x, alt_format_):
if isinstance(x, (float, complex)) and float_format_ is not None:
return float_format_(x)
else:
return alt_format_(x)
formatters_: list | tuple | dict | Callable | None = None
if isinstance(formatters, list):
formatters_ = {
c: partial(_wrap, alt_format_=formatters[i])
for i, c in enumerate(self.columns)
}
elif isinstance(formatters, dict):
index_formatter = formatters.pop("__index__", None)
column_formatter = formatters.pop("__columns__", None)
if index_formatter is not None:
index_format_.update({"formatter": index_formatter})
if column_formatter is not None:
column_format_.update({"formatter": column_formatter})
formatters_ = formatters
float_columns = self.select_dtypes(include="float").columns
for col in float_columns:
if col not in formatters.keys():
formatters_.update({col: float_format_})
elif formatters is None and float_format is not None:
formatters_ = partial(_wrap, alt_format_=lambda v: v)
format_index_ = [index_format_, column_format_]
# Deal with hiding indexes and relabelling column names
hide_: list[dict] = []
relabel_index_: list[dict] = []
if columns:
hide_.append(
{
"subset": [c for c in self.columns if c not in columns],
"axis": "columns",
}
)
if header is False:
hide_.append({"axis": "columns"})
elif isinstance(header, (list, tuple)):
relabel_index_.append({"labels": header, "axis": "columns"})
format_index_ = [index_format_] # column_format is overwritten
if index is False:
hide_.append({"axis": "index"})
if index_names is False:
hide_.append({"names": True, "axis": "index"})
render_kwargs_ = {
"hrules": True,
"sparse_index": sparsify,
"sparse_columns": sparsify,
"environment": "longtable" if longtable else None,
"multicol_align": multicolumn_format
if multicolumn
else f"naive-{multicolumn_format}",
"multirow_align": "t" if multirow else "naive",
"encoding": encoding,
"caption": caption,
"label": label,
"position": position,
"column_format": column_format,
"clines": "skip-last;data"
if (multirow and isinstance(self.index, MultiIndex))
else None,
"bold_rows": bold_rows,
}
return self._to_latex_via_styler(
buf,
hide=hide_,
relabel_index=relabel_index_,
format={"formatter": formatters_, **base_format_},
format_index=format_index_,
render_kwargs=render_kwargs_,
)
def _to_latex_via_styler(
self,
buf=None,
*,
hide: dict | list[dict] | None = None,
relabel_index: dict | list[dict] | None = None,
format: dict | list[dict] | None = None,
format_index: dict | list[dict] | None = None,
render_kwargs: dict | None = None,
):
"""
Render object to a LaTeX tabular, longtable, or nested table.
Uses the ``Styler`` implementation with the following, ordered, method chaining:
.. code-block:: python
styler = Styler(DataFrame)
styler.hide(**hide)
styler.relabel_index(**relabel_index)
styler.format(**format)
styler.format_index(**format_index)
styler.to_latex(buf=buf, **render_kwargs)
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
hide : dict, list of dict
Keyword args to pass to the method call of ``Styler.hide``. If a list will
call the method numerous times.
relabel_index : dict, list of dict
Keyword args to pass to the method of ``Styler.relabel_index``. If a list
will call the method numerous times.
format : dict, list of dict
Keyword args to pass to the method call of ``Styler.format``. If a list will
call the method numerous times.
format_index : dict, list of dict
Keyword args to pass to the method call of ``Styler.format_index``. If a
list will call the method numerous times.
render_kwargs : dict
Keyword args to pass to the method call of ``Styler.to_latex``.
Returns
-------
str or None
If buf is None, returns the result as a string. Otherwise returns None.
"""
from pandas.io.formats.style import Styler
self = cast("DataFrame", self)
styler = Styler(self, uuid="")
for kw_name in ["hide", "relabel_index", "format", "format_index"]:
kw = vars()[kw_name]
if isinstance(kw, dict):
getattr(styler, kw_name)(**kw)
elif isinstance(kw, list):
for sub_kw in kw:
getattr(styler, kw_name)(**sub_kw)
# bold_rows is not a direct kwarg of Styler.to_latex
render_kwargs = {} if render_kwargs is None else render_kwargs
if render_kwargs.pop("bold_rows"):
styler.applymap_index(lambda v: "textbf:--rwrap;")
return styler.to_latex(buf=buf, **render_kwargs)
def to_csv(
self,
path_or_buf: None = ...,
sep: str = ...,
na_rep: str = ...,
float_format: str | Callable | None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | list[str] = ...,
index: bool_t = ...,
index_label: IndexLabel | None = ...,
mode: str = ...,
encoding: str | None = ...,
compression: CompressionOptions = ...,
quoting: int | None = ...,
quotechar: str = ...,
lineterminator: str | None = ...,
chunksize: int | None = ...,
date_format: str | None = ...,
doublequote: bool_t = ...,
escapechar: str | None = ...,
decimal: str = ...,
errors: str = ...,
storage_options: StorageOptions = ...,
) -> str:
...
def to_csv(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str],
sep: str = ...,
na_rep: str = ...,
float_format: str | Callable | None = ...,
columns: Sequence[Hashable] | None = ...,
header: bool_t | list[str] = ...,
index: bool_t = ...,
index_label: IndexLabel | None = ...,
mode: str = ...,
encoding: str | None = ...,
compression: CompressionOptions = ...,
quoting: int | None = ...,
quotechar: str = ...,
lineterminator: str | None = ...,
chunksize: int | None = ...,
date_format: str | None = ...,
doublequote: bool_t = ...,
escapechar: str | None = ...,
decimal: str = ...,
errors: str = ...,
storage_options: StorageOptions = ...,
) -> None:
...
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buf",
)
def to_csv(
self,
path_or_buf: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
sep: str = ",",
na_rep: str = "",
float_format: str | Callable | None = None,
columns: Sequence[Hashable] | None = None,
header: bool_t | list[str] = True,
index: bool_t = True,
index_label: IndexLabel | None = None,
mode: str = "w",
encoding: str | None = None,
compression: CompressionOptions = "infer",
quoting: int | None = None,
quotechar: str = '"',
lineterminator: str | None = None,
chunksize: int | None = None,
date_format: str | None = None,
doublequote: bool_t = True,
escapechar: str | None = None,
decimal: str = ".",
errors: str = "strict",
storage_options: StorageOptions = None,
) -> str | None:
r"""
Write object to a comma-separated values (csv) file.
Parameters
----------
path_or_buf : str, path object, file-like object, or None, default None
String, path object (implementing os.PathLike[str]), or file-like
object implementing a write() function. If None, the result is
returned as a string. If a non-binary file object is passed, it should
be opened with `newline=''`, disabling universal newlines. If a binary
file object is passed, `mode` might need to contain a `'b'`.
.. versionchanged:: 1.2.0
Support for binary file objects was introduced.
sep : str, default ','
String of length 1. Field delimiter for the output file.
na_rep : str, default ''
Missing data representation.
float_format : str, Callable, default None
Format string for floating point numbers. If a Callable is given, it takes
precedence over other numeric formatting parameters, like decimal.
columns : sequence, optional
Columns to write.
header : bool or list of str, default True
Write out the column names. If a list of strings is given it is
assumed to be aliases for the column names.
index : bool, default True
Write row names (index).
index_label : str or sequence, or False, default None
Column label for index column(s) if desired. If None is given, and
`header` and `index` are True, then the index names are used. A
sequence should be given if the object uses MultiIndex. If
False do not print fields for index names. Use index_label=False
for easier importing in R.
mode : str, default 'w'
Python write mode. The available write modes are the same as
:py:func:`open`.
encoding : str, optional
A string representing the encoding to use in the output file,
defaults to 'utf-8'. `encoding` is not supported if `path_or_buf`
is a non-binary file object.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other entries as additional compression options if
compression mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is
supported for compression modes 'gzip', 'bz2', 'zstd', and 'zip'.
.. versionchanged:: 1.2.0
Compression is supported for binary file objects.
.. versionchanged:: 1.2.0
Previous versions forwarded dict entries for 'gzip' to
`gzip.open` instead of `gzip.GzipFile` which prevented
setting `mtime`.
quoting : optional constant from csv module
Defaults to csv.QUOTE_MINIMAL. If you have set a `float_format`
then floats are converted to strings and thus csv.QUOTE_NONNUMERIC
will treat them as non-numeric.
quotechar : str, default '\"'
String of length 1. Character used to quote fields.
lineterminator : str, optional
The newline character or character sequence to use in the output
file. Defaults to `os.linesep`, which depends on the OS in which
this method is called ('\\n' for linux, '\\r\\n' for Windows, i.e.).
.. versionchanged:: 1.5.0
Previously was line_terminator, changed for consistency with
read_csv and the standard library 'csv' module.
chunksize : int or None
Rows to write at a time.
date_format : str, default None
Format string for datetime objects.
doublequote : bool, default True
Control quoting of `quotechar` inside a field.
escapechar : str, default None
String of length 1. Character used to escape `sep` and `quotechar`
when appropriate.
decimal : str, default '.'
Character recognized as decimal separator. E.g. use ',' for
European data.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
Returns
-------
None or str
If path_or_buf is None, returns the resulting csv format as a
string. Otherwise returns None.
See Also
--------
read_csv : Load a CSV file into a DataFrame.
to_excel : Write DataFrame to an Excel file.
Examples
--------
>>> df = pd.DataFrame({{'name': ['Raphael', 'Donatello'],
... 'mask': ['red', 'purple'],
... 'weapon': ['sai', 'bo staff']}})
>>> df.to_csv(index=False)
'name,mask,weapon\nRaphael,red,sai\nDonatello,purple,bo staff\n'
Create 'out.zip' containing 'out.csv'
>>> compression_opts = dict(method='zip',
... archive_name='out.csv') # doctest: +SKIP
>>> df.to_csv('out.zip', index=False,
... compression=compression_opts) # doctest: +SKIP
To write a csv file to a new folder or nested folder you will first
need to create it using either Pathlib or os:
>>> from pathlib import Path # doctest: +SKIP
>>> filepath = Path('folder/subfolder/out.csv') # doctest: +SKIP
>>> filepath.parent.mkdir(parents=True, exist_ok=True) # doctest: +SKIP
>>> df.to_csv(filepath) # doctest: +SKIP
>>> import os # doctest: +SKIP
>>> os.makedirs('folder/subfolder', exist_ok=True) # doctest: +SKIP
>>> df.to_csv('folder/subfolder/out.csv') # doctest: +SKIP
"""
df = self if isinstance(self, ABCDataFrame) else self.to_frame()
formatter = DataFrameFormatter(
frame=df,
header=header,
index=index,
na_rep=na_rep,
float_format=float_format,
decimal=decimal,
)
return DataFrameRenderer(formatter).to_csv(
path_or_buf,
lineterminator=lineterminator,
sep=sep,
encoding=encoding,
errors=errors,
compression=compression,
quoting=quoting,
columns=columns,
index_label=index_label,
mode=mode,
chunksize=chunksize,
quotechar=quotechar,
date_format=date_format,
doublequote=doublequote,
escapechar=escapechar,
storage_options=storage_options,
)
# ----------------------------------------------------------------------
# Lookup Caching
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
raise AbstractMethodError(self)
def _maybe_update_cacher(
self,
clear: bool_t = False,
verify_is_copy: bool_t = True,
inplace: bool_t = False,
) -> None:
"""
See if we need to update our parent cacher if clear, then clear our
cache.
Parameters
----------
clear : bool, default False
Clear the item cache.
verify_is_copy : bool, default True
Provide is_copy checks.
"""
if using_copy_on_write():
return
if verify_is_copy:
self._check_setitem_copy(t="referent")
if clear:
self._clear_item_cache()
def _clear_item_cache(self) -> None:
raise AbstractMethodError(self)
# ----------------------------------------------------------------------
# Indexing Methods
def take(self: NDFrameT, indices, axis: Axis = 0, **kwargs) -> NDFrameT:
"""
Return the elements in the given *positional* indices along an axis.
This means that we are not indexing according to actual values in
the index attribute of the object. We are indexing according to the
actual position of the element in the object.
Parameters
----------
indices : array-like
An array of ints indicating which positions to take.
axis : {0 or 'index', 1 or 'columns', None}, default 0
The axis on which to select elements. ``0`` means that we are
selecting rows, ``1`` means that we are selecting columns.
For `Series` this parameter is unused and defaults to 0.
**kwargs
For compatibility with :meth:`numpy.take`. Has no effect on the
output.
Returns
-------
same type as caller
An array-like containing the elements taken from the object.
See Also
--------
DataFrame.loc : Select a subset of a DataFrame by labels.
DataFrame.iloc : Select a subset of a DataFrame by positions.
numpy.take : Take elements from an array along an axis.
Examples
--------
>>> df = pd.DataFrame([('falcon', 'bird', 389.0),
... ('parrot', 'bird', 24.0),
... ('lion', 'mammal', 80.5),
... ('monkey', 'mammal', np.nan)],
... columns=['name', 'class', 'max_speed'],
... index=[0, 2, 3, 1])
>>> df
name class max_speed
0 falcon bird 389.0
2 parrot bird 24.0
3 lion mammal 80.5
1 monkey mammal NaN
Take elements at positions 0 and 3 along the axis 0 (default).
Note how the actual indices selected (0 and 1) do not correspond to
our selected indices 0 and 3. That's because we are selecting the 0th
and 3rd rows, not rows whose indices equal 0 and 3.
>>> df.take([0, 3])
name class max_speed
0 falcon bird 389.0
1 monkey mammal NaN
Take elements at indices 1 and 2 along the axis 1 (column selection).
>>> df.take([1, 2], axis=1)
class max_speed
0 bird 389.0
2 bird 24.0
3 mammal 80.5
1 mammal NaN
We may take elements using negative integers for positive indices,
starting from the end of the object, just like with Python lists.
>>> df.take([-1, -2])
name class max_speed
1 monkey mammal NaN
3 lion mammal 80.5
"""
nv.validate_take((), kwargs)
return self._take(indices, axis)
def _take(
self: NDFrameT,
indices,
axis: Axis = 0,
convert_indices: bool_t = True,
) -> NDFrameT:
"""
Internal version of the `take` allowing specification of additional args.
See the docstring of `take` for full explanation of the parameters.
"""
if not isinstance(indices, slice):
indices = np.asarray(indices, dtype=np.intp)
if (
axis == 0
and indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_data = self._mgr.take(
indices,
axis=self._get_block_manager_axis(axis),
verify=True,
convert_indices=convert_indices,
)
return self._constructor(new_data).__finalize__(self, method="take")
def _take_with_is_copy(self: NDFrameT, indices, axis: Axis = 0) -> NDFrameT:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning).
See the docstring of `take` for full explanation of the parameters.
"""
result = self._take(indices=indices, axis=axis)
# Maybe set copy if we didn't actually change the index.
if not result._get_axis(axis).equals(self._get_axis(axis)):
result._set_is_copy(self)
return result
def xs(
self: NDFrameT,
key: IndexLabel,
axis: Axis = 0,
level: IndexLabel = None,
drop_level: bool_t = True,
) -> NDFrameT:
"""
Return cross-section from the Series/DataFrame.
This method takes a `key` argument to select data at a particular
level of a MultiIndex.
Parameters
----------
key : label or tuple of label
Label contained in the index, or partially in a MultiIndex.
axis : {0 or 'index', 1 or 'columns'}, default 0
Axis to retrieve cross-section on.
level : object, defaults to first n levels (n=1 or len(key))
In case of a key partially contained in a MultiIndex, indicate
which levels are used. Levels can be referred by label or position.
drop_level : bool, default True
If False, returns object with same levels as self.
Returns
-------
Series or DataFrame
Cross-section from the original Series or DataFrame
corresponding to the selected index levels.
See Also
--------
DataFrame.loc : Access a group of rows and columns
by label(s) or a boolean array.
DataFrame.iloc : Purely integer-location based indexing
for selection by position.
Notes
-----
`xs` can not be used to set values.
MultiIndex Slicers is a generic way to get/set values on
any level or levels.
It is a superset of `xs` functionality, see
:ref:`MultiIndex Slicers <advanced.mi_slicers>`.
Examples
--------
>>> d = {'num_legs': [4, 4, 2, 2],
... 'num_wings': [0, 0, 2, 2],
... 'class': ['mammal', 'mammal', 'mammal', 'bird'],
... 'animal': ['cat', 'dog', 'bat', 'penguin'],
... 'locomotion': ['walks', 'walks', 'flies', 'walks']}
>>> df = pd.DataFrame(data=d)
>>> df = df.set_index(['class', 'animal', 'locomotion'])
>>> df
num_legs num_wings
class animal locomotion
mammal cat walks 4 0
dog walks 4 0
bat flies 2 2
bird penguin walks 2 2
Get values at specified index
>>> df.xs('mammal')
num_legs num_wings
animal locomotion
cat walks 4 0
dog walks 4 0
bat flies 2 2
Get values at several indexes
>>> df.xs(('mammal', 'dog', 'walks'))
num_legs 4
num_wings 0
Name: (mammal, dog, walks), dtype: int64
Get values at specified index and level
>>> df.xs('cat', level=1)
num_legs num_wings
class locomotion
mammal walks 4 0
Get values at several indexes and levels
>>> df.xs(('bird', 'walks'),
... level=[0, 'locomotion'])
num_legs num_wings
animal
penguin 2 2
Get values at specified column and axis
>>> df.xs('num_wings', axis=1)
class animal locomotion
mammal cat walks 0
dog walks 0
bat flies 2
bird penguin walks 2
Name: num_wings, dtype: int64
"""
axis = self._get_axis_number(axis)
labels = self._get_axis(axis)
if isinstance(key, list):
raise TypeError("list keys are not supported in xs, pass a tuple instead")
if level is not None:
if not isinstance(labels, MultiIndex):
raise TypeError("Index must be a MultiIndex")
loc, new_ax = labels.get_loc_level(key, level=level, drop_level=drop_level)
# create the tuple of the indexer
_indexer = [slice(None)] * self.ndim
_indexer[axis] = loc
indexer = tuple(_indexer)
result = self.iloc[indexer]
setattr(result, result._get_axis_name(axis), new_ax)
return result
if axis == 1:
if drop_level:
return self[key]
index = self.columns
else:
index = self.index
if isinstance(index, MultiIndex):
loc, new_index = index._get_loc_level(key, level=0)
if not drop_level:
if lib.is_integer(loc):
new_index = index[loc : loc + 1]
else:
new_index = index[loc]
else:
loc = index.get_loc(key)
if isinstance(loc, np.ndarray):
if loc.dtype == np.bool_:
(inds,) = loc.nonzero()
return self._take_with_is_copy(inds, axis=axis)
else:
return self._take_with_is_copy(loc, axis=axis)
if not is_scalar(loc):
new_index = index[loc]
if is_scalar(loc) and axis == 0:
# In this case loc should be an integer
if self.ndim == 1:
# if we encounter an array-like and we only have 1 dim
# that means that their are list/ndarrays inside the Series!
# so just return them (GH 6394)
return self._values[loc]
new_mgr = self._mgr.fast_xs(loc)
result = self._constructor_sliced(
new_mgr, name=self.index[loc]
).__finalize__(self)
elif is_scalar(loc):
result = self.iloc[:, slice(loc, loc + 1)]
elif axis == 1:
result = self.iloc[:, loc]
else:
result = self.iloc[loc]
result.index = new_index
# this could be a view
# but only in a single-dtyped view sliceable case
result._set_is_copy(self, copy=not result._is_view)
return result
def __getitem__(self, item):
raise AbstractMethodError(self)
def _slice(self: NDFrameT, slobj: slice, axis: Axis = 0) -> NDFrameT:
"""
Construct a slice of this container.
Slicing with this method is *always* positional.
"""
assert isinstance(slobj, slice), type(slobj)
axis = self._get_block_manager_axis(axis)
result = self._constructor(self._mgr.get_slice(slobj, axis=axis))
result = result.__finalize__(self)
# this could be a view
# but only in a single-dtyped view sliceable case
is_copy = axis != 0 or result._is_view
result._set_is_copy(self, copy=is_copy)
return result
def _set_is_copy(self, ref: NDFrame, copy: bool_t = True) -> None:
if not copy:
self._is_copy = None
else:
assert ref is not None
self._is_copy = weakref.ref(ref)
def _check_is_chained_assignment_possible(self) -> bool_t:
"""
Check if we are a view, have a cacher, and are of mixed type.
If so, then force a setitem_copy check.
Should be called just near setting a value
Will return a boolean if it we are a view and are cached, but a
single-dtype meaning that the cacher should be updated following
setting.
"""
if self._is_copy:
self._check_setitem_copy(t="referent")
return False
def _check_setitem_copy(self, t: str = "setting", force: bool_t = False):
"""
Parameters
----------
t : str, the type of setting error
force : bool, default False
If True, then force showing an error.
validate if we are doing a setitem on a chained copy.
It is technically possible to figure out that we are setting on
a copy even WITH a multi-dtyped pandas object. In other words, some
blocks may be views while other are not. Currently _is_view will ALWAYS
return False for multi-blocks to avoid having to handle this case.
df = DataFrame(np.arange(0,9), columns=['count'])
df['group'] = 'b'
# This technically need not raise SettingWithCopy if both are view
# (which is not generally guaranteed but is usually True. However,
# this is in general not a good practice and we recommend using .loc.
df.iloc[0:5]['group'] = 'a'
"""
if using_copy_on_write():
return
# return early if the check is not needed
if not (force or self._is_copy):
return
value = config.get_option("mode.chained_assignment")
if value is None:
return
# see if the copy is not actually referred; if so, then dissolve
# the copy weakref
if self._is_copy is not None and not isinstance(self._is_copy, str):
r = self._is_copy()
if not gc.get_referents(r) or (r is not None and r.shape == self.shape):
self._is_copy = None
return
# a custom message
if isinstance(self._is_copy, str):
t = self._is_copy
elif t == "referent":
t = (
"\n"
"A value is trying to be set on a copy of a slice from a "
"DataFrame\n\n"
"See the caveats in the documentation: "
"https://pandas.pydata.org/pandas-docs/stable/user_guide/"
"indexing.html#returning-a-view-versus-a-copy"
)
else:
t = (
"\n"
"A value is trying to be set on a copy of a slice from a "
"DataFrame.\n"
"Try using .loc[row_indexer,col_indexer] = value "
"instead\n\nSee the caveats in the documentation: "
"https://pandas.pydata.org/pandas-docs/stable/user_guide/"
"indexing.html#returning-a-view-versus-a-copy"
)
if value == "raise":
raise SettingWithCopyError(t)
if value == "warn":
warnings.warn(t, SettingWithCopyWarning, stacklevel=find_stack_level())
def __delitem__(self, key) -> None:
"""
Delete item
"""
deleted = False
maybe_shortcut = False
if self.ndim == 2 and isinstance(self.columns, MultiIndex):
try:
# By using engine's __contains__ we effectively
# restrict to same-length tuples
maybe_shortcut = key not in self.columns._engine
except TypeError:
pass
if maybe_shortcut:
# Allow shorthand to delete all columns whose first len(key)
# elements match key:
if not isinstance(key, tuple):
key = (key,)
for col in self.columns:
if isinstance(col, tuple) and col[: len(key)] == key:
del self[col]
deleted = True
if not deleted:
# If the above loop ran and didn't delete anything because
# there was no match, this call should raise the appropriate
# exception:
loc = self.axes[-1].get_loc(key)
self._mgr = self._mgr.idelete(loc)
# delete from the caches
try:
del self._item_cache[key]
except KeyError:
pass
# ----------------------------------------------------------------------
# Unsorted
def _check_inplace_and_allows_duplicate_labels(self, inplace):
if inplace and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'inplace=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
def get(self, key, default=None):
"""
Get item from object for given key (ex: DataFrame column).
Returns default value if not found.
Parameters
----------
key : object
Returns
-------
same type as items contained in object
Examples
--------
>>> df = pd.DataFrame(
... [
... [24.3, 75.7, "high"],
... [31, 87.8, "high"],
... [22, 71.6, "medium"],
... [35, 95, "medium"],
... ],
... columns=["temp_celsius", "temp_fahrenheit", "windspeed"],
... index=pd.date_range(start="2014-02-12", end="2014-02-15", freq="D"),
... )
>>> df
temp_celsius temp_fahrenheit windspeed
2014-02-12 24.3 75.7 high
2014-02-13 31.0 87.8 high
2014-02-14 22.0 71.6 medium
2014-02-15 35.0 95.0 medium
>>> df.get(["temp_celsius", "windspeed"])
temp_celsius windspeed
2014-02-12 24.3 high
2014-02-13 31.0 high
2014-02-14 22.0 medium
2014-02-15 35.0 medium
>>> ser = df['windspeed']
>>> ser.get('2014-02-13')
'high'
If the key isn't found, the default value will be used.
>>> df.get(["temp_celsius", "temp_kelvin"], default="default_value")
'default_value'
>>> ser.get('2014-02-10', '[unknown]')
'[unknown]'
"""
try:
return self[key]
except (KeyError, ValueError, IndexError):
return default
def _is_view(self) -> bool_t:
"""Return boolean indicating if self is view of another array"""
return self._mgr.is_view
def reindex_like(
self: NDFrameT,
other,
method: Literal["backfill", "bfill", "pad", "ffill", "nearest"] | None = None,
copy: bool_t | None = None,
limit=None,
tolerance=None,
) -> NDFrameT:
"""
Return an object with matching indices as other object.
Conform the object to the same index on all axes. Optional
filling logic, placing NaN in locations having no value
in the previous index. A new object is produced unless the
new index is equivalent to the current one and copy=False.
Parameters
----------
other : Object of the same data type
Its row and column indices are used to define the new indices
of this object.
method : {None, 'backfill'/'bfill', 'pad'/'ffill', 'nearest'}
Method to use for filling holes in reindexed DataFrame.
Please note: this is only applicable to DataFrames/Series with a
monotonically increasing/decreasing index.
* None (default): don't fill gaps
* pad / ffill: propagate last valid observation forward to next
valid
* backfill / bfill: use next valid observation to fill gap
* nearest: use nearest valid observations to fill gap.
copy : bool, default True
Return a new object, even if the passed indexes are the same.
limit : int, default None
Maximum number of consecutive labels to fill for inexact matches.
tolerance : optional
Maximum distance between original and new labels for inexact
matches. The values of the index at the matching locations must
satisfy the equation ``abs(index[indexer] - target) <= tolerance``.
Tolerance may be a scalar value, which applies the same tolerance
to all values, or list-like, which applies variable tolerance per
element. List-like includes list, tuple, array, Series, and must be
the same size as the index and its dtype must exactly match the
index's type.
Returns
-------
Series or DataFrame
Same type as caller, but with changed indices on each axis.
See Also
--------
DataFrame.set_index : Set row labels.
DataFrame.reset_index : Remove row labels or move them to new columns.
DataFrame.reindex : Change to new indices or expand indices.
Notes
-----
Same as calling
``.reindex(index=other.index, columns=other.columns,...)``.
Examples
--------
>>> df1 = pd.DataFrame([[24.3, 75.7, 'high'],
... [31, 87.8, 'high'],
... [22, 71.6, 'medium'],
... [35, 95, 'medium']],
... columns=['temp_celsius', 'temp_fahrenheit',
... 'windspeed'],
... index=pd.date_range(start='2014-02-12',
... end='2014-02-15', freq='D'))
>>> df1
temp_celsius temp_fahrenheit windspeed
2014-02-12 24.3 75.7 high
2014-02-13 31.0 87.8 high
2014-02-14 22.0 71.6 medium
2014-02-15 35.0 95.0 medium
>>> df2 = pd.DataFrame([[28, 'low'],
... [30, 'low'],
... [35.1, 'medium']],
... columns=['temp_celsius', 'windspeed'],
... index=pd.DatetimeIndex(['2014-02-12', '2014-02-13',
... '2014-02-15']))
>>> df2
temp_celsius windspeed
2014-02-12 28.0 low
2014-02-13 30.0 low
2014-02-15 35.1 medium
>>> df2.reindex_like(df1)
temp_celsius temp_fahrenheit windspeed
2014-02-12 28.0 NaN low
2014-02-13 30.0 NaN low
2014-02-14 NaN NaN NaN
2014-02-15 35.1 NaN medium
"""
d = other._construct_axes_dict(
axes=self._AXIS_ORDERS,
method=method,
copy=copy,
limit=limit,
tolerance=tolerance,
)
return self.reindex(**d)
def drop(
self,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: Literal[True],
errors: IgnoreRaise = ...,
) -> None:
...
def drop(
self: NDFrameT,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: Literal[False] = ...,
errors: IgnoreRaise = ...,
) -> NDFrameT:
...
def drop(
self: NDFrameT,
labels: IndexLabel = ...,
*,
axis: Axis = ...,
index: IndexLabel = ...,
columns: IndexLabel = ...,
level: Level | None = ...,
inplace: bool_t = ...,
errors: IgnoreRaise = ...,
) -> NDFrameT | None:
...
def drop(
self: NDFrameT,
labels: IndexLabel = None,
*,
axis: Axis = 0,
index: IndexLabel = None,
columns: IndexLabel = None,
level: Level | None = None,
inplace: bool_t = False,
errors: IgnoreRaise = "raise",
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
if labels is not None:
if index is not None or columns is not None:
raise ValueError("Cannot specify both 'labels' and 'index'/'columns'")
axis_name = self._get_axis_name(axis)
axes = {axis_name: labels}
elif index is not None or columns is not None:
axes = {"index": index}
if self.ndim == 2:
axes["columns"] = columns
else:
raise ValueError(
"Need to specify at least one of 'labels', 'index' or 'columns'"
)
obj = self
for axis, labels in axes.items():
if labels is not None:
obj = obj._drop_axis(labels, axis, level=level, errors=errors)
if inplace:
self._update_inplace(obj)
return None
else:
return obj
def _drop_axis(
self: NDFrameT,
labels,
axis,
level=None,
errors: IgnoreRaise = "raise",
only_slice: bool_t = False,
) -> NDFrameT:
"""
Drop labels from specified axis. Used in the ``drop`` method
internally.
Parameters
----------
labels : single label or list-like
axis : int or axis name
level : int or level name, default None
For MultiIndex
errors : {'ignore', 'raise'}, default 'raise'
If 'ignore', suppress error and existing labels are dropped.
only_slice : bool, default False
Whether indexing along columns should be view-only.
"""
axis_num = self._get_axis_number(axis)
axis = self._get_axis(axis)
if axis.is_unique:
if level is not None:
if not isinstance(axis, MultiIndex):
raise AssertionError("axis must be a MultiIndex")
new_axis = axis.drop(labels, level=level, errors=errors)
else:
new_axis = axis.drop(labels, errors=errors)
indexer = axis.get_indexer(new_axis)
# Case for non-unique axis
else:
is_tuple_labels = is_nested_list_like(labels) or isinstance(labels, tuple)
labels = ensure_object(common.index_labels_to_array(labels))
if level is not None:
if not isinstance(axis, MultiIndex):
raise AssertionError("axis must be a MultiIndex")
mask = ~axis.get_level_values(level).isin(labels)
# GH 18561 MultiIndex.drop should raise if label is absent
if errors == "raise" and mask.all():
raise KeyError(f"{labels} not found in axis")
elif (
isinstance(axis, MultiIndex)
and labels.dtype == "object"
and not is_tuple_labels
):
# Set level to zero in case of MultiIndex and label is string,
# because isin can't handle strings for MultiIndexes GH#36293
# In case of tuples we get dtype object but have to use isin GH#42771
mask = ~axis.get_level_values(0).isin(labels)
else:
mask = ~axis.isin(labels)
# Check if label doesn't exist along axis
labels_missing = (axis.get_indexer_for(labels) == -1).any()
if errors == "raise" and labels_missing:
raise KeyError(f"{labels} not found in axis")
if is_extension_array_dtype(mask.dtype):
# GH#45860
mask = mask.to_numpy(dtype=bool)
indexer = mask.nonzero()[0]
new_axis = axis.take(indexer)
bm_axis = self.ndim - axis_num - 1
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=bm_axis,
allow_dups=True,
copy=None,
only_slice=only_slice,
)
result = self._constructor(new_mgr)
if self.ndim == 1:
result.name = self.name
return result.__finalize__(self)
def _update_inplace(self, result, verify_is_copy: bool_t = True) -> None:
"""
Replace self internals with result.
Parameters
----------
result : same type as self
verify_is_copy : bool, default True
Provide is_copy checks.
"""
# NOTE: This does *not* call __finalize__ and that's an explicit
# decision that we may revisit in the future.
self._reset_cache()
self._clear_item_cache()
self._mgr = result._mgr
self._maybe_update_cacher(verify_is_copy=verify_is_copy, inplace=True)
def add_prefix(self: NDFrameT, prefix: str, axis: Axis | None = None) -> NDFrameT:
"""
Prefix labels with string `prefix`.
For Series, the row labels are prefixed.
For DataFrame, the column labels are prefixed.
Parameters
----------
prefix : str
The string to add before each label.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to add prefix on
.. versionadded:: 2.0.0
Returns
-------
Series or DataFrame
New Series or DataFrame with updated labels.
See Also
--------
Series.add_suffix: Suffix row labels with string `suffix`.
DataFrame.add_suffix: Suffix column labels with string `suffix`.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.add_prefix('item_')
item_0 1
item_1 2
item_2 3
item_3 4
dtype: int64
>>> df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [3, 4, 5, 6]})
>>> df
A B
0 1 3
1 2 4
2 3 5
3 4 6
>>> df.add_prefix('col_')
col_A col_B
0 1 3
1 2 4
2 3 5
3 4 6
"""
f = lambda x: f"{prefix}{x}"
axis_name = self._info_axis_name
if axis is not None:
axis_name = self._get_axis_name(axis)
mapper = {axis_name: f}
# error: Incompatible return value type (got "Optional[NDFrameT]",
# expected "NDFrameT")
# error: Argument 1 to "rename" of "NDFrame" has incompatible type
# "**Dict[str, partial[str]]"; expected "Union[str, int, None]"
# error: Keywords must be strings
return self._rename(**mapper) # type: ignore[return-value, arg-type, misc]
def add_suffix(self: NDFrameT, suffix: str, axis: Axis | None = None) -> NDFrameT:
"""
Suffix labels with string `suffix`.
For Series, the row labels are suffixed.
For DataFrame, the column labels are suffixed.
Parameters
----------
suffix : str
The string to add after each label.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to add suffix on
.. versionadded:: 2.0.0
Returns
-------
Series or DataFrame
New Series or DataFrame with updated labels.
See Also
--------
Series.add_prefix: Prefix row labels with string `prefix`.
DataFrame.add_prefix: Prefix column labels with string `prefix`.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.add_suffix('_item')
0_item 1
1_item 2
2_item 3
3_item 4
dtype: int64
>>> df = pd.DataFrame({'A': [1, 2, 3, 4], 'B': [3, 4, 5, 6]})
>>> df
A B
0 1 3
1 2 4
2 3 5
3 4 6
>>> df.add_suffix('_col')
A_col B_col
0 1 3
1 2 4
2 3 5
3 4 6
"""
f = lambda x: f"{x}{suffix}"
axis_name = self._info_axis_name
if axis is not None:
axis_name = self._get_axis_name(axis)
mapper = {axis_name: f}
# error: Incompatible return value type (got "Optional[NDFrameT]",
# expected "NDFrameT")
# error: Argument 1 to "rename" of "NDFrame" has incompatible type
# "**Dict[str, partial[str]]"; expected "Union[str, int, None]"
# error: Keywords must be strings
return self._rename(**mapper) # type: ignore[return-value, arg-type, misc]
def sort_values(
self: NDFrameT,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> NDFrameT:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self: NDFrameT,
*,
axis: Axis = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: bool_t = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool_t = ...,
key: ValueKeyFunc = ...,
) -> NDFrameT | None:
...
def sort_values(
self: NDFrameT,
*,
axis: Axis = 0,
ascending: bool_t | Sequence[bool_t] = True,
inplace: bool_t = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool_t = False,
key: ValueKeyFunc = None,
) -> NDFrameT | None:
"""
Sort by the values along either axis.
Parameters
----------%(optional_by)s
axis : %(axes_single_arg)s, default 0
Axis to be sorted.
ascending : bool or list of bool, default True
Sort ascending vs. descending. Specify list for multiple sort
orders. If this is a list of bools, must match the length of
the by.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. `mergesort` and `stable` are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
Puts NaNs at the beginning if `first`; `last` puts NaNs at the
end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
Apply the key function to the values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return a Series with the same shape as the input.
It will be applied to each column in `by` independently.
.. versionadded:: 1.1.0
Returns
-------
DataFrame or None
DataFrame with sorted values or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index : Sort a DataFrame by the index.
Series.sort_values : Similar method for a Series.
Examples
--------
>>> df = pd.DataFrame({
... 'col1': ['A', 'A', 'B', np.nan, 'D', 'C'],
... 'col2': [2, 1, 9, 8, 7, 4],
... 'col3': [0, 1, 9, 4, 2, 3],
... 'col4': ['a', 'B', 'c', 'D', 'e', 'F']
... })
>>> df
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
Sort by col1
>>> df.sort_values(by=['col1'])
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
5 C 4 3 F
4 D 7 2 e
3 NaN 8 4 D
Sort by multiple columns
>>> df.sort_values(by=['col1', 'col2'])
col1 col2 col3 col4
1 A 1 1 B
0 A 2 0 a
2 B 9 9 c
5 C 4 3 F
4 D 7 2 e
3 NaN 8 4 D
Sort Descending
>>> df.sort_values(by='col1', ascending=False)
col1 col2 col3 col4
4 D 7 2 e
5 C 4 3 F
2 B 9 9 c
0 A 2 0 a
1 A 1 1 B
3 NaN 8 4 D
Putting NAs first
>>> df.sort_values(by='col1', ascending=False, na_position='first')
col1 col2 col3 col4
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
2 B 9 9 c
0 A 2 0 a
1 A 1 1 B
Sorting with a key function
>>> df.sort_values(by='col4', key=lambda col: col.str.lower())
col1 col2 col3 col4
0 A 2 0 a
1 A 1 1 B
2 B 9 9 c
3 NaN 8 4 D
4 D 7 2 e
5 C 4 3 F
Natural sort with the key argument,
using the `natsort <https://github.com/SethMMorton/natsort>` package.
>>> df = pd.DataFrame({
... "time": ['0hr', '128hr', '72hr', '48hr', '96hr'],
... "value": [10, 20, 30, 40, 50]
... })
>>> df
time value
0 0hr 10
1 128hr 20
2 72hr 30
3 48hr 40
4 96hr 50
>>> from natsort import index_natsorted
>>> df.sort_values(
... by="time",
... key=lambda x: np.argsort(index_natsorted(df["time"]))
... )
time value
0 0hr 10
3 48hr 40
2 72hr 30
4 96hr 50
1 128hr 20
"""
raise AbstractMethodError(self)
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> NDFrameT:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool_t | Sequence[bool_t] = ...,
inplace: bool_t = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool_t = ...,
ignore_index: bool_t = ...,
key: IndexKeyFunc = ...,
) -> NDFrameT | None:
...
def sort_index(
self: NDFrameT,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool_t | Sequence[bool_t] = True,
inplace: bool_t = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool_t = True,
ignore_index: bool_t = False,
key: IndexKeyFunc = None,
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
axis = self._get_axis_number(axis)
ascending = validate_ascending(ascending)
target = self._get_axis(axis)
indexer = get_indexer_indexer(
target, level, ascending, kind, na_position, sort_remaining, key
)
if indexer is None:
if inplace:
result = self
else:
result = self.copy(deep=None)
if ignore_index:
result.index = default_index(len(self))
if inplace:
return None
else:
return result
baxis = self._get_block_manager_axis(axis)
new_data = self._mgr.take(indexer, axis=baxis, verify=False)
# reconstruct axis if needed
new_data.set_axis(baxis, new_data.axes[baxis]._sort_levels_monotonic())
if ignore_index:
axis = 1 if isinstance(self, ABCDataFrame) else 0
new_data.set_axis(axis, default_index(len(indexer)))
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="sort_index")
klass=_shared_doc_kwargs["klass"],
optional_reindex="",
)
def reindex(
self: NDFrameT,
labels=None,
index=None,
columns=None,
axis: Axis | None = None,
method: str | None = None,
copy: bool_t | None = None,
level: Level | None = None,
fill_value: Scalar | None = np.nan,
limit: int | None = None,
tolerance=None,
) -> NDFrameT:
"""
Conform {klass} to new index with optional filling logic.
Places NA/NaN in locations having no value in the previous index. A new object
is produced unless the new index is equivalent to the current one and
``copy=False``.
Parameters
----------
{optional_reindex}
method : {{None, 'backfill'/'bfill', 'pad'/'ffill', 'nearest'}}
Method to use for filling holes in reindexed DataFrame.
Please note: this is only applicable to DataFrames/Series with a
monotonically increasing/decreasing index.
* None (default): don't fill gaps
* pad / ffill: Propagate last valid observation forward to next
valid.
* backfill / bfill: Use next valid observation to fill gap.
* nearest: Use nearest valid observations to fill gap.
copy : bool, default True
Return a new object, even if the passed indexes are the same.
level : int or name
Broadcast across a level, matching Index values on the
passed MultiIndex level.
fill_value : scalar, default np.NaN
Value to use for missing values. Defaults to NaN, but can be any
"compatible" value.
limit : int, default None
Maximum number of consecutive elements to forward or backward fill.
tolerance : optional
Maximum distance between original and new labels for inexact
matches. The values of the index at the matching locations most
satisfy the equation ``abs(index[indexer] - target) <= tolerance``.
Tolerance may be a scalar value, which applies the same tolerance
to all values, or list-like, which applies variable tolerance per
element. List-like includes list, tuple, array, Series, and must be
the same size as the index and its dtype must exactly match the
index's type.
Returns
-------
{klass} with changed index.
See Also
--------
DataFrame.set_index : Set row labels.
DataFrame.reset_index : Remove row labels or move them to new columns.
DataFrame.reindex_like : Change to same indices as other DataFrame.
Examples
--------
``DataFrame.reindex`` supports two calling conventions
* ``(index=index_labels, columns=column_labels, ...)``
* ``(labels, axis={{'index', 'columns'}}, ...)``
We *highly* recommend using keyword arguments to clarify your
intent.
Create a dataframe with some fictional data.
>>> index = ['Firefox', 'Chrome', 'Safari', 'IE10', 'Konqueror']
>>> df = pd.DataFrame({{'http_status': [200, 200, 404, 404, 301],
... 'response_time': [0.04, 0.02, 0.07, 0.08, 1.0]}},
... index=index)
>>> df
http_status response_time
Firefox 200 0.04
Chrome 200 0.02
Safari 404 0.07
IE10 404 0.08
Konqueror 301 1.00
Create a new index and reindex the dataframe. By default
values in the new index that do not have corresponding
records in the dataframe are assigned ``NaN``.
>>> new_index = ['Safari', 'Iceweasel', 'Comodo Dragon', 'IE10',
... 'Chrome']
>>> df.reindex(new_index)
http_status response_time
Safari 404.0 0.07
Iceweasel NaN NaN
Comodo Dragon NaN NaN
IE10 404.0 0.08
Chrome 200.0 0.02
We can fill in the missing values by passing a value to
the keyword ``fill_value``. Because the index is not monotonically
increasing or decreasing, we cannot use arguments to the keyword
``method`` to fill the ``NaN`` values.
>>> df.reindex(new_index, fill_value=0)
http_status response_time
Safari 404 0.07
Iceweasel 0 0.00
Comodo Dragon 0 0.00
IE10 404 0.08
Chrome 200 0.02
>>> df.reindex(new_index, fill_value='missing')
http_status response_time
Safari 404 0.07
Iceweasel missing missing
Comodo Dragon missing missing
IE10 404 0.08
Chrome 200 0.02
We can also reindex the columns.
>>> df.reindex(columns=['http_status', 'user_agent'])
http_status user_agent
Firefox 200 NaN
Chrome 200 NaN
Safari 404 NaN
IE10 404 NaN
Konqueror 301 NaN
Or we can use "axis-style" keyword arguments
>>> df.reindex(['http_status', 'user_agent'], axis="columns")
http_status user_agent
Firefox 200 NaN
Chrome 200 NaN
Safari 404 NaN
IE10 404 NaN
Konqueror 301 NaN
To further illustrate the filling functionality in
``reindex``, we will create a dataframe with a
monotonically increasing index (for example, a sequence
of dates).
>>> date_index = pd.date_range('1/1/2010', periods=6, freq='D')
>>> df2 = pd.DataFrame({{"prices": [100, 101, np.nan, 100, 89, 88]}},
... index=date_index)
>>> df2
prices
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
Suppose we decide to expand the dataframe to cover a wider
date range.
>>> date_index2 = pd.date_range('12/29/2009', periods=10, freq='D')
>>> df2.reindex(date_index2)
prices
2009-12-29 NaN
2009-12-30 NaN
2009-12-31 NaN
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
2010-01-07 NaN
The index entries that did not have a value in the original data frame
(for example, '2009-12-29') are by default filled with ``NaN``.
If desired, we can fill in the missing values using one of several
options.
For example, to back-propagate the last valid value to fill the ``NaN``
values, pass ``bfill`` as an argument to the ``method`` keyword.
>>> df2.reindex(date_index2, method='bfill')
prices
2009-12-29 100.0
2009-12-30 100.0
2009-12-31 100.0
2010-01-01 100.0
2010-01-02 101.0
2010-01-03 NaN
2010-01-04 100.0
2010-01-05 89.0
2010-01-06 88.0
2010-01-07 NaN
Please note that the ``NaN`` value present in the original dataframe
(at index value 2010-01-03) will not be filled by any of the
value propagation schemes. This is because filling while reindexing
does not look at dataframe values, but only compares the original and
desired indexes. If you do want to fill in the ``NaN`` values present
in the original dataframe, use the ``fillna()`` method.
See the :ref:`user guide <basics.reindexing>` for more.
"""
# TODO: Decide if we care about having different examples for different
# kinds
if index is not None and columns is not None and labels is not None:
raise TypeError("Cannot specify all of 'labels', 'index', 'columns'.")
elif index is not None or columns is not None:
if axis is not None:
raise TypeError(
"Cannot specify both 'axis' and any of 'index' or 'columns'"
)
if labels is not None:
if index is not None:
columns = labels
else:
index = labels
else:
if axis and self._get_axis_number(axis) == 1:
columns = labels
else:
index = labels
axes: dict[Literal["index", "columns"], Any] = {
"index": index,
"columns": columns,
}
method = clean_reindex_fill_method(method)
# if all axes that are requested to reindex are equal, then only copy
# if indicated must have index names equal here as well as values
if copy and using_copy_on_write():
copy = False
if all(
self._get_axis(axis_name).identical(ax)
for axis_name, ax in axes.items()
if ax is not None
):
return self.copy(deep=copy)
# check if we are a multi reindex
if self._needs_reindex_multi(axes, method, level):
return self._reindex_multi(axes, copy, fill_value)
# perform the reindex on the axes
return self._reindex_axes(
axes, level, limit, tolerance, method, fill_value, copy
).__finalize__(self, method="reindex")
def _reindex_axes(
self: NDFrameT, axes, level, limit, tolerance, method, fill_value, copy
) -> NDFrameT:
"""Perform the reindex for all the axes."""
obj = self
for a in self._AXIS_ORDERS:
labels = axes[a]
if labels is None:
continue
ax = self._get_axis(a)
new_index, indexer = ax.reindex(
labels, level=level, limit=limit, tolerance=tolerance, method=method
)
axis = self._get_axis_number(a)
obj = obj._reindex_with_indexers(
{axis: [new_index, indexer]},
fill_value=fill_value,
copy=copy,
allow_dups=False,
)
# If we've made a copy once, no need to make another one
copy = False
return obj
def _needs_reindex_multi(self, axes, method, level) -> bool_t:
"""Check if we do need a multi reindex."""
return (
(common.count_not_none(*axes.values()) == self._AXIS_LEN)
and method is None
and level is None
and not self._is_mixed_type
and not (
self.ndim == 2
and len(self.dtypes) == 1
and is_extension_array_dtype(self.dtypes.iloc[0])
)
)
def _reindex_multi(self, axes, copy, fill_value):
raise AbstractMethodError(self)
def _reindex_with_indexers(
self: NDFrameT,
reindexers,
fill_value=None,
copy: bool_t | None = False,
allow_dups: bool_t = False,
) -> NDFrameT:
"""allow_dups indicates an internal call here"""
# reindex doing multiple operations on different axes if indicated
new_data = self._mgr
for axis in sorted(reindexers.keys()):
index, indexer = reindexers[axis]
baxis = self._get_block_manager_axis(axis)
if index is None:
continue
index = ensure_index(index)
if indexer is not None:
indexer = ensure_platform_int(indexer)
# TODO: speed up on homogeneous DataFrame objects (see _reindex_multi)
new_data = new_data.reindex_indexer(
index,
indexer,
axis=baxis,
fill_value=fill_value,
allow_dups=allow_dups,
copy=copy,
)
# If we've made a copy once, no need to make another one
copy = False
if (
(copy or copy is None)
and new_data is self._mgr
and not using_copy_on_write()
):
new_data = new_data.copy(deep=copy)
elif using_copy_on_write() and new_data is self._mgr:
new_data = new_data.copy(deep=False)
return self._constructor(new_data).__finalize__(self)
def filter(
self: NDFrameT,
items=None,
like: str | None = None,
regex: str | None = None,
axis: Axis | None = None,
) -> NDFrameT:
"""
Subset the dataframe rows or columns according to the specified index labels.
Note that this routine does not filter a dataframe on its
contents. The filter is applied to the labels of the index.
Parameters
----------
items : list-like
Keep labels from axis which are in items.
like : str
Keep labels from axis for which "like in label == True".
regex : str (regular expression)
Keep labels from axis for which re.search(regex, label) == True.
axis : {0 or ‘index’, 1 or ‘columns’, None}, default None
The axis to filter on, expressed either as an index (int)
or axis name (str). By default this is the info axis, 'columns' for
DataFrame. For `Series` this parameter is unused and defaults to `None`.
Returns
-------
same type as input object
See Also
--------
DataFrame.loc : Access a group of rows and columns
by label(s) or a boolean array.
Notes
-----
The ``items``, ``like``, and ``regex`` parameters are
enforced to be mutually exclusive.
``axis`` defaults to the info axis that is used when indexing
with ``[]``.
Examples
--------
>>> df = pd.DataFrame(np.array(([1, 2, 3], [4, 5, 6])),
... index=['mouse', 'rabbit'],
... columns=['one', 'two', 'three'])
>>> df
one two three
mouse 1 2 3
rabbit 4 5 6
>>> # select columns by name
>>> df.filter(items=['one', 'three'])
one three
mouse 1 3
rabbit 4 6
>>> # select columns by regular expression
>>> df.filter(regex='e$', axis=1)
one three
mouse 1 3
rabbit 4 6
>>> # select rows containing 'bbi'
>>> df.filter(like='bbi', axis=0)
one two three
rabbit 4 5 6
"""
nkw = common.count_not_none(items, like, regex)
if nkw > 1:
raise TypeError(
"Keyword arguments `items`, `like`, or `regex` "
"are mutually exclusive"
)
if axis is None:
axis = self._info_axis_name
labels = self._get_axis(axis)
if items is not None:
name = self._get_axis_name(axis)
# error: Keywords must be strings
return self.reindex( # type: ignore[misc]
**{name: [r for r in items if r in labels]} # type: ignore[arg-type]
)
elif like:
def f(x) -> bool_t:
assert like is not None # needed for mypy
return like in ensure_str(x)
values = labels.map(f)
return self.loc(axis=axis)[values]
elif regex:
def f(x) -> bool_t:
return matcher.search(ensure_str(x)) is not None
matcher = re.compile(regex)
values = labels.map(f)
return self.loc(axis=axis)[values]
else:
raise TypeError("Must pass either `items`, `like`, or `regex`")
def head(self: NDFrameT, n: int = 5) -> NDFrameT:
"""
Return the first `n` rows.
This function returns the first `n` rows for the object based
on position. It is useful for quickly testing if your object
has the right type of data in it.
For negative values of `n`, this function returns all rows except
the last `|n|` rows, equivalent to ``df[:n]``.
If n is larger than the number of rows, this function returns all rows.
Parameters
----------
n : int, default 5
Number of rows to select.
Returns
-------
same type as caller
The first `n` rows of the caller object.
See Also
--------
DataFrame.tail: Returns the last `n` rows.
Examples
--------
>>> df = pd.DataFrame({'animal': ['alligator', 'bee', 'falcon', 'lion',
... 'monkey', 'parrot', 'shark', 'whale', 'zebra']})
>>> df
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the first 5 lines
>>> df.head()
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
Viewing the first `n` lines (three in this case)
>>> df.head(3)
animal
0 alligator
1 bee
2 falcon
For negative values of `n`
>>> df.head(-3)
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
"""
return self.iloc[:n]
def tail(self: NDFrameT, n: int = 5) -> NDFrameT:
"""
Return the last `n` rows.
This function returns last `n` rows from the object based on
position. It is useful for quickly verifying data, for example,
after sorting or appending rows.
For negative values of `n`, this function returns all rows except
the first `|n|` rows, equivalent to ``df[|n|:]``.
If n is larger than the number of rows, this function returns all rows.
Parameters
----------
n : int, default 5
Number of rows to select.
Returns
-------
type of caller
The last `n` rows of the caller object.
See Also
--------
DataFrame.head : The first `n` rows of the caller object.
Examples
--------
>>> df = pd.DataFrame({'animal': ['alligator', 'bee', 'falcon', 'lion',
... 'monkey', 'parrot', 'shark', 'whale', 'zebra']})
>>> df
animal
0 alligator
1 bee
2 falcon
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the last 5 lines
>>> df.tail()
animal
4 monkey
5 parrot
6 shark
7 whale
8 zebra
Viewing the last `n` lines (three in this case)
>>> df.tail(3)
animal
6 shark
7 whale
8 zebra
For negative values of `n`
>>> df.tail(-3)
animal
3 lion
4 monkey
5 parrot
6 shark
7 whale
8 zebra
"""
if n == 0:
return self.iloc[0:0]
return self.iloc[-n:]
def sample(
self: NDFrameT,
n: int | None = None,
frac: float | None = None,
replace: bool_t = False,
weights=None,
random_state: RandomState | None = None,
axis: Axis | None = None,
ignore_index: bool_t = False,
) -> NDFrameT:
"""
Return a random sample of items from an axis of object.
You can use `random_state` for reproducibility.
Parameters
----------
n : int, optional
Number of items from axis to return. Cannot be used with `frac`.
Default = 1 if `frac` = None.
frac : float, optional
Fraction of axis items to return. Cannot be used with `n`.
replace : bool, default False
Allow or disallow sampling of the same row more than once.
weights : str or ndarray-like, optional
Default 'None' results in equal probability weighting.
If passed a Series, will align with target object on index. Index
values in weights not found in sampled object will be ignored and
index values in sampled object not in weights will be assigned
weights of zero.
If called on a DataFrame, will accept the name of a column
when axis = 0.
Unless weights are a Series, weights must be same length as axis
being sampled.
If weights do not sum to 1, they will be normalized to sum to 1.
Missing values in the weights column will be treated as zero.
Infinite values not allowed.
random_state : int, array-like, BitGenerator, np.random.RandomState, np.random.Generator, optional
If int, array-like, or BitGenerator, seed for random number generator.
If np.random.RandomState or np.random.Generator, use as given.
.. versionchanged:: 1.1.0
array-like and BitGenerator object now passed to np.random.RandomState()
as seed
.. versionchanged:: 1.4.0
np.random.Generator objects now accepted
axis : {0 or ‘index’, 1 or ‘columns’, None}, default None
Axis to sample. Accepts axis number or name. Default is stat axis
for given data type. For `Series` this parameter is unused and defaults to `None`.
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.3.0
Returns
-------
Series or DataFrame
A new object of same type as caller containing `n` items randomly
sampled from the caller object.
See Also
--------
DataFrameGroupBy.sample: Generates random samples from each group of a
DataFrame object.
SeriesGroupBy.sample: Generates random samples from each group of a
Series object.
numpy.random.choice: Generates a random sample from a given 1-D numpy
array.
Notes
-----
If `frac` > 1, `replacement` should be set to `True`.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [2, 4, 8, 0],
... 'num_wings': [2, 0, 0, 0],
... 'num_specimen_seen': [10, 2, 1, 8]},
... index=['falcon', 'dog', 'spider', 'fish'])
>>> df
num_legs num_wings num_specimen_seen
falcon 2 2 10
dog 4 0 2
spider 8 0 1
fish 0 0 8
Extract 3 random elements from the ``Series`` ``df['num_legs']``:
Note that we use `random_state` to ensure the reproducibility of
the examples.
>>> df['num_legs'].sample(n=3, random_state=1)
fish 0
spider 8
falcon 2
Name: num_legs, dtype: int64
A random 50% sample of the ``DataFrame`` with replacement:
>>> df.sample(frac=0.5, replace=True, random_state=1)
num_legs num_wings num_specimen_seen
dog 4 0 2
fish 0 0 8
An upsample sample of the ``DataFrame`` with replacement:
Note that `replace` parameter has to be `True` for `frac` parameter > 1.
>>> df.sample(frac=2, replace=True, random_state=1)
num_legs num_wings num_specimen_seen
dog 4 0 2
fish 0 0 8
falcon 2 2 10
falcon 2 2 10
fish 0 0 8
dog 4 0 2
fish 0 0 8
dog 4 0 2
Using a DataFrame column as weights. Rows with larger value in the
`num_specimen_seen` column are more likely to be sampled.
>>> df.sample(n=2, weights='num_specimen_seen', random_state=1)
num_legs num_wings num_specimen_seen
falcon 2 2 10
fish 0 0 8
""" # noqa:E501
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
obj_len = self.shape[axis]
# Process random_state argument
rs = common.random_state(random_state)
size = sample.process_sampling_size(n, frac, replace)
if size is None:
assert frac is not None
size = round(frac * obj_len)
if weights is not None:
weights = sample.preprocess_weights(self, weights, axis)
sampled_indices = sample.sample(obj_len, size, replace, weights, rs)
result = self.take(sampled_indices, axis=axis)
if ignore_index:
result.index = default_index(len(result))
return result
def pipe(
self,
func: Callable[..., T] | tuple[Callable[..., T], str],
*args,
**kwargs,
) -> T:
r"""
Apply chainable functions that expect Series or DataFrames.
Parameters
----------
func : function
Function to apply to the {klass}.
``args``, and ``kwargs`` are passed into ``func``.
Alternatively a ``(callable, data_keyword)`` tuple where
``data_keyword`` is a string indicating the keyword of
``callable`` that expects the {klass}.
args : iterable, optional
Positional arguments passed into ``func``.
kwargs : mapping, optional
A dictionary of keyword arguments passed into ``func``.
Returns
-------
the return type of ``func``.
See Also
--------
DataFrame.apply : Apply a function along input axis of DataFrame.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Series.map : Apply a mapping correspondence on a
:class:`~pandas.Series`.
Notes
-----
Use ``.pipe`` when chaining together functions that expect
Series, DataFrames or GroupBy objects. Instead of writing
>>> func(g(h(df), arg1=a), arg2=b, arg3=c) # doctest: +SKIP
You can write
>>> (df.pipe(h)
... .pipe(g, arg1=a)
... .pipe(func, arg2=b, arg3=c)
... ) # doctest: +SKIP
If you have a function that takes the data as (say) the second
argument, pass a tuple indicating which keyword expects the
data. For example, suppose ``func`` takes its data as ``arg2``:
>>> (df.pipe(h)
... .pipe(g, arg1=a)
... .pipe((func, 'arg2'), arg1=a, arg3=c)
... ) # doctest: +SKIP
"""
if using_copy_on_write():
return common.pipe(self.copy(deep=None), func, *args, **kwargs)
return common.pipe(self, func, *args, **kwargs)
# ----------------------------------------------------------------------
# Attribute access
def __finalize__(
self: NDFrameT, other, method: str | None = None, **kwargs
) -> NDFrameT:
"""
Propagate metadata from other to self.
Parameters
----------
other : the object from which to get the attributes that we are going
to propagate
method : str, optional
A passed method name providing context on where ``__finalize__``
was called.
.. warning::
The value passed as `method` are not currently considered
stable across pandas releases.
"""
if isinstance(other, NDFrame):
for name in other.attrs:
self.attrs[name] = other.attrs[name]
self.flags.allows_duplicate_labels = other.flags.allows_duplicate_labels
# For subclasses using _metadata.
for name in set(self._metadata) & set(other._metadata):
assert isinstance(name, str)
object.__setattr__(self, name, getattr(other, name, None))
if method == "concat":
attrs = other.objs[0].attrs
check_attrs = all(objs.attrs == attrs for objs in other.objs[1:])
if check_attrs:
for name in attrs:
self.attrs[name] = attrs[name]
allows_duplicate_labels = all(
x.flags.allows_duplicate_labels for x in other.objs
)
self.flags.allows_duplicate_labels = allows_duplicate_labels
return self
def __getattr__(self, name: str):
"""
After regular attribute access, try looking up the name
This allows simpler access to columns for interactive use.
"""
# Note: obj.x will always call obj.__getattribute__('x') prior to
# calling obj.__getattr__('x').
if (
name not in self._internal_names_set
and name not in self._metadata
and name not in self._accessors
and self._info_axis._can_hold_identifiers_and_holds_name(name)
):
return self[name]
return object.__getattribute__(self, name)
def __setattr__(self, name: str, value) -> None:
"""
After regular attribute access, try setting the name
This allows simpler access to columns for interactive use.
"""
# first try regular attribute access via __getattribute__, so that
# e.g. ``obj.x`` and ``obj.x = 4`` will always reference/modify
# the same attribute.
try:
object.__getattribute__(self, name)
return object.__setattr__(self, name, value)
except AttributeError:
pass
# if this fails, go on to more involved attribute setting
# (note that this matches __getattr__, above).
if name in self._internal_names_set:
object.__setattr__(self, name, value)
elif name in self._metadata:
object.__setattr__(self, name, value)
else:
try:
existing = getattr(self, name)
if isinstance(existing, Index):
object.__setattr__(self, name, value)
elif name in self._info_axis:
self[name] = value
else:
object.__setattr__(self, name, value)
except (AttributeError, TypeError):
if isinstance(self, ABCDataFrame) and (is_list_like(value)):
warnings.warn(
"Pandas doesn't allow columns to be "
"created via a new attribute name - see "
"https://pandas.pydata.org/pandas-docs/"
"stable/indexing.html#attribute-access",
stacklevel=find_stack_level(),
)
object.__setattr__(self, name, value)
def _dir_additions(self) -> set[str]:
"""
add the string-like attributes from the info_axis.
If info_axis is a MultiIndex, its first level values are used.
"""
additions = super()._dir_additions()
if self._info_axis._can_hold_strings:
additions.update(self._info_axis._dir_additions_for_owner)
return additions
# ----------------------------------------------------------------------
# Consolidation of internals
def _protect_consolidate(self, f):
"""
Consolidate _mgr -- if the blocks have changed, then clear the
cache
"""
if isinstance(self._mgr, (ArrayManager, SingleArrayManager)):
return f()
blocks_before = len(self._mgr.blocks)
result = f()
if len(self._mgr.blocks) != blocks_before:
self._clear_item_cache()
return result
def _consolidate_inplace(self) -> None:
"""Consolidate data in place and return None"""
def f() -> None:
self._mgr = self._mgr.consolidate()
self._protect_consolidate(f)
def _consolidate(self):
"""
Compute NDFrame with "consolidated" internals (data of each dtype
grouped together in a single ndarray).
Returns
-------
consolidated : same type as caller
"""
f = lambda: self._mgr.consolidate()
cons_data = self._protect_consolidate(f)
return self._constructor(cons_data).__finalize__(self)
def _is_mixed_type(self) -> bool_t:
if self._mgr.is_single_block:
return False
if self._mgr.any_extension_types:
# Even if they have the same dtype, we can't consolidate them,
# so we pretend this is "mixed'"
return True
return self.dtypes.nunique() > 1
def _check_inplace_setting(self, value) -> bool_t:
"""check whether we allow in-place setting with this type of value"""
if self._is_mixed_type and not self._mgr.is_numeric_mixed_type:
# allow an actual np.nan through
if is_float(value) and np.isnan(value) or value is lib.no_default:
return True
raise TypeError(
"Cannot do inplace boolean setting on "
"mixed-types with a non np.nan value"
)
return True
def _get_numeric_data(self: NDFrameT) -> NDFrameT:
return self._constructor(self._mgr.get_numeric_data()).__finalize__(self)
def _get_bool_data(self):
return self._constructor(self._mgr.get_bool_data()).__finalize__(self)
# ----------------------------------------------------------------------
# Internal Interface Methods
def values(self):
raise AbstractMethodError(self)
def _values(self) -> ArrayLike:
"""internal implementation"""
raise AbstractMethodError(self)
def dtypes(self):
"""
Return the dtypes in the DataFrame.
This returns a Series with the data type of each column.
The result's index is the original DataFrame's columns. Columns
with mixed types are stored with the ``object`` dtype. See
:ref:`the User Guide <basics.dtypes>` for more.
Returns
-------
pandas.Series
The data type of each column.
Examples
--------
>>> df = pd.DataFrame({'float': [1.0],
... 'int': [1],
... 'datetime': [pd.Timestamp('20180310')],
... 'string': ['foo']})
>>> df.dtypes
float float64
int int64
datetime datetime64[ns]
string object
dtype: object
"""
data = self._mgr.get_dtypes()
return self._constructor_sliced(data, index=self._info_axis, dtype=np.object_)
def astype(
self: NDFrameT, dtype, copy: bool_t | None = None, errors: IgnoreRaise = "raise"
) -> NDFrameT:
"""
Cast a pandas object to a specified dtype ``dtype``.
Parameters
----------
dtype : str, data type, Series or Mapping of column name -> data type
Use a str, numpy.dtype, pandas.ExtensionDtype or Python type to
cast entire pandas object to the same type. Alternatively, use a
mapping, e.g. {col: dtype, ...}, where col is a column label and dtype is
a numpy.dtype or Python type to cast one or more of the DataFrame's
columns to column-specific types.
copy : bool, default True
Return a copy when ``copy=True`` (be very careful setting
``copy=False`` as changes to values then may propagate to other
pandas objects).
errors : {'raise', 'ignore'}, default 'raise'
Control raising of exceptions on invalid data for provided dtype.
- ``raise`` : allow exceptions to be raised
- ``ignore`` : suppress exceptions. On error return original object.
Returns
-------
same type as caller
See Also
--------
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to a numeric type.
numpy.ndarray.astype : Cast a numpy array to a specified type.
Notes
-----
.. versionchanged:: 2.0.0
Using ``astype`` to convert from timezone-naive dtype to
timezone-aware dtype will raise an exception.
Use :meth:`Series.dt.tz_localize` instead.
Examples
--------
Create a DataFrame:
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df.dtypes
col1 int64
col2 int64
dtype: object
Cast all columns to int32:
>>> df.astype('int32').dtypes
col1 int32
col2 int32
dtype: object
Cast col1 to int32 using a dictionary:
>>> df.astype({'col1': 'int32'}).dtypes
col1 int32
col2 int64
dtype: object
Create a series:
>>> ser = pd.Series([1, 2], dtype='int32')
>>> ser
0 1
1 2
dtype: int32
>>> ser.astype('int64')
0 1
1 2
dtype: int64
Convert to categorical type:
>>> ser.astype('category')
0 1
1 2
dtype: category
Categories (2, int32): [1, 2]
Convert to ordered categorical type with custom ordering:
>>> from pandas.api.types import CategoricalDtype
>>> cat_dtype = CategoricalDtype(
... categories=[2, 1], ordered=True)
>>> ser.astype(cat_dtype)
0 1
1 2
dtype: category
Categories (2, int64): [2 < 1]
Create a series of dates:
>>> ser_date = pd.Series(pd.date_range('20200101', periods=3))
>>> ser_date
0 2020-01-01
1 2020-01-02
2 2020-01-03
dtype: datetime64[ns]
"""
if copy and using_copy_on_write():
copy = False
if is_dict_like(dtype):
if self.ndim == 1: # i.e. Series
if len(dtype) > 1 or self.name not in dtype:
raise KeyError(
"Only the Series name can be used for "
"the key in Series dtype mappings."
)
new_type = dtype[self.name]
return self.astype(new_type, copy, errors)
# GH#44417 cast to Series so we can use .iat below, which will be
# robust in case we
from pandas import Series
dtype_ser = Series(dtype, dtype=object)
for col_name in dtype_ser.index:
if col_name not in self:
raise KeyError(
"Only a column name can be used for the "
"key in a dtype mappings argument. "
f"'{col_name}' not found in columns."
)
dtype_ser = dtype_ser.reindex(self.columns, fill_value=None, copy=False)
results = []
for i, (col_name, col) in enumerate(self.items()):
cdt = dtype_ser.iat[i]
if isna(cdt):
res_col = col.copy(deep=copy)
else:
try:
res_col = col.astype(dtype=cdt, copy=copy, errors=errors)
except ValueError as ex:
ex.args = (
f"{ex}: Error while type casting for column '{col_name}'",
)
raise
results.append(res_col)
elif is_extension_array_dtype(dtype) and self.ndim > 1:
# GH 18099/22869: columnwise conversion to extension dtype
# GH 24704: use iloc to handle duplicate column names
# TODO(EA2D): special case not needed with 2D EAs
results = [
self.iloc[:, i].astype(dtype, copy=copy)
for i in range(len(self.columns))
]
else:
# else, only a single dtype is given
new_data = self._mgr.astype(dtype=dtype, copy=copy, errors=errors)
return self._constructor(new_data).__finalize__(self, method="astype")
# GH 33113: handle empty frame or series
if not results:
return self.copy(deep=None)
# GH 19920: retain column metadata after concat
result = concat(results, axis=1, copy=False)
# GH#40810 retain subclass
# error: Incompatible types in assignment
# (expression has type "NDFrameT", variable has type "DataFrame")
result = self._constructor(result) # type: ignore[assignment]
result.columns = self.columns
result = result.__finalize__(self, method="astype")
# https://github.com/python/mypy/issues/8354
return cast(NDFrameT, result)
def copy(self: NDFrameT, deep: bool_t | None = True) -> NDFrameT:
"""
Make a copy of this object's indices and data.
When ``deep=True`` (default), a new object will be created with a
copy of the calling object's data and indices. Modifications to
the data or indices of the copy will not be reflected in the
original object (see notes below).
When ``deep=False``, a new object will be created without copying
the calling object's data or index (only references to the data
and index are copied). Any changes to the data of the original
will be reflected in the shallow copy (and vice versa).
Parameters
----------
deep : bool, default True
Make a deep copy, including a copy of the data and the indices.
With ``deep=False`` neither the indices nor the data are copied.
Returns
-------
Series or DataFrame
Object type matches caller.
Notes
-----
When ``deep=True``, data is copied but actual Python objects
will not be copied recursively, only the reference to the object.
This is in contrast to `copy.deepcopy` in the Standard Library,
which recursively copies object data (see examples below).
While ``Index`` objects are copied when ``deep=True``, the underlying
numpy array is not copied for performance reasons. Since ``Index`` is
immutable, the underlying data can be safely shared and a copy
is not needed.
Since pandas is not thread safe, see the
:ref:`gotchas <gotchas.thread-safety>` when copying in a threading
environment.
Examples
--------
>>> s = pd.Series([1, 2], index=["a", "b"])
>>> s
a 1
b 2
dtype: int64
>>> s_copy = s.copy()
>>> s_copy
a 1
b 2
dtype: int64
**Shallow copy versus default (deep) copy:**
>>> s = pd.Series([1, 2], index=["a", "b"])
>>> deep = s.copy()
>>> shallow = s.copy(deep=False)
Shallow copy shares data and index with original.
>>> s is shallow
False
>>> s.values is shallow.values and s.index is shallow.index
True
Deep copy has own copy of data and index.
>>> s is deep
False
>>> s.values is deep.values or s.index is deep.index
False
Updates to the data shared by shallow copy and original is reflected
in both; deep copy remains unchanged.
>>> s[0] = 3
>>> shallow[1] = 4
>>> s
a 3
b 4
dtype: int64
>>> shallow
a 3
b 4
dtype: int64
>>> deep
a 1
b 2
dtype: int64
Note that when copying an object containing Python objects, a deep copy
will copy the data, but will not do so recursively. Updating a nested
data object will be reflected in the deep copy.
>>> s = pd.Series([[1, 2], [3, 4]])
>>> deep = s.copy()
>>> s[0][0] = 10
>>> s
0 [10, 2]
1 [3, 4]
dtype: object
>>> deep
0 [10, 2]
1 [3, 4]
dtype: object
"""
data = self._mgr.copy(deep=deep)
self._clear_item_cache()
return self._constructor(data).__finalize__(self, method="copy")
def __copy__(self: NDFrameT, deep: bool_t = True) -> NDFrameT:
return self.copy(deep=deep)
def __deepcopy__(self: NDFrameT, memo=None) -> NDFrameT:
"""
Parameters
----------
memo, default None
Standard signature. Unused
"""
return self.copy(deep=True)
def infer_objects(self: NDFrameT, copy: bool_t | None = None) -> NDFrameT:
"""
Attempt to infer better dtypes for object columns.
Attempts soft conversion of object-dtyped
columns, leaving non-object and unconvertible
columns unchanged. The inference rules are the
same as during normal Series/DataFrame construction.
Parameters
----------
copy : bool, default True
Whether to make a copy for non-object or non-inferrable columns
or Series.
Returns
-------
same type as input object
See Also
--------
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to numeric type.
convert_dtypes : Convert argument to best possible dtype.
Examples
--------
>>> df = pd.DataFrame({"A": ["a", 1, 2, 3]})
>>> df = df.iloc[1:]
>>> df
A
1 1
2 2
3 3
>>> df.dtypes
A object
dtype: object
>>> df.infer_objects().dtypes
A int64
dtype: object
"""
new_mgr = self._mgr.convert(copy=copy)
return self._constructor(new_mgr).__finalize__(self, method="infer_objects")
def convert_dtypes(
self: NDFrameT,
infer_objects: bool_t = True,
convert_string: bool_t = True,
convert_integer: bool_t = True,
convert_boolean: bool_t = True,
convert_floating: bool_t = True,
dtype_backend: DtypeBackend = "numpy_nullable",
) -> NDFrameT:
"""
Convert columns to the best possible dtypes using dtypes supporting ``pd.NA``.
Parameters
----------
infer_objects : bool, default True
Whether object dtypes should be converted to the best possible types.
convert_string : bool, default True
Whether object dtypes should be converted to ``StringDtype()``.
convert_integer : bool, default True
Whether, if possible, conversion can be done to integer extension types.
convert_boolean : bool, defaults True
Whether object dtypes should be converted to ``BooleanDtypes()``.
convert_floating : bool, defaults True
Whether, if possible, conversion can be done to floating extension types.
If `convert_integer` is also True, preference will be give to integer
dtypes if the floats can be faithfully casted to integers.
.. versionadded:: 1.2.0
dtype_backend : {"numpy_nullable", "pyarrow"}, default "numpy_nullable"
Which dtype_backend to use, e.g. whether a DataFrame should use nullable
dtypes for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
Returns
-------
Series or DataFrame
Copy of input object with new dtype.
See Also
--------
infer_objects : Infer dtypes of objects.
to_datetime : Convert argument to datetime.
to_timedelta : Convert argument to timedelta.
to_numeric : Convert argument to a numeric type.
Notes
-----
By default, ``convert_dtypes`` will attempt to convert a Series (or each
Series in a DataFrame) to dtypes that support ``pd.NA``. By using the options
``convert_string``, ``convert_integer``, ``convert_boolean`` and
``convert_floating``, it is possible to turn off individual conversions
to ``StringDtype``, the integer extension types, ``BooleanDtype``
or floating extension types, respectively.
For object-dtyped columns, if ``infer_objects`` is ``True``, use the inference
rules as during normal Series/DataFrame construction. Then, if possible,
convert to ``StringDtype``, ``BooleanDtype`` or an appropriate integer
or floating extension type, otherwise leave as ``object``.
If the dtype is integer, convert to an appropriate integer extension type.
If the dtype is numeric, and consists of all integers, convert to an
appropriate integer extension type. Otherwise, convert to an
appropriate floating extension type.
.. versionchanged:: 1.2
Starting with pandas 1.2, this method also converts float columns
to the nullable floating extension type.
In the future, as new dtypes are added that support ``pd.NA``, the results
of this method will change to support those new dtypes.
.. versionadded:: 2.0
The nullable dtype implementation can be configured by calling
``pd.set_option("mode.dtype_backend", "pandas")`` to use
numpy-backed nullable dtypes or
``pd.set_option("mode.dtype_backend", "pyarrow")`` to use
pyarrow-backed nullable dtypes (using ``pd.ArrowDtype``).
Examples
--------
>>> df = pd.DataFrame(
... {
... "a": pd.Series([1, 2, 3], dtype=np.dtype("int32")),
... "b": pd.Series(["x", "y", "z"], dtype=np.dtype("O")),
... "c": pd.Series([True, False, np.nan], dtype=np.dtype("O")),
... "d": pd.Series(["h", "i", np.nan], dtype=np.dtype("O")),
... "e": pd.Series([10, np.nan, 20], dtype=np.dtype("float")),
... "f": pd.Series([np.nan, 100.5, 200], dtype=np.dtype("float")),
... }
... )
Start with a DataFrame with default dtypes.
>>> df
a b c d e f
0 1 x True h 10.0 NaN
1 2 y False i NaN 100.5
2 3 z NaN NaN 20.0 200.0
>>> df.dtypes
a int32
b object
c object
d object
e float64
f float64
dtype: object
Convert the DataFrame to use best possible dtypes.
>>> dfn = df.convert_dtypes()
>>> dfn
a b c d e f
0 1 x True h 10 <NA>
1 2 y False i <NA> 100.5
2 3 z <NA> <NA> 20 200.0
>>> dfn.dtypes
a Int32
b string[python]
c boolean
d string[python]
e Int64
f Float64
dtype: object
Start with a Series of strings and missing data represented by ``np.nan``.
>>> s = pd.Series(["a", "b", np.nan])
>>> s
0 a
1 b
2 NaN
dtype: object
Obtain a Series with dtype ``StringDtype``.
>>> s.convert_dtypes()
0 a
1 b
2 <NA>
dtype: string
"""
check_dtype_backend(dtype_backend)
if self.ndim == 1:
return self._convert_dtypes(
infer_objects,
convert_string,
convert_integer,
convert_boolean,
convert_floating,
dtype_backend=dtype_backend,
)
else:
results = [
col._convert_dtypes(
infer_objects,
convert_string,
convert_integer,
convert_boolean,
convert_floating,
dtype_backend=dtype_backend,
)
for col_name, col in self.items()
]
if len(results) > 0:
result = concat(results, axis=1, copy=False, keys=self.columns)
cons = cast(Type["DataFrame"], self._constructor)
result = cons(result)
result = result.__finalize__(self, method="convert_dtypes")
# https://github.com/python/mypy/issues/8354
return cast(NDFrameT, result)
else:
return self.copy(deep=None)
# ----------------------------------------------------------------------
# Filling NA's
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: Literal[False] = ...,
limit: int | None = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def fillna(
self,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: Literal[True],
limit: int | None = ...,
downcast: dict | None = ...,
) -> None:
...
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = ...,
*,
method: FillnaOptions | None = ...,
axis: Axis | None = ...,
inplace: bool_t = ...,
limit: int | None = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def fillna(
self: NDFrameT,
value: Hashable | Mapping | Series | DataFrame = None,
*,
method: FillnaOptions | None = None,
axis: Axis | None = None,
inplace: bool_t = False,
limit: int | None = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Fill NA/NaN values using the specified method.
Parameters
----------
value : scalar, dict, Series, or DataFrame
Value to use to fill holes (e.g. 0), alternately a
dict/Series/DataFrame of values specifying which value to use for
each index (for a Series) or column (for a DataFrame). Values not
in the dict/Series/DataFrame will not be filled. This value cannot
be a list.
method : {{'backfill', 'bfill', 'ffill', None}}, default None
Method to use for filling holes in reindexed Series:
* ffill: propagate last valid observation forward to next valid.
* backfill / bfill: use next valid observation to fill gap.
axis : {axes_single_arg}
Axis along which to fill missing values. For `Series`
this parameter is unused and defaults to 0.
inplace : bool, default False
If True, fill in-place. Note: this will modify any
other views on this object (e.g., a no-copy slice for a column in a
DataFrame).
limit : int, default None
If method is specified, this is the maximum number of consecutive
NaN values to forward/backward fill. In other words, if there is
a gap with more than this number of consecutive NaNs, it will only
be partially filled. If method is not specified, this is the
maximum number of entries along the entire axis where NaNs will be
filled. Must be greater than 0 if not None.
downcast : dict, default is None
A dict of item->dtype of what to downcast if possible,
or the string 'infer' which will try to downcast to an appropriate
equal type (e.g. float64 to int64 if possible).
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
See Also
--------
interpolate : Fill NaN values using interpolation.
reindex : Conform object to new index.
asfreq : Convert TimeSeries to specified frequency.
Examples
--------
>>> df = pd.DataFrame([[np.nan, 2, np.nan, 0],
... [3, 4, np.nan, 1],
... [np.nan, np.nan, np.nan, np.nan],
... [np.nan, 3, np.nan, 4]],
... columns=list("ABCD"))
>>> df
A B C D
0 NaN 2.0 NaN 0.0
1 3.0 4.0 NaN 1.0
2 NaN NaN NaN NaN
3 NaN 3.0 NaN 4.0
Replace all NaN elements with 0s.
>>> df.fillna(0)
A B C D
0 0.0 2.0 0.0 0.0
1 3.0 4.0 0.0 1.0
2 0.0 0.0 0.0 0.0
3 0.0 3.0 0.0 4.0
We can also propagate non-null values forward or backward.
>>> df.fillna(method="ffill")
A B C D
0 NaN 2.0 NaN 0.0
1 3.0 4.0 NaN 1.0
2 3.0 4.0 NaN 1.0
3 3.0 3.0 NaN 4.0
Replace all NaN elements in column 'A', 'B', 'C', and 'D', with 0, 1,
2, and 3 respectively.
>>> values = {{"A": 0, "B": 1, "C": 2, "D": 3}}
>>> df.fillna(value=values)
A B C D
0 0.0 2.0 2.0 0.0
1 3.0 4.0 2.0 1.0
2 0.0 1.0 2.0 3.0
3 0.0 3.0 2.0 4.0
Only replace the first NaN element.
>>> df.fillna(value=values, limit=1)
A B C D
0 0.0 2.0 2.0 0.0
1 3.0 4.0 NaN 1.0
2 NaN 1.0 NaN 3.0
3 NaN 3.0 NaN 4.0
When filling using a DataFrame, replacement happens along
the same column names and same indices
>>> df2 = pd.DataFrame(np.zeros((4, 4)), columns=list("ABCE"))
>>> df.fillna(df2)
A B C D
0 0.0 2.0 0.0 0.0
1 3.0 4.0 0.0 1.0
2 0.0 0.0 0.0 NaN
3 0.0 3.0 0.0 4.0
Note that column D is not affected since it is not present in df2.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
value, method = validate_fillna_kwargs(value, method)
# set the default here, so functions examining the signaure
# can detect if something was set (e.g. in groupby) (GH9221)
if axis is None:
axis = 0
axis = self._get_axis_number(axis)
if value is None:
if not self._mgr.is_single_block and axis == 1:
if inplace:
raise NotImplementedError()
result = self.T.fillna(method=method, limit=limit).T
return result
new_data = self._mgr.interpolate(
method=method,
axis=axis,
limit=limit,
inplace=inplace,
downcast=downcast,
)
else:
if self.ndim == 1:
if isinstance(value, (dict, ABCSeries)):
if not len(value):
# test_fillna_nonscalar
if inplace:
return None
return self.copy(deep=None)
from pandas import Series
value = Series(value)
value = value.reindex(self.index, copy=False)
value = value._values
elif not is_list_like(value):
pass
else:
raise TypeError(
'"value" parameter must be a scalar, dict '
"or Series, but you passed a "
f'"{type(value).__name__}"'
)
new_data = self._mgr.fillna(
value=value, limit=limit, inplace=inplace, downcast=downcast
)
elif isinstance(value, (dict, ABCSeries)):
if axis == 1:
raise NotImplementedError(
"Currently only can fill "
"with dict/Series column "
"by column"
)
if using_copy_on_write():
result = self.copy(deep=None)
else:
result = self if inplace else self.copy()
is_dict = isinstance(downcast, dict)
for k, v in value.items():
if k not in result:
continue
# error: Item "None" of "Optional[Dict[Any, Any]]" has no
# attribute "get"
downcast_k = (
downcast
if not is_dict
else downcast.get(k) # type: ignore[union-attr]
)
res_k = result[k].fillna(v, limit=limit, downcast=downcast_k)
if not inplace:
result[k] = res_k
else:
# We can write into our existing column(s) iff dtype
# was preserved.
if isinstance(res_k, ABCSeries):
# i.e. 'k' only shows up once in self.columns
if res_k.dtype == result[k].dtype:
result.loc[:, k] = res_k
else:
# Different dtype -> no way to do inplace.
result[k] = res_k
else:
# see test_fillna_dict_inplace_nonunique_columns
locs = result.columns.get_loc(k)
if isinstance(locs, slice):
locs = np.arange(self.shape[1])[locs]
elif (
isinstance(locs, np.ndarray) and locs.dtype.kind == "b"
):
locs = locs.nonzero()[0]
elif not (
isinstance(locs, np.ndarray) and locs.dtype.kind == "i"
):
# Should never be reached, but let's cover our bases
raise NotImplementedError(
"Unexpected get_loc result, please report a bug at "
"https://github.com/pandas-dev/pandas"
)
for i, loc in enumerate(locs):
res_loc = res_k.iloc[:, i]
target = self.iloc[:, loc]
if res_loc.dtype == target.dtype:
result.iloc[:, loc] = res_loc
else:
result.isetitem(loc, res_loc)
if inplace:
return self._update_inplace(result)
else:
return result
elif not is_list_like(value):
if axis == 1:
result = self.T.fillna(value=value, limit=limit).T
new_data = result
else:
new_data = self._mgr.fillna(
value=value, limit=limit, inplace=inplace, downcast=downcast
)
elif isinstance(value, ABCDataFrame) and self.ndim == 2:
new_data = self.where(self.notna(), value)._mgr
else:
raise ValueError(f"invalid fill value with a {type(value)}")
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="fillna")
def ffill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: Literal[False] = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def ffill(
self,
*,
axis: None | Axis = ...,
inplace: Literal[True],
limit: None | int = ...,
downcast: dict | None = ...,
) -> None:
...
def ffill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: bool_t = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def ffill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='ffill'``.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
return self.fillna(
method="ffill", axis=axis, inplace=inplace, limit=limit, downcast=downcast
)
def pad(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='ffill'``.
.. deprecated:: 2.0
{klass}.pad is deprecated. Use {klass}.ffill instead.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
warnings.warn(
"DataFrame.pad/Series.pad is deprecated. Use "
"DataFrame.ffill/Series.ffill instead",
FutureWarning,
stacklevel=find_stack_level(),
)
return self.ffill(axis=axis, inplace=inplace, limit=limit, downcast=downcast)
def bfill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: Literal[False] = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT:
...
def bfill(
self,
*,
axis: None | Axis = ...,
inplace: Literal[True],
limit: None | int = ...,
downcast: dict | None = ...,
) -> None:
...
def bfill(
self: NDFrameT,
*,
axis: None | Axis = ...,
inplace: bool_t = ...,
limit: None | int = ...,
downcast: dict | None = ...,
) -> NDFrameT | None:
...
def bfill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='bfill'``.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
return self.fillna(
method="bfill", axis=axis, inplace=inplace, limit=limit, downcast=downcast
)
def backfill(
self: NDFrameT,
*,
axis: None | Axis = None,
inplace: bool_t = False,
limit: None | int = None,
downcast: dict | None = None,
) -> NDFrameT | None:
"""
Synonym for :meth:`DataFrame.fillna` with ``method='bfill'``.
.. deprecated:: 2.0
{klass}.backfill is deprecated. Use {klass}.bfill instead.
Returns
-------
{klass} or None
Object with missing values filled or None if ``inplace=True``.
"""
warnings.warn(
"DataFrame.backfill/Series.backfill is deprecated. Use "
"DataFrame.bfill/Series.bfill instead",
FutureWarning,
stacklevel=find_stack_level(),
)
return self.bfill(axis=axis, inplace=inplace, limit=limit, downcast=downcast)
def replace(
self: NDFrameT,
to_replace=...,
value=...,
*,
inplace: Literal[False] = ...,
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> NDFrameT:
...
def replace(
self,
to_replace=...,
value=...,
*,
inplace: Literal[True],
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> None:
...
def replace(
self: NDFrameT,
to_replace=...,
value=...,
*,
inplace: bool_t = ...,
limit: int | None = ...,
regex: bool_t = ...,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = ...,
) -> NDFrameT | None:
...
_shared_docs["replace"],
klass=_shared_doc_kwargs["klass"],
inplace=_shared_doc_kwargs["inplace"],
replace_iloc=_shared_doc_kwargs["replace_iloc"],
)
def replace(
self: NDFrameT,
to_replace=None,
value=lib.no_default,
*,
inplace: bool_t = False,
limit: int | None = None,
regex: bool_t = False,
method: Literal["pad", "ffill", "bfill"] | lib.NoDefault = lib.no_default,
) -> NDFrameT | None:
if not (
is_scalar(to_replace)
or is_re_compilable(to_replace)
or is_list_like(to_replace)
):
raise TypeError(
"Expecting 'to_replace' to be either a scalar, array-like, "
"dict or None, got invalid type "
f"{repr(type(to_replace).__name__)}"
)
inplace = validate_bool_kwarg(inplace, "inplace")
if not is_bool(regex) and to_replace is not None:
raise ValueError("'to_replace' must be 'None' if 'regex' is not a bool")
if value is lib.no_default or method is not lib.no_default:
# GH#36984 if the user explicitly passes value=None we want to
# respect that. We have the corner case where the user explicitly
# passes value=None *and* a method, which we interpret as meaning
# they want the (documented) default behavior.
if method is lib.no_default:
# TODO: get this to show up as the default in the docs?
method = "pad"
# passing a single value that is scalar like
# when value is None (GH5319), for compat
if not is_dict_like(to_replace) and not is_dict_like(regex):
to_replace = [to_replace]
if isinstance(to_replace, (tuple, list)):
# TODO: Consider copy-on-write for non-replaced columns's here
if isinstance(self, ABCDataFrame):
from pandas import Series
result = self.apply(
Series._replace_single,
args=(to_replace, method, inplace, limit),
)
if inplace:
return None
return result
return self._replace_single(to_replace, method, inplace, limit)
if not is_dict_like(to_replace):
if not is_dict_like(regex):
raise TypeError(
'If "to_replace" and "value" are both None '
'and "to_replace" is not a list, then '
"regex must be a mapping"
)
to_replace = regex
regex = True
items = list(to_replace.items())
if items:
keys, values = zip(*items)
else:
keys, values = ([], [])
are_mappings = [is_dict_like(v) for v in values]
if any(are_mappings):
if not all(are_mappings):
raise TypeError(
"If a nested mapping is passed, all values "
"of the top level mapping must be mappings"
)
# passed a nested dict/Series
to_rep_dict = {}
value_dict = {}
for k, v in items:
keys, values = list(zip(*v.items())) or ([], [])
to_rep_dict[k] = list(keys)
value_dict[k] = list(values)
to_replace, value = to_rep_dict, value_dict
else:
to_replace, value = keys, values
return self.replace(
to_replace, value, inplace=inplace, limit=limit, regex=regex
)
else:
# need a non-zero len on all axes
if not self.size:
if inplace:
return None
return self.copy(deep=None)
if is_dict_like(to_replace):
if is_dict_like(value): # {'A' : NA} -> {'A' : 0}
# Note: Checking below for `in foo.keys()` instead of
# `in foo` is needed for when we have a Series and not dict
mapping = {
col: (to_replace[col], value[col])
for col in to_replace.keys()
if col in value.keys() and col in self
}
return self._replace_columnwise(mapping, inplace, regex)
# {'A': NA} -> 0
elif not is_list_like(value):
# Operate column-wise
if self.ndim == 1:
raise ValueError(
"Series.replace cannot use dict-like to_replace "
"and non-None value"
)
mapping = {
col: (to_rep, value) for col, to_rep in to_replace.items()
}
return self._replace_columnwise(mapping, inplace, regex)
else:
raise TypeError("value argument must be scalar, dict, or Series")
elif is_list_like(to_replace):
if not is_list_like(value):
# e.g. to_replace = [NA, ''] and value is 0,
# so we replace NA with 0 and then replace '' with 0
value = [value] * len(to_replace)
# e.g. we have to_replace = [NA, ''] and value = [0, 'missing']
if len(to_replace) != len(value):
raise ValueError(
f"Replacement lists must match in length. "
f"Expecting {len(to_replace)} got {len(value)} "
)
new_data = self._mgr.replace_list(
src_list=to_replace,
dest_list=value,
inplace=inplace,
regex=regex,
)
elif to_replace is None:
if not (
is_re_compilable(regex)
or is_list_like(regex)
or is_dict_like(regex)
):
raise TypeError(
f"'regex' must be a string or a compiled regular expression "
f"or a list or dict of strings or regular expressions, "
f"you passed a {repr(type(regex).__name__)}"
)
return self.replace(
regex, value, inplace=inplace, limit=limit, regex=True
)
else:
# dest iterable dict-like
if is_dict_like(value): # NA -> {'A' : 0, 'B' : -1}
# Operate column-wise
if self.ndim == 1:
raise ValueError(
"Series.replace cannot use dict-value and "
"non-None to_replace"
)
mapping = {col: (to_replace, val) for col, val in value.items()}
return self._replace_columnwise(mapping, inplace, regex)
elif not is_list_like(value): # NA -> 0
regex = should_use_regex(regex, to_replace)
if regex:
new_data = self._mgr.replace_regex(
to_replace=to_replace,
value=value,
inplace=inplace,
)
else:
new_data = self._mgr.replace(
to_replace=to_replace, value=value, inplace=inplace
)
else:
raise TypeError(
f'Invalid "to_replace" type: {repr(type(to_replace).__name__)}'
)
result = self._constructor(new_data)
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="replace")
def interpolate(
self: NDFrameT,
method: str = "linear",
*,
axis: Axis = 0,
limit: int | None = None,
inplace: bool_t = False,
limit_direction: str | None = None,
limit_area: str | None = None,
downcast: str | None = None,
**kwargs,
) -> NDFrameT | None:
"""
Fill NaN values using an interpolation method.
Please note that only ``method='linear'`` is supported for
DataFrame/Series with a MultiIndex.
Parameters
----------
method : str, default 'linear'
Interpolation technique to use. One of:
* 'linear': Ignore the index and treat the values as equally
spaced. This is the only method supported on MultiIndexes.
* 'time': Works on daily and higher resolution data to interpolate
given length of interval.
* 'index', 'values': use the actual numerical values of the index.
* 'pad': Fill in NaNs using existing values.
* 'nearest', 'zero', 'slinear', 'quadratic', 'cubic',
'barycentric', 'polynomial': Passed to
`scipy.interpolate.interp1d`, whereas 'spline' is passed to
`scipy.interpolate.UnivariateSpline`. These methods use the numerical
values of the index. Both 'polynomial' and 'spline' require that
you also specify an `order` (int), e.g.
``df.interpolate(method='polynomial', order=5)``. Note that,
`slinear` method in Pandas refers to the Scipy first order `spline`
instead of Pandas first order `spline`.
* 'krogh', 'piecewise_polynomial', 'spline', 'pchip', 'akima',
'cubicspline': Wrappers around the SciPy interpolation methods of
similar names. See `Notes`.
* 'from_derivatives': Refers to
`scipy.interpolate.BPoly.from_derivatives` which
replaces 'piecewise_polynomial' interpolation method in
scipy 0.18.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Axis to interpolate along. For `Series` this parameter is unused
and defaults to 0.
limit : int, optional
Maximum number of consecutive NaNs to fill. Must be greater than
0.
inplace : bool, default False
Update the data in place if possible.
limit_direction : {{'forward', 'backward', 'both'}}, Optional
Consecutive NaNs will be filled in this direction.
If limit is specified:
* If 'method' is 'pad' or 'ffill', 'limit_direction' must be 'forward'.
* If 'method' is 'backfill' or 'bfill', 'limit_direction' must be
'backwards'.
If 'limit' is not specified:
* If 'method' is 'backfill' or 'bfill', the default is 'backward'
* else the default is 'forward'
.. versionchanged:: 1.1.0
raises ValueError if `limit_direction` is 'forward' or 'both' and
method is 'backfill' or 'bfill'.
raises ValueError if `limit_direction` is 'backward' or 'both' and
method is 'pad' or 'ffill'.
limit_area : {{`None`, 'inside', 'outside'}}, default None
If limit is specified, consecutive NaNs will be filled with this
restriction.
* ``None``: No fill restriction.
* 'inside': Only fill NaNs surrounded by valid values
(interpolate).
* 'outside': Only fill NaNs outside valid values (extrapolate).
downcast : optional, 'infer' or None, defaults to None
Downcast dtypes if possible.
``**kwargs`` : optional
Keyword arguments to pass on to the interpolating function.
Returns
-------
Series or DataFrame or None
Returns the same object type as the caller, interpolated at
some or all ``NaN`` values or None if ``inplace=True``.
See Also
--------
fillna : Fill missing values using different methods.
scipy.interpolate.Akima1DInterpolator : Piecewise cubic polynomials
(Akima interpolator).
scipy.interpolate.BPoly.from_derivatives : Piecewise polynomial in the
Bernstein basis.
scipy.interpolate.interp1d : Interpolate a 1-D function.
scipy.interpolate.KroghInterpolator : Interpolate polynomial (Krogh
interpolator).
scipy.interpolate.PchipInterpolator : PCHIP 1-d monotonic cubic
interpolation.
scipy.interpolate.CubicSpline : Cubic spline data interpolator.
Notes
-----
The 'krogh', 'piecewise_polynomial', 'spline', 'pchip' and 'akima'
methods are wrappers around the respective SciPy implementations of
similar names. These use the actual numerical values of the index.
For more information on their behavior, see the
`SciPy documentation
<https://docs.scipy.org/doc/scipy/reference/interpolate.html#univariate-interpolation>`__.
Examples
--------
Filling in ``NaN`` in a :class:`~pandas.Series` via linear
interpolation.
>>> s = pd.Series([0, 1, np.nan, 3])
>>> s
0 0.0
1 1.0
2 NaN
3 3.0
dtype: float64
>>> s.interpolate()
0 0.0
1 1.0
2 2.0
3 3.0
dtype: float64
Filling in ``NaN`` in a Series by padding, but filling at most two
consecutive ``NaN`` at a time.
>>> s = pd.Series([np.nan, "single_one", np.nan,
... "fill_two_more", np.nan, np.nan, np.nan,
... 4.71, np.nan])
>>> s
0 NaN
1 single_one
2 NaN
3 fill_two_more
4 NaN
5 NaN
6 NaN
7 4.71
8 NaN
dtype: object
>>> s.interpolate(method='pad', limit=2)
0 NaN
1 single_one
2 single_one
3 fill_two_more
4 fill_two_more
5 fill_two_more
6 NaN
7 4.71
8 4.71
dtype: object
Filling in ``NaN`` in a Series via polynomial interpolation or splines:
Both 'polynomial' and 'spline' methods require that you also specify
an ``order`` (int).
>>> s = pd.Series([0, 2, np.nan, 8])
>>> s.interpolate(method='polynomial', order=2)
0 0.000000
1 2.000000
2 4.666667
3 8.000000
dtype: float64
Fill the DataFrame forward (that is, going down) along each column
using linear interpolation.
Note how the last entry in column 'a' is interpolated differently,
because there is no entry after it to use for interpolation.
Note how the first entry in column 'b' remains ``NaN``, because there
is no entry before it to use for interpolation.
>>> df = pd.DataFrame([(0.0, np.nan, -1.0, 1.0),
... (np.nan, 2.0, np.nan, np.nan),
... (2.0, 3.0, np.nan, 9.0),
... (np.nan, 4.0, -4.0, 16.0)],
... columns=list('abcd'))
>>> df
a b c d
0 0.0 NaN -1.0 1.0
1 NaN 2.0 NaN NaN
2 2.0 3.0 NaN 9.0
3 NaN 4.0 -4.0 16.0
>>> df.interpolate(method='linear', limit_direction='forward', axis=0)
a b c d
0 0.0 NaN -1.0 1.0
1 1.0 2.0 -2.0 5.0
2 2.0 3.0 -3.0 9.0
3 2.0 4.0 -4.0 16.0
Using polynomial interpolation.
>>> df['d'].interpolate(method='polynomial', order=2)
0 1.0
1 4.0
2 9.0
3 16.0
Name: d, dtype: float64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
axis = self._get_axis_number(axis)
fillna_methods = ["ffill", "bfill", "pad", "backfill"]
should_transpose = axis == 1 and method not in fillna_methods
obj = self.T if should_transpose else self
if obj.empty:
return self.copy()
if method not in fillna_methods:
axis = self._info_axis_number
if isinstance(obj.index, MultiIndex) and method != "linear":
raise ValueError(
"Only `method=linear` interpolation is supported on MultiIndexes."
)
# Set `limit_direction` depending on `method`
if limit_direction is None:
limit_direction = (
"backward" if method in ("backfill", "bfill") else "forward"
)
else:
if method in ("pad", "ffill") and limit_direction != "forward":
raise ValueError(
f"`limit_direction` must be 'forward' for method `{method}`"
)
if method in ("backfill", "bfill") and limit_direction != "backward":
raise ValueError(
f"`limit_direction` must be 'backward' for method `{method}`"
)
if obj.ndim == 2 and np.all(obj.dtypes == np.dtype("object")):
raise TypeError(
"Cannot interpolate with all object-dtype columns "
"in the DataFrame. Try setting at least one "
"column to a numeric dtype."
)
# create/use the index
if method == "linear":
# prior default
index = Index(np.arange(len(obj.index)))
else:
index = obj.index
methods = {"index", "values", "nearest", "time"}
is_numeric_or_datetime = (
is_numeric_dtype(index.dtype)
or is_datetime64_any_dtype(index.dtype)
or is_timedelta64_dtype(index.dtype)
)
if method not in methods and not is_numeric_or_datetime:
raise ValueError(
"Index column must be numeric or datetime type when "
f"using {method} method other than linear. "
"Try setting a numeric or datetime index column before "
"interpolating."
)
if isna(index).any():
raise NotImplementedError(
"Interpolation with NaNs in the index "
"has not been implemented. Try filling "
"those NaNs before interpolating."
)
new_data = obj._mgr.interpolate(
method=method,
axis=axis,
index=index,
limit=limit,
limit_direction=limit_direction,
limit_area=limit_area,
inplace=inplace,
downcast=downcast,
**kwargs,
)
result = self._constructor(new_data)
if should_transpose:
result = result.T
if inplace:
return self._update_inplace(result)
else:
return result.__finalize__(self, method="interpolate")
# ----------------------------------------------------------------------
# Timeseries methods Methods
def asof(self, where, subset=None):
"""
Return the last row(s) without any NaNs before `where`.
The last row (for each element in `where`, if list) without any
NaN is taken.
In case of a :class:`~pandas.DataFrame`, the last row without NaN
considering only the subset of columns (if not `None`)
If there is no good value, NaN is returned for a Series or
a Series of NaN values for a DataFrame
Parameters
----------
where : date or array-like of dates
Date(s) before which the last row(s) are returned.
subset : str or array-like of str, default `None`
For DataFrame, if not `None`, only use these columns to
check for NaNs.
Returns
-------
scalar, Series, or DataFrame
The return can be:
* scalar : when `self` is a Series and `where` is a scalar
* Series: when `self` is a Series and `where` is an array-like,
or when `self` is a DataFrame and `where` is a scalar
* DataFrame : when `self` is a DataFrame and `where` is an
array-like
Return scalar, Series, or DataFrame.
See Also
--------
merge_asof : Perform an asof merge. Similar to left join.
Notes
-----
Dates are assumed to be sorted. Raises if this is not the case.
Examples
--------
A Series and a scalar `where`.
>>> s = pd.Series([1, 2, np.nan, 4], index=[10, 20, 30, 40])
>>> s
10 1.0
20 2.0
30 NaN
40 4.0
dtype: float64
>>> s.asof(20)
2.0
For a sequence `where`, a Series is returned. The first value is
NaN, because the first element of `where` is before the first
index value.
>>> s.asof([5, 20])
5 NaN
20 2.0
dtype: float64
Missing values are not considered. The following is ``2.0``, not
NaN, even though NaN is at the index location for ``30``.
>>> s.asof(30)
2.0
Take all columns into consideration
>>> df = pd.DataFrame({'a': [10, 20, 30, 40, 50],
... 'b': [None, None, None, None, 500]},
... index=pd.DatetimeIndex(['2018-02-27 09:01:00',
... '2018-02-27 09:02:00',
... '2018-02-27 09:03:00',
... '2018-02-27 09:04:00',
... '2018-02-27 09:05:00']))
>>> df.asof(pd.DatetimeIndex(['2018-02-27 09:03:30',
... '2018-02-27 09:04:30']))
a b
2018-02-27 09:03:30 NaN NaN
2018-02-27 09:04:30 NaN NaN
Take a single column into consideration
>>> df.asof(pd.DatetimeIndex(['2018-02-27 09:03:30',
... '2018-02-27 09:04:30']),
... subset=['a'])
a b
2018-02-27 09:03:30 30 NaN
2018-02-27 09:04:30 40 NaN
"""
if isinstance(where, str):
where = Timestamp(where)
if not self.index.is_monotonic_increasing:
raise ValueError("asof requires a sorted index")
is_series = isinstance(self, ABCSeries)
if is_series:
if subset is not None:
raise ValueError("subset is not valid for Series")
else:
if subset is None:
subset = self.columns
if not is_list_like(subset):
subset = [subset]
is_list = is_list_like(where)
if not is_list:
start = self.index[0]
if isinstance(self.index, PeriodIndex):
where = Period(where, freq=self.index.freq)
if where < start:
if not is_series:
return self._constructor_sliced(
index=self.columns, name=where, dtype=np.float64
)
return np.nan
# It's always much faster to use a *while* loop here for
# Series than pre-computing all the NAs. However a
# *while* loop is extremely expensive for DataFrame
# so we later pre-compute all the NAs and use the same
# code path whether *where* is a scalar or list.
# See PR: https://github.com/pandas-dev/pandas/pull/14476
if is_series:
loc = self.index.searchsorted(where, side="right")
if loc > 0:
loc -= 1
values = self._values
while loc > 0 and isna(values[loc]):
loc -= 1
return values[loc]
if not isinstance(where, Index):
where = Index(where) if is_list else Index([where])
nulls = self.isna() if is_series else self[subset].isna().any(axis=1)
if nulls.all():
if is_series:
self = cast("Series", self)
return self._constructor(np.nan, index=where, name=self.name)
elif is_list:
self = cast("DataFrame", self)
return self._constructor(np.nan, index=where, columns=self.columns)
else:
self = cast("DataFrame", self)
return self._constructor_sliced(
np.nan, index=self.columns, name=where[0]
)
locs = self.index.asof_locs(where, ~(nulls._values))
# mask the missing
missing = locs == -1
data = self.take(locs)
data.index = where
if missing.any():
# GH#16063 only do this setting when necessary, otherwise
# we'd cast e.g. bools to floats
data.loc[missing] = np.nan
return data if is_list else data.iloc[-1]
# ----------------------------------------------------------------------
# Action Methods
def isna(self: NDFrameT) -> NDFrameT:
"""
Detect missing values.
Return a boolean same-sized object indicating if the values are NA.
NA values, such as None or :attr:`numpy.NaN`, gets mapped to True
values.
Everything else gets mapped to False values. Characters such as empty
strings ``''`` or :attr:`numpy.inf` are not considered NA values
(unless you set ``pandas.options.mode.use_inf_as_na = True``).
Returns
-------
{klass}
Mask of bool values for each element in {klass} that
indicates whether an element is an NA value.
See Also
--------
{klass}.isnull : Alias of isna.
{klass}.notna : Boolean inverse of isna.
{klass}.dropna : Omit axes labels with missing values.
isna : Top-level isna.
Examples
--------
Show which entries in a DataFrame are NA.
>>> df = pd.DataFrame(dict(age=[5, 6, np.NaN],
... born=[pd.NaT, pd.Timestamp('1939-05-27'),
... pd.Timestamp('1940-04-25')],
... name=['Alfred', 'Batman', ''],
... toy=[None, 'Batmobile', 'Joker']))
>>> df
age born name toy
0 5.0 NaT Alfred None
1 6.0 1939-05-27 Batman Batmobile
2 NaN 1940-04-25 Joker
>>> df.isna()
age born name toy
0 False True False True
1 False False False False
2 True False False False
Show which entries in a Series are NA.
>>> ser = pd.Series([5, 6, np.NaN])
>>> ser
0 5.0
1 6.0
2 NaN
dtype: float64
>>> ser.isna()
0 False
1 False
2 True
dtype: bool
"""
return isna(self).__finalize__(self, method="isna")
def isnull(self: NDFrameT) -> NDFrameT:
return isna(self).__finalize__(self, method="isnull")
def notna(self: NDFrameT) -> NDFrameT:
"""
Detect existing (non-missing) values.
Return a boolean same-sized object indicating if the values are not NA.
Non-missing values get mapped to True. Characters such as empty
strings ``''`` or :attr:`numpy.inf` are not considered NA values
(unless you set ``pandas.options.mode.use_inf_as_na = True``).
NA values, such as None or :attr:`numpy.NaN`, get mapped to False
values.
Returns
-------
{klass}
Mask of bool values for each element in {klass} that
indicates whether an element is not an NA value.
See Also
--------
{klass}.notnull : Alias of notna.
{klass}.isna : Boolean inverse of notna.
{klass}.dropna : Omit axes labels with missing values.
notna : Top-level notna.
Examples
--------
Show which entries in a DataFrame are not NA.
>>> df = pd.DataFrame(dict(age=[5, 6, np.NaN],
... born=[pd.NaT, pd.Timestamp('1939-05-27'),
... pd.Timestamp('1940-04-25')],
... name=['Alfred', 'Batman', ''],
... toy=[None, 'Batmobile', 'Joker']))
>>> df
age born name toy
0 5.0 NaT Alfred None
1 6.0 1939-05-27 Batman Batmobile
2 NaN 1940-04-25 Joker
>>> df.notna()
age born name toy
0 True False True False
1 True True True True
2 False True True True
Show which entries in a Series are not NA.
>>> ser = pd.Series([5, 6, np.NaN])
>>> ser
0 5.0
1 6.0
2 NaN
dtype: float64
>>> ser.notna()
0 True
1 True
2 False
dtype: bool
"""
return notna(self).__finalize__(self, method="notna")
def notnull(self: NDFrameT) -> NDFrameT:
return notna(self).__finalize__(self, method="notnull")
def _clip_with_scalar(self, lower, upper, inplace: bool_t = False):
if (lower is not None and np.any(isna(lower))) or (
upper is not None and np.any(isna(upper))
):
raise ValueError("Cannot use an NA value as a clip threshold")
result = self
mask = isna(self._values)
with np.errstate(all="ignore"):
if upper is not None:
subset = self <= upper
result = result.where(subset, upper, axis=None, inplace=False)
if lower is not None:
subset = self >= lower
result = result.where(subset, lower, axis=None, inplace=False)
if np.any(mask):
result[mask] = np.nan
if inplace:
return self._update_inplace(result)
else:
return result
def _clip_with_one_bound(self, threshold, method, axis, inplace):
if axis is not None:
axis = self._get_axis_number(axis)
# method is self.le for upper bound and self.ge for lower bound
if is_scalar(threshold) and is_number(threshold):
if method.__name__ == "le":
return self._clip_with_scalar(None, threshold, inplace=inplace)
return self._clip_with_scalar(threshold, None, inplace=inplace)
# GH #15390
# In order for where method to work, the threshold must
# be transformed to NDFrame from other array like structure.
if (not isinstance(threshold, ABCSeries)) and is_list_like(threshold):
if isinstance(self, ABCSeries):
threshold = self._constructor(threshold, index=self.index)
else:
threshold = align_method_FRAME(self, threshold, axis, flex=None)[1]
# GH 40420
# Treat missing thresholds as no bounds, not clipping the values
if is_list_like(threshold):
fill_value = np.inf if method.__name__ == "le" else -np.inf
threshold_inf = threshold.fillna(fill_value)
else:
threshold_inf = threshold
subset = method(threshold_inf, axis=axis) | isna(self)
# GH 40420
return self.where(subset, threshold, axis=axis, inplace=inplace)
def clip(
self: NDFrameT,
lower=None,
upper=None,
*,
axis: Axis | None = None,
inplace: bool_t = False,
**kwargs,
) -> NDFrameT | None:
"""
Trim values at input threshold(s).
Assigns values outside boundary to boundary values. Thresholds
can be singular values or array like, and in the latter case
the clipping is performed element-wise in the specified axis.
Parameters
----------
lower : float or array-like, default None
Minimum threshold value. All values below this
threshold will be set to it. A missing
threshold (e.g `NA`) will not clip the value.
upper : float or array-like, default None
Maximum threshold value. All values above this
threshold will be set to it. A missing
threshold (e.g `NA`) will not clip the value.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Align object with lower and upper along the given axis.
For `Series` this parameter is unused and defaults to `None`.
inplace : bool, default False
Whether to perform the operation in place on the data.
*args, **kwargs
Additional keywords have no effect but might be accepted
for compatibility with numpy.
Returns
-------
Series or DataFrame or None
Same type as calling object with the values outside the
clip boundaries replaced or None if ``inplace=True``.
See Also
--------
Series.clip : Trim values at input threshold in series.
DataFrame.clip : Trim values at input threshold in dataframe.
numpy.clip : Clip (limit) the values in an array.
Examples
--------
>>> data = {'col_0': [9, -3, 0, -1, 5], 'col_1': [-2, -7, 6, 8, -5]}
>>> df = pd.DataFrame(data)
>>> df
col_0 col_1
0 9 -2
1 -3 -7
2 0 6
3 -1 8
4 5 -5
Clips per column using lower and upper thresholds:
>>> df.clip(-4, 6)
col_0 col_1
0 6 -2
1 -3 -4
2 0 6
3 -1 6
4 5 -4
Clips using specific lower and upper thresholds per column element:
>>> t = pd.Series([2, -4, -1, 6, 3])
>>> t
0 2
1 -4
2 -1
3 6
4 3
dtype: int64
>>> df.clip(t, t + 4, axis=0)
col_0 col_1
0 6 2
1 -3 -4
2 0 3
3 6 8
4 5 3
Clips using specific lower threshold per column element, with missing values:
>>> t = pd.Series([2, -4, np.NaN, 6, 3])
>>> t
0 2.0
1 -4.0
2 NaN
3 6.0
4 3.0
dtype: float64
>>> df.clip(t, axis=0)
col_0 col_1
0 9 2
1 -3 -4
2 0 6
3 6 8
4 5 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
axis = nv.validate_clip_with_axis(axis, (), kwargs)
if axis is not None:
axis = self._get_axis_number(axis)
# GH 17276
# numpy doesn't like NaN as a clip value
# so ignore
# GH 19992
# numpy doesn't drop a list-like bound containing NaN
isna_lower = isna(lower)
if not is_list_like(lower):
if np.any(isna_lower):
lower = None
elif np.all(isna_lower):
lower = None
isna_upper = isna(upper)
if not is_list_like(upper):
if np.any(isna_upper):
upper = None
elif np.all(isna_upper):
upper = None
# GH 2747 (arguments were reversed)
if (
lower is not None
and upper is not None
and is_scalar(lower)
and is_scalar(upper)
):
lower, upper = min(lower, upper), max(lower, upper)
# fast-path for scalars
if (lower is None or (is_scalar(lower) and is_number(lower))) and (
upper is None or (is_scalar(upper) and is_number(upper))
):
return self._clip_with_scalar(lower, upper, inplace=inplace)
result = self
if lower is not None:
result = result._clip_with_one_bound(
lower, method=self.ge, axis=axis, inplace=inplace
)
if upper is not None:
if inplace:
result = self
result = result._clip_with_one_bound(
upper, method=self.le, axis=axis, inplace=inplace
)
return result
def asfreq(
self: NDFrameT,
freq: Frequency,
method: FillnaOptions | None = None,
how: str | None = None,
normalize: bool_t = False,
fill_value: Hashable = None,
) -> NDFrameT:
"""
Convert time series to specified frequency.
Returns the original data conformed to a new index with the specified
frequency.
If the index of this {klass} is a :class:`~pandas.PeriodIndex`, the new index
is the result of transforming the original index with
:meth:`PeriodIndex.asfreq <pandas.PeriodIndex.asfreq>` (so the original index
will map one-to-one to the new index).
Otherwise, the new index will be equivalent to ``pd.date_range(start, end,
freq=freq)`` where ``start`` and ``end`` are, respectively, the first and
last entries in the original index (see :func:`pandas.date_range`). The
values corresponding to any timesteps in the new index which were not present
in the original index will be null (``NaN``), unless a method for filling
such unknowns is provided (see the ``method`` parameter below).
The :meth:`resample` method is more appropriate if an operation on each group of
timesteps (such as an aggregate) is necessary to represent the data at the new
frequency.
Parameters
----------
freq : DateOffset or str
Frequency DateOffset or string.
method : {{'backfill'/'bfill', 'pad'/'ffill'}}, default None
Method to use for filling holes in reindexed Series (note this
does not fill NaNs that already were present):
* 'pad' / 'ffill': propagate last valid observation forward to next
valid
* 'backfill' / 'bfill': use NEXT valid observation to fill.
how : {{'start', 'end'}}, default end
For PeriodIndex only (see PeriodIndex.asfreq).
normalize : bool, default False
Whether to reset output index to midnight.
fill_value : scalar, optional
Value to use for missing values, applied during upsampling (note
this does not fill NaNs that already were present).
Returns
-------
{klass}
{klass} object reindexed to the specified frequency.
See Also
--------
reindex : Conform DataFrame to new index with optional filling logic.
Notes
-----
To learn more about the frequency strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__.
Examples
--------
Start by creating a series with 4 one minute timestamps.
>>> index = pd.date_range('1/1/2000', periods=4, freq='T')
>>> series = pd.Series([0.0, None, 2.0, 3.0], index=index)
>>> df = pd.DataFrame({{'s': series}})
>>> df
s
2000-01-01 00:00:00 0.0
2000-01-01 00:01:00 NaN
2000-01-01 00:02:00 2.0
2000-01-01 00:03:00 3.0
Upsample the series into 30 second bins.
>>> df.asfreq(freq='30S')
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 NaN
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 NaN
2000-01-01 00:03:00 3.0
Upsample again, providing a ``fill value``.
>>> df.asfreq(freq='30S', fill_value=9.0)
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 9.0
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 9.0
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 9.0
2000-01-01 00:03:00 3.0
Upsample again, providing a ``method``.
>>> df.asfreq(freq='30S', method='bfill')
s
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 NaN
2000-01-01 00:01:30 2.0
2000-01-01 00:02:00 2.0
2000-01-01 00:02:30 3.0
2000-01-01 00:03:00 3.0
"""
from pandas.core.resample import asfreq
return asfreq(
self,
freq,
method=method,
how=how,
normalize=normalize,
fill_value=fill_value,
)
def at_time(
self: NDFrameT, time, asof: bool_t = False, axis: Axis | None = None
) -> NDFrameT:
"""
Select values at particular time of day (e.g., 9:30AM).
Parameters
----------
time : datetime.time or str
The values to select.
axis : {0 or 'index', 1 or 'columns'}, default 0
For `Series` this parameter is unused and defaults to 0.
Returns
-------
Series or DataFrame
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
between_time : Select values between particular times of the day.
first : Select initial periods of time series based on a date offset.
last : Select final periods of time series based on a date offset.
DatetimeIndex.indexer_at_time : Get just the index locations for
values at particular time of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='12H')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 00:00:00 1
2018-04-09 12:00:00 2
2018-04-10 00:00:00 3
2018-04-10 12:00:00 4
>>> ts.at_time('12:00')
A
2018-04-09 12:00:00 2
2018-04-10 12:00:00 4
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
index = self._get_axis(axis)
if not isinstance(index, DatetimeIndex):
raise TypeError("Index must be DatetimeIndex")
indexer = index.indexer_at_time(time, asof=asof)
return self._take_with_is_copy(indexer, axis=axis)
def between_time(
self: NDFrameT,
start_time,
end_time,
inclusive: IntervalClosedType = "both",
axis: Axis | None = None,
) -> NDFrameT:
"""
Select values between particular times of the day (e.g., 9:00-9:30 AM).
By setting ``start_time`` to be later than ``end_time``,
you can get the times that are *not* between the two times.
Parameters
----------
start_time : datetime.time or str
Initial time as a time filter limit.
end_time : datetime.time or str
End time as a time filter limit.
inclusive : {"both", "neither", "left", "right"}, default "both"
Include boundaries; whether to set each bound as closed or open.
axis : {0 or 'index', 1 or 'columns'}, default 0
Determine range time on index or columns value.
For `Series` this parameter is unused and defaults to 0.
Returns
-------
Series or DataFrame
Data from the original object filtered to the specified dates range.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
at_time : Select values at a particular time of the day.
first : Select initial periods of time series based on a date offset.
last : Select final periods of time series based on a date offset.
DatetimeIndex.indexer_between_time : Get just the index locations for
values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='1D20min')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 00:00:00 1
2018-04-10 00:20:00 2
2018-04-11 00:40:00 3
2018-04-12 01:00:00 4
>>> ts.between_time('0:15', '0:45')
A
2018-04-10 00:20:00 2
2018-04-11 00:40:00 3
You get the times that are *not* between two times by setting
``start_time`` later than ``end_time``:
>>> ts.between_time('0:45', '0:15')
A
2018-04-09 00:00:00 1
2018-04-12 01:00:00 4
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
index = self._get_axis(axis)
if not isinstance(index, DatetimeIndex):
raise TypeError("Index must be DatetimeIndex")
left_inclusive, right_inclusive = validate_inclusive(inclusive)
indexer = index.indexer_between_time(
start_time,
end_time,
include_start=left_inclusive,
include_end=right_inclusive,
)
return self._take_with_is_copy(indexer, axis=axis)
def resample(
self,
rule,
axis: Axis = 0,
closed: str | None = None,
label: str | None = None,
convention: str = "start",
kind: str | None = None,
on: Level = None,
level: Level = None,
origin: str | TimestampConvertibleTypes = "start_day",
offset: TimedeltaConvertibleTypes | None = None,
group_keys: bool_t = False,
) -> Resampler:
"""
Resample time-series data.
Convenience method for frequency conversion and resampling of time series.
The object must have a datetime-like index (`DatetimeIndex`, `PeriodIndex`,
or `TimedeltaIndex`), or the caller must pass the label of a datetime-like
series/index to the ``on``/``level`` keyword parameter.
Parameters
----------
rule : DateOffset, Timedelta or str
The offset string or object representing target conversion.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
Which axis to use for up- or down-sampling. For `Series` this parameter
is unused and defaults to 0. Must be
`DatetimeIndex`, `TimedeltaIndex` or `PeriodIndex`.
closed : {{'right', 'left'}}, default None
Which side of bin interval is closed. The default is 'left'
for all frequency offsets except for 'M', 'A', 'Q', 'BM',
'BA', 'BQ', and 'W' which all have a default of 'right'.
label : {{'right', 'left'}}, default None
Which bin edge label to label bucket with. The default is 'left'
for all frequency offsets except for 'M', 'A', 'Q', 'BM',
'BA', 'BQ', and 'W' which all have a default of 'right'.
convention : {{'start', 'end', 's', 'e'}}, default 'start'
For `PeriodIndex` only, controls whether to use the start or
end of `rule`.
kind : {{'timestamp', 'period'}}, optional, default None
Pass 'timestamp' to convert the resulting index to a
`DateTimeIndex` or 'period' to convert it to a `PeriodIndex`.
By default the input representation is retained.
on : str, optional
For a DataFrame, column to use instead of index for resampling.
Column must be datetime-like.
level : str or int, optional
For a MultiIndex, level (name or number) to use for
resampling. `level` must be datetime-like.
origin : Timestamp or str, default 'start_day'
The timestamp on which to adjust the grouping. The timezone of origin
must match the timezone of the index.
If string, must be one of the following:
- 'epoch': `origin` is 1970-01-01
- 'start': `origin` is the first value of the timeseries
- 'start_day': `origin` is the first day at midnight of the timeseries
.. versionadded:: 1.1.0
- 'end': `origin` is the last value of the timeseries
- 'end_day': `origin` is the ceiling midnight of the last day
.. versionadded:: 1.3.0
offset : Timedelta or str, default is None
An offset timedelta added to the origin.
.. versionadded:: 1.1.0
group_keys : bool, default False
Whether to include the group keys in the result index when using
``.apply()`` on the resampled object.
.. versionadded:: 1.5.0
Not specifying ``group_keys`` will retain values-dependent behavior
from pandas 1.4 and earlier (see :ref:`pandas 1.5.0 Release notes
<whatsnew_150.enhancements.resample_group_keys>` for examples).
.. versionchanged:: 2.0.0
``group_keys`` now defaults to ``False``.
Returns
-------
pandas.core.Resampler
:class:`~pandas.core.Resampler` object.
See Also
--------
Series.resample : Resample a Series.
DataFrame.resample : Resample a DataFrame.
groupby : Group {klass} by mapping, function, label, or list of labels.
asfreq : Reindex a {klass} with the given frequency without grouping.
Notes
-----
See the `user guide
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#resampling>`__
for more.
To learn more about the offset strings, please see `this link
<https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#dateoffset-objects>`__.
Examples
--------
Start by creating a series with 9 one minute timestamps.
>>> index = pd.date_range('1/1/2000', periods=9, freq='T')
>>> series = pd.Series(range(9), index=index)
>>> series
2000-01-01 00:00:00 0
2000-01-01 00:01:00 1
2000-01-01 00:02:00 2
2000-01-01 00:03:00 3
2000-01-01 00:04:00 4
2000-01-01 00:05:00 5
2000-01-01 00:06:00 6
2000-01-01 00:07:00 7
2000-01-01 00:08:00 8
Freq: T, dtype: int64
Downsample the series into 3 minute bins and sum the values
of the timestamps falling into a bin.
>>> series.resample('3T').sum()
2000-01-01 00:00:00 3
2000-01-01 00:03:00 12
2000-01-01 00:06:00 21
Freq: 3T, dtype: int64
Downsample the series into 3 minute bins as above, but label each
bin using the right edge instead of the left. Please note that the
value in the bucket used as the label is not included in the bucket,
which it labels. For example, in the original series the
bucket ``2000-01-01 00:03:00`` contains the value 3, but the summed
value in the resampled bucket with the label ``2000-01-01 00:03:00``
does not include 3 (if it did, the summed value would be 6, not 3).
To include this value close the right side of the bin interval as
illustrated in the example below this one.
>>> series.resample('3T', label='right').sum()
2000-01-01 00:03:00 3
2000-01-01 00:06:00 12
2000-01-01 00:09:00 21
Freq: 3T, dtype: int64
Downsample the series into 3 minute bins as above, but close the right
side of the bin interval.
>>> series.resample('3T', label='right', closed='right').sum()
2000-01-01 00:00:00 0
2000-01-01 00:03:00 6
2000-01-01 00:06:00 15
2000-01-01 00:09:00 15
Freq: 3T, dtype: int64
Upsample the series into 30 second bins.
>>> series.resample('30S').asfreq()[0:5] # Select first 5 rows
2000-01-01 00:00:00 0.0
2000-01-01 00:00:30 NaN
2000-01-01 00:01:00 1.0
2000-01-01 00:01:30 NaN
2000-01-01 00:02:00 2.0
Freq: 30S, dtype: float64
Upsample the series into 30 second bins and fill the ``NaN``
values using the ``ffill`` method.
>>> series.resample('30S').ffill()[0:5]
2000-01-01 00:00:00 0
2000-01-01 00:00:30 0
2000-01-01 00:01:00 1
2000-01-01 00:01:30 1
2000-01-01 00:02:00 2
Freq: 30S, dtype: int64
Upsample the series into 30 second bins and fill the
``NaN`` values using the ``bfill`` method.
>>> series.resample('30S').bfill()[0:5]
2000-01-01 00:00:00 0
2000-01-01 00:00:30 1
2000-01-01 00:01:00 1
2000-01-01 00:01:30 2
2000-01-01 00:02:00 2
Freq: 30S, dtype: int64
Pass a custom function via ``apply``
>>> def custom_resampler(arraylike):
... return np.sum(arraylike) + 5
...
>>> series.resample('3T').apply(custom_resampler)
2000-01-01 00:00:00 8
2000-01-01 00:03:00 17
2000-01-01 00:06:00 26
Freq: 3T, dtype: int64
For a Series with a PeriodIndex, the keyword `convention` can be
used to control whether to use the start or end of `rule`.
Resample a year by quarter using 'start' `convention`. Values are
assigned to the first quarter of the period.
>>> s = pd.Series([1, 2], index=pd.period_range('2012-01-01',
... freq='A',
... periods=2))
>>> s
2012 1
2013 2
Freq: A-DEC, dtype: int64
>>> s.resample('Q', convention='start').asfreq()
2012Q1 1.0
2012Q2 NaN
2012Q3 NaN
2012Q4 NaN
2013Q1 2.0
2013Q2 NaN
2013Q3 NaN
2013Q4 NaN
Freq: Q-DEC, dtype: float64
Resample quarters by month using 'end' `convention`. Values are
assigned to the last month of the period.
>>> q = pd.Series([1, 2, 3, 4], index=pd.period_range('2018-01-01',
... freq='Q',
... periods=4))
>>> q
2018Q1 1
2018Q2 2
2018Q3 3
2018Q4 4
Freq: Q-DEC, dtype: int64
>>> q.resample('M', convention='end').asfreq()
2018-03 1.0
2018-04 NaN
2018-05 NaN
2018-06 2.0
2018-07 NaN
2018-08 NaN
2018-09 3.0
2018-10 NaN
2018-11 NaN
2018-12 4.0
Freq: M, dtype: float64
For DataFrame objects, the keyword `on` can be used to specify the
column instead of the index for resampling.
>>> d = {{'price': [10, 11, 9, 13, 14, 18, 17, 19],
... 'volume': [50, 60, 40, 100, 50, 100, 40, 50]}}
>>> df = pd.DataFrame(d)
>>> df['week_starting'] = pd.date_range('01/01/2018',
... periods=8,
... freq='W')
>>> df
price volume week_starting
0 10 50 2018-01-07
1 11 60 2018-01-14
2 9 40 2018-01-21
3 13 100 2018-01-28
4 14 50 2018-02-04
5 18 100 2018-02-11
6 17 40 2018-02-18
7 19 50 2018-02-25
>>> df.resample('M', on='week_starting').mean()
price volume
week_starting
2018-01-31 10.75 62.5
2018-02-28 17.00 60.0
For a DataFrame with MultiIndex, the keyword `level` can be used to
specify on which level the resampling needs to take place.
>>> days = pd.date_range('1/1/2000', periods=4, freq='D')
>>> d2 = {{'price': [10, 11, 9, 13, 14, 18, 17, 19],
... 'volume': [50, 60, 40, 100, 50, 100, 40, 50]}}
>>> df2 = pd.DataFrame(
... d2,
... index=pd.MultiIndex.from_product(
... [days, ['morning', 'afternoon']]
... )
... )
>>> df2
price volume
2000-01-01 morning 10 50
afternoon 11 60
2000-01-02 morning 9 40
afternoon 13 100
2000-01-03 morning 14 50
afternoon 18 100
2000-01-04 morning 17 40
afternoon 19 50
>>> df2.resample('D', level=0).sum()
price volume
2000-01-01 21 110
2000-01-02 22 140
2000-01-03 32 150
2000-01-04 36 90
If you want to adjust the start of the bins based on a fixed timestamp:
>>> start, end = '2000-10-01 23:30:00', '2000-10-02 00:30:00'
>>> rng = pd.date_range(start, end, freq='7min')
>>> ts = pd.Series(np.arange(len(rng)) * 3, index=rng)
>>> ts
2000-10-01 23:30:00 0
2000-10-01 23:37:00 3
2000-10-01 23:44:00 6
2000-10-01 23:51:00 9
2000-10-01 23:58:00 12
2000-10-02 00:05:00 15
2000-10-02 00:12:00 18
2000-10-02 00:19:00 21
2000-10-02 00:26:00 24
Freq: 7T, dtype: int64
>>> ts.resample('17min').sum()
2000-10-01 23:14:00 0
2000-10-01 23:31:00 9
2000-10-01 23:48:00 21
2000-10-02 00:05:00 54
2000-10-02 00:22:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', origin='epoch').sum()
2000-10-01 23:18:00 0
2000-10-01 23:35:00 18
2000-10-01 23:52:00 27
2000-10-02 00:09:00 39
2000-10-02 00:26:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', origin='2000-01-01').sum()
2000-10-01 23:24:00 3
2000-10-01 23:41:00 15
2000-10-01 23:58:00 45
2000-10-02 00:15:00 45
Freq: 17T, dtype: int64
If you want to adjust the start of the bins with an `offset` Timedelta, the two
following lines are equivalent:
>>> ts.resample('17min', origin='start').sum()
2000-10-01 23:30:00 9
2000-10-01 23:47:00 21
2000-10-02 00:04:00 54
2000-10-02 00:21:00 24
Freq: 17T, dtype: int64
>>> ts.resample('17min', offset='23h30min').sum()
2000-10-01 23:30:00 9
2000-10-01 23:47:00 21
2000-10-02 00:04:00 54
2000-10-02 00:21:00 24
Freq: 17T, dtype: int64
If you want to take the largest Timestamp as the end of the bins:
>>> ts.resample('17min', origin='end').sum()
2000-10-01 23:35:00 0
2000-10-01 23:52:00 18
2000-10-02 00:09:00 27
2000-10-02 00:26:00 63
Freq: 17T, dtype: int64
In contrast with the `start_day`, you can use `end_day` to take the ceiling
midnight of the largest Timestamp as the end of the bins and drop the bins
not containing data:
>>> ts.resample('17min', origin='end_day').sum()
2000-10-01 23:38:00 3
2000-10-01 23:55:00 15
2000-10-02 00:12:00 45
2000-10-02 00:29:00 45
Freq: 17T, dtype: int64
"""
from pandas.core.resample import get_resampler
axis = self._get_axis_number(axis)
return get_resampler(
cast("Series | DataFrame", self),
freq=rule,
label=label,
closed=closed,
axis=axis,
kind=kind,
convention=convention,
key=on,
level=level,
origin=origin,
offset=offset,
group_keys=group_keys,
)
def first(self: NDFrameT, offset) -> NDFrameT:
"""
Select initial periods of time series data based on a date offset.
When having a DataFrame with dates as index, this function can
select the first few rows based on a date offset.
Parameters
----------
offset : str, DateOffset or dateutil.relativedelta
The offset length of the data that will be selected. For instance,
'1M' will display all the rows having their index within the first month.
Returns
-------
Series or DataFrame
A subset of the caller.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
last : Select final periods of time series based on a date offset.
at_time : Select values at a particular time of the day.
between_time : Select values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='2D')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 1
2018-04-11 2
2018-04-13 3
2018-04-15 4
Get the rows for the first 3 days:
>>> ts.first('3D')
A
2018-04-09 1
2018-04-11 2
Notice the data for 3 first calendar days were returned, not the first
3 days observed in the dataset, and therefore data for 2018-04-13 was
not returned.
"""
if not isinstance(self.index, DatetimeIndex):
raise TypeError("'first' only supports a DatetimeIndex index")
if len(self.index) == 0:
return self.copy(deep=False)
offset = to_offset(offset)
if not isinstance(offset, Tick) and offset.is_on_offset(self.index[0]):
# GH#29623 if first value is end of period, remove offset with n = 1
# before adding the real offset
end_date = end = self.index[0] - offset.base + offset
else:
end_date = end = self.index[0] + offset
# Tick-like, e.g. 3 weeks
if isinstance(offset, Tick) and end_date in self.index:
end = self.index.searchsorted(end_date, side="left")
return self.iloc[:end]
return self.loc[:end]
def last(self: NDFrameT, offset) -> NDFrameT:
"""
Select final periods of time series data based on a date offset.
For a DataFrame with a sorted DatetimeIndex, this function
selects the last few rows based on a date offset.
Parameters
----------
offset : str, DateOffset, dateutil.relativedelta
The offset length of the data that will be selected. For instance,
'3D' will display all the rows having their index within the last 3 days.
Returns
-------
Series or DataFrame
A subset of the caller.
Raises
------
TypeError
If the index is not a :class:`DatetimeIndex`
See Also
--------
first : Select initial periods of time series based on a date offset.
at_time : Select values at a particular time of the day.
between_time : Select values between particular times of the day.
Examples
--------
>>> i = pd.date_range('2018-04-09', periods=4, freq='2D')
>>> ts = pd.DataFrame({'A': [1, 2, 3, 4]}, index=i)
>>> ts
A
2018-04-09 1
2018-04-11 2
2018-04-13 3
2018-04-15 4
Get the rows for the last 3 days:
>>> ts.last('3D')
A
2018-04-13 3
2018-04-15 4
Notice the data for 3 last calendar days were returned, not the last
3 observed days in the dataset, and therefore data for 2018-04-11 was
not returned.
"""
if not isinstance(self.index, DatetimeIndex):
raise TypeError("'last' only supports a DatetimeIndex index")
if len(self.index) == 0:
return self.copy(deep=False)
offset = to_offset(offset)
start_date = self.index[-1] - offset
start = self.index.searchsorted(start_date, side="right")
return self.iloc[start:]
def rank(
self: NDFrameT,
axis: Axis = 0,
method: str = "average",
numeric_only: bool_t = False,
na_option: str = "keep",
ascending: bool_t = True,
pct: bool_t = False,
) -> NDFrameT:
"""
Compute numerical data ranks (1 through n) along axis.
By default, equal values are assigned a rank that is the average of the
ranks of those values.
Parameters
----------
axis : {0 or 'index', 1 or 'columns'}, default 0
Index to direct ranking.
For `Series` this parameter is unused and defaults to 0.
method : {'average', 'min', 'max', 'first', 'dense'}, default 'average'
How to rank the group of records that have the same value (i.e. ties):
* average: average rank of the group
* min: lowest rank in the group
* max: highest rank in the group
* first: ranks assigned in order they appear in the array
* dense: like 'min', but rank always increases by 1 between groups.
numeric_only : bool, default False
For DataFrame objects, rank only numeric columns if set to True.
.. versionchanged:: 2.0.0
The default value of ``numeric_only`` is now ``False``.
na_option : {'keep', 'top', 'bottom'}, default 'keep'
How to rank NaN values:
* keep: assign NaN rank to NaN values
* top: assign lowest rank to NaN values
* bottom: assign highest rank to NaN values
ascending : bool, default True
Whether or not the elements should be ranked in ascending order.
pct : bool, default False
Whether or not to display the returned rankings in percentile
form.
Returns
-------
same type as caller
Return a Series or DataFrame with data ranks as values.
See Also
--------
core.groupby.DataFrameGroupBy.rank : Rank of values within each group.
core.groupby.SeriesGroupBy.rank : Rank of values within each group.
Examples
--------
>>> df = pd.DataFrame(data={'Animal': ['cat', 'penguin', 'dog',
... 'spider', 'snake'],
... 'Number_legs': [4, 2, 4, 8, np.nan]})
>>> df
Animal Number_legs
0 cat 4.0
1 penguin 2.0
2 dog 4.0
3 spider 8.0
4 snake NaN
Ties are assigned the mean of the ranks (by default) for the group.
>>> s = pd.Series(range(5), index=list("abcde"))
>>> s["d"] = s["b"]
>>> s.rank()
a 1.0
b 2.5
c 4.0
d 2.5
e 5.0
dtype: float64
The following example shows how the method behaves with the above
parameters:
* default_rank: this is the default behaviour obtained without using
any parameter.
* max_rank: setting ``method = 'max'`` the records that have the
same values are ranked using the highest rank (e.g.: since 'cat'
and 'dog' are both in the 2nd and 3rd position, rank 3 is assigned.)
* NA_bottom: choosing ``na_option = 'bottom'``, if there are records
with NaN values they are placed at the bottom of the ranking.
* pct_rank: when setting ``pct = True``, the ranking is expressed as
percentile rank.
>>> df['default_rank'] = df['Number_legs'].rank()
>>> df['max_rank'] = df['Number_legs'].rank(method='max')
>>> df['NA_bottom'] = df['Number_legs'].rank(na_option='bottom')
>>> df['pct_rank'] = df['Number_legs'].rank(pct=True)
>>> df
Animal Number_legs default_rank max_rank NA_bottom pct_rank
0 cat 4.0 2.5 3.0 2.5 0.625
1 penguin 2.0 1.0 1.0 1.0 0.250
2 dog 4.0 2.5 3.0 2.5 0.625
3 spider 8.0 4.0 4.0 4.0 1.000
4 snake NaN NaN NaN 5.0 NaN
"""
axis_int = self._get_axis_number(axis)
if na_option not in {"keep", "top", "bottom"}:
msg = "na_option must be one of 'keep', 'top', or 'bottom'"
raise ValueError(msg)
def ranker(data):
if data.ndim == 2:
# i.e. DataFrame, we cast to ndarray
values = data.values
else:
# i.e. Series, can dispatch to EA
values = data._values
if isinstance(values, ExtensionArray):
ranks = values._rank(
axis=axis_int,
method=method,
ascending=ascending,
na_option=na_option,
pct=pct,
)
else:
ranks = algos.rank(
values,
axis=axis_int,
method=method,
ascending=ascending,
na_option=na_option,
pct=pct,
)
ranks_obj = self._constructor(ranks, **data._construct_axes_dict())
return ranks_obj.__finalize__(self, method="rank")
if numeric_only:
if self.ndim == 1 and not is_numeric_dtype(self.dtype):
# GH#47500
raise TypeError(
"Series.rank does not allow numeric_only=True with "
"non-numeric dtype."
)
data = self._get_numeric_data()
else:
data = self
return ranker(data)
def compare(
self,
other,
align_axis: Axis = 1,
keep_shape: bool_t = False,
keep_equal: bool_t = False,
result_names: Suffixes = ("self", "other"),
):
if type(self) is not type(other):
cls_self, cls_other = type(self).__name__, type(other).__name__
raise TypeError(
f"can only compare '{cls_self}' (not '{cls_other}') with '{cls_self}'"
)
mask = ~((self == other) | (self.isna() & other.isna()))
mask.fillna(True, inplace=True)
if not keep_equal:
self = self.where(mask)
other = other.where(mask)
if not keep_shape:
if isinstance(self, ABCDataFrame):
cmask = mask.any()
rmask = mask.any(axis=1)
self = self.loc[rmask, cmask]
other = other.loc[rmask, cmask]
else:
self = self[mask]
other = other[mask]
if not isinstance(result_names, tuple):
raise TypeError(
f"Passing 'result_names' as a {type(result_names)} is not "
"supported. Provide 'result_names' as a tuple instead."
)
if align_axis in (1, "columns"): # This is needed for Series
axis = 1
else:
axis = self._get_axis_number(align_axis)
diff = concat([self, other], axis=axis, keys=result_names)
if axis >= self.ndim:
# No need to reorganize data if stacking on new axis
# This currently applies for stacking two Series on columns
return diff
ax = diff._get_axis(axis)
ax_names = np.array(ax.names)
# set index names to positions to avoid confusion
ax.names = np.arange(len(ax_names))
# bring self-other to inner level
order = list(range(1, ax.nlevels)) + [0]
if isinstance(diff, ABCDataFrame):
diff = diff.reorder_levels(order, axis=axis)
else:
diff = diff.reorder_levels(order)
# restore the index names in order
diff._get_axis(axis=axis).names = ax_names[order]
# reorder axis to keep things organized
indices = (
np.arange(diff.shape[axis]).reshape([2, diff.shape[axis] // 2]).T.flatten()
)
diff = diff.take(indices, axis=axis)
return diff
def align(
self: NDFrameT,
other: NDFrameT,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool_t | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> NDFrameT:
"""
Align two objects on their axes with the specified join method.
Join method is specified for each axis Index.
Parameters
----------
other : DataFrame or Series
join : {{'outer', 'inner', 'left', 'right'}}, default 'outer'
axis : allowed axis of the other object, default None
Align on index (0), columns (1), or both (None).
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
copy : bool, default True
Always returns new objects. If copy=False and no reindexing is
required then original objects are returned.
fill_value : scalar, default np.NaN
Value to use for missing values. Defaults to NaN, but can be any
"compatible" value.
method : {{'backfill', 'bfill', 'pad', 'ffill', None}}, default None
Method to use for filling holes in reindexed Series:
- pad / ffill: propagate last valid observation forward to next valid.
- backfill / bfill: use NEXT valid observation to fill gap.
limit : int, default None
If method is specified, this is the maximum number of consecutive
NaN values to forward/backward fill. In other words, if there is
a gap with more than this number of consecutive NaNs, it will only
be partially filled. If method is not specified, this is the
maximum number of entries along the entire axis where NaNs will be
filled. Must be greater than 0 if not None.
fill_axis : {axes_single_arg}, default 0
Filling axis, method and limit.
broadcast_axis : {axes_single_arg}, default None
Broadcast values along this axis, if aligning two objects of
different dimensions.
Returns
-------
tuple of ({klass}, type of other)
Aligned objects.
Examples
--------
>>> df = pd.DataFrame(
... [[1, 2, 3, 4], [6, 7, 8, 9]], columns=["D", "B", "E", "A"], index=[1, 2]
... )
>>> other = pd.DataFrame(
... [[10, 20, 30, 40], [60, 70, 80, 90], [600, 700, 800, 900]],
... columns=["A", "B", "C", "D"],
... index=[2, 3, 4],
... )
>>> df
D B E A
1 1 2 3 4
2 6 7 8 9
>>> other
A B C D
2 10 20 30 40
3 60 70 80 90
4 600 700 800 900
Align on columns:
>>> left, right = df.align(other, join="outer", axis=1)
>>> left
A B C D E
1 4 2 NaN 1 3
2 9 7 NaN 6 8
>>> right
A B C D E
2 10 20 30 40 NaN
3 60 70 80 90 NaN
4 600 700 800 900 NaN
We can also align on the index:
>>> left, right = df.align(other, join="outer", axis=0)
>>> left
D B E A
1 1.0 2.0 3.0 4.0
2 6.0 7.0 8.0 9.0
3 NaN NaN NaN NaN
4 NaN NaN NaN NaN
>>> right
A B C D
1 NaN NaN NaN NaN
2 10.0 20.0 30.0 40.0
3 60.0 70.0 80.0 90.0
4 600.0 700.0 800.0 900.0
Finally, the default `axis=None` will align on both index and columns:
>>> left, right = df.align(other, join="outer", axis=None)
>>> left
A B C D E
1 4.0 2.0 NaN 1.0 3.0
2 9.0 7.0 NaN 6.0 8.0
3 NaN NaN NaN NaN NaN
4 NaN NaN NaN NaN NaN
>>> right
A B C D E
1 NaN NaN NaN NaN NaN
2 10.0 20.0 30.0 40.0 NaN
3 60.0 70.0 80.0 90.0 NaN
4 600.0 700.0 800.0 900.0 NaN
"""
method = clean_fill_method(method)
if broadcast_axis == 1 and self.ndim != other.ndim:
if isinstance(self, ABCSeries):
# this means other is a DataFrame, and we need to broadcast
# self
cons = self._constructor_expanddim
df = cons(
{c: self for c in other.columns}, **other._construct_axes_dict()
)
return df._align_frame(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
elif isinstance(other, ABCSeries):
# this means self is a DataFrame, and we need to broadcast
# other
cons = other._constructor_expanddim
df = cons(
{c: other for c in self.columns}, **self._construct_axes_dict()
)
return self._align_frame(
df,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
if axis is not None:
axis = self._get_axis_number(axis)
if isinstance(other, ABCDataFrame):
return self._align_frame(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
elif isinstance(other, ABCSeries):
return self._align_series(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def _align_frame(
self,
other,
join: AlignJoin = "outer",
axis: Axis | None = None,
level=None,
copy: bool_t | None = None,
fill_value=None,
method=None,
limit=None,
fill_axis: Axis = 0,
):
# defaults
join_index, join_columns = None, None
ilidx, iridx = None, None
clidx, cridx = None, None
is_series = isinstance(self, ABCSeries)
if (axis is None or axis == 0) and not self.index.equals(other.index):
join_index, ilidx, iridx = self.index.join(
other.index, how=join, level=level, return_indexers=True
)
if (
(axis is None or axis == 1)
and not is_series
and not self.columns.equals(other.columns)
):
join_columns, clidx, cridx = self.columns.join(
other.columns, how=join, level=level, return_indexers=True
)
if is_series:
reindexers = {0: [join_index, ilidx]}
else:
reindexers = {0: [join_index, ilidx], 1: [join_columns, clidx]}
left = self._reindex_with_indexers(
reindexers, copy=copy, fill_value=fill_value, allow_dups=True
)
# other must be always DataFrame
right = other._reindex_with_indexers(
{0: [join_index, iridx], 1: [join_columns, cridx]},
copy=copy,
fill_value=fill_value,
allow_dups=True,
)
if method is not None:
_left = left.fillna(method=method, axis=fill_axis, limit=limit)
assert _left is not None # needed for mypy
left = _left
right = right.fillna(method=method, axis=fill_axis, limit=limit)
# if DatetimeIndex have different tz, convert to UTC
left, right = _align_as_utc(left, right, join_index)
return (
left.__finalize__(self),
right.__finalize__(other),
)
def _align_series(
self,
other,
join: AlignJoin = "outer",
axis: Axis | None = None,
level=None,
copy: bool_t | None = None,
fill_value=None,
method=None,
limit=None,
fill_axis: Axis = 0,
):
is_series = isinstance(self, ABCSeries)
if copy and using_copy_on_write():
copy = False
if (not is_series and axis is None) or axis not in [None, 0, 1]:
raise ValueError("Must specify axis=0 or 1")
if is_series and axis == 1:
raise ValueError("cannot align series to a series other than axis 0")
# series/series compat, other must always be a Series
if not axis:
# equal
if self.index.equals(other.index):
join_index, lidx, ridx = None, None, None
else:
join_index, lidx, ridx = self.index.join(
other.index, how=join, level=level, return_indexers=True
)
if is_series:
left = self._reindex_indexer(join_index, lidx, copy)
elif lidx is None or join_index is None:
left = self.copy(deep=copy)
else:
left = self._constructor(
self._mgr.reindex_indexer(join_index, lidx, axis=1, copy=copy)
)
right = other._reindex_indexer(join_index, ridx, copy)
else:
# one has > 1 ndim
fdata = self._mgr
join_index = self.axes[1]
lidx, ridx = None, None
if not join_index.equals(other.index):
join_index, lidx, ridx = join_index.join(
other.index, how=join, level=level, return_indexers=True
)
if lidx is not None:
bm_axis = self._get_block_manager_axis(1)
fdata = fdata.reindex_indexer(join_index, lidx, axis=bm_axis)
if copy and fdata is self._mgr:
fdata = fdata.copy()
left = self._constructor(fdata)
if ridx is None:
right = other.copy(deep=copy)
else:
right = other.reindex(join_index, level=level)
# fill
fill_na = notna(fill_value) or (method is not None)
if fill_na:
left = left.fillna(fill_value, method=method, limit=limit, axis=fill_axis)
right = right.fillna(fill_value, method=method, limit=limit)
# if DatetimeIndex have different tz, convert to UTC
if is_series or (not is_series and axis == 0):
left, right = _align_as_utc(left, right, join_index)
return (
left.__finalize__(self),
right.__finalize__(other),
)
def _where(
self,
cond,
other=lib.no_default,
inplace: bool_t = False,
axis: Axis | None = None,
level=None,
):
"""
Equivalent to public method `where`, except that `other` is not
applied as a function even if callable. Used in __setitem__.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if axis is not None:
axis = self._get_axis_number(axis)
# align the cond to same shape as myself
cond = common.apply_if_callable(cond, self)
if isinstance(cond, NDFrame):
# CoW: Make sure reference is not kept alive
cond = cond.align(self, join="right", broadcast_axis=1, copy=False)[0]
else:
if not hasattr(cond, "shape"):
cond = np.asanyarray(cond)
if cond.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
cond = self._constructor(cond, **self._construct_axes_dict(), copy=False)
# make sure we are boolean
fill_value = bool(inplace)
cond = cond.fillna(fill_value)
msg = "Boolean array expected for the condition, not {dtype}"
if not cond.empty:
if not isinstance(cond, ABCDataFrame):
# This is a single-dimensional object.
if not is_bool_dtype(cond):
raise ValueError(msg.format(dtype=cond.dtype))
else:
for _dt in cond.dtypes:
if not is_bool_dtype(_dt):
raise ValueError(msg.format(dtype=_dt))
else:
# GH#21947 we have an empty DataFrame/Series, could be object-dtype
cond = cond.astype(bool)
cond = -cond if inplace else cond
cond = cond.reindex(self._info_axis, axis=self._info_axis_number, copy=False)
# try to align with other
if isinstance(other, NDFrame):
# align with me
if other.ndim <= self.ndim:
# CoW: Make sure reference is not kept alive
other = self.align(
other,
join="left",
axis=axis,
level=level,
fill_value=None,
copy=False,
)[1]
# if we are NOT aligned, raise as we cannot where index
if axis is None and not other._indexed_same(self):
raise InvalidIndexError
if other.ndim < self.ndim:
# TODO(EA2D): avoid object-dtype cast in EA case GH#38729
other = other._values
if axis == 0:
other = np.reshape(other, (-1, 1))
elif axis == 1:
other = np.reshape(other, (1, -1))
other = np.broadcast_to(other, self.shape)
# slice me out of the other
else:
raise NotImplementedError(
"cannot align with a higher dimensional NDFrame"
)
elif not isinstance(other, (MultiIndex, NDFrame)):
# mainly just catching Index here
other = extract_array(other, extract_numpy=True)
if isinstance(other, (np.ndarray, ExtensionArray)):
if other.shape != self.shape:
if self.ndim != 1:
# In the ndim == 1 case we may have
# other length 1, which we treat as scalar (GH#2745, GH#4192)
# or len(other) == icond.sum(), which we treat like
# __setitem__ (GH#3235)
raise ValueError(
"other must be the same shape as self when an ndarray"
)
# we are the same shape, so create an actual object for alignment
else:
other = self._constructor(
other, **self._construct_axes_dict(), copy=False
)
if axis is None:
axis = 0
if self.ndim == getattr(other, "ndim", 0):
align = True
else:
align = self._get_axis_number(axis) == 1
if inplace:
# we may have different type blocks come out of putmask, so
# reconstruct the block manager
self._check_inplace_setting(other)
new_data = self._mgr.putmask(mask=cond, new=other, align=align)
result = self._constructor(new_data)
return self._update_inplace(result)
else:
new_data = self._mgr.where(
other=other,
cond=cond,
align=align,
)
result = self._constructor(new_data)
return result.__finalize__(self)
def where(
self: NDFrameT,
cond,
other=...,
*,
inplace: Literal[False] = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT:
...
def where(
self,
cond,
other=...,
*,
inplace: Literal[True],
axis: Axis | None = ...,
level: Level = ...,
) -> None:
...
def where(
self: NDFrameT,
cond,
other=...,
*,
inplace: bool_t = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT | None:
...
klass=_shared_doc_kwargs["klass"],
cond="True",
cond_rev="False",
name="where",
name_other="mask",
)
def where(
self: NDFrameT,
cond,
other=np.nan,
*,
inplace: bool_t = False,
axis: Axis | None = None,
level: Level = None,
) -> NDFrameT | None:
"""
Replace values where the condition is {cond_rev}.
Parameters
----------
cond : bool {klass}, array-like, or callable
Where `cond` is {cond}, keep the original value. Where
{cond_rev}, replace with corresponding value from `other`.
If `cond` is callable, it is computed on the {klass} and
should return boolean {klass} or array. The callable must
not change input {klass} (though pandas doesn't check it).
other : scalar, {klass}, or callable
Entries where `cond` is {cond_rev} are replaced with
corresponding value from `other`.
If other is callable, it is computed on the {klass} and
should return scalar or {klass}. The callable must not
change input {klass} (though pandas doesn't check it).
If not specified, entries will be filled with the corresponding
NULL value (``np.nan`` for numpy dtypes, ``pd.NA`` for extension
dtypes).
inplace : bool, default False
Whether to perform the operation in place on the data.
axis : int, default None
Alignment axis if needed. For `Series` this parameter is
unused and defaults to 0.
level : int, default None
Alignment level if needed.
Returns
-------
Same type as caller or None if ``inplace=True``.
See Also
--------
:func:`DataFrame.{name_other}` : Return an object of same shape as
self.
Notes
-----
The {name} method is an application of the if-then idiom. For each
element in the calling DataFrame, if ``cond`` is ``{cond}`` the
element is used; otherwise the corresponding element from the DataFrame
``other`` is used. If the axis of ``other`` does not align with axis of
``cond`` {klass}, the misaligned index positions will be filled with
{cond_rev}.
The signature for :func:`DataFrame.where` differs from
:func:`numpy.where`. Roughly ``df1.where(m, df2)`` is equivalent to
``np.where(m, df1, df2)``.
For further details and examples see the ``{name}`` documentation in
:ref:`indexing <indexing.where_mask>`.
The dtype of the object takes precedence. The fill value is casted to
the object's dtype, if this can be done losslessly.
Examples
--------
>>> s = pd.Series(range(5))
>>> s.where(s > 0)
0 NaN
1 1.0
2 2.0
3 3.0
4 4.0
dtype: float64
>>> s.mask(s > 0)
0 0.0
1 NaN
2 NaN
3 NaN
4 NaN
dtype: float64
>>> s = pd.Series(range(5))
>>> t = pd.Series([True, False])
>>> s.where(t, 99)
0 0
1 99
2 99
3 99
4 99
dtype: int64
>>> s.mask(t, 99)
0 99
1 1
2 99
3 99
4 99
dtype: int64
>>> s.where(s > 1, 10)
0 10
1 10
2 2
3 3
4 4
dtype: int64
>>> s.mask(s > 1, 10)
0 0
1 1
2 10
3 10
4 10
dtype: int64
>>> df = pd.DataFrame(np.arange(10).reshape(-1, 2), columns=['A', 'B'])
>>> df
A B
0 0 1
1 2 3
2 4 5
3 6 7
4 8 9
>>> m = df % 3 == 0
>>> df.where(m, -df)
A B
0 0 -1
1 -2 3
2 -4 -5
3 6 -7
4 -8 9
>>> df.where(m, -df) == np.where(m, df, -df)
A B
0 True True
1 True True
2 True True
3 True True
4 True True
>>> df.where(m, -df) == df.mask(~m, -df)
A B
0 True True
1 True True
2 True True
3 True True
4 True True
"""
other = common.apply_if_callable(other, self)
return self._where(cond, other, inplace, axis, level)
def mask(
self: NDFrameT,
cond,
other=...,
*,
inplace: Literal[False] = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT:
...
def mask(
self,
cond,
other=...,
*,
inplace: Literal[True],
axis: Axis | None = ...,
level: Level = ...,
) -> None:
...
def mask(
self: NDFrameT,
cond,
other=...,
*,
inplace: bool_t = ...,
axis: Axis | None = ...,
level: Level = ...,
) -> NDFrameT | None:
...
where,
klass=_shared_doc_kwargs["klass"],
cond="False",
cond_rev="True",
name="mask",
name_other="where",
)
def mask(
self: NDFrameT,
cond,
other=lib.no_default,
*,
inplace: bool_t = False,
axis: Axis | None = None,
level: Level = None,
) -> NDFrameT | None:
inplace = validate_bool_kwarg(inplace, "inplace")
cond = common.apply_if_callable(cond, self)
# see gh-21891
if not hasattr(cond, "__invert__"):
cond = np.array(cond)
return self.where(
~cond,
other=other,
inplace=inplace,
axis=axis,
level=level,
)
def shift(
self: NDFrameT,
periods: int = 1,
freq=None,
axis: Axis = 0,
fill_value: Hashable = None,
) -> NDFrameT:
"""
Shift index by desired number of periods with an optional time `freq`.
When `freq` is not passed, shift the index without realigning the data.
If `freq` is passed (in this case, the index must be date or datetime,
or it will raise a `NotImplementedError`), the index will be
increased using the periods and the `freq`. `freq` can be inferred
when specified as "infer" as long as either freq or inferred_freq
attribute is set in the index.
Parameters
----------
periods : int
Number of periods to shift. Can be positive or negative.
freq : DateOffset, tseries.offsets, timedelta, or str, optional
Offset to use from the tseries module or time rule (e.g. 'EOM').
If `freq` is specified then the index values are shifted but the
data is not realigned. That is, use `freq` if you would like to
extend the index when shifting and preserve the original data.
If `freq` is specified as "infer" then it will be inferred from
the freq or inferred_freq attributes of the index. If neither of
those attributes exist, a ValueError is thrown.
axis : {{0 or 'index', 1 or 'columns', None}}, default None
Shift direction. For `Series` this parameter is unused and defaults to 0.
fill_value : object, optional
The scalar value to use for newly introduced missing values.
the default depends on the dtype of `self`.
For numeric data, ``np.nan`` is used.
For datetime, timedelta, or period data, etc. :attr:`NaT` is used.
For extension dtypes, ``self.dtype.na_value`` is used.
.. versionchanged:: 1.1.0
Returns
-------
{klass}
Copy of input object, shifted.
See Also
--------
Index.shift : Shift values of Index.
DatetimeIndex.shift : Shift values of DatetimeIndex.
PeriodIndex.shift : Shift values of PeriodIndex.
Examples
--------
>>> df = pd.DataFrame({{"Col1": [10, 20, 15, 30, 45],
... "Col2": [13, 23, 18, 33, 48],
... "Col3": [17, 27, 22, 37, 52]}},
... index=pd.date_range("2020-01-01", "2020-01-05"))
>>> df
Col1 Col2 Col3
2020-01-01 10 13 17
2020-01-02 20 23 27
2020-01-03 15 18 22
2020-01-04 30 33 37
2020-01-05 45 48 52
>>> df.shift(periods=3)
Col1 Col2 Col3
2020-01-01 NaN NaN NaN
2020-01-02 NaN NaN NaN
2020-01-03 NaN NaN NaN
2020-01-04 10.0 13.0 17.0
2020-01-05 20.0 23.0 27.0
>>> df.shift(periods=1, axis="columns")
Col1 Col2 Col3
2020-01-01 NaN 10 13
2020-01-02 NaN 20 23
2020-01-03 NaN 15 18
2020-01-04 NaN 30 33
2020-01-05 NaN 45 48
>>> df.shift(periods=3, fill_value=0)
Col1 Col2 Col3
2020-01-01 0 0 0
2020-01-02 0 0 0
2020-01-03 0 0 0
2020-01-04 10 13 17
2020-01-05 20 23 27
>>> df.shift(periods=3, freq="D")
Col1 Col2 Col3
2020-01-04 10 13 17
2020-01-05 20 23 27
2020-01-06 15 18 22
2020-01-07 30 33 37
2020-01-08 45 48 52
>>> df.shift(periods=3, freq="infer")
Col1 Col2 Col3
2020-01-04 10 13 17
2020-01-05 20 23 27
2020-01-06 15 18 22
2020-01-07 30 33 37
2020-01-08 45 48 52
"""
if periods == 0:
return self.copy(deep=None)
if freq is None:
# when freq is None, data is shifted, index is not
axis = self._get_axis_number(axis)
new_data = self._mgr.shift(
periods=periods, axis=axis, fill_value=fill_value
)
return self._constructor(new_data).__finalize__(self, method="shift")
# when freq is given, index is shifted, data is not
index = self._get_axis(axis)
if freq == "infer":
freq = getattr(index, "freq", None)
if freq is None:
freq = getattr(index, "inferred_freq", None)
if freq is None:
msg = "Freq was not set in the index hence cannot be inferred"
raise ValueError(msg)
elif isinstance(freq, str):
freq = to_offset(freq)
if isinstance(index, PeriodIndex):
orig_freq = to_offset(index.freq)
if freq != orig_freq:
assert orig_freq is not None # for mypy
raise ValueError(
f"Given freq {freq.rule_code} does not match "
f"PeriodIndex freq {orig_freq.rule_code}"
)
new_ax = index.shift(periods)
else:
new_ax = index.shift(periods, freq)
result = self.set_axis(new_ax, axis=axis)
return result.__finalize__(self, method="shift")
def truncate(
self: NDFrameT,
before=None,
after=None,
axis: Axis | None = None,
copy: bool_t | None = None,
) -> NDFrameT:
"""
Truncate a Series or DataFrame before and after some index value.
This is a useful shorthand for boolean indexing based on index
values above or below certain thresholds.
Parameters
----------
before : date, str, int
Truncate all rows before this index value.
after : date, str, int
Truncate all rows after this index value.
axis : {0 or 'index', 1 or 'columns'}, optional
Axis to truncate. Truncates the index (rows) by default.
For `Series` this parameter is unused and defaults to 0.
copy : bool, default is True,
Return a copy of the truncated section.
Returns
-------
type of caller
The truncated Series or DataFrame.
See Also
--------
DataFrame.loc : Select a subset of a DataFrame by label.
DataFrame.iloc : Select a subset of a DataFrame by position.
Notes
-----
If the index being truncated contains only datetime values,
`before` and `after` may be specified as strings instead of
Timestamps.
Examples
--------
>>> df = pd.DataFrame({'A': ['a', 'b', 'c', 'd', 'e'],
... 'B': ['f', 'g', 'h', 'i', 'j'],
... 'C': ['k', 'l', 'm', 'n', 'o']},
... index=[1, 2, 3, 4, 5])
>>> df
A B C
1 a f k
2 b g l
3 c h m
4 d i n
5 e j o
>>> df.truncate(before=2, after=4)
A B C
2 b g l
3 c h m
4 d i n
The columns of a DataFrame can be truncated.
>>> df.truncate(before="A", after="B", axis="columns")
A B
1 a f
2 b g
3 c h
4 d i
5 e j
For Series, only rows can be truncated.
>>> df['A'].truncate(before=2, after=4)
2 b
3 c
4 d
Name: A, dtype: object
The index values in ``truncate`` can be datetimes or string
dates.
>>> dates = pd.date_range('2016-01-01', '2016-02-01', freq='s')
>>> df = pd.DataFrame(index=dates, data={'A': 1})
>>> df.tail()
A
2016-01-31 23:59:56 1
2016-01-31 23:59:57 1
2016-01-31 23:59:58 1
2016-01-31 23:59:59 1
2016-02-01 00:00:00 1
>>> df.truncate(before=pd.Timestamp('2016-01-05'),
... after=pd.Timestamp('2016-01-10')).tail()
A
2016-01-09 23:59:56 1
2016-01-09 23:59:57 1
2016-01-09 23:59:58 1
2016-01-09 23:59:59 1
2016-01-10 00:00:00 1
Because the index is a DatetimeIndex containing only dates, we can
specify `before` and `after` as strings. They will be coerced to
Timestamps before truncation.
>>> df.truncate('2016-01-05', '2016-01-10').tail()
A
2016-01-09 23:59:56 1
2016-01-09 23:59:57 1
2016-01-09 23:59:58 1
2016-01-09 23:59:59 1
2016-01-10 00:00:00 1
Note that ``truncate`` assumes a 0 value for any unspecified time
component (midnight). This differs from partial string slicing, which
returns any partially matching dates.
>>> df.loc['2016-01-05':'2016-01-10', :].tail()
A
2016-01-10 23:59:55 1
2016-01-10 23:59:56 1
2016-01-10 23:59:57 1
2016-01-10 23:59:58 1
2016-01-10 23:59:59 1
"""
if axis is None:
axis = self._stat_axis_number
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
# GH 17935
# Check that index is sorted
if not ax.is_monotonic_increasing and not ax.is_monotonic_decreasing:
raise ValueError("truncate requires a sorted index")
# if we have a date index, convert to dates, otherwise
# treat like a slice
if ax._is_all_dates:
from pandas.core.tools.datetimes import to_datetime
before = to_datetime(before)
after = to_datetime(after)
if before is not None and after is not None and before > after:
raise ValueError(f"Truncate: {after} must be after {before}")
if len(ax) > 1 and ax.is_monotonic_decreasing and ax.nunique() > 1:
before, after = after, before
slicer = [slice(None, None)] * self._AXIS_LEN
slicer[axis] = slice(before, after)
result = self.loc[tuple(slicer)]
if isinstance(ax, MultiIndex):
setattr(result, self._get_axis_name(axis), ax.truncate(before, after))
result = result.copy(deep=copy and not using_copy_on_write())
return result
def tz_convert(
self: NDFrameT, tz, axis: Axis = 0, level=None, copy: bool_t | None = None
) -> NDFrameT:
"""
Convert tz-aware axis to target time zone.
Parameters
----------
tz : str or tzinfo object or None
Target time zone. Passing ``None`` will convert to
UTC and remove the timezone information.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
The axis to convert
level : int, str, default None
If axis is a MultiIndex, convert a specific level. Otherwise
must be None.
copy : bool, default True
Also make a copy of the underlying data.
Returns
-------
{klass}
Object with time zone converted axis.
Raises
------
TypeError
If the axis is tz-naive.
Examples
--------
Change to another time zone:
>>> s = pd.Series(
... [1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']),
... )
>>> s.tz_convert('Asia/Shanghai')
2018-09-15 07:30:00+08:00 1
dtype: int64
Pass None to convert to UTC and get a tz-naive index:
>>> s = pd.Series([1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']))
>>> s.tz_convert(None)
2018-09-14 23:30:00 1
dtype: int64
"""
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
def _tz_convert(ax, tz):
if not hasattr(ax, "tz_convert"):
if len(ax) > 0:
ax_name = self._get_axis_name(axis)
raise TypeError(
f"{ax_name} is not a valid DatetimeIndex or PeriodIndex"
)
ax = DatetimeIndex([], tz=tz)
else:
ax = ax.tz_convert(tz)
return ax
# if a level is given it must be a MultiIndex level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
new_level = _tz_convert(ax.levels[level], tz)
ax = ax.set_levels(new_level, level=level)
else:
if level not in (None, 0, ax.name):
raise ValueError(f"The level {level} is not valid")
ax = _tz_convert(ax, tz)
result = self.copy(deep=copy and not using_copy_on_write())
result = result.set_axis(ax, axis=axis, copy=False)
return result.__finalize__(self, method="tz_convert")
def tz_localize(
self: NDFrameT,
tz,
axis: Axis = 0,
level=None,
copy: bool_t | None = None,
ambiguous: TimeAmbiguous = "raise",
nonexistent: TimeNonexistent = "raise",
) -> NDFrameT:
"""
Localize tz-naive index of a Series or DataFrame to target time zone.
This operation localizes the Index. To localize the values in a
timezone-naive Series, use :meth:`Series.dt.tz_localize`.
Parameters
----------
tz : str or tzinfo or None
Time zone to localize. Passing ``None`` will remove the
time zone information and preserve local time.
axis : {{0 or 'index', 1 or 'columns'}}, default 0
The axis to localize
level : int, str, default None
If axis ia a MultiIndex, localize a specific level. Otherwise
must be None.
copy : bool, default True
Also make a copy of the underlying data.
ambiguous : 'infer', bool-ndarray, 'NaT', default 'raise'
When clocks moved backward due to DST, ambiguous times may arise.
For example in Central European Time (UTC+01), when going from
03:00 DST to 02:00 non-DST, 02:30:00 local time occurs both at
00:30:00 UTC and at 01:30:00 UTC. In such a situation, the
`ambiguous` parameter dictates how ambiguous times should be
handled.
- 'infer' will attempt to infer fall dst-transition hours based on
order
- bool-ndarray where True signifies a DST time, False designates
a non-DST time (note that this flag is only applicable for
ambiguous times)
- 'NaT' will return NaT where there are ambiguous times
- 'raise' will raise an AmbiguousTimeError if there are ambiguous
times.
nonexistent : str, default 'raise'
A nonexistent time does not exist in a particular timezone
where clocks moved forward due to DST. Valid values are:
- 'shift_forward' will shift the nonexistent time forward to the
closest existing time
- 'shift_backward' will shift the nonexistent time backward to the
closest existing time
- 'NaT' will return NaT where there are nonexistent times
- timedelta objects will shift nonexistent times by the timedelta
- 'raise' will raise an NonExistentTimeError if there are
nonexistent times.
Returns
-------
{klass}
Same type as the input.
Raises
------
TypeError
If the TimeSeries is tz-aware and tz is not None.
Examples
--------
Localize local times:
>>> s = pd.Series(
... [1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00']),
... )
>>> s.tz_localize('CET')
2018-09-15 01:30:00+02:00 1
dtype: int64
Pass None to convert to tz-naive index and preserve local time:
>>> s = pd.Series([1],
... index=pd.DatetimeIndex(['2018-09-15 01:30:00+02:00']))
>>> s.tz_localize(None)
2018-09-15 01:30:00 1
dtype: int64
Be careful with DST changes. When there is sequential data, pandas
can infer the DST time:
>>> s = pd.Series(range(7),
... index=pd.DatetimeIndex(['2018-10-28 01:30:00',
... '2018-10-28 02:00:00',
... '2018-10-28 02:30:00',
... '2018-10-28 02:00:00',
... '2018-10-28 02:30:00',
... '2018-10-28 03:00:00',
... '2018-10-28 03:30:00']))
>>> s.tz_localize('CET', ambiguous='infer')
2018-10-28 01:30:00+02:00 0
2018-10-28 02:00:00+02:00 1
2018-10-28 02:30:00+02:00 2
2018-10-28 02:00:00+01:00 3
2018-10-28 02:30:00+01:00 4
2018-10-28 03:00:00+01:00 5
2018-10-28 03:30:00+01:00 6
dtype: int64
In some cases, inferring the DST is impossible. In such cases, you can
pass an ndarray to the ambiguous parameter to set the DST explicitly
>>> s = pd.Series(range(3),
... index=pd.DatetimeIndex(['2018-10-28 01:20:00',
... '2018-10-28 02:36:00',
... '2018-10-28 03:46:00']))
>>> s.tz_localize('CET', ambiguous=np.array([True, True, False]))
2018-10-28 01:20:00+02:00 0
2018-10-28 02:36:00+02:00 1
2018-10-28 03:46:00+01:00 2
dtype: int64
If the DST transition causes nonexistent times, you can shift these
dates forward or backward with a timedelta object or `'shift_forward'`
or `'shift_backward'`.
>>> s = pd.Series(range(2),
... index=pd.DatetimeIndex(['2015-03-29 02:30:00',
... '2015-03-29 03:30:00']))
>>> s.tz_localize('Europe/Warsaw', nonexistent='shift_forward')
2015-03-29 03:00:00+02:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
>>> s.tz_localize('Europe/Warsaw', nonexistent='shift_backward')
2015-03-29 01:59:59.999999999+01:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
>>> s.tz_localize('Europe/Warsaw', nonexistent=pd.Timedelta('1H'))
2015-03-29 03:30:00+02:00 0
2015-03-29 03:30:00+02:00 1
dtype: int64
"""
nonexistent_options = ("raise", "NaT", "shift_forward", "shift_backward")
if nonexistent not in nonexistent_options and not isinstance(
nonexistent, dt.timedelta
):
raise ValueError(
"The nonexistent argument must be one of 'raise', "
"'NaT', 'shift_forward', 'shift_backward' or "
"a timedelta object"
)
axis = self._get_axis_number(axis)
ax = self._get_axis(axis)
def _tz_localize(ax, tz, ambiguous, nonexistent):
if not hasattr(ax, "tz_localize"):
if len(ax) > 0:
ax_name = self._get_axis_name(axis)
raise TypeError(
f"{ax_name} is not a valid DatetimeIndex or PeriodIndex"
)
ax = DatetimeIndex([], tz=tz)
else:
ax = ax.tz_localize(tz, ambiguous=ambiguous, nonexistent=nonexistent)
return ax
# if a level is given it must be a MultiIndex level or
# equivalent to the axis name
if isinstance(ax, MultiIndex):
level = ax._get_level_number(level)
new_level = _tz_localize(ax.levels[level], tz, ambiguous, nonexistent)
ax = ax.set_levels(new_level, level=level)
else:
if level not in (None, 0, ax.name):
raise ValueError(f"The level {level} is not valid")
ax = _tz_localize(ax, tz, ambiguous, nonexistent)
result = self.copy(deep=copy and not using_copy_on_write())
result = result.set_axis(ax, axis=axis, copy=False)
return result.__finalize__(self, method="tz_localize")
# ----------------------------------------------------------------------
# Numeric Methods
def describe(
self: NDFrameT,
percentiles=None,
include=None,
exclude=None,
) -> NDFrameT:
"""
Generate descriptive statistics.
Descriptive statistics include those that summarize the central
tendency, dispersion and shape of a
dataset's distribution, excluding ``NaN`` values.
Analyzes both numeric and object series, as well
as ``DataFrame`` column sets of mixed data types. The output
will vary depending on what is provided. Refer to the notes
below for more detail.
Parameters
----------
percentiles : list-like of numbers, optional
The percentiles to include in the output. All should
fall between 0 and 1. The default is
``[.25, .5, .75]``, which returns the 25th, 50th, and
75th percentiles.
include : 'all', list-like of dtypes or None (default), optional
A white list of data types to include in the result. Ignored
for ``Series``. Here are the options:
- 'all' : All columns of the input will be included in the output.
- A list-like of dtypes : Limits the results to the
provided data types.
To limit the result to numeric types submit
``numpy.number``. To limit it instead to object columns submit
the ``numpy.object`` data type. Strings
can also be used in the style of
``select_dtypes`` (e.g. ``df.describe(include=['O'])``). To
select pandas categorical columns, use ``'category'``
- None (default) : The result will include all numeric columns.
exclude : list-like of dtypes or None (default), optional,
A black list of data types to omit from the result. Ignored
for ``Series``. Here are the options:
- A list-like of dtypes : Excludes the provided data types
from the result. To exclude numeric types submit
``numpy.number``. To exclude object columns submit the data
type ``numpy.object``. Strings can also be used in the style of
``select_dtypes`` (e.g. ``df.describe(exclude=['O'])``). To
exclude pandas categorical columns, use ``'category'``
- None (default) : The result will exclude nothing.
Returns
-------
Series or DataFrame
Summary statistics of the Series or Dataframe provided.
See Also
--------
DataFrame.count: Count number of non-NA/null observations.
DataFrame.max: Maximum of the values in the object.
DataFrame.min: Minimum of the values in the object.
DataFrame.mean: Mean of the values.
DataFrame.std: Standard deviation of the observations.
DataFrame.select_dtypes: Subset of a DataFrame including/excluding
columns based on their dtype.
Notes
-----
For numeric data, the result's index will include ``count``,
``mean``, ``std``, ``min``, ``max`` as well as lower, ``50`` and
upper percentiles. By default the lower percentile is ``25`` and the
upper percentile is ``75``. The ``50`` percentile is the
same as the median.
For object data (e.g. strings or timestamps), the result's index
will include ``count``, ``unique``, ``top``, and ``freq``. The ``top``
is the most common value. The ``freq`` is the most common value's
frequency. Timestamps also include the ``first`` and ``last`` items.
If multiple object values have the highest count, then the
``count`` and ``top`` results will be arbitrarily chosen from
among those with the highest count.
For mixed data types provided via a ``DataFrame``, the default is to
return only an analysis of numeric columns. If the dataframe consists
only of object and categorical data without any numeric columns, the
default is to return an analysis of both the object and categorical
columns. If ``include='all'`` is provided as an option, the result
will include a union of attributes of each type.
The `include` and `exclude` parameters can be used to limit
which columns in a ``DataFrame`` are analyzed for the output.
The parameters are ignored when analyzing a ``Series``.
Examples
--------
Describing a numeric ``Series``.
>>> s = pd.Series([1, 2, 3])
>>> s.describe()
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
dtype: float64
Describing a categorical ``Series``.
>>> s = pd.Series(['a', 'a', 'b', 'c'])
>>> s.describe()
count 4
unique 3
top a
freq 2
dtype: object
Describing a timestamp ``Series``.
>>> s = pd.Series([
... np.datetime64("2000-01-01"),
... np.datetime64("2010-01-01"),
... np.datetime64("2010-01-01")
... ])
>>> s.describe()
count 3
mean 2006-09-01 08:00:00
min 2000-01-01 00:00:00
25% 2004-12-31 12:00:00
50% 2010-01-01 00:00:00
75% 2010-01-01 00:00:00
max 2010-01-01 00:00:00
dtype: object
Describing a ``DataFrame``. By default only numeric fields
are returned.
>>> df = pd.DataFrame({'categorical': pd.Categorical(['d','e','f']),
... 'numeric': [1, 2, 3],
... 'object': ['a', 'b', 'c']
... })
>>> df.describe()
numeric
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Describing all columns of a ``DataFrame`` regardless of data type.
>>> df.describe(include='all') # doctest: +SKIP
categorical numeric object
count 3 3.0 3
unique 3 NaN 3
top f NaN a
freq 1 NaN 1
mean NaN 2.0 NaN
std NaN 1.0 NaN
min NaN 1.0 NaN
25% NaN 1.5 NaN
50% NaN 2.0 NaN
75% NaN 2.5 NaN
max NaN 3.0 NaN
Describing a column from a ``DataFrame`` by accessing it as
an attribute.
>>> df.numeric.describe()
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Name: numeric, dtype: float64
Including only numeric columns in a ``DataFrame`` description.
>>> df.describe(include=[np.number])
numeric
count 3.0
mean 2.0
std 1.0
min 1.0
25% 1.5
50% 2.0
75% 2.5
max 3.0
Including only string columns in a ``DataFrame`` description.
>>> df.describe(include=[object]) # doctest: +SKIP
object
count 3
unique 3
top a
freq 1
Including only categorical columns from a ``DataFrame`` description.
>>> df.describe(include=['category'])
categorical
count 3
unique 3
top d
freq 1
Excluding numeric columns from a ``DataFrame`` description.
>>> df.describe(exclude=[np.number]) # doctest: +SKIP
categorical object
count 3 3
unique 3 3
top f a
freq 1 1
Excluding object columns from a ``DataFrame`` description.
>>> df.describe(exclude=[object]) # doctest: +SKIP
categorical numeric
count 3 3.0
unique 3 NaN
top f NaN
freq 1 NaN
mean NaN 2.0
std NaN 1.0
min NaN 1.0
25% NaN 1.5
50% NaN 2.0
75% NaN 2.5
max NaN 3.0
"""
return describe_ndframe(
obj=self,
include=include,
exclude=exclude,
percentiles=percentiles,
)
def pct_change(
self: NDFrameT,
periods: int = 1,
fill_method: Literal["backfill", "bfill", "pad", "ffill"] | None = "pad",
limit=None,
freq=None,
**kwargs,
) -> NDFrameT:
"""
Percentage change between the current and a prior element.
Computes the percentage change from the immediately previous row by
default. This is useful in comparing the percentage of change in a time
series of elements.
Parameters
----------
periods : int, default 1
Periods to shift for forming percent change.
fill_method : {'backfill', 'bfill', 'pad', 'ffill', None}, default 'pad'
How to handle NAs **before** computing percent changes.
limit : int, default None
The number of consecutive NAs to fill before stopping.
freq : DateOffset, timedelta, or str, optional
Increment to use from time series API (e.g. 'M' or BDay()).
**kwargs
Additional keyword arguments are passed into
`DataFrame.shift` or `Series.shift`.
Returns
-------
Series or DataFrame
The same type as the calling object.
See Also
--------
Series.diff : Compute the difference of two elements in a Series.
DataFrame.diff : Compute the difference of two elements in a DataFrame.
Series.shift : Shift the index by some number of periods.
DataFrame.shift : Shift the index by some number of periods.
Examples
--------
**Series**
>>> s = pd.Series([90, 91, 85])
>>> s
0 90
1 91
2 85
dtype: int64
>>> s.pct_change()
0 NaN
1 0.011111
2 -0.065934
dtype: float64
>>> s.pct_change(periods=2)
0 NaN
1 NaN
2 -0.055556
dtype: float64
See the percentage change in a Series where filling NAs with last
valid observation forward to next valid.
>>> s = pd.Series([90, 91, None, 85])
>>> s
0 90.0
1 91.0
2 NaN
3 85.0
dtype: float64
>>> s.pct_change(fill_method='ffill')
0 NaN
1 0.011111
2 0.000000
3 -0.065934
dtype: float64
**DataFrame**
Percentage change in French franc, Deutsche Mark, and Italian lira from
1980-01-01 to 1980-03-01.
>>> df = pd.DataFrame({
... 'FR': [4.0405, 4.0963, 4.3149],
... 'GR': [1.7246, 1.7482, 1.8519],
... 'IT': [804.74, 810.01, 860.13]},
... index=['1980-01-01', '1980-02-01', '1980-03-01'])
>>> df
FR GR IT
1980-01-01 4.0405 1.7246 804.74
1980-02-01 4.0963 1.7482 810.01
1980-03-01 4.3149 1.8519 860.13
>>> df.pct_change()
FR GR IT
1980-01-01 NaN NaN NaN
1980-02-01 0.013810 0.013684 0.006549
1980-03-01 0.053365 0.059318 0.061876
Percentage of change in GOOG and APPL stock volume. Shows computing
the percentage change between columns.
>>> df = pd.DataFrame({
... '2016': [1769950, 30586265],
... '2015': [1500923, 40912316],
... '2014': [1371819, 41403351]},
... index=['GOOG', 'APPL'])
>>> df
2016 2015 2014
GOOG 1769950 1500923 1371819
APPL 30586265 40912316 41403351
>>> df.pct_change(axis='columns', periods=-1)
2016 2015 2014
GOOG 0.179241 0.094112 NaN
APPL -0.252395 -0.011860 NaN
"""
axis = self._get_axis_number(kwargs.pop("axis", self._stat_axis_name))
if fill_method is None:
data = self
else:
_data = self.fillna(method=fill_method, axis=axis, limit=limit)
assert _data is not None # needed for mypy
data = _data
shifted = data.shift(periods=periods, freq=freq, axis=axis, **kwargs)
# Unsupported left operand type for / ("NDFrameT")
rs = data / shifted - 1 # type: ignore[operator]
if freq is not None:
# Shift method is implemented differently when freq is not None
# We want to restore the original index
rs = rs.loc[~rs.index.duplicated()]
rs = rs.reindex_like(data)
return rs.__finalize__(self, method="pct_change")
def _logical_func(
self,
name: str,
func,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> Series | bool_t:
nv.validate_logical_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if self.ndim > 1 and axis is None:
# Reduce along one dimension then the other, to simplify DataFrame._reduce
res = self._logical_func(
name, func, axis=0, bool_only=bool_only, skipna=skipna, **kwargs
)
return res._logical_func(name, func, skipna=skipna, **kwargs)
if (
self.ndim > 1
and axis == 1
and len(self._mgr.arrays) > 1
# TODO(EA2D): special-case not needed
and all(x.ndim == 2 for x in self._mgr.arrays)
and not kwargs
):
# Fastpath avoiding potentially expensive transpose
obj = self
if bool_only:
obj = self._get_bool_data()
return obj._reduce_axis1(name, func, skipna=skipna)
return self._reduce(
func,
name=name,
axis=axis,
skipna=skipna,
numeric_only=bool_only,
filter_type="bool",
)
def any(
self,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> DataFrame | Series | bool_t:
return self._logical_func(
"any", nanops.nanany, axis, bool_only, skipna, **kwargs
)
def all(
self,
axis: Axis = 0,
bool_only: bool_t = False,
skipna: bool_t = True,
**kwargs,
) -> Series | bool_t:
return self._logical_func(
"all", nanops.nanall, axis, bool_only, skipna, **kwargs
)
def _accum_func(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
*args,
**kwargs,
):
skipna = nv.validate_cum_func_with_skipna(skipna, args, kwargs, name)
if axis is None:
axis = self._stat_axis_number
else:
axis = self._get_axis_number(axis)
if axis == 1:
return self.T._accum_func(
name, func, axis=0, skipna=skipna, *args, **kwargs # noqa: B026
).T
def block_accum_func(blk_values):
values = blk_values.T if hasattr(blk_values, "T") else blk_values
result: np.ndarray | ExtensionArray
if isinstance(values, ExtensionArray):
result = values._accumulate(name, skipna=skipna, **kwargs)
else:
result = nanops.na_accum_func(values, func, skipna=skipna)
result = result.T if hasattr(result, "T") else result
return result
result = self._mgr.apply(block_accum_func)
return self._constructor(result).__finalize__(self, method=name)
def cummax(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func(
"cummax", np.maximum.accumulate, axis, skipna, *args, **kwargs
)
def cummin(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func(
"cummin", np.minimum.accumulate, axis, skipna, *args, **kwargs
)
def cumsum(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func("cumsum", np.cumsum, axis, skipna, *args, **kwargs)
def cumprod(self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs):
return self._accum_func("cumprod", np.cumprod, axis, skipna, *args, **kwargs)
def _stat_function_ddof(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
nv.validate_stat_ddof_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if axis is None:
axis = self._stat_axis_number
return self._reduce(
func, name, axis=axis, numeric_only=numeric_only, skipna=skipna, ddof=ddof
)
def sem(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"sem", nanops.nansem, axis, skipna, ddof, numeric_only, **kwargs
)
def var(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"var", nanops.nanvar, axis, skipna, ddof, numeric_only, **kwargs
)
def std(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function_ddof(
"std", nanops.nanstd, axis, skipna, ddof, numeric_only, **kwargs
)
def _stat_function(
self,
name: str,
func,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
if name == "median":
nv.validate_median((), kwargs)
else:
nv.validate_stat_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
return self._reduce(
func, name=name, axis=axis, skipna=skipna, numeric_only=numeric_only
)
def min(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return self._stat_function(
"min",
nanops.nanmin,
axis,
skipna,
numeric_only,
**kwargs,
)
def max(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return self._stat_function(
"max",
nanops.nanmax,
axis,
skipna,
numeric_only,
**kwargs,
)
def mean(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"mean", nanops.nanmean, axis, skipna, numeric_only, **kwargs
)
def median(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"median", nanops.nanmedian, axis, skipna, numeric_only, **kwargs
)
def skew(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"skew", nanops.nanskew, axis, skipna, numeric_only, **kwargs
)
def kurt(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
) -> Series | float:
return self._stat_function(
"kurt", nanops.nankurt, axis, skipna, numeric_only, **kwargs
)
kurtosis = kurt
def _min_count_stat_function(
self,
name: str,
func,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
if name == "sum":
nv.validate_sum((), kwargs)
elif name == "prod":
nv.validate_prod((), kwargs)
else:
nv.validate_stat_func((), kwargs, fname=name)
validate_bool_kwarg(skipna, "skipna", none_allowed=False)
if axis is None:
axis = self._stat_axis_number
return self._reduce(
func,
name=name,
axis=axis,
skipna=skipna,
numeric_only=numeric_only,
min_count=min_count,
)
def sum(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return self._min_count_stat_function(
"sum", nanops.nansum, axis, skipna, numeric_only, min_count, **kwargs
)
def prod(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return self._min_count_stat_function(
"prod",
nanops.nanprod,
axis,
skipna,
numeric_only,
min_count,
**kwargs,
)
product = prod
def _add_numeric_operations(cls) -> None:
"""
Add the operations to the cls; evaluate the doc strings again
"""
axis_descr, name1, name2 = _doc_params(cls)
_bool_doc,
desc=_any_desc,
name1=name1,
name2=name2,
axis_descr=axis_descr,
see_also=_any_see_also,
examples=_any_examples,
empty_value=False,
)
def any(
self,
*,
axis: Axis = 0,
bool_only=None,
skipna: bool_t = True,
**kwargs,
):
return NDFrame.any(
self,
axis=axis,
bool_only=bool_only,
skipna=skipna,
**kwargs,
)
setattr(cls, "any", any)
_bool_doc,
desc=_all_desc,
name1=name1,
name2=name2,
axis_descr=axis_descr,
see_also=_all_see_also,
examples=_all_examples,
empty_value=True,
)
def all(
self,
axis: Axis = 0,
bool_only=None,
skipna: bool_t = True,
**kwargs,
):
return NDFrame.all(self, axis, bool_only, skipna, **kwargs)
setattr(cls, "all", all)
_num_ddof_doc,
desc="Return unbiased standard error of the mean over requested "
"axis.\n\nNormalized by N-1 by default. This can be changed "
"using the ddof argument",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes="",
examples="",
)
def sem(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.sem(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "sem", sem)
_num_ddof_doc,
desc="Return unbiased variance over requested axis.\n\nNormalized by "
"N-1 by default. This can be changed using the ddof argument.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes="",
examples=_var_examples,
)
def var(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.var(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "var", var)
_num_ddof_doc,
desc="Return sample standard deviation over requested axis."
"\n\nNormalized by N-1 by default. This can be changed using the "
"ddof argument.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
notes=_std_notes,
examples=_std_examples,
)
def std(
self,
axis: Axis | None = None,
skipna: bool_t = True,
ddof: int = 1,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.std(self, axis, skipna, ddof, numeric_only, **kwargs)
setattr(cls, "std", std)
_cnum_doc,
desc="minimum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="min",
examples=_cummin_examples,
)
def cummin(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cummin(self, axis, skipna, *args, **kwargs)
setattr(cls, "cummin", cummin)
_cnum_doc,
desc="maximum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="max",
examples=_cummax_examples,
)
def cummax(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cummax(self, axis, skipna, *args, **kwargs)
setattr(cls, "cummax", cummax)
_cnum_doc,
desc="sum",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="sum",
examples=_cumsum_examples,
)
def cumsum(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cumsum(self, axis, skipna, *args, **kwargs)
setattr(cls, "cumsum", cumsum)
_cnum_doc,
desc="product",
name1=name1,
name2=name2,
axis_descr=axis_descr,
accum_func_name="prod",
examples=_cumprod_examples,
)
def cumprod(
self, axis: Axis | None = None, skipna: bool_t = True, *args, **kwargs
):
return NDFrame.cumprod(self, axis, skipna, *args, **kwargs)
setattr(cls, "cumprod", cumprod)
# error: Untyped decorator makes function "sum" untyped
_num_doc,
desc="Return the sum of the values over the requested axis.\n\n"
"This is equivalent to the method ``numpy.sum``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count=_min_count_stub,
see_also=_stat_func_see_also,
examples=_sum_examples,
)
def sum(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return NDFrame.sum(self, axis, skipna, numeric_only, min_count, **kwargs)
setattr(cls, "sum", sum)
_num_doc,
desc="Return the product of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count=_min_count_stub,
see_also=_stat_func_see_also,
examples=_prod_examples,
)
def prod(
self,
axis: Axis | None = None,
skipna: bool_t = True,
numeric_only: bool_t = False,
min_count: int = 0,
**kwargs,
):
return NDFrame.prod(self, axis, skipna, numeric_only, min_count, **kwargs)
setattr(cls, "prod", prod)
cls.product = prod
_num_doc,
desc="Return the mean of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def mean(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.mean(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "mean", mean)
_num_doc,
desc="Return unbiased skew over requested axis.\n\nNormalized by N-1.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def skew(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.skew(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "skew", skew)
_num_doc,
desc="Return unbiased kurtosis over requested axis.\n\n"
"Kurtosis obtained using Fisher's definition of\n"
"kurtosis (kurtosis of normal == 0.0). Normalized "
"by N-1.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def kurt(
self,
axis: Axis | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.kurt(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "kurt", kurt)
cls.kurtosis = kurt
_num_doc,
desc="Return the median of the values over the requested axis.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also="",
examples="",
)
def median(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.median(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "median", median)
_num_doc,
desc="Return the maximum of the values over the requested axis.\n\n"
"If you want the *index* of the maximum, use ``idxmax``. This is "
"the equivalent of the ``numpy.ndarray`` method ``argmax``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also=_stat_func_see_also,
examples=_max_examples,
)
def max(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.max(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "max", max)
_num_doc,
desc="Return the minimum of the values over the requested axis.\n\n"
"If you want the *index* of the minimum, use ``idxmin``. This is "
"the equivalent of the ``numpy.ndarray`` method ``argmin``.",
name1=name1,
name2=name2,
axis_descr=axis_descr,
min_count="",
see_also=_stat_func_see_also,
examples=_min_examples,
)
def min(
self,
axis: AxisInt | None = 0,
skipna: bool_t = True,
numeric_only: bool_t = False,
**kwargs,
):
return NDFrame.min(self, axis, skipna, numeric_only, **kwargs)
setattr(cls, "min", min)
def rolling(
self,
window: int | dt.timedelta | str | BaseOffset | BaseIndexer,
min_periods: int | None = None,
center: bool_t = False,
win_type: str | None = None,
on: str | None = None,
axis: Axis = 0,
closed: str | None = None,
step: int | None = None,
method: str = "single",
) -> Window | Rolling:
axis = self._get_axis_number(axis)
if win_type is not None:
return Window(
self,
window=window,
min_periods=min_periods,
center=center,
win_type=win_type,
on=on,
axis=axis,
closed=closed,
step=step,
method=method,
)
return Rolling(
self,
window=window,
min_periods=min_periods,
center=center,
win_type=win_type,
on=on,
axis=axis,
closed=closed,
step=step,
method=method,
)
def expanding(
self,
min_periods: int = 1,
axis: Axis = 0,
method: str = "single",
) -> Expanding:
axis = self._get_axis_number(axis)
return Expanding(self, min_periods=min_periods, axis=axis, method=method)
def ewm(
self,
com: float | None = None,
span: float | None = None,
halflife: float | TimedeltaConvertibleTypes | None = None,
alpha: float | None = None,
min_periods: int | None = 0,
adjust: bool_t = True,
ignore_na: bool_t = False,
axis: Axis = 0,
times: np.ndarray | DataFrame | Series | None = None,
method: str = "single",
) -> ExponentialMovingWindow:
axis = self._get_axis_number(axis)
return ExponentialMovingWindow(
self,
com=com,
span=span,
halflife=halflife,
alpha=alpha,
min_periods=min_periods,
adjust=adjust,
ignore_na=ignore_na,
axis=axis,
times=times,
method=method,
)
# ----------------------------------------------------------------------
# Arithmetic Methods
def _inplace_method(self, other, op):
"""
Wrap arithmetic method to operate inplace.
"""
result = op(self, other)
if (
self.ndim == 1
and result._indexed_same(self)
and is_dtype_equal(result.dtype, self.dtype)
):
# GH#36498 this inplace op can _actually_ be inplace.
# Item "ArrayManager" of "Union[ArrayManager, SingleArrayManager,
# BlockManager, SingleBlockManager]" has no attribute "setitem_inplace"
self._mgr.setitem_inplace( # type: ignore[union-attr]
slice(None), result._values
)
return self
# Delete cacher
self._reset_cacher()
# this makes sure that we are aligned like the input
# we are updating inplace so we want to ignore is_copy
self._update_inplace(
result.reindex_like(self, copy=False), verify_is_copy=False
)
return self
def __iadd__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for + ("Type[NDFrame]")
return self._inplace_method(other, type(self).__add__) # type: ignore[operator]
def __isub__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for - ("Type[NDFrame]")
return self._inplace_method(other, type(self).__sub__) # type: ignore[operator]
def __imul__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for * ("Type[NDFrame]")
return self._inplace_method(other, type(self).__mul__) # type: ignore[operator]
def __itruediv__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for / ("Type[NDFrame]")
return self._inplace_method(
other, type(self).__truediv__ # type: ignore[operator]
)
def __ifloordiv__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for // ("Type[NDFrame]")
return self._inplace_method(
other, type(self).__floordiv__ # type: ignore[operator]
)
def __imod__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for % ("Type[NDFrame]")
return self._inplace_method(other, type(self).__mod__) # type: ignore[operator]
def __ipow__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for ** ("Type[NDFrame]")
return self._inplace_method(other, type(self).__pow__) # type: ignore[operator]
def __iand__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for & ("Type[NDFrame]")
return self._inplace_method(other, type(self).__and__) # type: ignore[operator]
def __ior__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for | ("Type[NDFrame]")
return self._inplace_method(other, type(self).__or__) # type: ignore[operator]
def __ixor__(self: NDFrameT, other) -> NDFrameT:
# error: Unsupported left operand type for ^ ("Type[NDFrame]")
return self._inplace_method(other, type(self).__xor__) # type: ignore[operator]
# ----------------------------------------------------------------------
# Misc methods
def _find_valid_index(self, *, how: str) -> Hashable | None:
"""
Retrieves the index of the first valid value.
Parameters
----------
how : {'first', 'last'}
Use this parameter to change between the first or last valid index.
Returns
-------
idx_first_valid : type of index
"""
idxpos = find_valid_index(self._values, how=how, is_valid=~isna(self._values))
if idxpos is None:
return None
return self.index[idxpos]
def first_valid_index(self) -> Hashable | None:
"""
Return index for {position} non-NA value or None, if no non-NA value is found.
Returns
-------
type of index
Notes
-----
If all elements are non-NA/null, returns None.
Also returns None for empty {klass}.
"""
return self._find_valid_index(how="first")
def last_valid_index(self) -> Hashable | None:
return self._find_valid_index(how="last")
def to_json(
path_or_buf: FilePath | WriteBuffer[str] | WriteBuffer[bytes] | None,
obj: NDFrame,
orient: str | None = None,
date_format: str = "epoch",
double_precision: int = 10,
force_ascii: bool = True,
date_unit: str = "ms",
default_handler: Callable[[Any], JSONSerializable] | None = None,
lines: bool = False,
compression: CompressionOptions = "infer",
index: bool = True,
indent: int = 0,
storage_options: StorageOptions = None,
mode: Literal["a", "w"] = "w",
) -> str | None:
if not index and orient not in ["split", "table"]:
raise ValueError(
"'index=False' is only valid when 'orient' is 'split' or 'table'"
)
if lines and orient != "records":
raise ValueError("'lines' keyword only valid when 'orient' is records")
if mode not in ["a", "w"]:
msg = (
f"mode={mode} is not a valid option."
"Only 'w' and 'a' are currently supported."
)
raise ValueError(msg)
if mode == "a" and (not lines or orient != "records"):
msg = (
"mode='a' (append) is only supported when"
"lines is True and orient is 'records'"
)
raise ValueError(msg)
if orient == "table" and isinstance(obj, Series):
obj = obj.to_frame(name=obj.name or "values")
writer: type[Writer]
if orient == "table" and isinstance(obj, DataFrame):
writer = JSONTableWriter
elif isinstance(obj, Series):
writer = SeriesWriter
elif isinstance(obj, DataFrame):
writer = FrameWriter
else:
raise NotImplementedError("'obj' should be a Series or a DataFrame")
s = writer(
obj,
orient=orient,
date_format=date_format,
double_precision=double_precision,
ensure_ascii=force_ascii,
date_unit=date_unit,
default_handler=default_handler,
index=index,
indent=indent,
).write()
if lines:
s = convert_to_line_delimits(s)
if path_or_buf is not None:
# apply compression and byte/text conversion
with get_handle(
path_or_buf, mode, compression=compression, storage_options=storage_options
) as handles:
handles.handle.write(s)
else:
return s
return None | null |
173,502 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
class JsonReader(abc.Iterator, Generic[FrameSeriesStrT]):
def __init__(
self,
filepath_or_buffer,
orient,
typ: FrameSeriesStrT,
dtype,
convert_axes,
convert_dates,
keep_default_dates: bool,
precise_float: bool,
date_unit,
encoding,
lines: bool,
chunksize: int | None,
compression: CompressionOptions,
nrows: int | None,
storage_options: StorageOptions = None,
encoding_errors: str | None = "strict",
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
engine: JSONEngine = "ujson",
) -> None:
def _preprocess_data(self, data):
def _get_data_from_filepath(self, filepath_or_buffer):
def _combine_lines(self, lines) -> str:
def read(self: JsonReader[Literal["frame"]]) -> DataFrame:
def read(self: JsonReader[Literal["series"]]) -> Series:
def read(self: JsonReader[Literal["frame", "series"]]) -> DataFrame | Series:
def read(self) -> DataFrame | Series:
def _get_object_parser(self, json) -> DataFrame | Series:
def close(self) -> None:
def __iter__(self: JsonReader[FrameSeriesStrT]) -> JsonReader[FrameSeriesStrT]:
def __next__(self: JsonReader[Literal["frame"]]) -> DataFrame:
def __next__(self: JsonReader[Literal["series"]]) -> Series:
def __next__(self: JsonReader[Literal["frame", "series"]]) -> DataFrame | Series:
def __next__(self) -> DataFrame | Series:
def __enter__(self) -> JsonReader[FrameSeriesStrT]:
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: TracebackType | None,
) -> None:
Literal: _SpecialForm = ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
JSONEngine = Literal["ujson", "pyarrow"]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_json(
path_or_buf: FilePath | ReadBuffer[str] | ReadBuffer[bytes],
*,
orient: str | None = ...,
typ: Literal["frame"] = ...,
dtype: DtypeArg | None = ...,
convert_axes=...,
convert_dates: bool | list[str] = ...,
keep_default_dates: bool = ...,
precise_float: bool = ...,
date_unit: str | None = ...,
encoding: str | None = ...,
encoding_errors: str | None = ...,
lines: bool = ...,
chunksize: int,
compression: CompressionOptions = ...,
nrows: int | None = ...,
storage_options: StorageOptions = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
engine: JSONEngine = ...,
) -> JsonReader[Literal["frame"]]:
... | null |
173,503 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
class JsonReader(abc.Iterator, Generic[FrameSeriesStrT]):
"""
JsonReader provides an interface for reading in a JSON file.
If initialized with ``lines=True`` and ``chunksize``, can be iterated over
``chunksize`` lines at a time. Otherwise, calling ``read`` reads in the
whole document.
"""
def __init__(
self,
filepath_or_buffer,
orient,
typ: FrameSeriesStrT,
dtype,
convert_axes,
convert_dates,
keep_default_dates: bool,
precise_float: bool,
date_unit,
encoding,
lines: bool,
chunksize: int | None,
compression: CompressionOptions,
nrows: int | None,
storage_options: StorageOptions = None,
encoding_errors: str | None = "strict",
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
engine: JSONEngine = "ujson",
) -> None:
self.orient = orient
self.typ = typ
self.dtype = dtype
self.convert_axes = convert_axes
self.convert_dates = convert_dates
self.keep_default_dates = keep_default_dates
self.precise_float = precise_float
self.date_unit = date_unit
self.encoding = encoding
self.engine = engine
self.compression = compression
self.storage_options = storage_options
self.lines = lines
self.chunksize = chunksize
self.nrows_seen = 0
self.nrows = nrows
self.encoding_errors = encoding_errors
self.handles: IOHandles[str] | None = None
self.dtype_backend = dtype_backend
if self.engine not in {"pyarrow", "ujson"}:
raise ValueError(
f"The engine type {self.engine} is currently not supported."
)
if self.chunksize is not None:
self.chunksize = validate_integer("chunksize", self.chunksize, 1)
if not self.lines:
raise ValueError("chunksize can only be passed if lines=True")
if self.engine == "pyarrow":
raise ValueError(
"currently pyarrow engine doesn't support chunksize parameter"
)
if self.nrows is not None:
self.nrows = validate_integer("nrows", self.nrows, 0)
if not self.lines:
raise ValueError("nrows can only be passed if lines=True")
if self.engine == "pyarrow":
if not self.lines:
raise ValueError(
"currently pyarrow engine only supports "
"the line-delimited JSON format"
)
self.data = filepath_or_buffer
elif self.engine == "ujson":
data = self._get_data_from_filepath(filepath_or_buffer)
self.data = self._preprocess_data(data)
def _preprocess_data(self, data):
"""
At this point, the data either has a `read` attribute (e.g. a file
object or a StringIO) or is a string that is a JSON document.
If self.chunksize, we prepare the data for the `__next__` method.
Otherwise, we read it into memory for the `read` method.
"""
if hasattr(data, "read") and not (self.chunksize or self.nrows):
with self:
data = data.read()
if not hasattr(data, "read") and (self.chunksize or self.nrows):
data = StringIO(data)
return data
def _get_data_from_filepath(self, filepath_or_buffer):
"""
The function read_json accepts three input types:
1. filepath (string-like)
2. file-like object (e.g. open file object, StringIO)
3. JSON string
This method turns (1) into (2) to simplify the rest of the processing.
It returns input types (2) and (3) unchanged.
It raises FileNotFoundError if the input is a string ending in
one of .json, .json.gz, .json.bz2, etc. but no such file exists.
"""
# if it is a string but the file does not exist, it might be a JSON string
filepath_or_buffer = stringify_path(filepath_or_buffer)
if (
not isinstance(filepath_or_buffer, str)
or is_url(filepath_or_buffer)
or is_fsspec_url(filepath_or_buffer)
or file_exists(filepath_or_buffer)
):
self.handles = get_handle(
filepath_or_buffer,
"r",
encoding=self.encoding,
compression=self.compression,
storage_options=self.storage_options,
errors=self.encoding_errors,
)
filepath_or_buffer = self.handles.handle
elif (
isinstance(filepath_or_buffer, str)
and filepath_or_buffer.lower().endswith(
(".json",) + tuple(f".json{c}" for c in extension_to_compression)
)
and not file_exists(filepath_or_buffer)
):
raise FileNotFoundError(f"File {filepath_or_buffer} does not exist")
return filepath_or_buffer
def _combine_lines(self, lines) -> str:
"""
Combines a list of JSON objects into one JSON object.
"""
return (
f'[{",".join([line for line in (line.strip() for line in lines) if line])}]'
)
def read(self: JsonReader[Literal["frame"]]) -> DataFrame:
...
def read(self: JsonReader[Literal["series"]]) -> Series:
...
def read(self: JsonReader[Literal["frame", "series"]]) -> DataFrame | Series:
...
def read(self) -> DataFrame | Series:
"""
Read the whole JSON input into a pandas object.
"""
obj: DataFrame | Series
with self:
if self.engine == "pyarrow":
pyarrow_json = import_optional_dependency("pyarrow.json")
pa_table = pyarrow_json.read_json(self.data)
mapping: type[ArrowDtype] | None | Callable
if self.dtype_backend == "pyarrow":
mapping = ArrowDtype
elif self.dtype_backend == "numpy_nullable":
from pandas.io._util import _arrow_dtype_mapping
mapping = _arrow_dtype_mapping().get
else:
mapping = None
return pa_table.to_pandas(types_mapper=mapping)
elif self.engine == "ujson":
if self.lines:
if self.chunksize:
obj = concat(self)
elif self.nrows:
lines = list(islice(self.data, self.nrows))
lines_json = self._combine_lines(lines)
obj = self._get_object_parser(lines_json)
else:
data = ensure_str(self.data)
data_lines = data.split("\n")
obj = self._get_object_parser(self._combine_lines(data_lines))
else:
obj = self._get_object_parser(self.data)
if self.dtype_backend is not lib.no_default:
return obj.convert_dtypes(
infer_objects=False, dtype_backend=self.dtype_backend
)
else:
return obj
def _get_object_parser(self, json) -> DataFrame | Series:
"""
Parses a json document into a pandas object.
"""
typ = self.typ
dtype = self.dtype
kwargs = {
"orient": self.orient,
"dtype": self.dtype,
"convert_axes": self.convert_axes,
"convert_dates": self.convert_dates,
"keep_default_dates": self.keep_default_dates,
"precise_float": self.precise_float,
"date_unit": self.date_unit,
"dtype_backend": self.dtype_backend,
}
obj = None
if typ == "frame":
obj = FrameParser(json, **kwargs).parse()
if typ == "series" or obj is None:
if not isinstance(dtype, bool):
kwargs["dtype"] = dtype
obj = SeriesParser(json, **kwargs).parse()
return obj
def close(self) -> None:
"""
If we opened a stream earlier, in _get_data_from_filepath, we should
close it.
If an open stream or file was passed, we leave it open.
"""
if self.handles is not None:
self.handles.close()
def __iter__(self: JsonReader[FrameSeriesStrT]) -> JsonReader[FrameSeriesStrT]:
return self
def __next__(self: JsonReader[Literal["frame"]]) -> DataFrame:
...
def __next__(self: JsonReader[Literal["series"]]) -> Series:
...
def __next__(self: JsonReader[Literal["frame", "series"]]) -> DataFrame | Series:
...
def __next__(self) -> DataFrame | Series:
if self.nrows and self.nrows_seen >= self.nrows:
self.close()
raise StopIteration
lines = list(islice(self.data, self.chunksize))
if not lines:
self.close()
raise StopIteration
try:
lines_json = self._combine_lines(lines)
obj = self._get_object_parser(lines_json)
# Make sure that the returned objects have the right index.
obj.index = range(self.nrows_seen, self.nrows_seen + len(obj))
self.nrows_seen += len(obj)
except Exception as ex:
self.close()
raise ex
if self.dtype_backend is not lib.no_default:
return obj.convert_dtypes(
infer_objects=False, dtype_backend=self.dtype_backend
)
else:
return obj
def __enter__(self) -> JsonReader[FrameSeriesStrT]:
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: TracebackType | None,
) -> None:
self.close()
Literal: _SpecialForm = ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
JSONEngine = Literal["ujson", "pyarrow"]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_json(
path_or_buf: FilePath | ReadBuffer[str] | ReadBuffer[bytes],
*,
orient: str | None = ...,
typ: Literal["series"],
dtype: DtypeArg | None = ...,
convert_axes=...,
convert_dates: bool | list[str] = ...,
keep_default_dates: bool = ...,
precise_float: bool = ...,
date_unit: str | None = ...,
encoding: str | None = ...,
encoding_errors: str | None = ...,
lines: bool = ...,
chunksize: int,
compression: CompressionOptions = ...,
nrows: int | None = ...,
storage_options: StorageOptions = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
engine: JSONEngine = ...,
) -> JsonReader[Literal["series"]]:
... | null |
173,504 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
Literal: _SpecialForm = ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
JSONEngine = Literal["ujson", "pyarrow"]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_json(
path_or_buf: FilePath | ReadBuffer[str] | ReadBuffer[bytes],
*,
orient: str | None = ...,
typ: Literal["series"],
dtype: DtypeArg | None = ...,
convert_axes=...,
convert_dates: bool | list[str] = ...,
keep_default_dates: bool = ...,
precise_float: bool = ...,
date_unit: str | None = ...,
encoding: str | None = ...,
encoding_errors: str | None = ...,
lines: bool = ...,
chunksize: None = ...,
compression: CompressionOptions = ...,
nrows: int | None = ...,
storage_options: StorageOptions = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
engine: JSONEngine = ...,
) -> Series:
... | null |
173,505 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
Literal: _SpecialForm = ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
JSONEngine = Literal["ujson", "pyarrow"]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def read_json(
path_or_buf: FilePath | ReadBuffer[str] | ReadBuffer[bytes],
*,
orient: str | None = ...,
typ: Literal["frame"] = ...,
dtype: DtypeArg | None = ...,
convert_axes=...,
convert_dates: bool | list[str] = ...,
keep_default_dates: bool = ...,
precise_float: bool = ...,
date_unit: str | None = ...,
encoding: str | None = ...,
encoding_errors: str | None = ...,
lines: bool = ...,
chunksize: None = ...,
compression: CompressionOptions = ...,
nrows: int | None = ...,
storage_options: StorageOptions = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
engine: JSONEngine = ...,
) -> DataFrame:
... | null |
173,506 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
from collections import abc
from io import StringIO
from itertools import islice
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Generic,
Literal,
Mapping,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas._libs.json import (
dumps,
loads,
)
from pandas._libs.tslibs import iNaT
from pandas._typing import (
CompressionOptions,
DtypeArg,
DtypeBackend,
FilePath,
IndexLabel,
JSONEngine,
JSONSerializable,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
ensure_str,
is_period_dtype,
)
from pandas.core.dtypes.generic import ABCIndex
from pandas import (
ArrowDtype,
DataFrame,
MultiIndex,
Series,
isna,
notna,
to_datetime,
)
from pandas.core.reshape.concat import concat
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import (
IOHandles,
dedup_names,
extension_to_compression,
file_exists,
get_handle,
is_fsspec_url,
is_potential_multi_index,
is_url,
stringify_path,
)
from pandas.io.json._normalize import convert_to_line_delimits
from pandas.io.json._table_schema import (
build_table_schema,
parse_table_schema,
)
from pandas.io.parsers.readers import validate_integer
class JsonReader(abc.Iterator, Generic[FrameSeriesStrT]):
"""
JsonReader provides an interface for reading in a JSON file.
If initialized with ``lines=True`` and ``chunksize``, can be iterated over
``chunksize`` lines at a time. Otherwise, calling ``read`` reads in the
whole document.
"""
def __init__(
self,
filepath_or_buffer,
orient,
typ: FrameSeriesStrT,
dtype,
convert_axes,
convert_dates,
keep_default_dates: bool,
precise_float: bool,
date_unit,
encoding,
lines: bool,
chunksize: int | None,
compression: CompressionOptions,
nrows: int | None,
storage_options: StorageOptions = None,
encoding_errors: str | None = "strict",
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
engine: JSONEngine = "ujson",
) -> None:
self.orient = orient
self.typ = typ
self.dtype = dtype
self.convert_axes = convert_axes
self.convert_dates = convert_dates
self.keep_default_dates = keep_default_dates
self.precise_float = precise_float
self.date_unit = date_unit
self.encoding = encoding
self.engine = engine
self.compression = compression
self.storage_options = storage_options
self.lines = lines
self.chunksize = chunksize
self.nrows_seen = 0
self.nrows = nrows
self.encoding_errors = encoding_errors
self.handles: IOHandles[str] | None = None
self.dtype_backend = dtype_backend
if self.engine not in {"pyarrow", "ujson"}:
raise ValueError(
f"The engine type {self.engine} is currently not supported."
)
if self.chunksize is not None:
self.chunksize = validate_integer("chunksize", self.chunksize, 1)
if not self.lines:
raise ValueError("chunksize can only be passed if lines=True")
if self.engine == "pyarrow":
raise ValueError(
"currently pyarrow engine doesn't support chunksize parameter"
)
if self.nrows is not None:
self.nrows = validate_integer("nrows", self.nrows, 0)
if not self.lines:
raise ValueError("nrows can only be passed if lines=True")
if self.engine == "pyarrow":
if not self.lines:
raise ValueError(
"currently pyarrow engine only supports "
"the line-delimited JSON format"
)
self.data = filepath_or_buffer
elif self.engine == "ujson":
data = self._get_data_from_filepath(filepath_or_buffer)
self.data = self._preprocess_data(data)
def _preprocess_data(self, data):
"""
At this point, the data either has a `read` attribute (e.g. a file
object or a StringIO) or is a string that is a JSON document.
If self.chunksize, we prepare the data for the `__next__` method.
Otherwise, we read it into memory for the `read` method.
"""
if hasattr(data, "read") and not (self.chunksize or self.nrows):
with self:
data = data.read()
if not hasattr(data, "read") and (self.chunksize or self.nrows):
data = StringIO(data)
return data
def _get_data_from_filepath(self, filepath_or_buffer):
"""
The function read_json accepts three input types:
1. filepath (string-like)
2. file-like object (e.g. open file object, StringIO)
3. JSON string
This method turns (1) into (2) to simplify the rest of the processing.
It returns input types (2) and (3) unchanged.
It raises FileNotFoundError if the input is a string ending in
one of .json, .json.gz, .json.bz2, etc. but no such file exists.
"""
# if it is a string but the file does not exist, it might be a JSON string
filepath_or_buffer = stringify_path(filepath_or_buffer)
if (
not isinstance(filepath_or_buffer, str)
or is_url(filepath_or_buffer)
or is_fsspec_url(filepath_or_buffer)
or file_exists(filepath_or_buffer)
):
self.handles = get_handle(
filepath_or_buffer,
"r",
encoding=self.encoding,
compression=self.compression,
storage_options=self.storage_options,
errors=self.encoding_errors,
)
filepath_or_buffer = self.handles.handle
elif (
isinstance(filepath_or_buffer, str)
and filepath_or_buffer.lower().endswith(
(".json",) + tuple(f".json{c}" for c in extension_to_compression)
)
and not file_exists(filepath_or_buffer)
):
raise FileNotFoundError(f"File {filepath_or_buffer} does not exist")
return filepath_or_buffer
def _combine_lines(self, lines) -> str:
"""
Combines a list of JSON objects into one JSON object.
"""
return (
f'[{",".join([line for line in (line.strip() for line in lines) if line])}]'
)
def read(self: JsonReader[Literal["frame"]]) -> DataFrame:
...
def read(self: JsonReader[Literal["series"]]) -> Series:
...
def read(self: JsonReader[Literal["frame", "series"]]) -> DataFrame | Series:
...
def read(self) -> DataFrame | Series:
"""
Read the whole JSON input into a pandas object.
"""
obj: DataFrame | Series
with self:
if self.engine == "pyarrow":
pyarrow_json = import_optional_dependency("pyarrow.json")
pa_table = pyarrow_json.read_json(self.data)
mapping: type[ArrowDtype] | None | Callable
if self.dtype_backend == "pyarrow":
mapping = ArrowDtype
elif self.dtype_backend == "numpy_nullable":
from pandas.io._util import _arrow_dtype_mapping
mapping = _arrow_dtype_mapping().get
else:
mapping = None
return pa_table.to_pandas(types_mapper=mapping)
elif self.engine == "ujson":
if self.lines:
if self.chunksize:
obj = concat(self)
elif self.nrows:
lines = list(islice(self.data, self.nrows))
lines_json = self._combine_lines(lines)
obj = self._get_object_parser(lines_json)
else:
data = ensure_str(self.data)
data_lines = data.split("\n")
obj = self._get_object_parser(self._combine_lines(data_lines))
else:
obj = self._get_object_parser(self.data)
if self.dtype_backend is not lib.no_default:
return obj.convert_dtypes(
infer_objects=False, dtype_backend=self.dtype_backend
)
else:
return obj
def _get_object_parser(self, json) -> DataFrame | Series:
"""
Parses a json document into a pandas object.
"""
typ = self.typ
dtype = self.dtype
kwargs = {
"orient": self.orient,
"dtype": self.dtype,
"convert_axes": self.convert_axes,
"convert_dates": self.convert_dates,
"keep_default_dates": self.keep_default_dates,
"precise_float": self.precise_float,
"date_unit": self.date_unit,
"dtype_backend": self.dtype_backend,
}
obj = None
if typ == "frame":
obj = FrameParser(json, **kwargs).parse()
if typ == "series" or obj is None:
if not isinstance(dtype, bool):
kwargs["dtype"] = dtype
obj = SeriesParser(json, **kwargs).parse()
return obj
def close(self) -> None:
"""
If we opened a stream earlier, in _get_data_from_filepath, we should
close it.
If an open stream or file was passed, we leave it open.
"""
if self.handles is not None:
self.handles.close()
def __iter__(self: JsonReader[FrameSeriesStrT]) -> JsonReader[FrameSeriesStrT]:
return self
def __next__(self: JsonReader[Literal["frame"]]) -> DataFrame:
...
def __next__(self: JsonReader[Literal["series"]]) -> Series:
...
def __next__(self: JsonReader[Literal["frame", "series"]]) -> DataFrame | Series:
...
def __next__(self) -> DataFrame | Series:
if self.nrows and self.nrows_seen >= self.nrows:
self.close()
raise StopIteration
lines = list(islice(self.data, self.chunksize))
if not lines:
self.close()
raise StopIteration
try:
lines_json = self._combine_lines(lines)
obj = self._get_object_parser(lines_json)
# Make sure that the returned objects have the right index.
obj.index = range(self.nrows_seen, self.nrows_seen + len(obj))
self.nrows_seen += len(obj)
except Exception as ex:
self.close()
raise ex
if self.dtype_backend is not lib.no_default:
return obj.convert_dtypes(
infer_objects=False, dtype_backend=self.dtype_backend
)
else:
return obj
def __enter__(self) -> JsonReader[FrameSeriesStrT]:
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: TracebackType | None,
) -> None:
self.close()
Literal: _SpecialForm = ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
JSONEngine = Literal["ujson", "pyarrow"]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
The provided code snippet includes necessary dependencies for implementing the `read_json` function. Write a Python function `def read_json( path_or_buf: FilePath | ReadBuffer[str] | ReadBuffer[bytes], *, orient: str | None = None, typ: Literal["frame", "series"] = "frame", dtype: DtypeArg | None = None, convert_axes=None, convert_dates: bool | list[str] = True, keep_default_dates: bool = True, precise_float: bool = False, date_unit: str | None = None, encoding: str | None = None, encoding_errors: str | None = "strict", lines: bool = False, chunksize: int | None = None, compression: CompressionOptions = "infer", nrows: int | None = None, storage_options: StorageOptions = None, dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, engine: JSONEngine = "ujson", ) -> DataFrame | Series | JsonReader` to solve the following problem:
Convert a JSON string to pandas object. Parameters ---------- path_or_buf : a valid JSON str, path object or file-like object Any valid string path is acceptable. The string could be a URL. Valid URL schemes include http, ftp, s3, and file. For file URLs, a host is expected. A local file could be: ``file://localhost/path/to/table.json``. If you want to pass in a path object, pandas accepts any ``os.PathLike``. By file-like object, we refer to objects with a ``read()`` method, such as a file handle (e.g. via builtin ``open`` function) or ``StringIO``. orient : str, optional Indication of expected JSON string format. Compatible JSON strings can be produced by ``to_json()`` with a corresponding orient value. The set of possible orients is: - ``'split'`` : dict like ``{{index -> [index], columns -> [columns], data -> [values]}}`` - ``'records'`` : list like ``[{{column -> value}}, ... , {{column -> value}}]`` - ``'index'`` : dict like ``{{index -> {{column -> value}}}}`` - ``'columns'`` : dict like ``{{column -> {{index -> value}}}}`` - ``'values'`` : just the values array The allowed and default values depend on the value of the `typ` parameter. * when ``typ == 'series'``, - allowed orients are ``{{'split','records','index'}}`` - default is ``'index'`` - The Series index must be unique for orient ``'index'``. * when ``typ == 'frame'``, - allowed orients are ``{{'split','records','index', 'columns','values', 'table'}}`` - default is ``'columns'`` - The DataFrame index must be unique for orients ``'index'`` and ``'columns'``. - The DataFrame columns must be unique for orients ``'index'``, ``'columns'``, and ``'records'``. typ : {{'frame', 'series'}}, default 'frame' The type of object to recover. dtype : bool or dict, default None If True, infer dtypes; if a dict of column to dtype, then use those; if False, then don't infer dtypes at all, applies only to the data. For all ``orient`` values except ``'table'``, default is True. convert_axes : bool, default None Try to convert the axes to the proper dtypes. For all ``orient`` values except ``'table'``, default is True. convert_dates : bool or list of str, default True If True then default datelike columns may be converted (depending on keep_default_dates). If False, no dates will be converted. If a list of column names, then those columns will be converted and default datelike columns may also be converted (depending on keep_default_dates). keep_default_dates : bool, default True If parsing dates (convert_dates is not False), then try to parse the default datelike columns. A column label is datelike if * it ends with ``'_at'``, * it ends with ``'_time'``, * it begins with ``'timestamp'``, * it is ``'modified'``, or * it is ``'date'``. precise_float : bool, default False Set to enable usage of higher precision (strtod) function when decoding string to double values. Default (False) is to use fast but less precise builtin functionality. date_unit : str, default None The timestamp unit to detect if converting dates. The default behaviour is to try and detect the correct precision, but if this is not desired then pass one of 's', 'ms', 'us' or 'ns' to force parsing only seconds, milliseconds, microseconds or nanoseconds respectively. encoding : str, default is 'utf-8' The encoding to use to decode py3 bytes. encoding_errors : str, optional, default "strict" How encoding errors are treated. `List of possible values <https://docs.python.org/3/library/codecs.html#error-handlers>`_ . .. versionadded:: 1.3.0 lines : bool, default False Read the file as a json object per line. chunksize : int, optional Return JsonReader object for iteration. See the `line-delimited json docs <https://pandas.pydata.org/pandas-docs/stable/user_guide/io.html#line-delimited-json>`_ for more information on ``chunksize``. This can only be passed if `lines=True`. If this is None, the file will be read into memory all at once. .. versionchanged:: 1.2 ``JsonReader`` is a context manager. {decompression_options} .. versionchanged:: 1.4.0 Zstandard support. nrows : int, optional The number of lines from the line-delimited jsonfile that has to be read. This can only be passed if `lines=True`. If this is None, all the rows will be returned. .. versionadded:: 1.1 {storage_options} .. versionadded:: 1.2.0 dtype_backend : {{"numpy_nullable", "pyarrow"}}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 engine : {{"ujson", "pyarrow"}}, default "ujson" Parser engine to use. The ``"pyarrow"`` engine is only available when ``lines=True``. .. versionadded:: 2.0 Returns ------- Series or DataFrame The type returned depends on the value of `typ`. See Also -------- DataFrame.to_json : Convert a DataFrame to a JSON string. Series.to_json : Convert a Series to a JSON string. json_normalize : Normalize semi-structured JSON data into a flat table. Notes ----- Specific to ``orient='table'``, if a :class:`DataFrame` with a literal :class:`Index` name of `index` gets written with :func:`to_json`, the subsequent read operation will incorrectly set the :class:`Index` name to ``None``. This is because `index` is also used by :func:`DataFrame.to_json` to denote a missing :class:`Index` name, and the subsequent :func:`read_json` operation cannot distinguish between the two. The same limitation is encountered with a :class:`MultiIndex` and any names beginning with ``'level_'``. Examples -------- >>> df = pd.DataFrame([['a', 'b'], ['c', 'd']], ... index=['row 1', 'row 2'], ... columns=['col 1', 'col 2']) Encoding/decoding a Dataframe using ``'split'`` formatted JSON: >>> df.to_json(orient='split') '\ {{\ "columns":["col 1","col 2"],\ "index":["row 1","row 2"],\ "data":[["a","b"],["c","d"]]\ }}\ ' >>> pd.read_json(_, orient='split') col 1 col 2 row 1 a b row 2 c d Encoding/decoding a Dataframe using ``'index'`` formatted JSON: >>> df.to_json(orient='index') '{{"row 1":{{"col 1":"a","col 2":"b"}},"row 2":{{"col 1":"c","col 2":"d"}}}}' >>> pd.read_json(_, orient='index') col 1 col 2 row 1 a b row 2 c d Encoding/decoding a Dataframe using ``'records'`` formatted JSON. Note that index labels are not preserved with this encoding. >>> df.to_json(orient='records') '[{{"col 1":"a","col 2":"b"}},{{"col 1":"c","col 2":"d"}}]' >>> pd.read_json(_, orient='records') col 1 col 2 0 a b 1 c d Encoding with Table Schema >>> df.to_json(orient='table') '\ {{"schema":{{"fields":[\ {{"name":"index","type":"string"}},\ {{"name":"col 1","type":"string"}},\ {{"name":"col 2","type":"string"}}],\ "primaryKey":["index"],\ "pandas_version":"1.4.0"}},\ "data":[\ {{"index":"row 1","col 1":"a","col 2":"b"}},\ {{"index":"row 2","col 1":"c","col 2":"d"}}]\ }}\ '
Here is the function:
def read_json(
path_or_buf: FilePath | ReadBuffer[str] | ReadBuffer[bytes],
*,
orient: str | None = None,
typ: Literal["frame", "series"] = "frame",
dtype: DtypeArg | None = None,
convert_axes=None,
convert_dates: bool | list[str] = True,
keep_default_dates: bool = True,
precise_float: bool = False,
date_unit: str | None = None,
encoding: str | None = None,
encoding_errors: str | None = "strict",
lines: bool = False,
chunksize: int | None = None,
compression: CompressionOptions = "infer",
nrows: int | None = None,
storage_options: StorageOptions = None,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
engine: JSONEngine = "ujson",
) -> DataFrame | Series | JsonReader:
"""
Convert a JSON string to pandas object.
Parameters
----------
path_or_buf : a valid JSON str, path object or file-like object
Any valid string path is acceptable. The string could be a URL. Valid
URL schemes include http, ftp, s3, and file. For file URLs, a host is
expected. A local file could be:
``file://localhost/path/to/table.json``.
If you want to pass in a path object, pandas accepts any
``os.PathLike``.
By file-like object, we refer to objects with a ``read()`` method,
such as a file handle (e.g. via builtin ``open`` function)
or ``StringIO``.
orient : str, optional
Indication of expected JSON string format.
Compatible JSON strings can be produced by ``to_json()`` with a
corresponding orient value.
The set of possible orients is:
- ``'split'`` : dict like
``{{index -> [index], columns -> [columns], data -> [values]}}``
- ``'records'`` : list like
``[{{column -> value}}, ... , {{column -> value}}]``
- ``'index'`` : dict like ``{{index -> {{column -> value}}}}``
- ``'columns'`` : dict like ``{{column -> {{index -> value}}}}``
- ``'values'`` : just the values array
The allowed and default values depend on the value
of the `typ` parameter.
* when ``typ == 'series'``,
- allowed orients are ``{{'split','records','index'}}``
- default is ``'index'``
- The Series index must be unique for orient ``'index'``.
* when ``typ == 'frame'``,
- allowed orients are ``{{'split','records','index',
'columns','values', 'table'}}``
- default is ``'columns'``
- The DataFrame index must be unique for orients ``'index'`` and
``'columns'``.
- The DataFrame columns must be unique for orients ``'index'``,
``'columns'``, and ``'records'``.
typ : {{'frame', 'series'}}, default 'frame'
The type of object to recover.
dtype : bool or dict, default None
If True, infer dtypes; if a dict of column to dtype, then use those;
if False, then don't infer dtypes at all, applies only to the data.
For all ``orient`` values except ``'table'``, default is True.
convert_axes : bool, default None
Try to convert the axes to the proper dtypes.
For all ``orient`` values except ``'table'``, default is True.
convert_dates : bool or list of str, default True
If True then default datelike columns may be converted (depending on
keep_default_dates).
If False, no dates will be converted.
If a list of column names, then those columns will be converted and
default datelike columns may also be converted (depending on
keep_default_dates).
keep_default_dates : bool, default True
If parsing dates (convert_dates is not False), then try to parse the
default datelike columns.
A column label is datelike if
* it ends with ``'_at'``,
* it ends with ``'_time'``,
* it begins with ``'timestamp'``,
* it is ``'modified'``, or
* it is ``'date'``.
precise_float : bool, default False
Set to enable usage of higher precision (strtod) function when
decoding string to double values. Default (False) is to use fast but
less precise builtin functionality.
date_unit : str, default None
The timestamp unit to detect if converting dates. The default behaviour
is to try and detect the correct precision, but if this is not desired
then pass one of 's', 'ms', 'us' or 'ns' to force parsing only seconds,
milliseconds, microseconds or nanoseconds respectively.
encoding : str, default is 'utf-8'
The encoding to use to decode py3 bytes.
encoding_errors : str, optional, default "strict"
How encoding errors are treated. `List of possible values
<https://docs.python.org/3/library/codecs.html#error-handlers>`_ .
.. versionadded:: 1.3.0
lines : bool, default False
Read the file as a json object per line.
chunksize : int, optional
Return JsonReader object for iteration.
See the `line-delimited json docs
<https://pandas.pydata.org/pandas-docs/stable/user_guide/io.html#line-delimited-json>`_
for more information on ``chunksize``.
This can only be passed if `lines=True`.
If this is None, the file will be read into memory all at once.
.. versionchanged:: 1.2
``JsonReader`` is a context manager.
{decompression_options}
.. versionchanged:: 1.4.0 Zstandard support.
nrows : int, optional
The number of lines from the line-delimited jsonfile that has to be read.
This can only be passed if `lines=True`.
If this is None, all the rows will be returned.
.. versionadded:: 1.1
{storage_options}
.. versionadded:: 1.2.0
dtype_backend : {{"numpy_nullable", "pyarrow"}}, defaults to NumPy backed DataFrames
Which dtype_backend to use, e.g. whether a DataFrame should have NumPy
arrays, nullable dtypes are used for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
engine : {{"ujson", "pyarrow"}}, default "ujson"
Parser engine to use. The ``"pyarrow"`` engine is only available when
``lines=True``.
.. versionadded:: 2.0
Returns
-------
Series or DataFrame
The type returned depends on the value of `typ`.
See Also
--------
DataFrame.to_json : Convert a DataFrame to a JSON string.
Series.to_json : Convert a Series to a JSON string.
json_normalize : Normalize semi-structured JSON data into a flat table.
Notes
-----
Specific to ``orient='table'``, if a :class:`DataFrame` with a literal
:class:`Index` name of `index` gets written with :func:`to_json`, the
subsequent read operation will incorrectly set the :class:`Index` name to
``None``. This is because `index` is also used by :func:`DataFrame.to_json`
to denote a missing :class:`Index` name, and the subsequent
:func:`read_json` operation cannot distinguish between the two. The same
limitation is encountered with a :class:`MultiIndex` and any names
beginning with ``'level_'``.
Examples
--------
>>> df = pd.DataFrame([['a', 'b'], ['c', 'd']],
... index=['row 1', 'row 2'],
... columns=['col 1', 'col 2'])
Encoding/decoding a Dataframe using ``'split'`` formatted JSON:
>>> df.to_json(orient='split')
'\
{{\
"columns":["col 1","col 2"],\
"index":["row 1","row 2"],\
"data":[["a","b"],["c","d"]]\
}}\
'
>>> pd.read_json(_, orient='split')
col 1 col 2
row 1 a b
row 2 c d
Encoding/decoding a Dataframe using ``'index'`` formatted JSON:
>>> df.to_json(orient='index')
'{{"row 1":{{"col 1":"a","col 2":"b"}},"row 2":{{"col 1":"c","col 2":"d"}}}}'
>>> pd.read_json(_, orient='index')
col 1 col 2
row 1 a b
row 2 c d
Encoding/decoding a Dataframe using ``'records'`` formatted JSON.
Note that index labels are not preserved with this encoding.
>>> df.to_json(orient='records')
'[{{"col 1":"a","col 2":"b"}},{{"col 1":"c","col 2":"d"}}]'
>>> pd.read_json(_, orient='records')
col 1 col 2
0 a b
1 c d
Encoding with Table Schema
>>> df.to_json(orient='table')
'\
{{"schema":{{"fields":[\
{{"name":"index","type":"string"}},\
{{"name":"col 1","type":"string"}},\
{{"name":"col 2","type":"string"}}],\
"primaryKey":["index"],\
"pandas_version":"1.4.0"}},\
"data":[\
{{"index":"row 1","col 1":"a","col 2":"b"}},\
{{"index":"row 2","col 1":"c","col 2":"d"}}]\
}}\
'
"""
if orient == "table" and dtype:
raise ValueError("cannot pass both dtype and orient='table'")
if orient == "table" and convert_axes:
raise ValueError("cannot pass both convert_axes and orient='table'")
check_dtype_backend(dtype_backend)
if dtype is None and orient != "table":
# error: Incompatible types in assignment (expression has type "bool", variable
# has type "Union[ExtensionDtype, str, dtype[Any], Type[str], Type[float],
# Type[int], Type[complex], Type[bool], Type[object], Dict[Hashable,
# Union[ExtensionDtype, Union[str, dtype[Any]], Type[str], Type[float],
# Type[int], Type[complex], Type[bool], Type[object]]], None]")
dtype = True # type: ignore[assignment]
if convert_axes is None and orient != "table":
convert_axes = True
json_reader = JsonReader(
path_or_buf,
orient=orient,
typ=typ,
dtype=dtype,
convert_axes=convert_axes,
convert_dates=convert_dates,
keep_default_dates=keep_default_dates,
precise_float=precise_float,
date_unit=date_unit,
encoding=encoding,
lines=lines,
chunksize=chunksize,
compression=compression,
nrows=nrows,
storage_options=storage_options,
encoding_errors=encoding_errors,
dtype_backend=dtype_backend,
engine=engine,
)
if chunksize:
return json_reader
else:
return json_reader.read() | Convert a JSON string to pandas object. Parameters ---------- path_or_buf : a valid JSON str, path object or file-like object Any valid string path is acceptable. The string could be a URL. Valid URL schemes include http, ftp, s3, and file. For file URLs, a host is expected. A local file could be: ``file://localhost/path/to/table.json``. If you want to pass in a path object, pandas accepts any ``os.PathLike``. By file-like object, we refer to objects with a ``read()`` method, such as a file handle (e.g. via builtin ``open`` function) or ``StringIO``. orient : str, optional Indication of expected JSON string format. Compatible JSON strings can be produced by ``to_json()`` with a corresponding orient value. The set of possible orients is: - ``'split'`` : dict like ``{{index -> [index], columns -> [columns], data -> [values]}}`` - ``'records'`` : list like ``[{{column -> value}}, ... , {{column -> value}}]`` - ``'index'`` : dict like ``{{index -> {{column -> value}}}}`` - ``'columns'`` : dict like ``{{column -> {{index -> value}}}}`` - ``'values'`` : just the values array The allowed and default values depend on the value of the `typ` parameter. * when ``typ == 'series'``, - allowed orients are ``{{'split','records','index'}}`` - default is ``'index'`` - The Series index must be unique for orient ``'index'``. * when ``typ == 'frame'``, - allowed orients are ``{{'split','records','index', 'columns','values', 'table'}}`` - default is ``'columns'`` - The DataFrame index must be unique for orients ``'index'`` and ``'columns'``. - The DataFrame columns must be unique for orients ``'index'``, ``'columns'``, and ``'records'``. typ : {{'frame', 'series'}}, default 'frame' The type of object to recover. dtype : bool or dict, default None If True, infer dtypes; if a dict of column to dtype, then use those; if False, then don't infer dtypes at all, applies only to the data. For all ``orient`` values except ``'table'``, default is True. convert_axes : bool, default None Try to convert the axes to the proper dtypes. For all ``orient`` values except ``'table'``, default is True. convert_dates : bool or list of str, default True If True then default datelike columns may be converted (depending on keep_default_dates). If False, no dates will be converted. If a list of column names, then those columns will be converted and default datelike columns may also be converted (depending on keep_default_dates). keep_default_dates : bool, default True If parsing dates (convert_dates is not False), then try to parse the default datelike columns. A column label is datelike if * it ends with ``'_at'``, * it ends with ``'_time'``, * it begins with ``'timestamp'``, * it is ``'modified'``, or * it is ``'date'``. precise_float : bool, default False Set to enable usage of higher precision (strtod) function when decoding string to double values. Default (False) is to use fast but less precise builtin functionality. date_unit : str, default None The timestamp unit to detect if converting dates. The default behaviour is to try and detect the correct precision, but if this is not desired then pass one of 's', 'ms', 'us' or 'ns' to force parsing only seconds, milliseconds, microseconds or nanoseconds respectively. encoding : str, default is 'utf-8' The encoding to use to decode py3 bytes. encoding_errors : str, optional, default "strict" How encoding errors are treated. `List of possible values <https://docs.python.org/3/library/codecs.html#error-handlers>`_ . .. versionadded:: 1.3.0 lines : bool, default False Read the file as a json object per line. chunksize : int, optional Return JsonReader object for iteration. See the `line-delimited json docs <https://pandas.pydata.org/pandas-docs/stable/user_guide/io.html#line-delimited-json>`_ for more information on ``chunksize``. This can only be passed if `lines=True`. If this is None, the file will be read into memory all at once. .. versionchanged:: 1.2 ``JsonReader`` is a context manager. {decompression_options} .. versionchanged:: 1.4.0 Zstandard support. nrows : int, optional The number of lines from the line-delimited jsonfile that has to be read. This can only be passed if `lines=True`. If this is None, all the rows will be returned. .. versionadded:: 1.1 {storage_options} .. versionadded:: 1.2.0 dtype_backend : {{"numpy_nullable", "pyarrow"}}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 engine : {{"ujson", "pyarrow"}}, default "ujson" Parser engine to use. The ``"pyarrow"`` engine is only available when ``lines=True``. .. versionadded:: 2.0 Returns ------- Series or DataFrame The type returned depends on the value of `typ`. See Also -------- DataFrame.to_json : Convert a DataFrame to a JSON string. Series.to_json : Convert a Series to a JSON string. json_normalize : Normalize semi-structured JSON data into a flat table. Notes ----- Specific to ``orient='table'``, if a :class:`DataFrame` with a literal :class:`Index` name of `index` gets written with :func:`to_json`, the subsequent read operation will incorrectly set the :class:`Index` name to ``None``. This is because `index` is also used by :func:`DataFrame.to_json` to denote a missing :class:`Index` name, and the subsequent :func:`read_json` operation cannot distinguish between the two. The same limitation is encountered with a :class:`MultiIndex` and any names beginning with ``'level_'``. Examples -------- >>> df = pd.DataFrame([['a', 'b'], ['c', 'd']], ... index=['row 1', 'row 2'], ... columns=['col 1', 'col 2']) Encoding/decoding a Dataframe using ``'split'`` formatted JSON: >>> df.to_json(orient='split') '\ {{\ "columns":["col 1","col 2"],\ "index":["row 1","row 2"],\ "data":[["a","b"],["c","d"]]\ }}\ ' >>> pd.read_json(_, orient='split') col 1 col 2 row 1 a b row 2 c d Encoding/decoding a Dataframe using ``'index'`` formatted JSON: >>> df.to_json(orient='index') '{{"row 1":{{"col 1":"a","col 2":"b"}},"row 2":{{"col 1":"c","col 2":"d"}}}}' >>> pd.read_json(_, orient='index') col 1 col 2 row 1 a b row 2 c d Encoding/decoding a Dataframe using ``'records'`` formatted JSON. Note that index labels are not preserved with this encoding. >>> df.to_json(orient='records') '[{{"col 1":"a","col 2":"b"}},{{"col 1":"c","col 2":"d"}}]' >>> pd.read_json(_, orient='records') col 1 col 2 0 a b 1 c d Encoding with Table Schema >>> df.to_json(orient='table') '\ {{"schema":{{"fields":[\ {{"name":"index","type":"string"}},\ {{"name":"col 1","type":"string"}},\ {{"name":"col 2","type":"string"}}],\ "primaryKey":["index"],\ "pandas_version":"1.4.0"}},\ "data":[\ {{"index":"row 1","col 1":"a","col 2":"b"}},\ {{"index":"row 2","col 1":"c","col 2":"d"}}]\ }}\ ' |
173,507 | from __future__ import annotations
from collections import (
abc,
defaultdict,
)
import copy
import sys
from typing import (
Any,
DefaultDict,
Iterable,
)
import numpy as np
from pandas._libs.writers import convert_json_to_lines
from pandas._typing import (
IgnoreRaise,
Scalar,
)
import pandas as pd
from pandas import DataFrame
def nested_to_record(
ds,
prefix: str = "",
sep: str = ".",
level: int = 0,
max_level: int | None = None,
):
"""
A simplified json_normalize
Converts a nested dict into a flat dict ("record"), unlike json_normalize,
it does not attempt to extract a subset of the data.
Parameters
----------
ds : dict or list of dicts
prefix: the prefix, optional, default: ""
sep : str, default '.'
Nested records will generate names separated by sep,
e.g., for sep='.', { 'foo' : { 'bar' : 0 } } -> foo.bar
level: int, optional, default: 0
The number of levels in the json string.
max_level: int, optional, default: None
The max depth to normalize.
Returns
-------
d - dict or list of dicts, matching `ds`
Examples
--------
>>> nested_to_record(
... dict(flat1=1, dict1=dict(c=1, d=2), nested=dict(e=dict(c=1, d=2), d=2))
... )
{\
'flat1': 1, \
'dict1.c': 1, \
'dict1.d': 2, \
'nested.e.c': 1, \
'nested.e.d': 2, \
'nested.d': 2\
}
"""
singleton = False
if isinstance(ds, dict):
ds = [ds]
singleton = True
new_ds = []
for d in ds:
new_d = copy.deepcopy(d)
for k, v in d.items():
# each key gets renamed with prefix
if not isinstance(k, str):
k = str(k)
if level == 0:
newkey = k
else:
newkey = prefix + sep + k
# flatten if type is dict and
# current dict level < maximum level provided and
# only dicts gets recurse-flattened
# only at level>1 do we rename the rest of the keys
if not isinstance(v, dict) or (
max_level is not None and level >= max_level
):
if level != 0: # so we skip copying for top level, common case
v = new_d.pop(k)
new_d[newkey] = v
continue
v = new_d.pop(k)
new_d.update(nested_to_record(v, newkey, sep, level + 1, max_level))
new_ds.append(new_d)
if singleton:
return new_ds[0]
return new_ds
def _simple_json_normalize(
ds: dict | list[dict],
sep: str = ".",
) -> dict | list[dict] | Any:
"""
A optimized basic json_normalize
Converts a nested dict into a flat dict ("record"), unlike
json_normalize and nested_to_record it doesn't do anything clever.
But for the most basic use cases it enhances performance.
E.g. pd.json_normalize(data)
Parameters
----------
ds : dict or list of dicts
sep : str, default '.'
Nested records will generate names separated by sep,
e.g., for sep='.', { 'foo' : { 'bar' : 0 } } -> foo.bar
Returns
-------
frame : DataFrame
d - dict or list of dicts, matching `normalised_json_object`
Examples
--------
>>> _simple_json_normalize(
... {
... "flat1": 1,
... "dict1": {"c": 1, "d": 2},
... "nested": {"e": {"c": 1, "d": 2}, "d": 2},
... }
... )
{\
'flat1': 1, \
'dict1.c': 1, \
'dict1.d': 2, \
'nested.e.c': 1, \
'nested.e.d': 2, \
'nested.d': 2\
}
"""
normalised_json_object = {}
# expect a dictionary, as most jsons are. However, lists are perfectly valid
if isinstance(ds, dict):
normalised_json_object = _normalise_json_ordered(data=ds, separator=sep)
elif isinstance(ds, list):
normalised_json_list = [_simple_json_normalize(row, sep=sep) for row in ds]
return normalised_json_list
return normalised_json_object
class defaultdict(Dict[_KT, _VT], Generic[_KT, _VT]):
default_factory: Callable[[], _VT]
def __init__(self, **kwargs: _VT) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]]) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], **kwargs: _VT) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], map: Mapping[_KT, _VT]) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], map: Mapping[_KT, _VT], **kwargs: _VT) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], iterable: Iterable[Tuple[_KT, _VT]]) -> None: ...
def __init__(
self, default_factory: Optional[Callable[[], _VT]], iterable: Iterable[Tuple[_KT, _VT]], **kwargs: _VT
) -> None: ...
def __missing__(self, key: _KT) -> _VT: ...
def copy(self: _S) -> _S: ...
Any = object()
DefaultDict = _Alias()
class Iterable(Protocol[_T_co]):
def __iter__(self) -> Iterator[_T_co]: ...
Scalar = Union[PythonScalar, PandasScalar, np.datetime64, np.timedelta64, datetime]
IgnoreRaise = Literal["ignore", "raise"]
The provided code snippet includes necessary dependencies for implementing the `json_normalize` function. Write a Python function `def json_normalize( data: dict | list[dict], record_path: str | list | None = None, meta: str | list[str | list[str]] | None = None, meta_prefix: str | None = None, record_prefix: str | None = None, errors: IgnoreRaise = "raise", sep: str = ".", max_level: int | None = None, ) -> DataFrame` to solve the following problem:
Normalize semi-structured JSON data into a flat table. Parameters ---------- data : dict or list of dicts Unserialized JSON objects. record_path : str or list of str, default None Path in each object to list of records. If not passed, data will be assumed to be an array of records. meta : list of paths (str or list of str), default None Fields to use as metadata for each record in resulting table. meta_prefix : str, default None If True, prefix records with dotted (?) path, e.g. foo.bar.field if meta is ['foo', 'bar']. record_prefix : str, default None If True, prefix records with dotted (?) path, e.g. foo.bar.field if path to records is ['foo', 'bar']. errors : {'raise', 'ignore'}, default 'raise' Configures error handling. * 'ignore' : will ignore KeyError if keys listed in meta are not always present. * 'raise' : will raise KeyError if keys listed in meta are not always present. sep : str, default '.' Nested records will generate names separated by sep. e.g., for sep='.', {'foo': {'bar': 0}} -> foo.bar. max_level : int, default None Max number of levels(depth of dict) to normalize. if None, normalizes all levels. Returns ------- frame : DataFrame Normalize semi-structured JSON data into a flat table. Examples -------- >>> data = [ ... {"id": 1, "name": {"first": "Coleen", "last": "Volk"}}, ... {"name": {"given": "Mark", "family": "Regner"}}, ... {"id": 2, "name": "Faye Raker"}, ... ] >>> pd.json_normalize(data) id name.first name.last name.given name.family name 0 1.0 Coleen Volk NaN NaN NaN 1 NaN NaN NaN Mark Regner NaN 2 2.0 NaN NaN NaN NaN Faye Raker >>> data = [ ... { ... "id": 1, ... "name": "Cole Volk", ... "fitness": {"height": 130, "weight": 60}, ... }, ... {"name": "Mark Reg", "fitness": {"height": 130, "weight": 60}}, ... { ... "id": 2, ... "name": "Faye Raker", ... "fitness": {"height": 130, "weight": 60}, ... }, ... ] >>> pd.json_normalize(data, max_level=0) id name fitness 0 1.0 Cole Volk {'height': 130, 'weight': 60} 1 NaN Mark Reg {'height': 130, 'weight': 60} 2 2.0 Faye Raker {'height': 130, 'weight': 60} Normalizes nested data up to level 1. >>> data = [ ... { ... "id": 1, ... "name": "Cole Volk", ... "fitness": {"height": 130, "weight": 60}, ... }, ... {"name": "Mark Reg", "fitness": {"height": 130, "weight": 60}}, ... { ... "id": 2, ... "name": "Faye Raker", ... "fitness": {"height": 130, "weight": 60}, ... }, ... ] >>> pd.json_normalize(data, max_level=1) id name fitness.height fitness.weight 0 1.0 Cole Volk 130 60 1 NaN Mark Reg 130 60 2 2.0 Faye Raker 130 60 >>> data = [ ... { ... "state": "Florida", ... "shortname": "FL", ... "info": {"governor": "Rick Scott"}, ... "counties": [ ... {"name": "Dade", "population": 12345}, ... {"name": "Broward", "population": 40000}, ... {"name": "Palm Beach", "population": 60000}, ... ], ... }, ... { ... "state": "Ohio", ... "shortname": "OH", ... "info": {"governor": "John Kasich"}, ... "counties": [ ... {"name": "Summit", "population": 1234}, ... {"name": "Cuyahoga", "population": 1337}, ... ], ... }, ... ] >>> result = pd.json_normalize( ... data, "counties", ["state", "shortname", ["info", "governor"]] ... ) >>> result name population state shortname info.governor 0 Dade 12345 Florida FL Rick Scott 1 Broward 40000 Florida FL Rick Scott 2 Palm Beach 60000 Florida FL Rick Scott 3 Summit 1234 Ohio OH John Kasich 4 Cuyahoga 1337 Ohio OH John Kasich >>> data = {"A": [1, 2]} >>> pd.json_normalize(data, "A", record_prefix="Prefix.") Prefix.0 0 1 1 2 Returns normalized data with columns prefixed with the given string.
Here is the function:
def json_normalize(
data: dict | list[dict],
record_path: str | list | None = None,
meta: str | list[str | list[str]] | None = None,
meta_prefix: str | None = None,
record_prefix: str | None = None,
errors: IgnoreRaise = "raise",
sep: str = ".",
max_level: int | None = None,
) -> DataFrame:
"""
Normalize semi-structured JSON data into a flat table.
Parameters
----------
data : dict or list of dicts
Unserialized JSON objects.
record_path : str or list of str, default None
Path in each object to list of records. If not passed, data will be
assumed to be an array of records.
meta : list of paths (str or list of str), default None
Fields to use as metadata for each record in resulting table.
meta_prefix : str, default None
If True, prefix records with dotted (?) path, e.g. foo.bar.field if
meta is ['foo', 'bar'].
record_prefix : str, default None
If True, prefix records with dotted (?) path, e.g. foo.bar.field if
path to records is ['foo', 'bar'].
errors : {'raise', 'ignore'}, default 'raise'
Configures error handling.
* 'ignore' : will ignore KeyError if keys listed in meta are not
always present.
* 'raise' : will raise KeyError if keys listed in meta are not
always present.
sep : str, default '.'
Nested records will generate names separated by sep.
e.g., for sep='.', {'foo': {'bar': 0}} -> foo.bar.
max_level : int, default None
Max number of levels(depth of dict) to normalize.
if None, normalizes all levels.
Returns
-------
frame : DataFrame
Normalize semi-structured JSON data into a flat table.
Examples
--------
>>> data = [
... {"id": 1, "name": {"first": "Coleen", "last": "Volk"}},
... {"name": {"given": "Mark", "family": "Regner"}},
... {"id": 2, "name": "Faye Raker"},
... ]
>>> pd.json_normalize(data)
id name.first name.last name.given name.family name
0 1.0 Coleen Volk NaN NaN NaN
1 NaN NaN NaN Mark Regner NaN
2 2.0 NaN NaN NaN NaN Faye Raker
>>> data = [
... {
... "id": 1,
... "name": "Cole Volk",
... "fitness": {"height": 130, "weight": 60},
... },
... {"name": "Mark Reg", "fitness": {"height": 130, "weight": 60}},
... {
... "id": 2,
... "name": "Faye Raker",
... "fitness": {"height": 130, "weight": 60},
... },
... ]
>>> pd.json_normalize(data, max_level=0)
id name fitness
0 1.0 Cole Volk {'height': 130, 'weight': 60}
1 NaN Mark Reg {'height': 130, 'weight': 60}
2 2.0 Faye Raker {'height': 130, 'weight': 60}
Normalizes nested data up to level 1.
>>> data = [
... {
... "id": 1,
... "name": "Cole Volk",
... "fitness": {"height": 130, "weight": 60},
... },
... {"name": "Mark Reg", "fitness": {"height": 130, "weight": 60}},
... {
... "id": 2,
... "name": "Faye Raker",
... "fitness": {"height": 130, "weight": 60},
... },
... ]
>>> pd.json_normalize(data, max_level=1)
id name fitness.height fitness.weight
0 1.0 Cole Volk 130 60
1 NaN Mark Reg 130 60
2 2.0 Faye Raker 130 60
>>> data = [
... {
... "state": "Florida",
... "shortname": "FL",
... "info": {"governor": "Rick Scott"},
... "counties": [
... {"name": "Dade", "population": 12345},
... {"name": "Broward", "population": 40000},
... {"name": "Palm Beach", "population": 60000},
... ],
... },
... {
... "state": "Ohio",
... "shortname": "OH",
... "info": {"governor": "John Kasich"},
... "counties": [
... {"name": "Summit", "population": 1234},
... {"name": "Cuyahoga", "population": 1337},
... ],
... },
... ]
>>> result = pd.json_normalize(
... data, "counties", ["state", "shortname", ["info", "governor"]]
... )
>>> result
name population state shortname info.governor
0 Dade 12345 Florida FL Rick Scott
1 Broward 40000 Florida FL Rick Scott
2 Palm Beach 60000 Florida FL Rick Scott
3 Summit 1234 Ohio OH John Kasich
4 Cuyahoga 1337 Ohio OH John Kasich
>>> data = {"A": [1, 2]}
>>> pd.json_normalize(data, "A", record_prefix="Prefix.")
Prefix.0
0 1
1 2
Returns normalized data with columns prefixed with the given string.
"""
def _pull_field(
js: dict[str, Any], spec: list | str, extract_record: bool = False
) -> Scalar | Iterable:
"""Internal function to pull field"""
result = js
try:
if isinstance(spec, list):
for field in spec:
if result is None:
raise KeyError(field)
result = result[field]
else:
result = result[spec]
except KeyError as e:
if extract_record:
raise KeyError(
f"Key {e} not found. If specifying a record_path, all elements of "
f"data should have the path."
) from e
if errors == "ignore":
return np.nan
else:
raise KeyError(
f"Key {e} not found. To replace missing values of {e} with "
f"np.nan, pass in errors='ignore'"
) from e
return result
def _pull_records(js: dict[str, Any], spec: list | str) -> list:
"""
Internal function to pull field for records, and similar to
_pull_field, but require to return list. And will raise error
if has non iterable value.
"""
result = _pull_field(js, spec, extract_record=True)
# GH 31507 GH 30145, GH 26284 if result is not list, raise TypeError if not
# null, otherwise return an empty list
if not isinstance(result, list):
if pd.isnull(result):
result = []
else:
raise TypeError(
f"{js} has non list value {result} for path {spec}. "
"Must be list or null."
)
return result
if isinstance(data, list) and not data:
return DataFrame()
elif isinstance(data, dict):
# A bit of a hackjob
data = [data]
elif isinstance(data, abc.Iterable) and not isinstance(data, str):
# GH35923 Fix pd.json_normalize to not skip the first element of a
# generator input
data = list(data)
else:
raise NotImplementedError
# check to see if a simple recursive function is possible to
# improve performance (see #15621) but only for cases such
# as pd.Dataframe(data) or pd.Dataframe(data, sep)
if (
record_path is None
and meta is None
and meta_prefix is None
and record_prefix is None
and max_level is None
):
return DataFrame(_simple_json_normalize(data, sep=sep))
if record_path is None:
if any([isinstance(x, dict) for x in y.values()] for y in data):
# naive normalization, this is idempotent for flat records
# and potentially will inflate the data considerably for
# deeply nested structures:
# {VeryLong: { b: 1,c:2}} -> {VeryLong.b:1 ,VeryLong.c:@}
#
# TODO: handle record value which are lists, at least error
# reasonably
data = nested_to_record(data, sep=sep, max_level=max_level)
return DataFrame(data)
elif not isinstance(record_path, list):
record_path = [record_path]
if meta is None:
meta = []
elif not isinstance(meta, list):
meta = [meta]
_meta = [m if isinstance(m, list) else [m] for m in meta]
# Disastrously inefficient for now
records: list = []
lengths = []
meta_vals: DefaultDict = defaultdict(list)
meta_keys = [sep.join(val) for val in _meta]
def _recursive_extract(data, path, seen_meta, level: int = 0) -> None:
if isinstance(data, dict):
data = [data]
if len(path) > 1:
for obj in data:
for val, key in zip(_meta, meta_keys):
if level + 1 == len(val):
seen_meta[key] = _pull_field(obj, val[-1])
_recursive_extract(obj[path[0]], path[1:], seen_meta, level=level + 1)
else:
for obj in data:
recs = _pull_records(obj, path[0])
recs = [
nested_to_record(r, sep=sep, max_level=max_level)
if isinstance(r, dict)
else r
for r in recs
]
# For repeating the metadata later
lengths.append(len(recs))
for val, key in zip(_meta, meta_keys):
if level + 1 > len(val):
meta_val = seen_meta[key]
else:
meta_val = _pull_field(obj, val[level:])
meta_vals[key].append(meta_val)
records.extend(recs)
_recursive_extract(data, record_path, {}, level=0)
result = DataFrame(records)
if record_prefix is not None:
result = result.rename(columns=lambda x: f"{record_prefix}{x}")
# Data types, a problem
for k, v in meta_vals.items():
if meta_prefix is not None:
k = meta_prefix + k
if k in result:
raise ValueError(
f"Conflicting metadata name {k}, need distinguishing prefix "
)
result[k] = np.array(v, dtype=object).repeat(lengths)
return result | Normalize semi-structured JSON data into a flat table. Parameters ---------- data : dict or list of dicts Unserialized JSON objects. record_path : str or list of str, default None Path in each object to list of records. If not passed, data will be assumed to be an array of records. meta : list of paths (str or list of str), default None Fields to use as metadata for each record in resulting table. meta_prefix : str, default None If True, prefix records with dotted (?) path, e.g. foo.bar.field if meta is ['foo', 'bar']. record_prefix : str, default None If True, prefix records with dotted (?) path, e.g. foo.bar.field if path to records is ['foo', 'bar']. errors : {'raise', 'ignore'}, default 'raise' Configures error handling. * 'ignore' : will ignore KeyError if keys listed in meta are not always present. * 'raise' : will raise KeyError if keys listed in meta are not always present. sep : str, default '.' Nested records will generate names separated by sep. e.g., for sep='.', {'foo': {'bar': 0}} -> foo.bar. max_level : int, default None Max number of levels(depth of dict) to normalize. if None, normalizes all levels. Returns ------- frame : DataFrame Normalize semi-structured JSON data into a flat table. Examples -------- >>> data = [ ... {"id": 1, "name": {"first": "Coleen", "last": "Volk"}}, ... {"name": {"given": "Mark", "family": "Regner"}}, ... {"id": 2, "name": "Faye Raker"}, ... ] >>> pd.json_normalize(data) id name.first name.last name.given name.family name 0 1.0 Coleen Volk NaN NaN NaN 1 NaN NaN NaN Mark Regner NaN 2 2.0 NaN NaN NaN NaN Faye Raker >>> data = [ ... { ... "id": 1, ... "name": "Cole Volk", ... "fitness": {"height": 130, "weight": 60}, ... }, ... {"name": "Mark Reg", "fitness": {"height": 130, "weight": 60}}, ... { ... "id": 2, ... "name": "Faye Raker", ... "fitness": {"height": 130, "weight": 60}, ... }, ... ] >>> pd.json_normalize(data, max_level=0) id name fitness 0 1.0 Cole Volk {'height': 130, 'weight': 60} 1 NaN Mark Reg {'height': 130, 'weight': 60} 2 2.0 Faye Raker {'height': 130, 'weight': 60} Normalizes nested data up to level 1. >>> data = [ ... { ... "id": 1, ... "name": "Cole Volk", ... "fitness": {"height": 130, "weight": 60}, ... }, ... {"name": "Mark Reg", "fitness": {"height": 130, "weight": 60}}, ... { ... "id": 2, ... "name": "Faye Raker", ... "fitness": {"height": 130, "weight": 60}, ... }, ... ] >>> pd.json_normalize(data, max_level=1) id name fitness.height fitness.weight 0 1.0 Cole Volk 130 60 1 NaN Mark Reg 130 60 2 2.0 Faye Raker 130 60 >>> data = [ ... { ... "state": "Florida", ... "shortname": "FL", ... "info": {"governor": "Rick Scott"}, ... "counties": [ ... {"name": "Dade", "population": 12345}, ... {"name": "Broward", "population": 40000}, ... {"name": "Palm Beach", "population": 60000}, ... ], ... }, ... { ... "state": "Ohio", ... "shortname": "OH", ... "info": {"governor": "John Kasich"}, ... "counties": [ ... {"name": "Summit", "population": 1234}, ... {"name": "Cuyahoga", "population": 1337}, ... ], ... }, ... ] >>> result = pd.json_normalize( ... data, "counties", ["state", "shortname", ["info", "governor"]] ... ) >>> result name population state shortname info.governor 0 Dade 12345 Florida FL Rick Scott 1 Broward 40000 Florida FL Rick Scott 2 Palm Beach 60000 Florida FL Rick Scott 3 Summit 1234 Ohio OH John Kasich 4 Cuyahoga 1337 Ohio OH John Kasich >>> data = {"A": [1, 2]} >>> pd.json_normalize(data, "A", record_prefix="Prefix.") Prefix.0 0 1 1 2 Returns normalized data with columns prefixed with the given string. |
173,508 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
_default_encoding = "UTF-8"
def _ensure_encoding(encoding: str | None) -> str:
# set the encoding if we need
if encoding is None:
encoding = _default_encoding
return encoding | null |
173,509 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
The provided code snippet includes necessary dependencies for implementing the `_ensure_str` function. Write a Python function `def _ensure_str(name)` to solve the following problem:
Ensure that an index / column name is a str (python 3); otherwise they may be np.string dtype. Non-string dtypes are passed through unchanged. https://github.com/pandas-dev/pandas/issues/13492
Here is the function:
def _ensure_str(name):
"""
Ensure that an index / column name is a str (python 3); otherwise they
may be np.string dtype. Non-string dtypes are passed through unchanged.
https://github.com/pandas-dev/pandas/issues/13492
"""
if isinstance(name, str):
name = str(name)
return name | Ensure that an index / column name is a str (python 3); otherwise they may be np.string dtype. Non-string dtypes are passed through unchanged. https://github.com/pandas-dev/pandas/issues/13492 |
173,510 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
class HDFStore:
"""
Dict-like IO interface for storing pandas objects in PyTables.
Either Fixed or Table format.
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
path : str
File path to HDF5 file.
mode : {'a', 'w', 'r', 'r+'}, default 'a'
``'r'``
Read-only; no data can be modified.
``'w'``
Write; a new file is created (an existing file with the same
name would be deleted).
``'a'``
Append; an existing file is opened for reading and writing,
and if the file does not exist it is created.
``'r+'``
It is similar to ``'a'``, but the file must already exist.
complevel : int, 0-9, default None
Specifies a compression level for data.
A value of 0 or None disables compression.
complib : {'zlib', 'lzo', 'bzip2', 'blosc'}, default 'zlib'
Specifies the compression library to be used.
As of v0.20.2 these additional compressors for Blosc are supported
(default if no compressor specified: 'blosc:blosclz'):
{'blosc:blosclz', 'blosc:lz4', 'blosc:lz4hc', 'blosc:snappy',
'blosc:zlib', 'blosc:zstd'}.
Specifying a compression library which is not available issues
a ValueError.
fletcher32 : bool, default False
If applying compression use the fletcher32 checksum.
**kwargs
These parameters will be passed to the PyTables open_file method.
Examples
--------
>>> bar = pd.DataFrame(np.random.randn(10, 4))
>>> store = pd.HDFStore('test.h5')
>>> store['foo'] = bar # write to HDF5
>>> bar = store['foo'] # retrieve
>>> store.close()
**Create or load HDF5 file in-memory**
When passing the `driver` option to the PyTables open_file method through
**kwargs, the HDF5 file is loaded or created in-memory and will only be
written when closed:
>>> bar = pd.DataFrame(np.random.randn(10, 4))
>>> store = pd.HDFStore('test.h5', driver='H5FD_CORE')
>>> store['foo'] = bar
>>> store.close() # only now, data is written to disk
"""
_handle: File | None
_mode: str
def __init__(
self,
path,
mode: str = "a",
complevel: int | None = None,
complib=None,
fletcher32: bool = False,
**kwargs,
) -> None:
if "format" in kwargs:
raise ValueError("format is not a defined argument for HDFStore")
tables = import_optional_dependency("tables")
if complib is not None and complib not in tables.filters.all_complibs:
raise ValueError(
f"complib only supports {tables.filters.all_complibs} compression."
)
if complib is None and complevel is not None:
complib = tables.filters.default_complib
self._path = stringify_path(path)
if mode is None:
mode = "a"
self._mode = mode
self._handle = None
self._complevel = complevel if complevel else 0
self._complib = complib
self._fletcher32 = fletcher32
self._filters = None
self.open(mode=mode, **kwargs)
def __fspath__(self) -> str:
return self._path
def root(self):
"""return the root node"""
self._check_if_open()
assert self._handle is not None # for mypy
return self._handle.root
def filename(self) -> str:
return self._path
def __getitem__(self, key: str):
return self.get(key)
def __setitem__(self, key: str, value) -> None:
self.put(key, value)
def __delitem__(self, key: str) -> None:
return self.remove(key)
def __getattr__(self, name: str):
"""allow attribute access to get stores"""
try:
return self.get(name)
except (KeyError, ClosedFileError):
pass
raise AttributeError(
f"'{type(self).__name__}' object has no attribute '{name}'"
)
def __contains__(self, key: str) -> bool:
"""
check for existence of this key
can match the exact pathname or the pathnm w/o the leading '/'
"""
node = self.get_node(key)
if node is not None:
name = node._v_pathname
if key in (name, name[1:]):
return True
return False
def __len__(self) -> int:
return len(self.groups())
def __repr__(self) -> str:
pstr = pprint_thing(self._path)
return f"{type(self)}\nFile path: {pstr}\n"
def __enter__(self) -> HDFStore:
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: TracebackType | None,
) -> None:
self.close()
def keys(self, include: str = "pandas") -> list[str]:
"""
Return a list of keys corresponding to objects stored in HDFStore.
Parameters
----------
include : str, default 'pandas'
When kind equals 'pandas' return pandas objects.
When kind equals 'native' return native HDF5 Table objects.
.. versionadded:: 1.1.0
Returns
-------
list
List of ABSOLUTE path-names (e.g. have the leading '/').
Raises
------
raises ValueError if kind has an illegal value
"""
if include == "pandas":
return [n._v_pathname for n in self.groups()]
elif include == "native":
assert self._handle is not None # mypy
return [
n._v_pathname for n in self._handle.walk_nodes("/", classname="Table")
]
raise ValueError(
f"`include` should be either 'pandas' or 'native' but is '{include}'"
)
def __iter__(self) -> Iterator[str]:
return iter(self.keys())
def items(self) -> Iterator[tuple[str, list]]:
"""
iterate on key->group
"""
for g in self.groups():
yield g._v_pathname, g
def open(self, mode: str = "a", **kwargs) -> None:
"""
Open the file in the specified mode
Parameters
----------
mode : {'a', 'w', 'r', 'r+'}, default 'a'
See HDFStore docstring or tables.open_file for info about modes
**kwargs
These parameters will be passed to the PyTables open_file method.
"""
tables = _tables()
if self._mode != mode:
# if we are changing a write mode to read, ok
if self._mode in ["a", "w"] and mode in ["r", "r+"]:
pass
elif mode in ["w"]:
# this would truncate, raise here
if self.is_open:
raise PossibleDataLossError(
f"Re-opening the file [{self._path}] with mode [{self._mode}] "
"will delete the current file!"
)
self._mode = mode
# close and reopen the handle
if self.is_open:
self.close()
if self._complevel and self._complevel > 0:
self._filters = _tables().Filters(
self._complevel, self._complib, fletcher32=self._fletcher32
)
if _table_file_open_policy_is_strict and self.is_open:
msg = (
"Cannot open HDF5 file, which is already opened, "
"even in read-only mode."
)
raise ValueError(msg)
self._handle = tables.open_file(self._path, self._mode, **kwargs)
def close(self) -> None:
"""
Close the PyTables file handle
"""
if self._handle is not None:
self._handle.close()
self._handle = None
def is_open(self) -> bool:
"""
return a boolean indicating whether the file is open
"""
if self._handle is None:
return False
return bool(self._handle.isopen)
def flush(self, fsync: bool = False) -> None:
"""
Force all buffered modifications to be written to disk.
Parameters
----------
fsync : bool (default False)
call ``os.fsync()`` on the file handle to force writing to disk.
Notes
-----
Without ``fsync=True``, flushing may not guarantee that the OS writes
to disk. With fsync, the operation will block until the OS claims the
file has been written; however, other caching layers may still
interfere.
"""
if self._handle is not None:
self._handle.flush()
if fsync:
with suppress(OSError):
os.fsync(self._handle.fileno())
def get(self, key: str):
"""
Retrieve pandas object stored in file.
Parameters
----------
key : str
Returns
-------
object
Same type as object stored in file.
"""
with patch_pickle():
# GH#31167 Without this patch, pickle doesn't know how to unpickle
# old DateOffset objects now that they are cdef classes.
group = self.get_node(key)
if group is None:
raise KeyError(f"No object named {key} in the file")
return self._read_group(group)
def select(
self,
key: str,
where=None,
start=None,
stop=None,
columns=None,
iterator: bool = False,
chunksize=None,
auto_close: bool = False,
):
"""
Retrieve pandas object stored in file, optionally based on where criteria.
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
key : str
Object being retrieved from file.
where : list or None
List of Term (or convertible) objects, optional.
start : int or None
Row number to start selection.
stop : int, default None
Row number to stop selection.
columns : list or None
A list of columns that if not None, will limit the return columns.
iterator : bool or False
Returns an iterator.
chunksize : int or None
Number or rows to include in iteration, return an iterator.
auto_close : bool or False
Should automatically close the store when finished.
Returns
-------
object
Retrieved object from file.
"""
group = self.get_node(key)
if group is None:
raise KeyError(f"No object named {key} in the file")
# create the storer and axes
where = _ensure_term(where, scope_level=1)
s = self._create_storer(group)
s.infer_axes()
# function to call on iteration
def func(_start, _stop, _where):
return s.read(start=_start, stop=_stop, where=_where, columns=columns)
# create the iterator
it = TableIterator(
self,
s,
func,
where=where,
nrows=s.nrows,
start=start,
stop=stop,
iterator=iterator,
chunksize=chunksize,
auto_close=auto_close,
)
return it.get_result()
def select_as_coordinates(
self,
key: str,
where=None,
start: int | None = None,
stop: int | None = None,
):
"""
return the selection as an Index
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
key : str
where : list of Term (or convertible) objects, optional
start : integer (defaults to None), row number to start selection
stop : integer (defaults to None), row number to stop selection
"""
where = _ensure_term(where, scope_level=1)
tbl = self.get_storer(key)
if not isinstance(tbl, Table):
raise TypeError("can only read_coordinates with a table")
return tbl.read_coordinates(where=where, start=start, stop=stop)
def select_column(
self,
key: str,
column: str,
start: int | None = None,
stop: int | None = None,
):
"""
return a single column from the table. This is generally only useful to
select an indexable
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
key : str
column : str
The column of interest.
start : int or None, default None
stop : int or None, default None
Raises
------
raises KeyError if the column is not found (or key is not a valid
store)
raises ValueError if the column can not be extracted individually (it
is part of a data block)
"""
tbl = self.get_storer(key)
if not isinstance(tbl, Table):
raise TypeError("can only read_column with a table")
return tbl.read_column(column=column, start=start, stop=stop)
def select_as_multiple(
self,
keys,
where=None,
selector=None,
columns=None,
start=None,
stop=None,
iterator: bool = False,
chunksize=None,
auto_close: bool = False,
):
"""
Retrieve pandas objects from multiple tables.
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
keys : a list of the tables
selector : the table to apply the where criteria (defaults to keys[0]
if not supplied)
columns : the columns I want back
start : integer (defaults to None), row number to start selection
stop : integer (defaults to None), row number to stop selection
iterator : bool, return an iterator, default False
chunksize : nrows to include in iteration, return an iterator
auto_close : bool, default False
Should automatically close the store when finished.
Raises
------
raises KeyError if keys or selector is not found or keys is empty
raises TypeError if keys is not a list or tuple
raises ValueError if the tables are not ALL THE SAME DIMENSIONS
"""
# default to single select
where = _ensure_term(where, scope_level=1)
if isinstance(keys, (list, tuple)) and len(keys) == 1:
keys = keys[0]
if isinstance(keys, str):
return self.select(
key=keys,
where=where,
columns=columns,
start=start,
stop=stop,
iterator=iterator,
chunksize=chunksize,
auto_close=auto_close,
)
if not isinstance(keys, (list, tuple)):
raise TypeError("keys must be a list/tuple")
if not len(keys):
raise ValueError("keys must have a non-zero length")
if selector is None:
selector = keys[0]
# collect the tables
tbls = [self.get_storer(k) for k in keys]
s = self.get_storer(selector)
# validate rows
nrows = None
for t, k in itertools.chain([(s, selector)], zip(tbls, keys)):
if t is None:
raise KeyError(f"Invalid table [{k}]")
if not t.is_table:
raise TypeError(
f"object [{t.pathname}] is not a table, and cannot be used in all "
"select as multiple"
)
if nrows is None:
nrows = t.nrows
elif t.nrows != nrows:
raise ValueError("all tables must have exactly the same nrows!")
# The isinstance checks here are redundant with the check above,
# but necessary for mypy; see GH#29757
_tbls = [x for x in tbls if isinstance(x, Table)]
# axis is the concentration axes
axis = {t.non_index_axes[0][0] for t in _tbls}.pop()
def func(_start, _stop, _where):
# retrieve the objs, _where is always passed as a set of
# coordinates here
objs = [
t.read(where=_where, columns=columns, start=_start, stop=_stop)
for t in tbls
]
# concat and return
return concat(objs, axis=axis, verify_integrity=False)._consolidate()
# create the iterator
it = TableIterator(
self,
s,
func,
where=where,
nrows=nrows,
start=start,
stop=stop,
iterator=iterator,
chunksize=chunksize,
auto_close=auto_close,
)
return it.get_result(coordinates=True)
def put(
self,
key: str,
value: DataFrame | Series,
format=None,
index: bool = True,
append: bool = False,
complib=None,
complevel: int | None = None,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
data_columns: Literal[True] | list[str] | None = None,
encoding=None,
errors: str = "strict",
track_times: bool = True,
dropna: bool = False,
) -> None:
"""
Store object in HDFStore.
Parameters
----------
key : str
value : {Series, DataFrame}
format : 'fixed(f)|table(t)', default is 'fixed'
Format to use when storing object in HDFStore. Value can be one of:
``'fixed'``
Fixed format. Fast writing/reading. Not-appendable, nor searchable.
``'table'``
Table format. Write as a PyTables Table structure which may perform
worse but allow more flexible operations like searching / selecting
subsets of the data.
index : bool, default True
Write DataFrame index as a column.
append : bool, default False
This will force Table format, append the input data to the existing.
data_columns : list of columns or True, default None
List of columns to create as data columns, or True to use all columns.
See `here
<https://pandas.pydata.org/pandas-docs/stable/user_guide/io.html#query-via-data-columns>`__.
encoding : str, default None
Provide an encoding for strings.
track_times : bool, default True
Parameter is propagated to 'create_table' method of 'PyTables'.
If set to False it enables to have the same h5 files (same hashes)
independent on creation time.
dropna : bool, default False, optional
Remove missing values.
.. versionadded:: 1.1.0
"""
if format is None:
format = get_option("io.hdf.default_format") or "fixed"
format = self._validate_format(format)
self._write_to_group(
key,
value,
format=format,
index=index,
append=append,
complib=complib,
complevel=complevel,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
data_columns=data_columns,
encoding=encoding,
errors=errors,
track_times=track_times,
dropna=dropna,
)
def remove(self, key: str, where=None, start=None, stop=None) -> None:
"""
Remove pandas object partially by specifying the where condition
Parameters
----------
key : str
Node to remove or delete rows from
where : list of Term (or convertible) objects, optional
start : integer (defaults to None), row number to start selection
stop : integer (defaults to None), row number to stop selection
Returns
-------
number of rows removed (or None if not a Table)
Raises
------
raises KeyError if key is not a valid store
"""
where = _ensure_term(where, scope_level=1)
try:
s = self.get_storer(key)
except KeyError:
# the key is not a valid store, re-raising KeyError
raise
except AssertionError:
# surface any assertion errors for e.g. debugging
raise
except Exception as err:
# In tests we get here with ClosedFileError, TypeError, and
# _table_mod.NoSuchNodeError. TODO: Catch only these?
if where is not None:
raise ValueError(
"trying to remove a node with a non-None where clause!"
) from err
# we are actually trying to remove a node (with children)
node = self.get_node(key)
if node is not None:
node._f_remove(recursive=True)
return None
# remove the node
if com.all_none(where, start, stop):
s.group._f_remove(recursive=True)
# delete from the table
else:
if not s.is_table:
raise ValueError(
"can only remove with where on objects written as tables"
)
return s.delete(where=where, start=start, stop=stop)
def append(
self,
key: str,
value: DataFrame | Series,
format=None,
axes=None,
index: bool | list[str] = True,
append: bool = True,
complib=None,
complevel: int | None = None,
columns=None,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
chunksize=None,
expectedrows=None,
dropna: bool | None = None,
data_columns: Literal[True] | list[str] | None = None,
encoding=None,
errors: str = "strict",
) -> None:
"""
Append to Table in file.
Node must already exist and be Table format.
Parameters
----------
key : str
value : {Series, DataFrame}
format : 'table' is the default
Format to use when storing object in HDFStore. Value can be one of:
``'table'``
Table format. Write as a PyTables Table structure which may perform
worse but allow more flexible operations like searching / selecting
subsets of the data.
index : bool, default True
Write DataFrame index as a column.
append : bool, default True
Append the input data to the existing.
data_columns : list of columns, or True, default None
List of columns to create as indexed data columns for on-disk
queries, or True to use all columns. By default only the axes
of the object are indexed. See `here
<https://pandas.pydata.org/pandas-docs/stable/user_guide/io.html#query-via-data-columns>`__.
min_itemsize : dict of columns that specify minimum str sizes
nan_rep : str to use as str nan representation
chunksize : size to chunk the writing
expectedrows : expected TOTAL row size of this table
encoding : default None, provide an encoding for str
dropna : bool, default False, optional
Do not write an ALL nan row to the store settable
by the option 'io.hdf.dropna_table'.
Notes
-----
Does *not* check if data being appended overlaps with existing
data in the table, so be careful
"""
if columns is not None:
raise TypeError(
"columns is not a supported keyword in append, try data_columns"
)
if dropna is None:
dropna = get_option("io.hdf.dropna_table")
if format is None:
format = get_option("io.hdf.default_format") or "table"
format = self._validate_format(format)
self._write_to_group(
key,
value,
format=format,
axes=axes,
index=index,
append=append,
complib=complib,
complevel=complevel,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
chunksize=chunksize,
expectedrows=expectedrows,
dropna=dropna,
data_columns=data_columns,
encoding=encoding,
errors=errors,
)
def append_to_multiple(
self,
d: dict,
value,
selector,
data_columns=None,
axes=None,
dropna: bool = False,
**kwargs,
) -> None:
"""
Append to multiple tables
Parameters
----------
d : a dict of table_name to table_columns, None is acceptable as the
values of one node (this will get all the remaining columns)
value : a pandas object
selector : a string that designates the indexable table; all of its
columns will be designed as data_columns, unless data_columns is
passed, in which case these are used
data_columns : list of columns to create as data columns, or True to
use all columns
dropna : if evaluates to True, drop rows from all tables if any single
row in each table has all NaN. Default False.
Notes
-----
axes parameter is currently not accepted
"""
if axes is not None:
raise TypeError(
"axes is currently not accepted as a parameter to append_to_multiple; "
"you can create the tables independently instead"
)
if not isinstance(d, dict):
raise ValueError(
"append_to_multiple must have a dictionary specified as the "
"way to split the value"
)
if selector not in d:
raise ValueError(
"append_to_multiple requires a selector that is in passed dict"
)
# figure out the splitting axis (the non_index_axis)
axis = list(set(range(value.ndim)) - set(_AXES_MAP[type(value)]))[0]
# figure out how to split the value
remain_key = None
remain_values: list = []
for k, v in d.items():
if v is None:
if remain_key is not None:
raise ValueError(
"append_to_multiple can only have one value in d that is None"
)
remain_key = k
else:
remain_values.extend(v)
if remain_key is not None:
ordered = value.axes[axis]
ordd = ordered.difference(Index(remain_values))
ordd = sorted(ordered.get_indexer(ordd))
d[remain_key] = ordered.take(ordd)
# data_columns
if data_columns is None:
data_columns = d[selector]
# ensure rows are synchronized across the tables
if dropna:
idxs = (value[cols].dropna(how="all").index for cols in d.values())
valid_index = next(idxs)
for index in idxs:
valid_index = valid_index.intersection(index)
value = value.loc[valid_index]
min_itemsize = kwargs.pop("min_itemsize", None)
# append
for k, v in d.items():
dc = data_columns if k == selector else None
# compute the val
val = value.reindex(v, axis=axis)
filtered = (
{key: value for (key, value) in min_itemsize.items() if key in v}
if min_itemsize is not None
else None
)
self.append(k, val, data_columns=dc, min_itemsize=filtered, **kwargs)
def create_table_index(
self,
key: str,
columns=None,
optlevel: int | None = None,
kind: str | None = None,
) -> None:
"""
Create a pytables index on the table.
Parameters
----------
key : str
columns : None, bool, or listlike[str]
Indicate which columns to create an index on.
* False : Do not create any indexes.
* True : Create indexes on all columns.
* None : Create indexes on all columns.
* listlike : Create indexes on the given columns.
optlevel : int or None, default None
Optimization level, if None, pytables defaults to 6.
kind : str or None, default None
Kind of index, if None, pytables defaults to "medium".
Raises
------
TypeError: raises if the node is not a table
"""
# version requirements
_tables()
s = self.get_storer(key)
if s is None:
return
if not isinstance(s, Table):
raise TypeError("cannot create table index on a Fixed format store")
s.create_index(columns=columns, optlevel=optlevel, kind=kind)
def groups(self) -> list:
"""
Return a list of all the top-level nodes.
Each node returned is not a pandas storage object.
Returns
-------
list
List of objects.
"""
_tables()
self._check_if_open()
assert self._handle is not None # for mypy
assert _table_mod is not None # for mypy
return [
g
for g in self._handle.walk_groups()
if (
not isinstance(g, _table_mod.link.Link)
and (
getattr(g._v_attrs, "pandas_type", None)
or getattr(g, "table", None)
or (isinstance(g, _table_mod.table.Table) and g._v_name != "table")
)
)
]
def walk(self, where: str = "/") -> Iterator[tuple[str, list[str], list[str]]]:
"""
Walk the pytables group hierarchy for pandas objects.
This generator will yield the group path, subgroups and pandas object
names for each group.
Any non-pandas PyTables objects that are not a group will be ignored.
The `where` group itself is listed first (preorder), then each of its
child groups (following an alphanumerical order) is also traversed,
following the same procedure.
Parameters
----------
where : str, default "/"
Group where to start walking.
Yields
------
path : str
Full path to a group (without trailing '/').
groups : list
Names (strings) of the groups contained in `path`.
leaves : list
Names (strings) of the pandas objects contained in `path`.
"""
_tables()
self._check_if_open()
assert self._handle is not None # for mypy
assert _table_mod is not None # for mypy
for g in self._handle.walk_groups(where):
if getattr(g._v_attrs, "pandas_type", None) is not None:
continue
groups = []
leaves = []
for child in g._v_children.values():
pandas_type = getattr(child._v_attrs, "pandas_type", None)
if pandas_type is None:
if isinstance(child, _table_mod.group.Group):
groups.append(child._v_name)
else:
leaves.append(child._v_name)
yield (g._v_pathname.rstrip("/"), groups, leaves)
def get_node(self, key: str) -> Node | None:
"""return the node with the key or None if it does not exist"""
self._check_if_open()
if not key.startswith("/"):
key = "/" + key
assert self._handle is not None
assert _table_mod is not None # for mypy
try:
node = self._handle.get_node(self.root, key)
except _table_mod.exceptions.NoSuchNodeError:
return None
assert isinstance(node, _table_mod.Node), type(node)
return node
def get_storer(self, key: str) -> GenericFixed | Table:
"""return the storer object for a key, raise if not in the file"""
group = self.get_node(key)
if group is None:
raise KeyError(f"No object named {key} in the file")
s = self._create_storer(group)
s.infer_axes()
return s
def copy(
self,
file,
mode: str = "w",
propindexes: bool = True,
keys=None,
complib=None,
complevel: int | None = None,
fletcher32: bool = False,
overwrite: bool = True,
) -> HDFStore:
"""
Copy the existing store to a new file, updating in place.
Parameters
----------
propindexes : bool, default True
Restore indexes in copied file.
keys : list, optional
List of keys to include in the copy (defaults to all).
overwrite : bool, default True
Whether to overwrite (remove and replace) existing nodes in the new store.
mode, complib, complevel, fletcher32 same as in HDFStore.__init__
Returns
-------
open file handle of the new store
"""
new_store = HDFStore(
file, mode=mode, complib=complib, complevel=complevel, fletcher32=fletcher32
)
if keys is None:
keys = list(self.keys())
if not isinstance(keys, (tuple, list)):
keys = [keys]
for k in keys:
s = self.get_storer(k)
if s is not None:
if k in new_store:
if overwrite:
new_store.remove(k)
data = self.select(k)
if isinstance(s, Table):
index: bool | list[str] = False
if propindexes:
index = [a.name for a in s.axes if a.is_indexed]
new_store.append(
k,
data,
index=index,
data_columns=getattr(s, "data_columns", None),
encoding=s.encoding,
)
else:
new_store.put(k, data, encoding=s.encoding)
return new_store
def info(self) -> str:
"""
Print detailed information on the store.
Returns
-------
str
"""
path = pprint_thing(self._path)
output = f"{type(self)}\nFile path: {path}\n"
if self.is_open:
lkeys = sorted(self.keys())
if len(lkeys):
keys = []
values = []
for k in lkeys:
try:
s = self.get_storer(k)
if s is not None:
keys.append(pprint_thing(s.pathname or k))
values.append(pprint_thing(s or "invalid_HDFStore node"))
except AssertionError:
# surface any assertion errors for e.g. debugging
raise
except Exception as detail:
keys.append(k)
dstr = pprint_thing(detail)
values.append(f"[invalid_HDFStore node: {dstr}]")
output += adjoin(12, keys, values)
else:
output += "Empty"
else:
output += "File is CLOSED"
return output
# ------------------------------------------------------------------------
# private methods
def _check_if_open(self):
if not self.is_open:
raise ClosedFileError(f"{self._path} file is not open!")
def _validate_format(self, format: str) -> str:
"""validate / deprecate formats"""
# validate
try:
format = _FORMAT_MAP[format.lower()]
except KeyError as err:
raise TypeError(f"invalid HDFStore format specified [{format}]") from err
return format
def _create_storer(
self,
group,
format=None,
value: DataFrame | Series | None = None,
encoding: str = "UTF-8",
errors: str = "strict",
) -> GenericFixed | Table:
"""return a suitable class to operate"""
cls: type[GenericFixed] | type[Table]
if value is not None and not isinstance(value, (Series, DataFrame)):
raise TypeError("value must be None, Series, or DataFrame")
pt = _ensure_decoded(getattr(group._v_attrs, "pandas_type", None))
tt = _ensure_decoded(getattr(group._v_attrs, "table_type", None))
# infer the pt from the passed value
if pt is None:
if value is None:
_tables()
assert _table_mod is not None # for mypy
if getattr(group, "table", None) or isinstance(
group, _table_mod.table.Table
):
pt = "frame_table"
tt = "generic_table"
else:
raise TypeError(
"cannot create a storer if the object is not existing "
"nor a value are passed"
)
else:
if isinstance(value, Series):
pt = "series"
else:
pt = "frame"
# we are actually a table
if format == "table":
pt += "_table"
# a storer node
if "table" not in pt:
_STORER_MAP = {"series": SeriesFixed, "frame": FrameFixed}
try:
cls = _STORER_MAP[pt]
except KeyError as err:
raise TypeError(
f"cannot properly create the storer for: [_STORER_MAP] [group->"
f"{group},value->{type(value)},format->{format}"
) from err
return cls(self, group, encoding=encoding, errors=errors)
# existing node (and must be a table)
if tt is None:
# if we are a writer, determine the tt
if value is not None:
if pt == "series_table":
index = getattr(value, "index", None)
if index is not None:
if index.nlevels == 1:
tt = "appendable_series"
elif index.nlevels > 1:
tt = "appendable_multiseries"
elif pt == "frame_table":
index = getattr(value, "index", None)
if index is not None:
if index.nlevels == 1:
tt = "appendable_frame"
elif index.nlevels > 1:
tt = "appendable_multiframe"
_TABLE_MAP = {
"generic_table": GenericTable,
"appendable_series": AppendableSeriesTable,
"appendable_multiseries": AppendableMultiSeriesTable,
"appendable_frame": AppendableFrameTable,
"appendable_multiframe": AppendableMultiFrameTable,
"worm": WORMTable,
}
try:
cls = _TABLE_MAP[tt]
except KeyError as err:
raise TypeError(
f"cannot properly create the storer for: [_TABLE_MAP] [group->"
f"{group},value->{type(value)},format->{format}"
) from err
return cls(self, group, encoding=encoding, errors=errors)
def _write_to_group(
self,
key: str,
value: DataFrame | Series,
format,
axes=None,
index: bool | list[str] = True,
append: bool = False,
complib=None,
complevel: int | None = None,
fletcher32=None,
min_itemsize: int | dict[str, int] | None = None,
chunksize=None,
expectedrows=None,
dropna: bool = False,
nan_rep=None,
data_columns=None,
encoding=None,
errors: str = "strict",
track_times: bool = True,
) -> None:
# we don't want to store a table node at all if our object is 0-len
# as there are not dtypes
if getattr(value, "empty", None) and (format == "table" or append):
return
group = self._identify_group(key, append)
s = self._create_storer(group, format, value, encoding=encoding, errors=errors)
if append:
# raise if we are trying to append to a Fixed format,
# or a table that exists (and we are putting)
if not s.is_table or (s.is_table and format == "fixed" and s.is_exists):
raise ValueError("Can only append to Tables")
if not s.is_exists:
s.set_object_info()
else:
s.set_object_info()
if not s.is_table and complib:
raise ValueError("Compression not supported on Fixed format stores")
# write the object
s.write(
obj=value,
axes=axes,
append=append,
complib=complib,
complevel=complevel,
fletcher32=fletcher32,
min_itemsize=min_itemsize,
chunksize=chunksize,
expectedrows=expectedrows,
dropna=dropna,
nan_rep=nan_rep,
data_columns=data_columns,
track_times=track_times,
)
if isinstance(s, Table) and index:
s.create_index(columns=index)
def _read_group(self, group: Node):
s = self._create_storer(group)
s.infer_axes()
return s.read()
def _identify_group(self, key: str, append: bool) -> Node:
"""Identify HDF5 group based on key, delete/create group if needed."""
group = self.get_node(key)
# we make this assertion for mypy; the get_node call will already
# have raised if this is incorrect
assert self._handle is not None
# remove the node if we are not appending
if group is not None and not append:
self._handle.remove_node(group, recursive=True)
group = None
if group is None:
group = self._create_nodes_and_group(key)
return group
def _create_nodes_and_group(self, key: str) -> Node:
"""Create nodes from key and return group name."""
# assertion for mypy
assert self._handle is not None
paths = key.split("/")
# recursively create the groups
path = "/"
for p in paths:
if not len(p):
continue
new_path = path
if not path.endswith("/"):
new_path += "/"
new_path += p
group = self.get_node(new_path)
if group is None:
group = self._handle.create_group(path, p)
path = new_path
return group
Literal: _SpecialForm = ...
FilePath = Union[str, "PathLike[str]"]
def stringify_path(filepath_or_buffer: FilePath, convert_file_like: bool = ...) -> str:
...
def stringify_path(
filepath_or_buffer: BaseBufferT, convert_file_like: bool = ...
) -> BaseBufferT:
...
def stringify_path(
filepath_or_buffer: FilePath | BaseBufferT,
convert_file_like: bool = False,
) -> str | BaseBufferT:
"""
Attempt to convert a path-like object to a string.
Parameters
----------
filepath_or_buffer : object to be converted
Returns
-------
str_filepath_or_buffer : maybe a string version of the object
Notes
-----
Objects supporting the fspath protocol (python 3.6+) are coerced
according to its __fspath__ method.
Any other object is passed through unchanged, which includes bytes,
strings, buffers, or anything else that's not even path-like.
"""
if not convert_file_like and is_file_like(filepath_or_buffer):
# GH 38125: some fsspec objects implement os.PathLike but have already opened a
# file. This prevents opening the file a second time. infer_compression calls
# this function with convert_file_like=True to infer the compression.
return cast(BaseBufferT, filepath_or_buffer)
if isinstance(filepath_or_buffer, os.PathLike):
filepath_or_buffer = filepath_or_buffer.__fspath__()
return _expand_user(filepath_or_buffer)
)
The provided code snippet includes necessary dependencies for implementing the `to_hdf` function. Write a Python function `def to_hdf( path_or_buf: FilePath | HDFStore, key: str, value: DataFrame | Series, mode: str = "a", complevel: int | None = None, complib: str | None = None, append: bool = False, format: str | None = None, index: bool = True, min_itemsize: int | dict[str, int] | None = None, nan_rep=None, dropna: bool | None = None, data_columns: Literal[True] | list[str] | None = None, errors: str = "strict", encoding: str = "UTF-8", ) -> None` to solve the following problem:
store this object, close it if we opened it
Here is the function:
def to_hdf(
path_or_buf: FilePath | HDFStore,
key: str,
value: DataFrame | Series,
mode: str = "a",
complevel: int | None = None,
complib: str | None = None,
append: bool = False,
format: str | None = None,
index: bool = True,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
dropna: bool | None = None,
data_columns: Literal[True] | list[str] | None = None,
errors: str = "strict",
encoding: str = "UTF-8",
) -> None:
"""store this object, close it if we opened it"""
if append:
f = lambda store: store.append(
key,
value,
format=format,
index=index,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
dropna=dropna,
data_columns=data_columns,
errors=errors,
encoding=encoding,
)
else:
# NB: dropna is not passed to `put`
f = lambda store: store.put(
key,
value,
format=format,
index=index,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
data_columns=data_columns,
errors=errors,
encoding=encoding,
dropna=dropna,
)
path_or_buf = stringify_path(path_or_buf)
if isinstance(path_or_buf, str):
with HDFStore(
path_or_buf, mode=mode, complevel=complevel, complib=complib
) as store:
f(store)
else:
f(path_or_buf) | store this object, close it if we opened it |
173,511 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
def _ensure_term(where, scope_level: int):
"""
Ensure that the where is a Term or a list of Term.
This makes sure that we are capturing the scope of variables that are
passed create the terms here with a frame_level=2 (we are 2 levels down)
"""
# only consider list/tuple here as an ndarray is automatically a coordinate
# list
level = scope_level + 1
if isinstance(where, (list, tuple)):
where = [
Term(term, scope_level=level + 1) if maybe_expression(term) else term
for term in where
if term is not None
]
elif maybe_expression(where):
where = Term(where, scope_level=level)
return where if where is None or len(where) else None
def _is_metadata_of(group: Node, parent_group: Node) -> bool:
"""Check if a given group is a metadata group for a given parent_group."""
if group._v_depth <= parent_group._v_depth:
return False
current = group
while current._v_depth > 1:
parent = current._v_parent
if parent == parent_group and current._v_name == "meta":
return True
current = current._v_parent
return False
class HDFStore:
"""
Dict-like IO interface for storing pandas objects in PyTables.
Either Fixed or Table format.
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
path : str
File path to HDF5 file.
mode : {'a', 'w', 'r', 'r+'}, default 'a'
``'r'``
Read-only; no data can be modified.
``'w'``
Write; a new file is created (an existing file with the same
name would be deleted).
``'a'``
Append; an existing file is opened for reading and writing,
and if the file does not exist it is created.
``'r+'``
It is similar to ``'a'``, but the file must already exist.
complevel : int, 0-9, default None
Specifies a compression level for data.
A value of 0 or None disables compression.
complib : {'zlib', 'lzo', 'bzip2', 'blosc'}, default 'zlib'
Specifies the compression library to be used.
As of v0.20.2 these additional compressors for Blosc are supported
(default if no compressor specified: 'blosc:blosclz'):
{'blosc:blosclz', 'blosc:lz4', 'blosc:lz4hc', 'blosc:snappy',
'blosc:zlib', 'blosc:zstd'}.
Specifying a compression library which is not available issues
a ValueError.
fletcher32 : bool, default False
If applying compression use the fletcher32 checksum.
**kwargs
These parameters will be passed to the PyTables open_file method.
Examples
--------
>>> bar = pd.DataFrame(np.random.randn(10, 4))
>>> store = pd.HDFStore('test.h5')
>>> store['foo'] = bar # write to HDF5
>>> bar = store['foo'] # retrieve
>>> store.close()
**Create or load HDF5 file in-memory**
When passing the `driver` option to the PyTables open_file method through
**kwargs, the HDF5 file is loaded or created in-memory and will only be
written when closed:
>>> bar = pd.DataFrame(np.random.randn(10, 4))
>>> store = pd.HDFStore('test.h5', driver='H5FD_CORE')
>>> store['foo'] = bar
>>> store.close() # only now, data is written to disk
"""
_handle: File | None
_mode: str
def __init__(
self,
path,
mode: str = "a",
complevel: int | None = None,
complib=None,
fletcher32: bool = False,
**kwargs,
) -> None:
if "format" in kwargs:
raise ValueError("format is not a defined argument for HDFStore")
tables = import_optional_dependency("tables")
if complib is not None and complib not in tables.filters.all_complibs:
raise ValueError(
f"complib only supports {tables.filters.all_complibs} compression."
)
if complib is None and complevel is not None:
complib = tables.filters.default_complib
self._path = stringify_path(path)
if mode is None:
mode = "a"
self._mode = mode
self._handle = None
self._complevel = complevel if complevel else 0
self._complib = complib
self._fletcher32 = fletcher32
self._filters = None
self.open(mode=mode, **kwargs)
def __fspath__(self) -> str:
return self._path
def root(self):
"""return the root node"""
self._check_if_open()
assert self._handle is not None # for mypy
return self._handle.root
def filename(self) -> str:
return self._path
def __getitem__(self, key: str):
return self.get(key)
def __setitem__(self, key: str, value) -> None:
self.put(key, value)
def __delitem__(self, key: str) -> None:
return self.remove(key)
def __getattr__(self, name: str):
"""allow attribute access to get stores"""
try:
return self.get(name)
except (KeyError, ClosedFileError):
pass
raise AttributeError(
f"'{type(self).__name__}' object has no attribute '{name}'"
)
def __contains__(self, key: str) -> bool:
"""
check for existence of this key
can match the exact pathname or the pathnm w/o the leading '/'
"""
node = self.get_node(key)
if node is not None:
name = node._v_pathname
if key in (name, name[1:]):
return True
return False
def __len__(self) -> int:
return len(self.groups())
def __repr__(self) -> str:
pstr = pprint_thing(self._path)
return f"{type(self)}\nFile path: {pstr}\n"
def __enter__(self) -> HDFStore:
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: TracebackType | None,
) -> None:
self.close()
def keys(self, include: str = "pandas") -> list[str]:
"""
Return a list of keys corresponding to objects stored in HDFStore.
Parameters
----------
include : str, default 'pandas'
When kind equals 'pandas' return pandas objects.
When kind equals 'native' return native HDF5 Table objects.
.. versionadded:: 1.1.0
Returns
-------
list
List of ABSOLUTE path-names (e.g. have the leading '/').
Raises
------
raises ValueError if kind has an illegal value
"""
if include == "pandas":
return [n._v_pathname for n in self.groups()]
elif include == "native":
assert self._handle is not None # mypy
return [
n._v_pathname for n in self._handle.walk_nodes("/", classname="Table")
]
raise ValueError(
f"`include` should be either 'pandas' or 'native' but is '{include}'"
)
def __iter__(self) -> Iterator[str]:
return iter(self.keys())
def items(self) -> Iterator[tuple[str, list]]:
"""
iterate on key->group
"""
for g in self.groups():
yield g._v_pathname, g
def open(self, mode: str = "a", **kwargs) -> None:
"""
Open the file in the specified mode
Parameters
----------
mode : {'a', 'w', 'r', 'r+'}, default 'a'
See HDFStore docstring or tables.open_file for info about modes
**kwargs
These parameters will be passed to the PyTables open_file method.
"""
tables = _tables()
if self._mode != mode:
# if we are changing a write mode to read, ok
if self._mode in ["a", "w"] and mode in ["r", "r+"]:
pass
elif mode in ["w"]:
# this would truncate, raise here
if self.is_open:
raise PossibleDataLossError(
f"Re-opening the file [{self._path}] with mode [{self._mode}] "
"will delete the current file!"
)
self._mode = mode
# close and reopen the handle
if self.is_open:
self.close()
if self._complevel and self._complevel > 0:
self._filters = _tables().Filters(
self._complevel, self._complib, fletcher32=self._fletcher32
)
if _table_file_open_policy_is_strict and self.is_open:
msg = (
"Cannot open HDF5 file, which is already opened, "
"even in read-only mode."
)
raise ValueError(msg)
self._handle = tables.open_file(self._path, self._mode, **kwargs)
def close(self) -> None:
"""
Close the PyTables file handle
"""
if self._handle is not None:
self._handle.close()
self._handle = None
def is_open(self) -> bool:
"""
return a boolean indicating whether the file is open
"""
if self._handle is None:
return False
return bool(self._handle.isopen)
def flush(self, fsync: bool = False) -> None:
"""
Force all buffered modifications to be written to disk.
Parameters
----------
fsync : bool (default False)
call ``os.fsync()`` on the file handle to force writing to disk.
Notes
-----
Without ``fsync=True``, flushing may not guarantee that the OS writes
to disk. With fsync, the operation will block until the OS claims the
file has been written; however, other caching layers may still
interfere.
"""
if self._handle is not None:
self._handle.flush()
if fsync:
with suppress(OSError):
os.fsync(self._handle.fileno())
def get(self, key: str):
"""
Retrieve pandas object stored in file.
Parameters
----------
key : str
Returns
-------
object
Same type as object stored in file.
"""
with patch_pickle():
# GH#31167 Without this patch, pickle doesn't know how to unpickle
# old DateOffset objects now that they are cdef classes.
group = self.get_node(key)
if group is None:
raise KeyError(f"No object named {key} in the file")
return self._read_group(group)
def select(
self,
key: str,
where=None,
start=None,
stop=None,
columns=None,
iterator: bool = False,
chunksize=None,
auto_close: bool = False,
):
"""
Retrieve pandas object stored in file, optionally based on where criteria.
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
key : str
Object being retrieved from file.
where : list or None
List of Term (or convertible) objects, optional.
start : int or None
Row number to start selection.
stop : int, default None
Row number to stop selection.
columns : list or None
A list of columns that if not None, will limit the return columns.
iterator : bool or False
Returns an iterator.
chunksize : int or None
Number or rows to include in iteration, return an iterator.
auto_close : bool or False
Should automatically close the store when finished.
Returns
-------
object
Retrieved object from file.
"""
group = self.get_node(key)
if group is None:
raise KeyError(f"No object named {key} in the file")
# create the storer and axes
where = _ensure_term(where, scope_level=1)
s = self._create_storer(group)
s.infer_axes()
# function to call on iteration
def func(_start, _stop, _where):
return s.read(start=_start, stop=_stop, where=_where, columns=columns)
# create the iterator
it = TableIterator(
self,
s,
func,
where=where,
nrows=s.nrows,
start=start,
stop=stop,
iterator=iterator,
chunksize=chunksize,
auto_close=auto_close,
)
return it.get_result()
def select_as_coordinates(
self,
key: str,
where=None,
start: int | None = None,
stop: int | None = None,
):
"""
return the selection as an Index
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
key : str
where : list of Term (or convertible) objects, optional
start : integer (defaults to None), row number to start selection
stop : integer (defaults to None), row number to stop selection
"""
where = _ensure_term(where, scope_level=1)
tbl = self.get_storer(key)
if not isinstance(tbl, Table):
raise TypeError("can only read_coordinates with a table")
return tbl.read_coordinates(where=where, start=start, stop=stop)
def select_column(
self,
key: str,
column: str,
start: int | None = None,
stop: int | None = None,
):
"""
return a single column from the table. This is generally only useful to
select an indexable
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
key : str
column : str
The column of interest.
start : int or None, default None
stop : int or None, default None
Raises
------
raises KeyError if the column is not found (or key is not a valid
store)
raises ValueError if the column can not be extracted individually (it
is part of a data block)
"""
tbl = self.get_storer(key)
if not isinstance(tbl, Table):
raise TypeError("can only read_column with a table")
return tbl.read_column(column=column, start=start, stop=stop)
def select_as_multiple(
self,
keys,
where=None,
selector=None,
columns=None,
start=None,
stop=None,
iterator: bool = False,
chunksize=None,
auto_close: bool = False,
):
"""
Retrieve pandas objects from multiple tables.
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
keys : a list of the tables
selector : the table to apply the where criteria (defaults to keys[0]
if not supplied)
columns : the columns I want back
start : integer (defaults to None), row number to start selection
stop : integer (defaults to None), row number to stop selection
iterator : bool, return an iterator, default False
chunksize : nrows to include in iteration, return an iterator
auto_close : bool, default False
Should automatically close the store when finished.
Raises
------
raises KeyError if keys or selector is not found or keys is empty
raises TypeError if keys is not a list or tuple
raises ValueError if the tables are not ALL THE SAME DIMENSIONS
"""
# default to single select
where = _ensure_term(where, scope_level=1)
if isinstance(keys, (list, tuple)) and len(keys) == 1:
keys = keys[0]
if isinstance(keys, str):
return self.select(
key=keys,
where=where,
columns=columns,
start=start,
stop=stop,
iterator=iterator,
chunksize=chunksize,
auto_close=auto_close,
)
if not isinstance(keys, (list, tuple)):
raise TypeError("keys must be a list/tuple")
if not len(keys):
raise ValueError("keys must have a non-zero length")
if selector is None:
selector = keys[0]
# collect the tables
tbls = [self.get_storer(k) for k in keys]
s = self.get_storer(selector)
# validate rows
nrows = None
for t, k in itertools.chain([(s, selector)], zip(tbls, keys)):
if t is None:
raise KeyError(f"Invalid table [{k}]")
if not t.is_table:
raise TypeError(
f"object [{t.pathname}] is not a table, and cannot be used in all "
"select as multiple"
)
if nrows is None:
nrows = t.nrows
elif t.nrows != nrows:
raise ValueError("all tables must have exactly the same nrows!")
# The isinstance checks here are redundant with the check above,
# but necessary for mypy; see GH#29757
_tbls = [x for x in tbls if isinstance(x, Table)]
# axis is the concentration axes
axis = {t.non_index_axes[0][0] for t in _tbls}.pop()
def func(_start, _stop, _where):
# retrieve the objs, _where is always passed as a set of
# coordinates here
objs = [
t.read(where=_where, columns=columns, start=_start, stop=_stop)
for t in tbls
]
# concat and return
return concat(objs, axis=axis, verify_integrity=False)._consolidate()
# create the iterator
it = TableIterator(
self,
s,
func,
where=where,
nrows=nrows,
start=start,
stop=stop,
iterator=iterator,
chunksize=chunksize,
auto_close=auto_close,
)
return it.get_result(coordinates=True)
def put(
self,
key: str,
value: DataFrame | Series,
format=None,
index: bool = True,
append: bool = False,
complib=None,
complevel: int | None = None,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
data_columns: Literal[True] | list[str] | None = None,
encoding=None,
errors: str = "strict",
track_times: bool = True,
dropna: bool = False,
) -> None:
"""
Store object in HDFStore.
Parameters
----------
key : str
value : {Series, DataFrame}
format : 'fixed(f)|table(t)', default is 'fixed'
Format to use when storing object in HDFStore. Value can be one of:
``'fixed'``
Fixed format. Fast writing/reading. Not-appendable, nor searchable.
``'table'``
Table format. Write as a PyTables Table structure which may perform
worse but allow more flexible operations like searching / selecting
subsets of the data.
index : bool, default True
Write DataFrame index as a column.
append : bool, default False
This will force Table format, append the input data to the existing.
data_columns : list of columns or True, default None
List of columns to create as data columns, or True to use all columns.
See `here
<https://pandas.pydata.org/pandas-docs/stable/user_guide/io.html#query-via-data-columns>`__.
encoding : str, default None
Provide an encoding for strings.
track_times : bool, default True
Parameter is propagated to 'create_table' method of 'PyTables'.
If set to False it enables to have the same h5 files (same hashes)
independent on creation time.
dropna : bool, default False, optional
Remove missing values.
.. versionadded:: 1.1.0
"""
if format is None:
format = get_option("io.hdf.default_format") or "fixed"
format = self._validate_format(format)
self._write_to_group(
key,
value,
format=format,
index=index,
append=append,
complib=complib,
complevel=complevel,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
data_columns=data_columns,
encoding=encoding,
errors=errors,
track_times=track_times,
dropna=dropna,
)
def remove(self, key: str, where=None, start=None, stop=None) -> None:
"""
Remove pandas object partially by specifying the where condition
Parameters
----------
key : str
Node to remove or delete rows from
where : list of Term (or convertible) objects, optional
start : integer (defaults to None), row number to start selection
stop : integer (defaults to None), row number to stop selection
Returns
-------
number of rows removed (or None if not a Table)
Raises
------
raises KeyError if key is not a valid store
"""
where = _ensure_term(where, scope_level=1)
try:
s = self.get_storer(key)
except KeyError:
# the key is not a valid store, re-raising KeyError
raise
except AssertionError:
# surface any assertion errors for e.g. debugging
raise
except Exception as err:
# In tests we get here with ClosedFileError, TypeError, and
# _table_mod.NoSuchNodeError. TODO: Catch only these?
if where is not None:
raise ValueError(
"trying to remove a node with a non-None where clause!"
) from err
# we are actually trying to remove a node (with children)
node = self.get_node(key)
if node is not None:
node._f_remove(recursive=True)
return None
# remove the node
if com.all_none(where, start, stop):
s.group._f_remove(recursive=True)
# delete from the table
else:
if not s.is_table:
raise ValueError(
"can only remove with where on objects written as tables"
)
return s.delete(where=where, start=start, stop=stop)
def append(
self,
key: str,
value: DataFrame | Series,
format=None,
axes=None,
index: bool | list[str] = True,
append: bool = True,
complib=None,
complevel: int | None = None,
columns=None,
min_itemsize: int | dict[str, int] | None = None,
nan_rep=None,
chunksize=None,
expectedrows=None,
dropna: bool | None = None,
data_columns: Literal[True] | list[str] | None = None,
encoding=None,
errors: str = "strict",
) -> None:
"""
Append to Table in file.
Node must already exist and be Table format.
Parameters
----------
key : str
value : {Series, DataFrame}
format : 'table' is the default
Format to use when storing object in HDFStore. Value can be one of:
``'table'``
Table format. Write as a PyTables Table structure which may perform
worse but allow more flexible operations like searching / selecting
subsets of the data.
index : bool, default True
Write DataFrame index as a column.
append : bool, default True
Append the input data to the existing.
data_columns : list of columns, or True, default None
List of columns to create as indexed data columns for on-disk
queries, or True to use all columns. By default only the axes
of the object are indexed. See `here
<https://pandas.pydata.org/pandas-docs/stable/user_guide/io.html#query-via-data-columns>`__.
min_itemsize : dict of columns that specify minimum str sizes
nan_rep : str to use as str nan representation
chunksize : size to chunk the writing
expectedrows : expected TOTAL row size of this table
encoding : default None, provide an encoding for str
dropna : bool, default False, optional
Do not write an ALL nan row to the store settable
by the option 'io.hdf.dropna_table'.
Notes
-----
Does *not* check if data being appended overlaps with existing
data in the table, so be careful
"""
if columns is not None:
raise TypeError(
"columns is not a supported keyword in append, try data_columns"
)
if dropna is None:
dropna = get_option("io.hdf.dropna_table")
if format is None:
format = get_option("io.hdf.default_format") or "table"
format = self._validate_format(format)
self._write_to_group(
key,
value,
format=format,
axes=axes,
index=index,
append=append,
complib=complib,
complevel=complevel,
min_itemsize=min_itemsize,
nan_rep=nan_rep,
chunksize=chunksize,
expectedrows=expectedrows,
dropna=dropna,
data_columns=data_columns,
encoding=encoding,
errors=errors,
)
def append_to_multiple(
self,
d: dict,
value,
selector,
data_columns=None,
axes=None,
dropna: bool = False,
**kwargs,
) -> None:
"""
Append to multiple tables
Parameters
----------
d : a dict of table_name to table_columns, None is acceptable as the
values of one node (this will get all the remaining columns)
value : a pandas object
selector : a string that designates the indexable table; all of its
columns will be designed as data_columns, unless data_columns is
passed, in which case these are used
data_columns : list of columns to create as data columns, or True to
use all columns
dropna : if evaluates to True, drop rows from all tables if any single
row in each table has all NaN. Default False.
Notes
-----
axes parameter is currently not accepted
"""
if axes is not None:
raise TypeError(
"axes is currently not accepted as a parameter to append_to_multiple; "
"you can create the tables independently instead"
)
if not isinstance(d, dict):
raise ValueError(
"append_to_multiple must have a dictionary specified as the "
"way to split the value"
)
if selector not in d:
raise ValueError(
"append_to_multiple requires a selector that is in passed dict"
)
# figure out the splitting axis (the non_index_axis)
axis = list(set(range(value.ndim)) - set(_AXES_MAP[type(value)]))[0]
# figure out how to split the value
remain_key = None
remain_values: list = []
for k, v in d.items():
if v is None:
if remain_key is not None:
raise ValueError(
"append_to_multiple can only have one value in d that is None"
)
remain_key = k
else:
remain_values.extend(v)
if remain_key is not None:
ordered = value.axes[axis]
ordd = ordered.difference(Index(remain_values))
ordd = sorted(ordered.get_indexer(ordd))
d[remain_key] = ordered.take(ordd)
# data_columns
if data_columns is None:
data_columns = d[selector]
# ensure rows are synchronized across the tables
if dropna:
idxs = (value[cols].dropna(how="all").index for cols in d.values())
valid_index = next(idxs)
for index in idxs:
valid_index = valid_index.intersection(index)
value = value.loc[valid_index]
min_itemsize = kwargs.pop("min_itemsize", None)
# append
for k, v in d.items():
dc = data_columns if k == selector else None
# compute the val
val = value.reindex(v, axis=axis)
filtered = (
{key: value for (key, value) in min_itemsize.items() if key in v}
if min_itemsize is not None
else None
)
self.append(k, val, data_columns=dc, min_itemsize=filtered, **kwargs)
def create_table_index(
self,
key: str,
columns=None,
optlevel: int | None = None,
kind: str | None = None,
) -> None:
"""
Create a pytables index on the table.
Parameters
----------
key : str
columns : None, bool, or listlike[str]
Indicate which columns to create an index on.
* False : Do not create any indexes.
* True : Create indexes on all columns.
* None : Create indexes on all columns.
* listlike : Create indexes on the given columns.
optlevel : int or None, default None
Optimization level, if None, pytables defaults to 6.
kind : str or None, default None
Kind of index, if None, pytables defaults to "medium".
Raises
------
TypeError: raises if the node is not a table
"""
# version requirements
_tables()
s = self.get_storer(key)
if s is None:
return
if not isinstance(s, Table):
raise TypeError("cannot create table index on a Fixed format store")
s.create_index(columns=columns, optlevel=optlevel, kind=kind)
def groups(self) -> list:
"""
Return a list of all the top-level nodes.
Each node returned is not a pandas storage object.
Returns
-------
list
List of objects.
"""
_tables()
self._check_if_open()
assert self._handle is not None # for mypy
assert _table_mod is not None # for mypy
return [
g
for g in self._handle.walk_groups()
if (
not isinstance(g, _table_mod.link.Link)
and (
getattr(g._v_attrs, "pandas_type", None)
or getattr(g, "table", None)
or (isinstance(g, _table_mod.table.Table) and g._v_name != "table")
)
)
]
def walk(self, where: str = "/") -> Iterator[tuple[str, list[str], list[str]]]:
"""
Walk the pytables group hierarchy for pandas objects.
This generator will yield the group path, subgroups and pandas object
names for each group.
Any non-pandas PyTables objects that are not a group will be ignored.
The `where` group itself is listed first (preorder), then each of its
child groups (following an alphanumerical order) is also traversed,
following the same procedure.
Parameters
----------
where : str, default "/"
Group where to start walking.
Yields
------
path : str
Full path to a group (without trailing '/').
groups : list
Names (strings) of the groups contained in `path`.
leaves : list
Names (strings) of the pandas objects contained in `path`.
"""
_tables()
self._check_if_open()
assert self._handle is not None # for mypy
assert _table_mod is not None # for mypy
for g in self._handle.walk_groups(where):
if getattr(g._v_attrs, "pandas_type", None) is not None:
continue
groups = []
leaves = []
for child in g._v_children.values():
pandas_type = getattr(child._v_attrs, "pandas_type", None)
if pandas_type is None:
if isinstance(child, _table_mod.group.Group):
groups.append(child._v_name)
else:
leaves.append(child._v_name)
yield (g._v_pathname.rstrip("/"), groups, leaves)
def get_node(self, key: str) -> Node | None:
"""return the node with the key or None if it does not exist"""
self._check_if_open()
if not key.startswith("/"):
key = "/" + key
assert self._handle is not None
assert _table_mod is not None # for mypy
try:
node = self._handle.get_node(self.root, key)
except _table_mod.exceptions.NoSuchNodeError:
return None
assert isinstance(node, _table_mod.Node), type(node)
return node
def get_storer(self, key: str) -> GenericFixed | Table:
"""return the storer object for a key, raise if not in the file"""
group = self.get_node(key)
if group is None:
raise KeyError(f"No object named {key} in the file")
s = self._create_storer(group)
s.infer_axes()
return s
def copy(
self,
file,
mode: str = "w",
propindexes: bool = True,
keys=None,
complib=None,
complevel: int | None = None,
fletcher32: bool = False,
overwrite: bool = True,
) -> HDFStore:
"""
Copy the existing store to a new file, updating in place.
Parameters
----------
propindexes : bool, default True
Restore indexes in copied file.
keys : list, optional
List of keys to include in the copy (defaults to all).
overwrite : bool, default True
Whether to overwrite (remove and replace) existing nodes in the new store.
mode, complib, complevel, fletcher32 same as in HDFStore.__init__
Returns
-------
open file handle of the new store
"""
new_store = HDFStore(
file, mode=mode, complib=complib, complevel=complevel, fletcher32=fletcher32
)
if keys is None:
keys = list(self.keys())
if not isinstance(keys, (tuple, list)):
keys = [keys]
for k in keys:
s = self.get_storer(k)
if s is not None:
if k in new_store:
if overwrite:
new_store.remove(k)
data = self.select(k)
if isinstance(s, Table):
index: bool | list[str] = False
if propindexes:
index = [a.name for a in s.axes if a.is_indexed]
new_store.append(
k,
data,
index=index,
data_columns=getattr(s, "data_columns", None),
encoding=s.encoding,
)
else:
new_store.put(k, data, encoding=s.encoding)
return new_store
def info(self) -> str:
"""
Print detailed information on the store.
Returns
-------
str
"""
path = pprint_thing(self._path)
output = f"{type(self)}\nFile path: {path}\n"
if self.is_open:
lkeys = sorted(self.keys())
if len(lkeys):
keys = []
values = []
for k in lkeys:
try:
s = self.get_storer(k)
if s is not None:
keys.append(pprint_thing(s.pathname or k))
values.append(pprint_thing(s or "invalid_HDFStore node"))
except AssertionError:
# surface any assertion errors for e.g. debugging
raise
except Exception as detail:
keys.append(k)
dstr = pprint_thing(detail)
values.append(f"[invalid_HDFStore node: {dstr}]")
output += adjoin(12, keys, values)
else:
output += "Empty"
else:
output += "File is CLOSED"
return output
# ------------------------------------------------------------------------
# private methods
def _check_if_open(self):
if not self.is_open:
raise ClosedFileError(f"{self._path} file is not open!")
def _validate_format(self, format: str) -> str:
"""validate / deprecate formats"""
# validate
try:
format = _FORMAT_MAP[format.lower()]
except KeyError as err:
raise TypeError(f"invalid HDFStore format specified [{format}]") from err
return format
def _create_storer(
self,
group,
format=None,
value: DataFrame | Series | None = None,
encoding: str = "UTF-8",
errors: str = "strict",
) -> GenericFixed | Table:
"""return a suitable class to operate"""
cls: type[GenericFixed] | type[Table]
if value is not None and not isinstance(value, (Series, DataFrame)):
raise TypeError("value must be None, Series, or DataFrame")
pt = _ensure_decoded(getattr(group._v_attrs, "pandas_type", None))
tt = _ensure_decoded(getattr(group._v_attrs, "table_type", None))
# infer the pt from the passed value
if pt is None:
if value is None:
_tables()
assert _table_mod is not None # for mypy
if getattr(group, "table", None) or isinstance(
group, _table_mod.table.Table
):
pt = "frame_table"
tt = "generic_table"
else:
raise TypeError(
"cannot create a storer if the object is not existing "
"nor a value are passed"
)
else:
if isinstance(value, Series):
pt = "series"
else:
pt = "frame"
# we are actually a table
if format == "table":
pt += "_table"
# a storer node
if "table" not in pt:
_STORER_MAP = {"series": SeriesFixed, "frame": FrameFixed}
try:
cls = _STORER_MAP[pt]
except KeyError as err:
raise TypeError(
f"cannot properly create the storer for: [_STORER_MAP] [group->"
f"{group},value->{type(value)},format->{format}"
) from err
return cls(self, group, encoding=encoding, errors=errors)
# existing node (and must be a table)
if tt is None:
# if we are a writer, determine the tt
if value is not None:
if pt == "series_table":
index = getattr(value, "index", None)
if index is not None:
if index.nlevels == 1:
tt = "appendable_series"
elif index.nlevels > 1:
tt = "appendable_multiseries"
elif pt == "frame_table":
index = getattr(value, "index", None)
if index is not None:
if index.nlevels == 1:
tt = "appendable_frame"
elif index.nlevels > 1:
tt = "appendable_multiframe"
_TABLE_MAP = {
"generic_table": GenericTable,
"appendable_series": AppendableSeriesTable,
"appendable_multiseries": AppendableMultiSeriesTable,
"appendable_frame": AppendableFrameTable,
"appendable_multiframe": AppendableMultiFrameTable,
"worm": WORMTable,
}
try:
cls = _TABLE_MAP[tt]
except KeyError as err:
raise TypeError(
f"cannot properly create the storer for: [_TABLE_MAP] [group->"
f"{group},value->{type(value)},format->{format}"
) from err
return cls(self, group, encoding=encoding, errors=errors)
def _write_to_group(
self,
key: str,
value: DataFrame | Series,
format,
axes=None,
index: bool | list[str] = True,
append: bool = False,
complib=None,
complevel: int | None = None,
fletcher32=None,
min_itemsize: int | dict[str, int] | None = None,
chunksize=None,
expectedrows=None,
dropna: bool = False,
nan_rep=None,
data_columns=None,
encoding=None,
errors: str = "strict",
track_times: bool = True,
) -> None:
# we don't want to store a table node at all if our object is 0-len
# as there are not dtypes
if getattr(value, "empty", None) and (format == "table" or append):
return
group = self._identify_group(key, append)
s = self._create_storer(group, format, value, encoding=encoding, errors=errors)
if append:
# raise if we are trying to append to a Fixed format,
# or a table that exists (and we are putting)
if not s.is_table or (s.is_table and format == "fixed" and s.is_exists):
raise ValueError("Can only append to Tables")
if not s.is_exists:
s.set_object_info()
else:
s.set_object_info()
if not s.is_table and complib:
raise ValueError("Compression not supported on Fixed format stores")
# write the object
s.write(
obj=value,
axes=axes,
append=append,
complib=complib,
complevel=complevel,
fletcher32=fletcher32,
min_itemsize=min_itemsize,
chunksize=chunksize,
expectedrows=expectedrows,
dropna=dropna,
nan_rep=nan_rep,
data_columns=data_columns,
track_times=track_times,
)
if isinstance(s, Table) and index:
s.create_index(columns=index)
def _read_group(self, group: Node):
s = self._create_storer(group)
s.infer_axes()
return s.read()
def _identify_group(self, key: str, append: bool) -> Node:
"""Identify HDF5 group based on key, delete/create group if needed."""
group = self.get_node(key)
# we make this assertion for mypy; the get_node call will already
# have raised if this is incorrect
assert self._handle is not None
# remove the node if we are not appending
if group is not None and not append:
self._handle.remove_node(group, recursive=True)
group = None
if group is None:
group = self._create_nodes_and_group(key)
return group
def _create_nodes_and_group(self, key: str) -> Node:
"""Create nodes from key and return group name."""
# assertion for mypy
assert self._handle is not None
paths = key.split("/")
# recursively create the groups
path = "/"
for p in paths:
if not len(p):
continue
new_path = path
if not path.endswith("/"):
new_path += "/"
new_path += p
group = self.get_node(new_path)
if group is None:
group = self._handle.create_group(path, p)
path = new_path
return group
FilePath = Union[str, "PathLike[str]"]
def stringify_path(filepath_or_buffer: FilePath, convert_file_like: bool = ...) -> str:
...
def stringify_path(
filepath_or_buffer: BaseBufferT, convert_file_like: bool = ...
) -> BaseBufferT:
...
def stringify_path(
filepath_or_buffer: FilePath | BaseBufferT,
convert_file_like: bool = False,
) -> str | BaseBufferT:
"""
Attempt to convert a path-like object to a string.
Parameters
----------
filepath_or_buffer : object to be converted
Returns
-------
str_filepath_or_buffer : maybe a string version of the object
Notes
-----
Objects supporting the fspath protocol (python 3.6+) are coerced
according to its __fspath__ method.
Any other object is passed through unchanged, which includes bytes,
strings, buffers, or anything else that's not even path-like.
"""
if not convert_file_like and is_file_like(filepath_or_buffer):
# GH 38125: some fsspec objects implement os.PathLike but have already opened a
# file. This prevents opening the file a second time. infer_compression calls
# this function with convert_file_like=True to infer the compression.
return cast(BaseBufferT, filepath_or_buffer)
if isinstance(filepath_or_buffer, os.PathLike):
filepath_or_buffer = filepath_or_buffer.__fspath__()
return _expand_user(filepath_or_buffer)
)
The provided code snippet includes necessary dependencies for implementing the `read_hdf` function. Write a Python function `def read_hdf( path_or_buf: FilePath | HDFStore, key=None, mode: str = "r", errors: str = "strict", where: str | list | None = None, start: int | None = None, stop: int | None = None, columns: list[str] | None = None, iterator: bool = False, chunksize: int | None = None, **kwargs, )` to solve the following problem:
Read from the store, close it if we opened it. Retrieve pandas object stored in file, optionally based on where criteria. .. warning:: Pandas uses PyTables for reading and writing HDF5 files, which allows serializing object-dtype data with pickle when using the "fixed" format. Loading pickled data received from untrusted sources can be unsafe. See: https://docs.python.org/3/library/pickle.html for more. Parameters ---------- path_or_buf : str, path object, pandas.HDFStore Any valid string path is acceptable. Only supports the local file system, remote URLs and file-like objects are not supported. If you want to pass in a path object, pandas accepts any ``os.PathLike``. Alternatively, pandas accepts an open :class:`pandas.HDFStore` object. key : object, optional The group identifier in the store. Can be omitted if the HDF file contains a single pandas object. mode : {'r', 'r+', 'a'}, default 'r' Mode to use when opening the file. Ignored if path_or_buf is a :class:`pandas.HDFStore`. Default is 'r'. errors : str, default 'strict' Specifies how encoding and decoding errors are to be handled. See the errors argument for :func:`open` for a full list of options. where : list, optional A list of Term (or convertible) objects. start : int, optional Row number to start selection. stop : int, optional Row number to stop selection. columns : list, optional A list of columns names to return. iterator : bool, optional Return an iterator object. chunksize : int, optional Number of rows to include in an iteration when using an iterator. **kwargs Additional keyword arguments passed to HDFStore. Returns ------- object The selected object. Return type depends on the object stored. See Also -------- DataFrame.to_hdf : Write a HDF file from a DataFrame. HDFStore : Low-level access to HDF files. Examples -------- >>> df = pd.DataFrame([[1, 1.0, 'a']], columns=['x', 'y', 'z']) # doctest: +SKIP >>> df.to_hdf('./store.h5', 'data') # doctest: +SKIP >>> reread = pd.read_hdf('./store.h5') # doctest: +SKIP
Here is the function:
def read_hdf(
path_or_buf: FilePath | HDFStore,
key=None,
mode: str = "r",
errors: str = "strict",
where: str | list | None = None,
start: int | None = None,
stop: int | None = None,
columns: list[str] | None = None,
iterator: bool = False,
chunksize: int | None = None,
**kwargs,
):
"""
Read from the store, close it if we opened it.
Retrieve pandas object stored in file, optionally based on where
criteria.
.. warning::
Pandas uses PyTables for reading and writing HDF5 files, which allows
serializing object-dtype data with pickle when using the "fixed" format.
Loading pickled data received from untrusted sources can be unsafe.
See: https://docs.python.org/3/library/pickle.html for more.
Parameters
----------
path_or_buf : str, path object, pandas.HDFStore
Any valid string path is acceptable. Only supports the local file system,
remote URLs and file-like objects are not supported.
If you want to pass in a path object, pandas accepts any
``os.PathLike``.
Alternatively, pandas accepts an open :class:`pandas.HDFStore` object.
key : object, optional
The group identifier in the store. Can be omitted if the HDF file
contains a single pandas object.
mode : {'r', 'r+', 'a'}, default 'r'
Mode to use when opening the file. Ignored if path_or_buf is a
:class:`pandas.HDFStore`. Default is 'r'.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
where : list, optional
A list of Term (or convertible) objects.
start : int, optional
Row number to start selection.
stop : int, optional
Row number to stop selection.
columns : list, optional
A list of columns names to return.
iterator : bool, optional
Return an iterator object.
chunksize : int, optional
Number of rows to include in an iteration when using an iterator.
**kwargs
Additional keyword arguments passed to HDFStore.
Returns
-------
object
The selected object. Return type depends on the object stored.
See Also
--------
DataFrame.to_hdf : Write a HDF file from a DataFrame.
HDFStore : Low-level access to HDF files.
Examples
--------
>>> df = pd.DataFrame([[1, 1.0, 'a']], columns=['x', 'y', 'z']) # doctest: +SKIP
>>> df.to_hdf('./store.h5', 'data') # doctest: +SKIP
>>> reread = pd.read_hdf('./store.h5') # doctest: +SKIP
"""
if mode not in ["r", "r+", "a"]:
raise ValueError(
f"mode {mode} is not allowed while performing a read. "
f"Allowed modes are r, r+ and a."
)
# grab the scope
if where is not None:
where = _ensure_term(where, scope_level=1)
if isinstance(path_or_buf, HDFStore):
if not path_or_buf.is_open:
raise OSError("The HDFStore must be open for reading.")
store = path_or_buf
auto_close = False
else:
path_or_buf = stringify_path(path_or_buf)
if not isinstance(path_or_buf, str):
raise NotImplementedError(
"Support for generic buffers has not been implemented."
)
try:
exists = os.path.exists(path_or_buf)
# if filepath is too long
except (TypeError, ValueError):
exists = False
if not exists:
raise FileNotFoundError(f"File {path_or_buf} does not exist")
store = HDFStore(path_or_buf, mode=mode, errors=errors, **kwargs)
# can't auto open/close if we are using an iterator
# so delegate to the iterator
auto_close = True
try:
if key is None:
groups = store.groups()
if len(groups) == 0:
raise ValueError(
"Dataset(s) incompatible with Pandas data types, "
"not table, or no datasets found in HDF5 file."
)
candidate_only_group = groups[0]
# For the HDF file to have only one dataset, all other groups
# should then be metadata groups for that candidate group. (This
# assumes that the groups() method enumerates parent groups
# before their children.)
for group_to_check in groups[1:]:
if not _is_metadata_of(group_to_check, candidate_only_group):
raise ValueError(
"key must be provided when HDF5 "
"file contains multiple datasets."
)
key = candidate_only_group._v_pathname
return store.select(
key,
where=where,
start=start,
stop=stop,
columns=columns,
iterator=iterator,
chunksize=chunksize,
auto_close=auto_close,
)
except (ValueError, TypeError, KeyError):
if not isinstance(path_or_buf, HDFStore):
# if there is an error, close the store if we opened it.
with suppress(AttributeError):
store.close()
raise | Read from the store, close it if we opened it. Retrieve pandas object stored in file, optionally based on where criteria. .. warning:: Pandas uses PyTables for reading and writing HDF5 files, which allows serializing object-dtype data with pickle when using the "fixed" format. Loading pickled data received from untrusted sources can be unsafe. See: https://docs.python.org/3/library/pickle.html for more. Parameters ---------- path_or_buf : str, path object, pandas.HDFStore Any valid string path is acceptable. Only supports the local file system, remote URLs and file-like objects are not supported. If you want to pass in a path object, pandas accepts any ``os.PathLike``. Alternatively, pandas accepts an open :class:`pandas.HDFStore` object. key : object, optional The group identifier in the store. Can be omitted if the HDF file contains a single pandas object. mode : {'r', 'r+', 'a'}, default 'r' Mode to use when opening the file. Ignored if path_or_buf is a :class:`pandas.HDFStore`. Default is 'r'. errors : str, default 'strict' Specifies how encoding and decoding errors are to be handled. See the errors argument for :func:`open` for a full list of options. where : list, optional A list of Term (or convertible) objects. start : int, optional Row number to start selection. stop : int, optional Row number to stop selection. columns : list, optional A list of columns names to return. iterator : bool, optional Return an iterator object. chunksize : int, optional Number of rows to include in an iteration when using an iterator. **kwargs Additional keyword arguments passed to HDFStore. Returns ------- object The selected object. Return type depends on the object stored. See Also -------- DataFrame.to_hdf : Write a HDF file from a DataFrame. HDFStore : Low-level access to HDF files. Examples -------- >>> df = pd.DataFrame([[1, 1.0, 'a']], columns=['x', 'y', 'z']) # doctest: +SKIP >>> df.to_hdf('./store.h5', 'data') # doctest: +SKIP >>> reread = pd.read_hdf('./store.h5') # doctest: +SKIP |
173,512 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
AxisInt = int
def _reindex_axis(
obj: DataFrame, axis: AxisInt, labels: Index, other=None
) -> DataFrame:
ax = obj._get_axis(axis)
labels = ensure_index(labels)
# try not to reindex even if other is provided
# if it equals our current index
if other is not None:
other = ensure_index(other)
if (other is None or labels.equals(other)) and labels.equals(ax):
return obj
labels = ensure_index(labels.unique())
if other is not None:
labels = ensure_index(other.unique()).intersection(labels, sort=False)
if not labels.equals(ax):
slicer: list[slice | Index] = [slice(None, None)] * obj.ndim
slicer[axis] = labels
obj = obj.loc[tuple(slicer)]
return obj | null |
173,513 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
class tzinfo:
def tzname(self, dt: Optional[datetime]) -> Optional[str]: ...
def utcoffset(self, dt: Optional[datetime]) -> Optional[timedelta]: ...
def dst(self, dt: Optional[datetime]) -> Optional[timedelta]: ...
def fromutc(self, dt: datetime) -> datetime: ...
The provided code snippet includes necessary dependencies for implementing the `_get_tz` function. Write a Python function `def _get_tz(tz: tzinfo) -> str | tzinfo` to solve the following problem:
for a tz-aware type, return an encoded zone
Here is the function:
def _get_tz(tz: tzinfo) -> str | tzinfo:
"""for a tz-aware type, return an encoded zone"""
zone = timezones.get_timezone(tz)
return zone | for a tz-aware type, return an encoded zone |
173,514 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
class tzinfo:
def tzname(self, dt: Optional[datetime]) -> Optional[str]: ...
def utcoffset(self, dt: Optional[datetime]) -> Optional[timedelta]: ...
def dst(self, dt: Optional[datetime]) -> Optional[timedelta]: ...
def fromutc(self, dt: datetime) -> datetime: ...
def _set_tz(
values: np.ndarray | Index, tz: str | tzinfo, coerce: bool = False
) -> DatetimeIndex:
... | null |
173,515 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
def _set_tz(values: np.ndarray | Index, tz: None, coerce: bool = False) -> np.ndarray:
... | null |
173,516 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
def _ensure_decoded(s):
"""if we have bytes, decode them to unicode"""
if isinstance(s, np.bytes_):
s = s.decode("UTF-8")
return s
class tzinfo:
def tzname(self, dt: Optional[datetime]) -> Optional[str]: ...
def utcoffset(self, dt: Optional[datetime]) -> Optional[timedelta]: ...
def dst(self, dt: Optional[datetime]) -> Optional[timedelta]: ...
def fromutc(self, dt: datetime) -> datetime: ...
The provided code snippet includes necessary dependencies for implementing the `_set_tz` function. Write a Python function `def _set_tz( values: np.ndarray | Index, tz: str | tzinfo | None, coerce: bool = False ) -> np.ndarray | DatetimeIndex` to solve the following problem:
coerce the values to a DatetimeIndex if tz is set preserve the input shape if possible Parameters ---------- values : ndarray or Index tz : str or tzinfo coerce : if we do not have a passed timezone, coerce to M8[ns] ndarray
Here is the function:
def _set_tz(
values: np.ndarray | Index, tz: str | tzinfo | None, coerce: bool = False
) -> np.ndarray | DatetimeIndex:
"""
coerce the values to a DatetimeIndex if tz is set
preserve the input shape if possible
Parameters
----------
values : ndarray or Index
tz : str or tzinfo
coerce : if we do not have a passed timezone, coerce to M8[ns] ndarray
"""
if isinstance(values, DatetimeIndex):
# If values is tzaware, the tz gets dropped in the values.ravel()
# call below (which returns an ndarray). So we are only non-lossy
# if `tz` matches `values.tz`.
assert values.tz is None or values.tz == tz
if tz is not None:
if isinstance(values, DatetimeIndex):
name = values.name
values = values.asi8
else:
name = None
values = values.ravel()
tz = _ensure_decoded(tz)
values = DatetimeIndex(values, name=name)
values = values.tz_localize("UTC").tz_convert(tz)
elif coerce:
values = np.asarray(values, dtype="M8[ns]")
# error: Incompatible return value type (got "Union[ndarray, Index]",
# expected "Union[ndarray, DatetimeIndex]")
return values # type: ignore[return-value] | coerce the values to a DatetimeIndex if tz is set preserve the input shape if possible Parameters ---------- values : ndarray or Index tz : str or tzinfo coerce : if we do not have a passed timezone, coerce to M8[ns] ndarray |
173,517 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
def _tables():
class IndexCol:
def __init__(
self,
name: str,
values=None,
kind=None,
typ=None,
cname: str | None = None,
axis=None,
pos=None,
freq=None,
tz=None,
index_name=None,
ordered=None,
table=None,
meta=None,
metadata=None,
) -> None:
def itemsize(self) -> int:
def kind_attr(self) -> str:
def set_pos(self, pos: int) -> None:
def __repr__(self) -> str:
def __eq__(self, other: Any) -> bool:
def __ne__(self, other) -> bool:
def is_indexed(self) -> bool:
def convert(
self, values: np.ndarray, nan_rep, encoding: str, errors: str
) -> tuple[np.ndarray, np.ndarray] | tuple[Index, Index]:
def take_data(self):
def attrs(self):
def description(self):
def col(self):
def cvalues(self):
def __iter__(self) -> Iterator:
def maybe_set_size(self, min_itemsize=None) -> None:
def validate_names(self) -> None:
def validate_and_set(self, handler: AppendableTable, append: bool) -> None:
def validate_col(self, itemsize=None):
def validate_attr(self, append: bool) -> None:
def update_info(self, info) -> None:
def set_info(self, info) -> None:
def set_attr(self) -> None:
def validate_metadata(self, handler: AppendableTable) -> None:
def write_metadata(self, handler: AppendableTable) -> None:
class DataIndexableCol(DataCol):
def validate_names(self) -> None:
def get_atom_string(cls, shape, itemsize):
def get_atom_data(cls, shape, kind: str) -> Col:
def get_atom_datetime64(cls, shape):
def get_atom_timedelta64(cls, shape):
def _convert_string_array(data: np.ndarray, encoding: str, errors: str) -> np.ndarray:
def _dtype_to_kind(dtype_str: str) -> str:
def _get_data_and_dtype_name(data: ArrayLike):
def is_integer_dtype(arr_or_dtype) -> bool:
def needs_i8_conversion(arr_or_dtype) -> bool:
def is_bool_dtype(arr_or_dtype) -> bool:
def _convert_index(name: str, index: Index, encoding: str, errors: str) -> IndexCol:
assert isinstance(name, str)
index_name = index.name
# error: Argument 1 to "_get_data_and_dtype_name" has incompatible type "Index";
# expected "Union[ExtensionArray, ndarray]"
converted, dtype_name = _get_data_and_dtype_name(index) # type: ignore[arg-type]
kind = _dtype_to_kind(dtype_name)
atom = DataIndexableCol._get_atom(converted)
if (
(isinstance(index.dtype, np.dtype) and is_integer_dtype(index))
or needs_i8_conversion(index.dtype)
or is_bool_dtype(index.dtype)
):
# Includes Index, RangeIndex, DatetimeIndex, TimedeltaIndex, PeriodIndex,
# in which case "kind" is "integer", "integer", "datetime64",
# "timedelta64", and "integer", respectively.
return IndexCol(
name,
values=converted,
kind=kind,
typ=atom,
freq=getattr(index, "freq", None),
tz=getattr(index, "tz", None),
index_name=index_name,
)
if isinstance(index, MultiIndex):
raise TypeError("MultiIndex not supported here!")
inferred_type = lib.infer_dtype(index, skipna=False)
# we won't get inferred_type of "datetime64" or "timedelta64" as these
# would go through the DatetimeIndex/TimedeltaIndex paths above
values = np.asarray(index)
if inferred_type == "date":
converted = np.asarray([v.toordinal() for v in values], dtype=np.int32)
return IndexCol(
name, converted, "date", _tables().Time32Col(), index_name=index_name
)
elif inferred_type == "string":
converted = _convert_string_array(values, encoding, errors)
itemsize = converted.dtype.itemsize
return IndexCol(
name,
converted,
"string",
_tables().StringCol(itemsize),
index_name=index_name,
)
elif inferred_type in ["integer", "floating"]:
return IndexCol(
name, values=converted, kind=kind, typ=atom, index_name=index_name
)
else:
assert isinstance(converted, np.ndarray) and converted.dtype == object
assert kind == "object", kind
atom = _tables().ObjectAtom()
return IndexCol(name, converted, kind, atom, index_name=index_name) | null |
173,518 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
def _unconvert_string_array(
data: np.ndarray, nan_rep, encoding: str, errors: str
) -> np.ndarray:
class date:
def __new__(cls: Type[_S], year: int, month: int, day: int) -> _S:
def fromtimestamp(cls: Type[_S], __timestamp: float) -> _S:
def today(cls: Type[_S]) -> _S:
def fromordinal(cls: Type[_S], n: int) -> _S:
def fromisoformat(cls: Type[_S], date_string: str) -> _S:
def fromisocalendar(cls: Type[_S], year: int, week: int, day: int) -> _S:
def year(self) -> int:
def month(self) -> int:
def day(self) -> int:
def ctime(self) -> str:
def strftime(self, fmt: _Text) -> str:
def __format__(self, fmt: str) -> str:
def __format__(self, fmt: AnyStr) -> AnyStr:
def isoformat(self) -> str:
def timetuple(self) -> struct_time:
def toordinal(self) -> int:
def replace(self, year: int = ..., month: int = ..., day: int = ...) -> date:
def __le__(self, other: date) -> bool:
def __lt__(self, other: date) -> bool:
def __ge__(self, other: date) -> bool:
def __gt__(self, other: date) -> bool:
def __add__(self: _S, other: timedelta) -> _S:
def __radd__(self: _S, other: timedelta) -> _S:
def __add__(self, other: timedelta) -> date:
def __radd__(self, other: timedelta) -> date:
def __sub__(self, other: timedelta) -> date:
def __sub__(self, other: date) -> timedelta:
def __hash__(self) -> int:
def weekday(self) -> int:
def isoweekday(self) -> int:
def isocalendar(self) -> Tuple[int, int, int]:
def _unconvert_index(data, kind: str, encoding: str, errors: str) -> np.ndarray | Index:
index: Index | np.ndarray
if kind == "datetime64":
index = DatetimeIndex(data)
elif kind == "timedelta64":
index = TimedeltaIndex(data)
elif kind == "date":
try:
index = np.asarray([date.fromordinal(v) for v in data], dtype=object)
except ValueError:
index = np.asarray([date.fromtimestamp(v) for v in data], dtype=object)
elif kind in ("integer", "float", "bool"):
index = np.asarray(data)
elif kind in ("string"):
index = _unconvert_string_array(
data, nan_rep=None, encoding=encoding, errors=errors
)
elif kind == "object":
index = np.asarray(data[0])
else: # pragma: no cover
raise ValueError(f"unrecognized index type {kind}")
return index | null |
173,519 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
def _convert_string_array(data: np.ndarray, encoding: str, errors: str) -> np.ndarray:
"""
Take a string-like that is object dtype and coerce to a fixed size string type.
Parameters
----------
data : np.ndarray[object]
encoding : str
errors : str
Handler for encoding errors.
Returns
-------
np.ndarray[fixed-length-string]
"""
# encode if needed
if len(data):
data = (
Series(data.ravel(), copy=False)
.str.encode(encoding, errors)
._values.reshape(data.shape)
)
# create the sized dtype
ensured = ensure_object(data.ravel())
itemsize = max(1, libwriters.max_len_string_array(ensured))
data = np.asarray(data, dtype=f"S{itemsize}")
return data
def cast(typ: Type[_T], val: Any) -> _T: ...
def cast(typ: str, val: Any) -> Any: ...
def cast(typ: object, val: Any) -> Any: ...
ArrayLike = Union["ExtensionArray", np.ndarray]
def _maybe_convert_for_string_atom(
name: str,
bvalues: ArrayLike,
existing_col,
min_itemsize,
nan_rep,
encoding,
errors,
columns: list[str],
):
if bvalues.dtype != object:
return bvalues
bvalues = cast(np.ndarray, bvalues)
dtype_name = bvalues.dtype.name
inferred_type = lib.infer_dtype(bvalues, skipna=False)
if inferred_type == "date":
raise TypeError("[date] is not implemented as a table column")
if inferred_type == "datetime":
# after GH#8260
# this only would be hit for a multi-timezone dtype which is an error
raise TypeError(
"too many timezones in this block, create separate data columns"
)
if not (inferred_type == "string" or dtype_name == "object"):
return bvalues
mask = isna(bvalues)
data = bvalues.copy()
data[mask] = nan_rep
# see if we have a valid string type
inferred_type = lib.infer_dtype(data, skipna=False)
if inferred_type != "string":
# we cannot serialize this data, so report an exception on a column
# by column basis
# expected behaviour:
# search block for a non-string object column by column
for i in range(data.shape[0]):
col = data[i]
inferred_type = lib.infer_dtype(col, skipna=False)
if inferred_type != "string":
error_column_label = columns[i] if len(columns) > i else f"No.{i}"
raise TypeError(
f"Cannot serialize the column [{error_column_label}]\n"
f"because its data contents are not [string] but "
f"[{inferred_type}] object dtype"
)
# itemsize is the maximum length of a string (along any dimension)
data_converted = _convert_string_array(data, encoding, errors).reshape(data.shape)
itemsize = data_converted.itemsize
# specified min_itemsize?
if isinstance(min_itemsize, dict):
min_itemsize = int(min_itemsize.get(name) or min_itemsize.get("values") or 0)
itemsize = max(min_itemsize or 0, itemsize)
# check for column in the values conflicts
if existing_col is not None:
eci = existing_col.validate_col(itemsize)
if eci is not None and eci > itemsize:
itemsize = eci
data_converted = data_converted.astype(f"|S{itemsize}", copy=False)
return data_converted | null |
173,520 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
def _get_converter(kind: str, encoding: str, errors: str):
if kind == "datetime64":
return lambda x: np.asarray(x, dtype="M8[ns]")
elif kind == "string":
return lambda x: _unconvert_string_array(
x, nan_rep=None, encoding=encoding, errors=errors
)
else: # pragma: no cover
raise ValueError(f"invalid kind {kind}")
def _need_convert(kind: str) -> bool:
if kind in ("datetime64", "string"):
return True
return False
def _maybe_convert(values: np.ndarray, val_kind: str, encoding: str, errors: str):
assert isinstance(val_kind, str), type(val_kind)
if _need_convert(val_kind):
conv = _get_converter(val_kind, encoding, errors)
values = conv(values)
return values | null |
173,521 | from __future__ import annotations
from contextlib import suppress
import copy
from datetime import (
date,
tzinfo,
)
import itertools
import os
import re
from textwrap import dedent
from types import TracebackType
from typing import (
TYPE_CHECKING,
Any,
Callable,
Final,
Hashable,
Iterator,
Literal,
Sequence,
cast,
overload,
)
import warnings
import numpy as np
from pandas._config import (
config,
get_option,
)
from pandas._libs import (
lib,
writers as libwriters,
)
from pandas._libs.tslibs import timezones
from pandas._typing import (
AnyArrayLike,
ArrayLike,
AxisInt,
DtypeArg,
FilePath,
Shape,
npt,
)
from pandas.compat._optional import import_optional_dependency
from pandas.compat.pickle_compat import patch_pickle
from pandas.errors import (
AttributeConflictWarning,
ClosedFileError,
IncompatibilityWarning,
PerformanceWarning,
PossibleDataLossError,
)
from pandas.util._decorators import cache_readonly
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_bool_dtype,
is_categorical_dtype,
is_complex_dtype,
is_datetime64_dtype,
is_datetime64tz_dtype,
is_extension_array_dtype,
is_integer_dtype,
is_list_like,
is_object_dtype,
is_string_dtype,
is_timedelta64_dtype,
needs_i8_conversion,
)
from pandas.core.dtypes.missing import array_equivalent
from pandas import (
DataFrame,
DatetimeIndex,
Index,
MultiIndex,
PeriodIndex,
RangeIndex,
Series,
TimedeltaIndex,
concat,
isna,
)
from pandas.core.arrays import (
Categorical,
DatetimeArray,
PeriodArray,
)
import pandas.core.common as com
from pandas.core.computation.pytables import (
PyTablesExpr,
maybe_expression,
)
from pandas.core.construction import extract_array
from pandas.core.indexes.api import ensure_index
from pandas.core.internals import (
ArrayManager,
BlockManager,
)
from pandas.io.common import stringify_path
from pandas.io.formats.printing import (
adjoin,
pprint_thing,
)
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
The provided code snippet includes necessary dependencies for implementing the `_maybe_adjust_name` function. Write a Python function `def _maybe_adjust_name(name: str, version: Sequence[int]) -> str` to solve the following problem:
Prior to 0.10.1, we named values blocks like: values_block_0 an the name values_0, adjust the given name if necessary. Parameters ---------- name : str version : Tuple[int, int, int] Returns ------- str
Here is the function:
def _maybe_adjust_name(name: str, version: Sequence[int]) -> str:
"""
Prior to 0.10.1, we named values blocks like: values_block_0 an the
name values_0, adjust the given name if necessary.
Parameters
----------
name : str
version : Tuple[int, int, int]
Returns
-------
str
"""
if isinstance(version, str) or len(version) < 3:
raise ValueError("Version is incorrect, expected sequence of 3 integers.")
if version[0] == 0 and version[1] <= 10 and version[2] == 0:
m = re.search(r"values_block_(\d+)", name)
if m:
grp = m.groups()[0]
name = f"values_{grp}"
return name | Prior to 0.10.1, we named values blocks like: values_block_0 an the name values_0, adjust the given name if necessary. Parameters ---------- name : str version : Tuple[int, int, int] Returns ------- str |
173,522 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
import codecs
from collections import defaultdict
import dataclasses
import functools
import gzip
from io import (
BufferedIOBase,
BytesIO,
RawIOBase,
StringIO,
TextIOBase,
TextIOWrapper,
)
import mmap
import os
from pathlib import Path
import re
import tarfile
from typing import (
IO,
Any,
AnyStr,
DefaultDict,
Generic,
Hashable,
Literal,
Mapping,
Sequence,
TypeVar,
cast,
overload,
)
from urllib.parse import (
urljoin,
urlparse as parse_url,
uses_netloc,
uses_params,
uses_relative,
)
import warnings
import zipfile
from pandas._typing import (
BaseBuffer,
CompressionDict,
CompressionOptions,
FilePath,
ReadBuffer,
ReadCsvBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat import get_lzma_file
from pandas.compat._optional import import_optional_dependency
from pandas.compat.compressors import BZ2File as _BZ2File
from pandas.util._decorators import doc
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
is_bool,
is_file_like,
is_integer,
is_list_like,
)
from pandas.core.indexes.api import MultiIndex
from pandas.core.shared_docs import _shared_docs
The provided code snippet includes necessary dependencies for implementing the `file_path_to_url` function. Write a Python function `def file_path_to_url(path: str) -> str` to solve the following problem:
converts an absolute native path to a FILE URL. Parameters ---------- path : a path in native format Returns ------- a valid FILE URL
Here is the function:
def file_path_to_url(path: str) -> str:
"""
converts an absolute native path to a FILE URL.
Parameters
----------
path : a path in native format
Returns
-------
a valid FILE URL
"""
# lazify expensive import (~30ms)
from urllib.request import pathname2url
return urljoin("file:", pathname2url(path)) | converts an absolute native path to a FILE URL. Parameters ---------- path : a path in native format Returns ------- a valid FILE URL |
173,523 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
import codecs
from collections import defaultdict
import dataclasses
import functools
import gzip
from io import (
BufferedIOBase,
BytesIO,
RawIOBase,
StringIO,
TextIOBase,
TextIOWrapper,
)
import mmap
import os
from pathlib import Path
import re
import tarfile
from typing import (
IO,
Any,
AnyStr,
DefaultDict,
Generic,
Hashable,
Literal,
Mapping,
Sequence,
TypeVar,
cast,
overload,
)
from urllib.parse import (
urljoin,
urlparse as parse_url,
uses_netloc,
uses_params,
uses_relative,
)
import warnings
import zipfile
from pandas._typing import (
BaseBuffer,
CompressionDict,
CompressionOptions,
FilePath,
ReadBuffer,
ReadCsvBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat import get_lzma_file
from pandas.compat._optional import import_optional_dependency
from pandas.compat.compressors import BZ2File as _BZ2File
from pandas.util._decorators import doc
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
is_bool,
is_file_like,
is_integer,
is_list_like,
)
from pandas.core.indexes.api import MultiIndex
from pandas.core.shared_docs import _shared_docs
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
The provided code snippet includes necessary dependencies for implementing the `is_potential_multi_index` function. Write a Python function `def is_potential_multi_index( columns: Sequence[Hashable] | MultiIndex, index_col: bool | Sequence[int] | None = None, ) -> bool` to solve the following problem:
Check whether or not the `columns` parameter could be converted into a MultiIndex. Parameters ---------- columns : array-like Object which may or may not be convertible into a MultiIndex index_col : None, bool or list, optional Column or columns to use as the (possibly hierarchical) index Returns ------- bool : Whether or not columns could become a MultiIndex
Here is the function:
def is_potential_multi_index(
columns: Sequence[Hashable] | MultiIndex,
index_col: bool | Sequence[int] | None = None,
) -> bool:
"""
Check whether or not the `columns` parameter
could be converted into a MultiIndex.
Parameters
----------
columns : array-like
Object which may or may not be convertible into a MultiIndex
index_col : None, bool or list, optional
Column or columns to use as the (possibly hierarchical) index
Returns
-------
bool : Whether or not columns could become a MultiIndex
"""
if index_col is None or isinstance(index_col, bool):
index_col = []
return bool(
len(columns)
and not isinstance(columns, MultiIndex)
and all(isinstance(c, tuple) for c in columns if c not in list(index_col))
) | Check whether or not the `columns` parameter could be converted into a MultiIndex. Parameters ---------- columns : array-like Object which may or may not be convertible into a MultiIndex index_col : None, bool or list, optional Column or columns to use as the (possibly hierarchical) index Returns ------- bool : Whether or not columns could become a MultiIndex |
173,524 | from __future__ import annotations
from abc import (
ABC,
abstractmethod,
)
import codecs
from collections import defaultdict
import dataclasses
import functools
import gzip
from io import (
BufferedIOBase,
BytesIO,
RawIOBase,
StringIO,
TextIOBase,
TextIOWrapper,
)
import mmap
import os
from pathlib import Path
import re
import tarfile
from typing import (
IO,
Any,
AnyStr,
DefaultDict,
Generic,
Hashable,
Literal,
Mapping,
Sequence,
TypeVar,
cast,
overload,
)
from urllib.parse import (
urljoin,
urlparse as parse_url,
uses_netloc,
uses_params,
uses_relative,
)
import warnings
import zipfile
from pandas._typing import (
BaseBuffer,
CompressionDict,
CompressionOptions,
FilePath,
ReadBuffer,
ReadCsvBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat import get_lzma_file
from pandas.compat._optional import import_optional_dependency
from pandas.compat.compressors import BZ2File as _BZ2File
from pandas.util._decorators import doc
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
is_bool,
is_file_like,
is_integer,
is_list_like,
)
from pandas.core.indexes.api import MultiIndex
from pandas.core.shared_docs import _shared_docs
class defaultdict(Dict[_KT, _VT], Generic[_KT, _VT]):
default_factory: Callable[[], _VT]
def __init__(self, **kwargs: _VT) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]]) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], **kwargs: _VT) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], map: Mapping[_KT, _VT]) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], map: Mapping[_KT, _VT], **kwargs: _VT) -> None: ...
def __init__(self, default_factory: Optional[Callable[[], _VT]], iterable: Iterable[Tuple[_KT, _VT]]) -> None: ...
def __init__(
self, default_factory: Optional[Callable[[], _VT]], iterable: Iterable[Tuple[_KT, _VT]], **kwargs: _VT
) -> None: ...
def __missing__(self, key: _KT) -> _VT: ...
def copy(self: _S) -> _S: ...
DefaultDict = _Alias()
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
The provided code snippet includes necessary dependencies for implementing the `dedup_names` function. Write a Python function `def dedup_names( names: Sequence[Hashable], is_potential_multiindex: bool ) -> Sequence[Hashable]` to solve the following problem:
Rename column names if duplicates exist. Currently the renaming is done by appending a period and an autonumeric, but a custom pattern may be supported in the future. Examples -------- >>> dedup_names(["x", "y", "x", "x"], is_potential_multiindex=False) ['x', 'y', 'x.1', 'x.2']
Here is the function:
def dedup_names(
names: Sequence[Hashable], is_potential_multiindex: bool
) -> Sequence[Hashable]:
"""
Rename column names if duplicates exist.
Currently the renaming is done by appending a period and an autonumeric,
but a custom pattern may be supported in the future.
Examples
--------
>>> dedup_names(["x", "y", "x", "x"], is_potential_multiindex=False)
['x', 'y', 'x.1', 'x.2']
"""
names = list(names) # so we can index
counts: DefaultDict[Hashable, int] = defaultdict(int)
for i, col in enumerate(names):
cur_count = counts[col]
while cur_count > 0:
counts[col] = cur_count + 1
if is_potential_multiindex:
# for mypy
assert isinstance(col, tuple)
col = col[:-1] + (f"{col[-1]}.{cur_count}",)
else:
col = f"{col}.{cur_count}"
cur_count = counts[col]
names[i] = col
counts[col] = cur_count + 1
return names | Rename column names if duplicates exist. Currently the renaming is done by appending a period and an autonumeric, but a custom pattern may be supported in the future. Examples -------- >>> dedup_names(["x", "y", "x", "x"], is_potential_multiindex=False) ['x', 'y', 'x.1', 'x.2'] |
173,525 | from __future__ import annotations
import io
import os
from typing import (
Any,
Literal,
)
import warnings
from warnings import catch_warnings
from pandas._libs import lib
from pandas._typing import (
DtypeBackend,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
import pandas as pd
from pandas import (
DataFrame,
get_option,
)
from pandas.core.shared_docs import _shared_docs
from pandas.util.version import Version
from pandas.io.common import (
IOHandles,
get_handle,
is_fsspec_url,
is_url,
stringify_path,
)
Any = object()
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
class WriteBuffer(BaseBuffer, Protocol[AnyStr_contra]):
def write(self, __b: AnyStr_contra) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
def flush(self) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
def import_optional_dependency(
name: str,
extra: str = "",
errors: str = "raise",
min_version: str | None = None,
):
"""
Import an optional dependency.
By default, if a dependency is missing an ImportError with a nice
message will be raised. If a dependency is present, but too old,
we raise.
Parameters
----------
name : str
The module name.
extra : str
Additional text to include in the ImportError message.
errors : str {'raise', 'warn', 'ignore'}
What to do when a dependency is not found or its version is too old.
* raise : Raise an ImportError
* warn : Only applicable when a module's version is to old.
Warns that the version is too old and returns None
* ignore: If the module is not installed, return None, otherwise,
return the module, even if the version is too old.
It's expected that users validate the version locally when
using ``errors="ignore"`` (see. ``io/html.py``)
min_version : str, default None
Specify a minimum version that is different from the global pandas
minimum version required.
Returns
-------
maybe_module : Optional[ModuleType]
The imported module, when found and the version is correct.
None is returned when the package is not found and `errors`
is False, or when the package's version is too old and `errors`
is ``'warn'``.
"""
assert errors in {"warn", "raise", "ignore"}
package_name = INSTALL_MAPPING.get(name)
install_name = package_name if package_name is not None else name
msg = (
f"Missing optional dependency '{install_name}'. {extra} "
f"Use pip or conda to install {install_name}."
)
try:
module = importlib.import_module(name)
except ImportError:
if errors == "raise":
raise ImportError(msg)
return None
# Handle submodules: if we have submodule, grab parent module from sys.modules
parent = name.split(".")[0]
if parent != name:
install_name = parent
module_to_get = sys.modules[install_name]
else:
module_to_get = module
minimum_version = min_version if min_version is not None else VERSIONS.get(parent)
if minimum_version:
version = get_version(module_to_get)
if version and Version(version) < Version(minimum_version):
msg = (
f"Pandas requires version '{minimum_version}' or newer of '{parent}' "
f"(version '{version}' currently installed)."
)
if errors == "warn":
warnings.warn(
msg,
UserWarning,
stacklevel=find_stack_level(),
)
return None
elif errors == "raise":
raise ImportError(msg)
return module
class IOHandles(Generic[AnyStr]):
"""
Return value of io/common.py:get_handle
Can be used as a context manager.
This is used to easily close created buffers and to handle corner cases when
TextIOWrapper is inserted.
handle: The file handle to be used.
created_handles: All file handles that are created by get_handle
is_wrapped: Whether a TextIOWrapper needs to be detached.
"""
# handle might not implement the IO-interface
handle: IO[AnyStr]
compression: CompressionDict
created_handles: list[IO[bytes] | IO[str]] = dataclasses.field(default_factory=list)
is_wrapped: bool = False
def close(self) -> None:
"""
Close all created buffers.
Note: If a TextIOWrapper was inserted, it is flushed and detached to
avoid closing the potentially user-created buffer.
"""
if self.is_wrapped:
assert isinstance(self.handle, TextIOWrapper)
self.handle.flush()
self.handle.detach()
self.created_handles.remove(self.handle)
for handle in self.created_handles:
handle.close()
self.created_handles = []
self.is_wrapped = False
def __enter__(self) -> IOHandles[AnyStr]:
return self
def __exit__(self, *args: Any) -> None:
self.close()
def is_url(url: object) -> bool:
"""
Check to see if a URL has a valid protocol.
Parameters
----------
url : str or unicode
Returns
-------
isurl : bool
If `url` has a valid protocol return True otherwise False.
"""
if not isinstance(url, str):
return False
return parse_url(url).scheme in _VALID_URLS
def stringify_path(filepath_or_buffer: FilePath, convert_file_like: bool = ...) -> str:
...
def stringify_path(
filepath_or_buffer: BaseBufferT, convert_file_like: bool = ...
) -> BaseBufferT:
...
def stringify_path(
filepath_or_buffer: FilePath | BaseBufferT,
convert_file_like: bool = False,
) -> str | BaseBufferT:
"""
Attempt to convert a path-like object to a string.
Parameters
----------
filepath_or_buffer : object to be converted
Returns
-------
str_filepath_or_buffer : maybe a string version of the object
Notes
-----
Objects supporting the fspath protocol (python 3.6+) are coerced
according to its __fspath__ method.
Any other object is passed through unchanged, which includes bytes,
strings, buffers, or anything else that's not even path-like.
"""
if not convert_file_like and is_file_like(filepath_or_buffer):
# GH 38125: some fsspec objects implement os.PathLike but have already opened a
# file. This prevents opening the file a second time. infer_compression calls
# this function with convert_file_like=True to infer the compression.
return cast(BaseBufferT, filepath_or_buffer)
if isinstance(filepath_or_buffer, os.PathLike):
filepath_or_buffer = filepath_or_buffer.__fspath__()
return _expand_user(filepath_or_buffer)
def is_fsspec_url(url: FilePath | BaseBuffer) -> bool:
"""
Returns true if the given URL looks like
something fsspec can handle
"""
return (
isinstance(url, str)
and bool(_RFC_3986_PATTERN.match(url))
and not url.startswith(("http://", "https://"))
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "filepath_or_buffer",
)
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[False],
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[True] = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: bool = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str] | IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = None,
compression: CompressionOptions = None,
memory_map: bool = False,
is_text: bool = True,
errors: str | None = None,
storage_options: StorageOptions = None,
) -> IOHandles[str] | IOHandles[bytes]:
"""
Get file handle for given path/buffer and mode.
Parameters
----------
path_or_buf : str or file handle
File path or object.
mode : str
Mode to open path_or_buf with.
encoding : str or None
Encoding to use.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other keys as compression options if compression
mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is now
supported for compression modes 'gzip', 'bz2', 'zstd' and 'zip'.
.. versionchanged:: 1.4.0 Zstandard support.
memory_map : bool, default False
See parsers._parser_params for more information. Only used by read_csv.
is_text : bool, default True
Whether the type of the content passed to the file/buffer is string or
bytes. This is not the same as `"b" not in mode`. If a string content is
passed to a binary file/buffer, a wrapper is inserted.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
storage_options: StorageOptions = None
Passed to _get_filepath_or_buffer
.. versionchanged:: 1.2.0
Returns the dataclass IOHandles
"""
# Windows does not default to utf-8. Set to utf-8 for a consistent behavior
encoding = encoding or "utf-8"
errors = errors or "strict"
# read_csv does not know whether the buffer is opened in binary/text mode
if _is_binary_mode(path_or_buf, mode) and "b" not in mode:
mode += "b"
# validate encoding and errors
codecs.lookup(encoding)
if isinstance(errors, str):
codecs.lookup_error(errors)
# open URLs
ioargs = _get_filepath_or_buffer(
path_or_buf,
encoding=encoding,
compression=compression,
mode=mode,
storage_options=storage_options,
)
handle = ioargs.filepath_or_buffer
handles: list[BaseBuffer]
# memory mapping needs to be the first step
# only used for read_csv
handle, memory_map, handles = _maybe_memory_map(handle, memory_map)
is_path = isinstance(handle, str)
compression_args = dict(ioargs.compression)
compression = compression_args.pop("method")
# Only for write methods
if "r" not in mode and is_path:
check_parent_directory(str(handle))
if compression:
if compression != "zstd":
# compression libraries do not like an explicit text-mode
ioargs.mode = ioargs.mode.replace("t", "")
elif compression == "zstd" and "b" not in ioargs.mode:
# python-zstandard defaults to text mode, but we always expect
# compression libraries to use binary mode.
ioargs.mode += "b"
# GZ Compression
if compression == "gzip":
if isinstance(handle, str):
# error: Incompatible types in assignment (expression has type
# "GzipFile", variable has type "Union[str, BaseBuffer]")
handle = gzip.GzipFile( # type: ignore[assignment]
filename=handle,
mode=ioargs.mode,
**compression_args,
)
else:
handle = gzip.GzipFile(
# No overload variant of "GzipFile" matches argument types
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
fileobj=handle, # type: ignore[call-overload]
mode=ioargs.mode,
**compression_args,
)
# BZ Compression
elif compression == "bz2":
# Overload of "BZ2File" to handle pickle protocol 5
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
handle = _BZ2File( # type: ignore[call-overload]
handle,
mode=ioargs.mode,
**compression_args,
)
# ZIP Compression
elif compression == "zip":
# error: Argument 1 to "_BytesZipFile" has incompatible type
# "Union[str, BaseBuffer]"; expected "Union[Union[str, PathLike[str]],
# ReadBuffer[bytes], WriteBuffer[bytes]]"
handle = _BytesZipFile(
handle, ioargs.mode, **compression_args # type: ignore[arg-type]
)
if handle.buffer.mode == "r":
handles.append(handle)
zip_names = handle.buffer.namelist()
if len(zip_names) == 1:
handle = handle.buffer.open(zip_names.pop())
elif not zip_names:
raise ValueError(f"Zero files found in ZIP file {path_or_buf}")
else:
raise ValueError(
"Multiple files found in ZIP file. "
f"Only one file per ZIP: {zip_names}"
)
# TAR Encoding
elif compression == "tar":
compression_args.setdefault("mode", ioargs.mode)
if isinstance(handle, str):
handle = _BytesTarFile(name=handle, **compression_args)
else:
# error: Argument "fileobj" to "_BytesTarFile" has incompatible
# type "BaseBuffer"; expected "Union[ReadBuffer[bytes],
# WriteBuffer[bytes], None]"
handle = _BytesTarFile(
fileobj=handle, **compression_args # type: ignore[arg-type]
)
assert isinstance(handle, _BytesTarFile)
if "r" in handle.buffer.mode:
handles.append(handle)
files = handle.buffer.getnames()
if len(files) == 1:
file = handle.buffer.extractfile(files[0])
assert file is not None
handle = file
elif not files:
raise ValueError(f"Zero files found in TAR archive {path_or_buf}")
else:
raise ValueError(
"Multiple files found in TAR archive. "
f"Only one file per TAR archive: {files}"
)
# XZ Compression
elif compression == "xz":
# error: Argument 1 to "LZMAFile" has incompatible type "Union[str,
# BaseBuffer]"; expected "Optional[Union[Union[str, bytes, PathLike[str],
# PathLike[bytes]], IO[bytes]]]"
handle = get_lzma_file()(handle, ioargs.mode) # type: ignore[arg-type]
# Zstd Compression
elif compression == "zstd":
zstd = import_optional_dependency("zstandard")
if "r" in ioargs.mode:
open_args = {"dctx": zstd.ZstdDecompressor(**compression_args)}
else:
open_args = {"cctx": zstd.ZstdCompressor(**compression_args)}
handle = zstd.open(
handle,
mode=ioargs.mode,
**open_args,
)
# Unrecognized Compression
else:
msg = f"Unrecognized compression type: {compression}"
raise ValueError(msg)
assert not isinstance(handle, str)
handles.append(handle)
elif isinstance(handle, str):
# Check whether the filename is to be opened in binary mode.
# Binary mode does not support 'encoding' and 'newline'.
if ioargs.encoding and "b" not in ioargs.mode:
# Encoding
handle = open(
handle,
ioargs.mode,
encoding=ioargs.encoding,
errors=errors,
newline="",
)
else:
# Binary mode
handle = open(handle, ioargs.mode)
handles.append(handle)
# Convert BytesIO or file objects passed with an encoding
is_wrapped = False
if not is_text and ioargs.mode == "rb" and isinstance(handle, TextIOBase):
# not added to handles as it does not open/buffer resources
handle = _BytesIOWrapper(
handle,
encoding=ioargs.encoding,
)
elif is_text and (
compression or memory_map or _is_binary_mode(handle, ioargs.mode)
):
if (
not hasattr(handle, "readable")
or not hasattr(handle, "writable")
or not hasattr(handle, "seekable")
):
handle = _IOWrapper(handle)
# error: Argument 1 to "TextIOWrapper" has incompatible type
# "_IOWrapper"; expected "IO[bytes]"
handle = TextIOWrapper(
handle, # type: ignore[arg-type]
encoding=ioargs.encoding,
errors=errors,
newline="",
)
handles.append(handle)
# only marked as wrapped when the caller provided a handle
is_wrapped = not (
isinstance(ioargs.filepath_or_buffer, str) or ioargs.should_close
)
if "r" in ioargs.mode and not hasattr(handle, "read"):
raise TypeError(
"Expected file path name or file-like object, "
f"got {type(ioargs.filepath_or_buffer)} type"
)
handles.reverse() # close the most recently added buffer first
if ioargs.should_close:
assert not isinstance(ioargs.filepath_or_buffer, str)
handles.append(ioargs.filepath_or_buffer)
return IOHandles(
# error: Argument "handle" to "IOHandles" has incompatible type
# "Union[TextIOWrapper, GzipFile, BaseBuffer, typing.IO[bytes],
# typing.IO[Any]]"; expected "pandas._typing.IO[Any]"
handle=handle, # type: ignore[arg-type]
# error: Argument "created_handles" to "IOHandles" has incompatible type
# "List[BaseBuffer]"; expected "List[Union[IO[bytes], IO[str]]]"
created_handles=handles, # type: ignore[arg-type]
is_wrapped=is_wrapped,
compression=ioargs.compression,
)
The provided code snippet includes necessary dependencies for implementing the `_get_path_or_handle` function. Write a Python function `def _get_path_or_handle( path: FilePath | ReadBuffer[bytes] | WriteBuffer[bytes], fs: Any, storage_options: StorageOptions = None, mode: str = "rb", is_dir: bool = False, ) -> tuple[ FilePath | ReadBuffer[bytes] | WriteBuffer[bytes], IOHandles[bytes] | None, Any ]` to solve the following problem:
File handling for PyArrow.
Here is the function:
def _get_path_or_handle(
path: FilePath | ReadBuffer[bytes] | WriteBuffer[bytes],
fs: Any,
storage_options: StorageOptions = None,
mode: str = "rb",
is_dir: bool = False,
) -> tuple[
FilePath | ReadBuffer[bytes] | WriteBuffer[bytes], IOHandles[bytes] | None, Any
]:
"""File handling for PyArrow."""
path_or_handle = stringify_path(path)
if is_fsspec_url(path_or_handle) and fs is None:
fsspec = import_optional_dependency("fsspec")
fs, path_or_handle = fsspec.core.url_to_fs(
path_or_handle, **(storage_options or {})
)
elif storage_options and (not is_url(path_or_handle) or mode != "rb"):
# can't write to a remote url
# without making use of fsspec at the moment
raise ValueError("storage_options passed with buffer, or non-supported URL")
handles = None
if (
not fs
and not is_dir
and isinstance(path_or_handle, str)
and not os.path.isdir(path_or_handle)
):
# use get_handle only when we are very certain that it is not a directory
# fsspec resources can also point to directories
# this branch is used for example when reading from non-fsspec URLs
handles = get_handle(
path_or_handle, mode, is_text=False, storage_options=storage_options
)
fs = None
path_or_handle = handles.handle
return path_or_handle, handles, fs | File handling for PyArrow. |
173,526 | from __future__ import annotations
import io
import os
from typing import (
Any,
Literal,
)
import warnings
from warnings import catch_warnings
from pandas._libs import lib
from pandas._typing import (
DtypeBackend,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
import pandas as pd
from pandas import (
DataFrame,
get_option,
)
from pandas.core.shared_docs import _shared_docs
from pandas.util.version import Version
from pandas.io.common import (
IOHandles,
get_handle,
is_fsspec_url,
is_url,
stringify_path,
)
def get_engine(engine: str) -> BaseImpl:
"""return our implementation"""
if engine == "auto":
engine = get_option("io.parquet.engine")
if engine == "auto":
# try engines in this order
engine_classes = [PyArrowImpl, FastParquetImpl]
error_msgs = ""
for engine_class in engine_classes:
try:
return engine_class()
except ImportError as err:
error_msgs += "\n - " + str(err)
raise ImportError(
"Unable to find a usable engine; "
"tried using: 'pyarrow', 'fastparquet'.\n"
"A suitable version of "
"pyarrow or fastparquet is required for parquet "
"support.\n"
"Trying to import the above resulted in these errors:"
f"{error_msgs}"
)
if engine == "pyarrow":
return PyArrowImpl()
elif engine == "fastparquet":
return FastParquetImpl()
raise ValueError("engine must be one of 'pyarrow', 'fastparquet'")
class WriteBuffer(BaseBuffer, Protocol[AnyStr_contra]):
def write(self, __b: AnyStr_contra) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
def flush(self) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
The provided code snippet includes necessary dependencies for implementing the `to_parquet` function. Write a Python function `def to_parquet( df: DataFrame, path: FilePath | WriteBuffer[bytes] | None = None, engine: str = "auto", compression: str | None = "snappy", index: bool | None = None, storage_options: StorageOptions = None, partition_cols: list[str] | None = None, **kwargs, ) -> bytes | None` to solve the following problem:
Write a DataFrame to the parquet format. Parameters ---------- df : DataFrame path : str, path object, file-like object, or None, default None String, path object (implementing ``os.PathLike[str]``), or file-like object implementing a binary ``write()`` function. If None, the result is returned as bytes. If a string, it will be used as Root Directory path when writing a partitioned dataset. The engine fastparquet does not accept file-like objects. .. versionchanged:: 1.2.0 engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto' Parquet library to use. If 'auto', then the option ``io.parquet.engine`` is used. The default ``io.parquet.engine`` behavior is to try 'pyarrow', falling back to 'fastparquet' if 'pyarrow' is unavailable. compression : {{'snappy', 'gzip', 'brotli', 'lz4', 'zstd', None}}, default 'snappy'. Name of the compression to use. Use ``None`` for no compression. The supported compression methods actually depend on which engine is used. For 'pyarrow', 'snappy', 'gzip', 'brotli', 'lz4', 'zstd' are all supported. For 'fastparquet', only 'gzip' and 'snappy' are supported. index : bool, default None If ``True``, include the dataframe's index(es) in the file output. If ``False``, they will not be written to the file. If ``None``, similar to ``True`` the dataframe's index(es) will be saved. However, instead of being saved as values, the RangeIndex will be stored as a range in the metadata so it doesn't require much space and is faster. Other indexes will be included as columns in the file output. partition_cols : str or list, optional, default None Column names by which to partition the dataset. Columns are partitioned in the order they are given. Must be None if path is not a string. {storage_options} .. versionadded:: 1.2.0 kwargs Additional keyword arguments passed to the engine Returns ------- bytes if no path argument is provided else None
Here is the function:
def to_parquet(
df: DataFrame,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
storage_options: StorageOptions = None,
partition_cols: list[str] | None = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the parquet format.
Parameters
----------
df : DataFrame
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string, it will be used as Root Directory path
when writing a partitioned dataset. The engine fastparquet does not
accept file-like objects.
.. versionchanged:: 1.2.0
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', 'lz4', 'zstd', None}},
default 'snappy'. Name of the compression to use. Use ``None``
for no compression. The supported compression methods actually
depend on which engine is used. For 'pyarrow', 'snappy', 'gzip',
'brotli', 'lz4', 'zstd' are all supported. For 'fastparquet',
only 'gzip' and 'snappy' are supported.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output. If
``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : str or list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
kwargs
Additional keyword arguments passed to the engine
Returns
-------
bytes if no path argument is provided else None
"""
if isinstance(partition_cols, str):
partition_cols = [partition_cols]
impl = get_engine(engine)
path_or_buf: FilePath | WriteBuffer[bytes] = io.BytesIO() if path is None else path
impl.write(
df,
path_or_buf,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
if path is None:
assert isinstance(path_or_buf, io.BytesIO)
return path_or_buf.getvalue()
else:
return None | Write a DataFrame to the parquet format. Parameters ---------- df : DataFrame path : str, path object, file-like object, or None, default None String, path object (implementing ``os.PathLike[str]``), or file-like object implementing a binary ``write()`` function. If None, the result is returned as bytes. If a string, it will be used as Root Directory path when writing a partitioned dataset. The engine fastparquet does not accept file-like objects. .. versionchanged:: 1.2.0 engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto' Parquet library to use. If 'auto', then the option ``io.parquet.engine`` is used. The default ``io.parquet.engine`` behavior is to try 'pyarrow', falling back to 'fastparquet' if 'pyarrow' is unavailable. compression : {{'snappy', 'gzip', 'brotli', 'lz4', 'zstd', None}}, default 'snappy'. Name of the compression to use. Use ``None`` for no compression. The supported compression methods actually depend on which engine is used. For 'pyarrow', 'snappy', 'gzip', 'brotli', 'lz4', 'zstd' are all supported. For 'fastparquet', only 'gzip' and 'snappy' are supported. index : bool, default None If ``True``, include the dataframe's index(es) in the file output. If ``False``, they will not be written to the file. If ``None``, similar to ``True`` the dataframe's index(es) will be saved. However, instead of being saved as values, the RangeIndex will be stored as a range in the metadata so it doesn't require much space and is faster. Other indexes will be included as columns in the file output. partition_cols : str or list, optional, default None Column names by which to partition the dataset. Columns are partitioned in the order they are given. Must be None if path is not a string. {storage_options} .. versionadded:: 1.2.0 kwargs Additional keyword arguments passed to the engine Returns ------- bytes if no path argument is provided else None |
173,527 | from __future__ import annotations
import io
import os
from typing import (
Any,
Literal,
)
import warnings
from warnings import catch_warnings
from pandas._libs import lib
from pandas._typing import (
DtypeBackend,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.errors import AbstractMethodError
from pandas.util._decorators import doc
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
import pandas as pd
from pandas import (
DataFrame,
get_option,
)
from pandas.core.shared_docs import _shared_docs
from pandas.util.version import Version
from pandas.io.common import (
IOHandles,
get_handle,
is_fsspec_url,
is_url,
stringify_path,
)
def get_engine(engine: str) -> BaseImpl:
"""return our implementation"""
if engine == "auto":
engine = get_option("io.parquet.engine")
if engine == "auto":
# try engines in this order
engine_classes = [PyArrowImpl, FastParquetImpl]
error_msgs = ""
for engine_class in engine_classes:
try:
return engine_class()
except ImportError as err:
error_msgs += "\n - " + str(err)
raise ImportError(
"Unable to find a usable engine; "
"tried using: 'pyarrow', 'fastparquet'.\n"
"A suitable version of "
"pyarrow or fastparquet is required for parquet "
"support.\n"
"Trying to import the above resulted in these errors:"
f"{error_msgs}"
)
if engine == "pyarrow":
return PyArrowImpl()
elif engine == "fastparquet":
return FastParquetImpl()
raise ValueError("engine must be one of 'pyarrow', 'fastparquet'")
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
The provided code snippet includes necessary dependencies for implementing the `read_parquet` function. Write a Python function `def read_parquet( path: FilePath | ReadBuffer[bytes], engine: str = "auto", columns: list[str] | None = None, storage_options: StorageOptions = None, use_nullable_dtypes: bool | lib.NoDefault = lib.no_default, dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, **kwargs, ) -> DataFrame` to solve the following problem:
Load a parquet object from the file path, returning a DataFrame. Parameters ---------- path : str, path object or file-like object String, path object (implementing ``os.PathLike[str]``), or file-like object implementing a binary ``read()`` function. The string could be a URL. Valid URL schemes include http, ftp, s3, gs, and file. For file URLs, a host is expected. A local file could be: ``file://localhost/path/to/table.parquet``. A file URL can also be a path to a directory that contains multiple partitioned parquet files. Both pyarrow and fastparquet support paths to directories as well as file URLs. A directory path could be: ``file://localhost/path/to/tables`` or ``s3://bucket/partition_dir``. engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto' Parquet library to use. If 'auto', then the option ``io.parquet.engine`` is used. The default ``io.parquet.engine`` behavior is to try 'pyarrow', falling back to 'fastparquet' if 'pyarrow' is unavailable. columns : list, default=None If not None, only these columns will be read from the file. {storage_options} .. versionadded:: 1.3.0 use_nullable_dtypes : bool, default False If True, use dtypes that use ``pd.NA`` as missing value indicator for the resulting DataFrame. (only applicable for the ``pyarrow`` engine) As new dtypes are added that support ``pd.NA`` in the future, the output with this option will change to use those dtypes. Note: this is an experimental option, and behaviour (e.g. additional support dtypes) may change without notice. .. deprecated:: 2.0 dtype_backend : {{"numpy_nullable", "pyarrow"}}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 **kwargs Any additional kwargs are passed to the engine. Returns ------- DataFrame
Here is the function:
def read_parquet(
path: FilePath | ReadBuffer[bytes],
engine: str = "auto",
columns: list[str] | None = None,
storage_options: StorageOptions = None,
use_nullable_dtypes: bool | lib.NoDefault = lib.no_default,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
**kwargs,
) -> DataFrame:
"""
Load a parquet object from the file path, returning a DataFrame.
Parameters
----------
path : str, path object or file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``read()`` function.
The string could be a URL. Valid URL schemes include http, ftp, s3,
gs, and file. For file URLs, a host is expected. A local file could be:
``file://localhost/path/to/table.parquet``.
A file URL can also be a path to a directory that contains multiple
partitioned parquet files. Both pyarrow and fastparquet support
paths to directories as well as file URLs. A directory path could be:
``file://localhost/path/to/tables`` or ``s3://bucket/partition_dir``.
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
columns : list, default=None
If not None, only these columns will be read from the file.
{storage_options}
.. versionadded:: 1.3.0
use_nullable_dtypes : bool, default False
If True, use dtypes that use ``pd.NA`` as missing value indicator
for the resulting DataFrame. (only applicable for the ``pyarrow``
engine)
As new dtypes are added that support ``pd.NA`` in the future, the
output with this option will change to use those dtypes.
Note: this is an experimental option, and behaviour (e.g. additional
support dtypes) may change without notice.
.. deprecated:: 2.0
dtype_backend : {{"numpy_nullable", "pyarrow"}}, defaults to NumPy backed DataFrames
Which dtype_backend to use, e.g. whether a DataFrame should have NumPy
arrays, nullable dtypes are used for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
**kwargs
Any additional kwargs are passed to the engine.
Returns
-------
DataFrame
"""
impl = get_engine(engine)
if use_nullable_dtypes is not lib.no_default:
msg = (
"The argument 'use_nullable_dtypes' is deprecated and will be removed "
"in a future version."
)
if use_nullable_dtypes is True:
msg += (
"Use dtype_backend='numpy_nullable' instead of use_nullable_dtype=True."
)
warnings.warn(msg, FutureWarning, stacklevel=find_stack_level())
else:
use_nullable_dtypes = False
check_dtype_backend(dtype_backend)
return impl.read(
path,
columns=columns,
storage_options=storage_options,
use_nullable_dtypes=use_nullable_dtypes,
dtype_backend=dtype_backend,
**kwargs,
) | Load a parquet object from the file path, returning a DataFrame. Parameters ---------- path : str, path object or file-like object String, path object (implementing ``os.PathLike[str]``), or file-like object implementing a binary ``read()`` function. The string could be a URL. Valid URL schemes include http, ftp, s3, gs, and file. For file URLs, a host is expected. A local file could be: ``file://localhost/path/to/table.parquet``. A file URL can also be a path to a directory that contains multiple partitioned parquet files. Both pyarrow and fastparquet support paths to directories as well as file URLs. A directory path could be: ``file://localhost/path/to/tables`` or ``s3://bucket/partition_dir``. engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto' Parquet library to use. If 'auto', then the option ``io.parquet.engine`` is used. The default ``io.parquet.engine`` behavior is to try 'pyarrow', falling back to 'fastparquet' if 'pyarrow' is unavailable. columns : list, default=None If not None, only these columns will be read from the file. {storage_options} .. versionadded:: 1.3.0 use_nullable_dtypes : bool, default False If True, use dtypes that use ``pd.NA`` as missing value indicator for the resulting DataFrame. (only applicable for the ``pyarrow`` engine) As new dtypes are added that support ``pd.NA`` in the future, the output with this option will change to use those dtypes. Note: this is an experimental option, and behaviour (e.g. additional support dtypes) may change without notice. .. deprecated:: 2.0 dtype_backend : {{"numpy_nullable", "pyarrow"}}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 **kwargs Any additional kwargs are passed to the engine. Returns ------- DataFrame |
173,528 | from __future__ import annotations
from io import StringIO
from typing import TYPE_CHECKING
import warnings
from pandas._libs import lib
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.generic import ABCDataFrame
from pandas import (
get_option,
option_context,
)
class StringIO(TextIOWrapper):
def __init__(self, initial_value: Optional[str] = ..., newline: Optional[str] = ...) -> None: ...
# StringIO does not contain a "name" field. This workaround is necessary
# to allow StringIO sub-classes to add this field, as it is defined
# as a read-only property on IO[].
name: Any
def getvalue(self) -> str: ...
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
clipboard_get = paste
The provided code snippet includes necessary dependencies for implementing the `read_clipboard` function. Write a Python function `def read_clipboard( sep: str = r"\s+", dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, **kwargs, )` to solve the following problem:
r""" Read text from clipboard and pass to read_csv. Parameters ---------- sep : str, default '\s+' A string or regex delimiter. The default of '\s+' denotes one or more whitespace characters. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 **kwargs See read_csv for the full argument list. Returns ------- DataFrame A parsed DataFrame object.
Here is the function:
def read_clipboard(
sep: str = r"\s+",
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
**kwargs,
): # pragma: no cover
r"""
Read text from clipboard and pass to read_csv.
Parameters
----------
sep : str, default '\s+'
A string or regex delimiter. The default of '\s+' denotes
one or more whitespace characters.
dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames
Which dtype_backend to use, e.g. whether a DataFrame should have NumPy
arrays, nullable dtypes are used for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
**kwargs
See read_csv for the full argument list.
Returns
-------
DataFrame
A parsed DataFrame object.
"""
encoding = kwargs.pop("encoding", "utf-8")
# only utf-8 is valid for passed value because that's what clipboard
# supports
if encoding is not None and encoding.lower().replace("-", "") != "utf8":
raise NotImplementedError("reading from clipboard only supports utf-8 encoding")
check_dtype_backend(dtype_backend)
from pandas.io.clipboard import clipboard_get
from pandas.io.parsers import read_csv
text = clipboard_get()
# Try to decode (if needed, as "text" might already be a string here).
try:
text = text.decode(kwargs.get("encoding") or get_option("display.encoding"))
except AttributeError:
pass
# Excel copies into clipboard with \t separation
# inspect no more then the 10 first lines, if they
# all contain an equal number (>0) of tabs, infer
# that this came from excel and set 'sep' accordingly
lines = text[:10000].split("\n")[:-1][:10]
# Need to remove leading white space, since read_csv
# accepts:
# a b
# 0 1 2
# 1 3 4
counts = {x.lstrip(" ").count("\t") for x in lines}
if len(lines) > 1 and len(counts) == 1 and counts.pop() != 0:
sep = "\t"
# check the number of leading tabs in the first line
# to account for index columns
index_length = len(lines[0]) - len(lines[0].lstrip(" \t"))
if index_length != 0:
kwargs.setdefault("index_col", list(range(index_length)))
# Edge case where sep is specified to be None, return to default
if sep is None and kwargs.get("delim_whitespace") is None:
sep = r"\s+"
# Regex separator currently only works with python engine.
# Default to python if separator is multi-character (regex)
if len(sep) > 1 and kwargs.get("engine") is None:
kwargs["engine"] = "python"
elif len(sep) > 1 and kwargs.get("engine") == "c":
warnings.warn(
"read_clipboard with regex separator does not work properly with c engine.",
stacklevel=find_stack_level(),
)
return read_csv(StringIO(text), sep=sep, dtype_backend=dtype_backend, **kwargs) | r""" Read text from clipboard and pass to read_csv. Parameters ---------- sep : str, default '\s+' A string or regex delimiter. The default of '\s+' denotes one or more whitespace characters. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 **kwargs See read_csv for the full argument list. Returns ------- DataFrame A parsed DataFrame object. |
173,529 | from __future__ import annotations
from io import StringIO
from typing import TYPE_CHECKING
import warnings
from pandas._libs import lib
from pandas.util._exceptions import find_stack_level
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.generic import ABCDataFrame
from pandas import (
get_option,
option_context,
)
class StringIO(TextIOWrapper):
def __init__(self, initial_value: Optional[str] = ..., newline: Optional[str] = ...) -> None: ...
# StringIO does not contain a "name" field. This workaround is necessary
# to allow StringIO sub-classes to add this field, as it is defined
# as a read-only property on IO[].
name: Any
def getvalue(self) -> str: ...
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
ABCDataFrame = cast(
"Type[DataFrame]", create_pandas_abc_type("ABCDataFrame", "_typ", ("dataframe",))
)
clipboard_set = copy
The provided code snippet includes necessary dependencies for implementing the `to_clipboard` function. Write a Python function `def to_clipboard( obj, excel: bool | None = True, sep: str | None = None, **kwargs ) -> None` to solve the following problem:
Attempt to write text representation of object to the system clipboard The clipboard can be then pasted into Excel for example. Parameters ---------- obj : the object to write to the clipboard excel : bool, defaults to True if True, use the provided separator, writing in a csv format for allowing easy pasting into excel. if False, write a string representation of the object to the clipboard sep : optional, defaults to tab other keywords are passed to to_csv Notes ----- Requirements for your platform - Linux: xclip, or xsel (with PyQt4 modules) - Windows: - OS X:
Here is the function:
def to_clipboard(
obj, excel: bool | None = True, sep: str | None = None, **kwargs
) -> None: # pragma: no cover
"""
Attempt to write text representation of object to the system clipboard
The clipboard can be then pasted into Excel for example.
Parameters
----------
obj : the object to write to the clipboard
excel : bool, defaults to True
if True, use the provided separator, writing in a csv
format for allowing easy pasting into excel.
if False, write a string representation of the object
to the clipboard
sep : optional, defaults to tab
other keywords are passed to to_csv
Notes
-----
Requirements for your platform
- Linux: xclip, or xsel (with PyQt4 modules)
- Windows:
- OS X:
"""
encoding = kwargs.pop("encoding", "utf-8")
# testing if an invalid encoding is passed to clipboard
if encoding is not None and encoding.lower().replace("-", "") != "utf8":
raise ValueError("clipboard only supports utf-8 encoding")
from pandas.io.clipboard import clipboard_set
if excel is None:
excel = True
if excel:
try:
if sep is None:
sep = "\t"
buf = StringIO()
# clipboard_set (pyperclip) expects unicode
obj.to_csv(buf, sep=sep, encoding="utf-8", **kwargs)
text = buf.getvalue()
clipboard_set(text)
return
except TypeError:
warnings.warn(
"to_clipboard in excel mode requires a single character separator.",
stacklevel=find_stack_level(),
)
elif sep is not None:
warnings.warn(
"to_clipboard with excel=False ignores the sep argument.",
stacklevel=find_stack_level(),
)
if isinstance(obj, ABCDataFrame):
# str(df) has various unhelpful defaults, like truncation
with option_context("display.max_colwidth", None):
objstr = obj.to_string(**kwargs)
else:
objstr = str(obj)
clipboard_set(objstr) | Attempt to write text representation of object to the system clipboard The clipboard can be then pasted into Excel for example. Parameters ---------- obj : the object to write to the clipboard excel : bool, defaults to True if True, use the provided separator, writing in a csv format for allowing easy pasting into excel. if False, write a string representation of the object to the clipboard sep : optional, defaults to tab other keywords are passed to to_csv Notes ----- Requirements for your platform - Linux: xclip, or xsel (with PyQt4 modules) - Windows: - OS X: |
173,530 | from __future__ import annotations
import io
from types import ModuleType
from typing import (
Any,
Literal,
)
from pandas._libs import lib
from pandas._typing import (
DtypeBackend,
FilePath,
ReadBuffer,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_categorical_dtype,
is_interval_dtype,
is_period_dtype,
is_unsigned_integer_dtype,
)
import pandas as pd
from pandas.core.frame import DataFrame
from pandas.io.common import get_handle
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def import_optional_dependency(
name: str,
extra: str = "",
errors: str = "raise",
min_version: str | None = None,
):
"""
Import an optional dependency.
By default, if a dependency is missing an ImportError with a nice
message will be raised. If a dependency is present, but too old,
we raise.
Parameters
----------
name : str
The module name.
extra : str
Additional text to include in the ImportError message.
errors : str {'raise', 'warn', 'ignore'}
What to do when a dependency is not found or its version is too old.
* raise : Raise an ImportError
* warn : Only applicable when a module's version is to old.
Warns that the version is too old and returns None
* ignore: If the module is not installed, return None, otherwise,
return the module, even if the version is too old.
It's expected that users validate the version locally when
using ``errors="ignore"`` (see. ``io/html.py``)
min_version : str, default None
Specify a minimum version that is different from the global pandas
minimum version required.
Returns
-------
maybe_module : Optional[ModuleType]
The imported module, when found and the version is correct.
None is returned when the package is not found and `errors`
is False, or when the package's version is too old and `errors`
is ``'warn'``.
"""
assert errors in {"warn", "raise", "ignore"}
package_name = INSTALL_MAPPING.get(name)
install_name = package_name if package_name is not None else name
msg = (
f"Missing optional dependency '{install_name}'. {extra} "
f"Use pip or conda to install {install_name}."
)
try:
module = importlib.import_module(name)
except ImportError:
if errors == "raise":
raise ImportError(msg)
return None
# Handle submodules: if we have submodule, grab parent module from sys.modules
parent = name.split(".")[0]
if parent != name:
install_name = parent
module_to_get = sys.modules[install_name]
else:
module_to_get = module
minimum_version = min_version if min_version is not None else VERSIONS.get(parent)
if minimum_version:
version = get_version(module_to_get)
if version and Version(version) < Version(minimum_version):
msg = (
f"Pandas requires version '{minimum_version}' or newer of '{parent}' "
f"(version '{version}' currently installed)."
)
if errors == "warn":
warnings.warn(
msg,
UserWarning,
stacklevel=find_stack_level(),
)
return None
elif errors == "raise":
raise ImportError(msg)
return module
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
)
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[False],
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[True] = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: bool = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str] | IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = None,
compression: CompressionOptions = None,
memory_map: bool = False,
is_text: bool = True,
errors: str | None = None,
storage_options: StorageOptions = None,
) -> IOHandles[str] | IOHandles[bytes]:
"""
Get file handle for given path/buffer and mode.
Parameters
----------
path_or_buf : str or file handle
File path or object.
mode : str
Mode to open path_or_buf with.
encoding : str or None
Encoding to use.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other keys as compression options if compression
mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is now
supported for compression modes 'gzip', 'bz2', 'zstd' and 'zip'.
.. versionchanged:: 1.4.0 Zstandard support.
memory_map : bool, default False
See parsers._parser_params for more information. Only used by read_csv.
is_text : bool, default True
Whether the type of the content passed to the file/buffer is string or
bytes. This is not the same as `"b" not in mode`. If a string content is
passed to a binary file/buffer, a wrapper is inserted.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
storage_options: StorageOptions = None
Passed to _get_filepath_or_buffer
.. versionchanged:: 1.2.0
Returns the dataclass IOHandles
"""
# Windows does not default to utf-8. Set to utf-8 for a consistent behavior
encoding = encoding or "utf-8"
errors = errors or "strict"
# read_csv does not know whether the buffer is opened in binary/text mode
if _is_binary_mode(path_or_buf, mode) and "b" not in mode:
mode += "b"
# validate encoding and errors
codecs.lookup(encoding)
if isinstance(errors, str):
codecs.lookup_error(errors)
# open URLs
ioargs = _get_filepath_or_buffer(
path_or_buf,
encoding=encoding,
compression=compression,
mode=mode,
storage_options=storage_options,
)
handle = ioargs.filepath_or_buffer
handles: list[BaseBuffer]
# memory mapping needs to be the first step
# only used for read_csv
handle, memory_map, handles = _maybe_memory_map(handle, memory_map)
is_path = isinstance(handle, str)
compression_args = dict(ioargs.compression)
compression = compression_args.pop("method")
# Only for write methods
if "r" not in mode and is_path:
check_parent_directory(str(handle))
if compression:
if compression != "zstd":
# compression libraries do not like an explicit text-mode
ioargs.mode = ioargs.mode.replace("t", "")
elif compression == "zstd" and "b" not in ioargs.mode:
# python-zstandard defaults to text mode, but we always expect
# compression libraries to use binary mode.
ioargs.mode += "b"
# GZ Compression
if compression == "gzip":
if isinstance(handle, str):
# error: Incompatible types in assignment (expression has type
# "GzipFile", variable has type "Union[str, BaseBuffer]")
handle = gzip.GzipFile( # type: ignore[assignment]
filename=handle,
mode=ioargs.mode,
**compression_args,
)
else:
handle = gzip.GzipFile(
# No overload variant of "GzipFile" matches argument types
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
fileobj=handle, # type: ignore[call-overload]
mode=ioargs.mode,
**compression_args,
)
# BZ Compression
elif compression == "bz2":
# Overload of "BZ2File" to handle pickle protocol 5
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
handle = _BZ2File( # type: ignore[call-overload]
handle,
mode=ioargs.mode,
**compression_args,
)
# ZIP Compression
elif compression == "zip":
# error: Argument 1 to "_BytesZipFile" has incompatible type
# "Union[str, BaseBuffer]"; expected "Union[Union[str, PathLike[str]],
# ReadBuffer[bytes], WriteBuffer[bytes]]"
handle = _BytesZipFile(
handle, ioargs.mode, **compression_args # type: ignore[arg-type]
)
if handle.buffer.mode == "r":
handles.append(handle)
zip_names = handle.buffer.namelist()
if len(zip_names) == 1:
handle = handle.buffer.open(zip_names.pop())
elif not zip_names:
raise ValueError(f"Zero files found in ZIP file {path_or_buf}")
else:
raise ValueError(
"Multiple files found in ZIP file. "
f"Only one file per ZIP: {zip_names}"
)
# TAR Encoding
elif compression == "tar":
compression_args.setdefault("mode", ioargs.mode)
if isinstance(handle, str):
handle = _BytesTarFile(name=handle, **compression_args)
else:
# error: Argument "fileobj" to "_BytesTarFile" has incompatible
# type "BaseBuffer"; expected "Union[ReadBuffer[bytes],
# WriteBuffer[bytes], None]"
handle = _BytesTarFile(
fileobj=handle, **compression_args # type: ignore[arg-type]
)
assert isinstance(handle, _BytesTarFile)
if "r" in handle.buffer.mode:
handles.append(handle)
files = handle.buffer.getnames()
if len(files) == 1:
file = handle.buffer.extractfile(files[0])
assert file is not None
handle = file
elif not files:
raise ValueError(f"Zero files found in TAR archive {path_or_buf}")
else:
raise ValueError(
"Multiple files found in TAR archive. "
f"Only one file per TAR archive: {files}"
)
# XZ Compression
elif compression == "xz":
# error: Argument 1 to "LZMAFile" has incompatible type "Union[str,
# BaseBuffer]"; expected "Optional[Union[Union[str, bytes, PathLike[str],
# PathLike[bytes]], IO[bytes]]]"
handle = get_lzma_file()(handle, ioargs.mode) # type: ignore[arg-type]
# Zstd Compression
elif compression == "zstd":
zstd = import_optional_dependency("zstandard")
if "r" in ioargs.mode:
open_args = {"dctx": zstd.ZstdDecompressor(**compression_args)}
else:
open_args = {"cctx": zstd.ZstdCompressor(**compression_args)}
handle = zstd.open(
handle,
mode=ioargs.mode,
**open_args,
)
# Unrecognized Compression
else:
msg = f"Unrecognized compression type: {compression}"
raise ValueError(msg)
assert not isinstance(handle, str)
handles.append(handle)
elif isinstance(handle, str):
# Check whether the filename is to be opened in binary mode.
# Binary mode does not support 'encoding' and 'newline'.
if ioargs.encoding and "b" not in ioargs.mode:
# Encoding
handle = open(
handle,
ioargs.mode,
encoding=ioargs.encoding,
errors=errors,
newline="",
)
else:
# Binary mode
handle = open(handle, ioargs.mode)
handles.append(handle)
# Convert BytesIO or file objects passed with an encoding
is_wrapped = False
if not is_text and ioargs.mode == "rb" and isinstance(handle, TextIOBase):
# not added to handles as it does not open/buffer resources
handle = _BytesIOWrapper(
handle,
encoding=ioargs.encoding,
)
elif is_text and (
compression or memory_map or _is_binary_mode(handle, ioargs.mode)
):
if (
not hasattr(handle, "readable")
or not hasattr(handle, "writable")
or not hasattr(handle, "seekable")
):
handle = _IOWrapper(handle)
# error: Argument 1 to "TextIOWrapper" has incompatible type
# "_IOWrapper"; expected "IO[bytes]"
handle = TextIOWrapper(
handle, # type: ignore[arg-type]
encoding=ioargs.encoding,
errors=errors,
newline="",
)
handles.append(handle)
# only marked as wrapped when the caller provided a handle
is_wrapped = not (
isinstance(ioargs.filepath_or_buffer, str) or ioargs.should_close
)
if "r" in ioargs.mode and not hasattr(handle, "read"):
raise TypeError(
"Expected file path name or file-like object, "
f"got {type(ioargs.filepath_or_buffer)} type"
)
handles.reverse() # close the most recently added buffer first
if ioargs.should_close:
assert not isinstance(ioargs.filepath_or_buffer, str)
handles.append(ioargs.filepath_or_buffer)
return IOHandles(
# error: Argument "handle" to "IOHandles" has incompatible type
# "Union[TextIOWrapper, GzipFile, BaseBuffer, typing.IO[bytes],
# typing.IO[Any]]"; expected "pandas._typing.IO[Any]"
handle=handle, # type: ignore[arg-type]
# error: Argument "created_handles" to "IOHandles" has incompatible type
# "List[BaseBuffer]"; expected "List[Union[IO[bytes], IO[str]]]"
created_handles=handles, # type: ignore[arg-type]
is_wrapped=is_wrapped,
compression=ioargs.compression,
)
def _arrow_dtype_mapping() -> dict:
pa = import_optional_dependency("pyarrow")
return {
pa.int8(): pd.Int8Dtype(),
pa.int16(): pd.Int16Dtype(),
pa.int32(): pd.Int32Dtype(),
pa.int64(): pd.Int64Dtype(),
pa.uint8(): pd.UInt8Dtype(),
pa.uint16(): pd.UInt16Dtype(),
pa.uint32(): pd.UInt32Dtype(),
pa.uint64(): pd.UInt64Dtype(),
pa.bool_(): pd.BooleanDtype(),
pa.string(): pd.StringDtype(),
pa.float32(): pd.Float32Dtype(),
pa.float64(): pd.Float64Dtype(),
}
The provided code snippet includes necessary dependencies for implementing the `read_orc` function. Write a Python function `def read_orc( path: FilePath | ReadBuffer[bytes], columns: list[str] | None = None, dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default, **kwargs, ) -> DataFrame` to solve the following problem:
Load an ORC object from the file path, returning a DataFrame. Parameters ---------- path : str, path object, or file-like object String, path object (implementing ``os.PathLike[str]``), or file-like object implementing a binary ``read()`` function. The string could be a URL. Valid URL schemes include http, ftp, s3, and file. For file URLs, a host is expected. A local file could be: ``file://localhost/path/to/table.orc``. columns : list, default None If not None, only these columns will be read from the file. Output always follows the ordering of the file and not the columns list. This mirrors the original behaviour of :external+pyarrow:py:meth:`pyarrow.orc.ORCFile.read`. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 **kwargs Any additional kwargs are passed to pyarrow. Returns ------- DataFrame Notes ----- Before using this function you should read the :ref:`user guide about ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
Here is the function:
def read_orc(
path: FilePath | ReadBuffer[bytes],
columns: list[str] | None = None,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
**kwargs,
) -> DataFrame:
"""
Load an ORC object from the file path, returning a DataFrame.
Parameters
----------
path : str, path object, or file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``read()`` function. The string could be a URL.
Valid URL schemes include http, ftp, s3, and file. For file URLs, a host is
expected. A local file could be:
``file://localhost/path/to/table.orc``.
columns : list, default None
If not None, only these columns will be read from the file.
Output always follows the ordering of the file and not the columns list.
This mirrors the original behaviour of
:external+pyarrow:py:meth:`pyarrow.orc.ORCFile.read`.
dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames
Which dtype_backend to use, e.g. whether a DataFrame should have NumPy
arrays, nullable dtypes are used for all dtypes that have a nullable
implementation when "numpy_nullable" is set, pyarrow is used for all
dtypes if "pyarrow" is set.
The dtype_backends are still experimential.
.. versionadded:: 2.0
**kwargs
Any additional kwargs are passed to pyarrow.
Returns
-------
DataFrame
Notes
-----
Before using this function you should read the :ref:`user guide about ORC <io.orc>`
and :ref:`install optional dependencies <install.warn_orc>`.
"""
# we require a newer version of pyarrow than we support for parquet
orc = import_optional_dependency("pyarrow.orc")
check_dtype_backend(dtype_backend)
with get_handle(path, "rb", is_text=False) as handles:
orc_file = orc.ORCFile(handles.handle)
pa_table = orc_file.read(columns=columns, **kwargs)
if dtype_backend is not lib.no_default:
if dtype_backend == "pyarrow":
df = pa_table.to_pandas(types_mapper=pd.ArrowDtype)
else:
from pandas.io._util import _arrow_dtype_mapping
mapping = _arrow_dtype_mapping()
df = pa_table.to_pandas(types_mapper=mapping.get)
return df
else:
return pa_table.to_pandas() | Load an ORC object from the file path, returning a DataFrame. Parameters ---------- path : str, path object, or file-like object String, path object (implementing ``os.PathLike[str]``), or file-like object implementing a binary ``read()`` function. The string could be a URL. Valid URL schemes include http, ftp, s3, and file. For file URLs, a host is expected. A local file could be: ``file://localhost/path/to/table.orc``. columns : list, default None If not None, only these columns will be read from the file. Output always follows the ordering of the file and not the columns list. This mirrors the original behaviour of :external+pyarrow:py:meth:`pyarrow.orc.ORCFile.read`. dtype_backend : {"numpy_nullable", "pyarrow"}, defaults to NumPy backed DataFrames Which dtype_backend to use, e.g. whether a DataFrame should have NumPy arrays, nullable dtypes are used for all dtypes that have a nullable implementation when "numpy_nullable" is set, pyarrow is used for all dtypes if "pyarrow" is set. The dtype_backends are still experimential. .. versionadded:: 2.0 **kwargs Any additional kwargs are passed to pyarrow. Returns ------- DataFrame Notes ----- Before using this function you should read the :ref:`user guide about ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`. |
173,531 | from __future__ import annotations
import io
from types import ModuleType
from typing import (
Any,
Literal,
)
from pandas._libs import lib
from pandas._typing import (
DtypeBackend,
FilePath,
ReadBuffer,
WriteBuffer,
)
from pandas.compat._optional import import_optional_dependency
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_categorical_dtype,
is_interval_dtype,
is_period_dtype,
is_unsigned_integer_dtype,
)
import pandas as pd
from pandas.core.frame import DataFrame
from pandas.io.common import get_handle
class ModuleType:
__doc__: Optional[str]
__file__: Optional[str]
__name__: str
__package__: Optional[str]
__path__: Optional[Iterable[str]]
__dict__: Dict[str, Any]
def __init__(self, name: str, doc: Optional[str] = ...) -> None: ...
Any = object()
Literal: _SpecialForm = ...
class WriteBuffer(BaseBuffer, Protocol[AnyStr_contra]):
def write(self, __b: AnyStr_contra) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
def flush(self) -> Any:
# for gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
def import_optional_dependency(
name: str,
extra: str = "",
errors: str = "raise",
min_version: str | None = None,
):
"""
Import an optional dependency.
By default, if a dependency is missing an ImportError with a nice
message will be raised. If a dependency is present, but too old,
we raise.
Parameters
----------
name : str
The module name.
extra : str
Additional text to include in the ImportError message.
errors : str {'raise', 'warn', 'ignore'}
What to do when a dependency is not found or its version is too old.
* raise : Raise an ImportError
* warn : Only applicable when a module's version is to old.
Warns that the version is too old and returns None
* ignore: If the module is not installed, return None, otherwise,
return the module, even if the version is too old.
It's expected that users validate the version locally when
using ``errors="ignore"`` (see. ``io/html.py``)
min_version : str, default None
Specify a minimum version that is different from the global pandas
minimum version required.
Returns
-------
maybe_module : Optional[ModuleType]
The imported module, when found and the version is correct.
None is returned when the package is not found and `errors`
is False, or when the package's version is too old and `errors`
is ``'warn'``.
"""
assert errors in {"warn", "raise", "ignore"}
package_name = INSTALL_MAPPING.get(name)
install_name = package_name if package_name is not None else name
msg = (
f"Missing optional dependency '{install_name}'. {extra} "
f"Use pip or conda to install {install_name}."
)
try:
module = importlib.import_module(name)
except ImportError:
if errors == "raise":
raise ImportError(msg)
return None
# Handle submodules: if we have submodule, grab parent module from sys.modules
parent = name.split(".")[0]
if parent != name:
install_name = parent
module_to_get = sys.modules[install_name]
else:
module_to_get = module
minimum_version = min_version if min_version is not None else VERSIONS.get(parent)
if minimum_version:
version = get_version(module_to_get)
if version and Version(version) < Version(minimum_version):
msg = (
f"Pandas requires version '{minimum_version}' or newer of '{parent}' "
f"(version '{version}' currently installed)."
)
if errors == "warn":
warnings.warn(
msg,
UserWarning,
stacklevel=find_stack_level(),
)
return None
elif errors == "raise":
raise ImportError(msg)
return module
def is_period_dtype(arr_or_dtype) -> bool:
"""
Check whether an array-like or dtype is of the Period dtype.
Parameters
----------
arr_or_dtype : array-like or dtype
The array-like or dtype to check.
Returns
-------
boolean
Whether or not the array-like or dtype is of the Period dtype.
Examples
--------
>>> is_period_dtype(object)
False
>>> is_period_dtype(PeriodDtype(freq="D"))
True
>>> is_period_dtype([1, 2, 3])
False
>>> is_period_dtype(pd.Period("2017-01-01"))
False
>>> is_period_dtype(pd.PeriodIndex([], freq="A"))
True
"""
if isinstance(arr_or_dtype, ExtensionDtype):
# GH#33400 fastpath for dtype object
return arr_or_dtype.type is Period
if arr_or_dtype is None:
return False
return PeriodDtype.is_dtype(arr_or_dtype)
def is_interval_dtype(arr_or_dtype) -> bool:
"""
Check whether an array-like or dtype is of the Interval dtype.
Parameters
----------
arr_or_dtype : array-like or dtype
The array-like or dtype to check.
Returns
-------
boolean
Whether or not the array-like or dtype is of the Interval dtype.
Examples
--------
>>> is_interval_dtype(object)
False
>>> is_interval_dtype(IntervalDtype())
True
>>> is_interval_dtype([1, 2, 3])
False
>>>
>>> interval = pd.Interval(1, 2, closed="right")
>>> is_interval_dtype(interval)
False
>>> is_interval_dtype(pd.IntervalIndex([interval]))
True
"""
if isinstance(arr_or_dtype, ExtensionDtype):
# GH#33400 fastpath for dtype object
return arr_or_dtype.type is Interval
if arr_or_dtype is None:
return False
return IntervalDtype.is_dtype(arr_or_dtype)
def is_categorical_dtype(arr_or_dtype) -> bool:
"""
Check whether an array-like or dtype is of the Categorical dtype.
Parameters
----------
arr_or_dtype : array-like or dtype
The array-like or dtype to check.
Returns
-------
boolean
Whether or not the array-like or dtype is of the Categorical dtype.
Examples
--------
>>> from pandas.api.types import is_categorical_dtype
>>> from pandas import CategoricalDtype
>>> is_categorical_dtype(object)
False
>>> is_categorical_dtype(CategoricalDtype())
True
>>> is_categorical_dtype([1, 2, 3])
False
>>> is_categorical_dtype(pd.Categorical([1, 2, 3]))
True
>>> is_categorical_dtype(pd.CategoricalIndex([1, 2, 3]))
True
"""
if isinstance(arr_or_dtype, ExtensionDtype):
# GH#33400 fastpath for dtype object
return arr_or_dtype.name == "category"
if arr_or_dtype is None:
return False
return CategoricalDtype.is_dtype(arr_or_dtype)
def is_unsigned_integer_dtype(arr_or_dtype) -> bool:
"""
Check whether the provided array or dtype is of an unsigned integer dtype.
The nullable Integer dtypes (e.g. pandas.UInt64Dtype) are also
considered as integer by this function.
Parameters
----------
arr_or_dtype : array-like or dtype
The array or dtype to check.
Returns
-------
boolean
Whether or not the array or dtype is of an unsigned integer dtype.
Examples
--------
>>> is_unsigned_integer_dtype(str)
False
>>> is_unsigned_integer_dtype(int) # signed
False
>>> is_unsigned_integer_dtype(float)
False
>>> is_unsigned_integer_dtype(np.uint64)
True
>>> is_unsigned_integer_dtype('uint8')
True
>>> is_unsigned_integer_dtype('UInt8')
True
>>> is_unsigned_integer_dtype(pd.UInt8Dtype)
True
>>> is_unsigned_integer_dtype(np.array(['a', 'b']))
False
>>> is_unsigned_integer_dtype(pd.Series([1, 2])) # signed
False
>>> is_unsigned_integer_dtype(pd.Index([1, 2.])) # float
False
>>> is_unsigned_integer_dtype(np.array([1, 2], dtype=np.uint32))
True
"""
return _is_dtype_type(
arr_or_dtype, classes_and_not_datetimelike(np.unsignedinteger)
) or _is_dtype(
arr_or_dtype, lambda typ: isinstance(typ, ExtensionDtype) and typ.kind == "u"
)
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
)
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[False],
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[True] = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: bool = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str] | IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = None,
compression: CompressionOptions = None,
memory_map: bool = False,
is_text: bool = True,
errors: str | None = None,
storage_options: StorageOptions = None,
) -> IOHandles[str] | IOHandles[bytes]:
"""
Get file handle for given path/buffer and mode.
Parameters
----------
path_or_buf : str or file handle
File path or object.
mode : str
Mode to open path_or_buf with.
encoding : str or None
Encoding to use.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other keys as compression options if compression
mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is now
supported for compression modes 'gzip', 'bz2', 'zstd' and 'zip'.
.. versionchanged:: 1.4.0 Zstandard support.
memory_map : bool, default False
See parsers._parser_params for more information. Only used by read_csv.
is_text : bool, default True
Whether the type of the content passed to the file/buffer is string or
bytes. This is not the same as `"b" not in mode`. If a string content is
passed to a binary file/buffer, a wrapper is inserted.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
storage_options: StorageOptions = None
Passed to _get_filepath_or_buffer
.. versionchanged:: 1.2.0
Returns the dataclass IOHandles
"""
# Windows does not default to utf-8. Set to utf-8 for a consistent behavior
encoding = encoding or "utf-8"
errors = errors or "strict"
# read_csv does not know whether the buffer is opened in binary/text mode
if _is_binary_mode(path_or_buf, mode) and "b" not in mode:
mode += "b"
# validate encoding and errors
codecs.lookup(encoding)
if isinstance(errors, str):
codecs.lookup_error(errors)
# open URLs
ioargs = _get_filepath_or_buffer(
path_or_buf,
encoding=encoding,
compression=compression,
mode=mode,
storage_options=storage_options,
)
handle = ioargs.filepath_or_buffer
handles: list[BaseBuffer]
# memory mapping needs to be the first step
# only used for read_csv
handle, memory_map, handles = _maybe_memory_map(handle, memory_map)
is_path = isinstance(handle, str)
compression_args = dict(ioargs.compression)
compression = compression_args.pop("method")
# Only for write methods
if "r" not in mode and is_path:
check_parent_directory(str(handle))
if compression:
if compression != "zstd":
# compression libraries do not like an explicit text-mode
ioargs.mode = ioargs.mode.replace("t", "")
elif compression == "zstd" and "b" not in ioargs.mode:
# python-zstandard defaults to text mode, but we always expect
# compression libraries to use binary mode.
ioargs.mode += "b"
# GZ Compression
if compression == "gzip":
if isinstance(handle, str):
# error: Incompatible types in assignment (expression has type
# "GzipFile", variable has type "Union[str, BaseBuffer]")
handle = gzip.GzipFile( # type: ignore[assignment]
filename=handle,
mode=ioargs.mode,
**compression_args,
)
else:
handle = gzip.GzipFile(
# No overload variant of "GzipFile" matches argument types
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
fileobj=handle, # type: ignore[call-overload]
mode=ioargs.mode,
**compression_args,
)
# BZ Compression
elif compression == "bz2":
# Overload of "BZ2File" to handle pickle protocol 5
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
handle = _BZ2File( # type: ignore[call-overload]
handle,
mode=ioargs.mode,
**compression_args,
)
# ZIP Compression
elif compression == "zip":
# error: Argument 1 to "_BytesZipFile" has incompatible type
# "Union[str, BaseBuffer]"; expected "Union[Union[str, PathLike[str]],
# ReadBuffer[bytes], WriteBuffer[bytes]]"
handle = _BytesZipFile(
handle, ioargs.mode, **compression_args # type: ignore[arg-type]
)
if handle.buffer.mode == "r":
handles.append(handle)
zip_names = handle.buffer.namelist()
if len(zip_names) == 1:
handle = handle.buffer.open(zip_names.pop())
elif not zip_names:
raise ValueError(f"Zero files found in ZIP file {path_or_buf}")
else:
raise ValueError(
"Multiple files found in ZIP file. "
f"Only one file per ZIP: {zip_names}"
)
# TAR Encoding
elif compression == "tar":
compression_args.setdefault("mode", ioargs.mode)
if isinstance(handle, str):
handle = _BytesTarFile(name=handle, **compression_args)
else:
# error: Argument "fileobj" to "_BytesTarFile" has incompatible
# type "BaseBuffer"; expected "Union[ReadBuffer[bytes],
# WriteBuffer[bytes], None]"
handle = _BytesTarFile(
fileobj=handle, **compression_args # type: ignore[arg-type]
)
assert isinstance(handle, _BytesTarFile)
if "r" in handle.buffer.mode:
handles.append(handle)
files = handle.buffer.getnames()
if len(files) == 1:
file = handle.buffer.extractfile(files[0])
assert file is not None
handle = file
elif not files:
raise ValueError(f"Zero files found in TAR archive {path_or_buf}")
else:
raise ValueError(
"Multiple files found in TAR archive. "
f"Only one file per TAR archive: {files}"
)
# XZ Compression
elif compression == "xz":
# error: Argument 1 to "LZMAFile" has incompatible type "Union[str,
# BaseBuffer]"; expected "Optional[Union[Union[str, bytes, PathLike[str],
# PathLike[bytes]], IO[bytes]]]"
handle = get_lzma_file()(handle, ioargs.mode) # type: ignore[arg-type]
# Zstd Compression
elif compression == "zstd":
zstd = import_optional_dependency("zstandard")
if "r" in ioargs.mode:
open_args = {"dctx": zstd.ZstdDecompressor(**compression_args)}
else:
open_args = {"cctx": zstd.ZstdCompressor(**compression_args)}
handle = zstd.open(
handle,
mode=ioargs.mode,
**open_args,
)
# Unrecognized Compression
else:
msg = f"Unrecognized compression type: {compression}"
raise ValueError(msg)
assert not isinstance(handle, str)
handles.append(handle)
elif isinstance(handle, str):
# Check whether the filename is to be opened in binary mode.
# Binary mode does not support 'encoding' and 'newline'.
if ioargs.encoding and "b" not in ioargs.mode:
# Encoding
handle = open(
handle,
ioargs.mode,
encoding=ioargs.encoding,
errors=errors,
newline="",
)
else:
# Binary mode
handle = open(handle, ioargs.mode)
handles.append(handle)
# Convert BytesIO or file objects passed with an encoding
is_wrapped = False
if not is_text and ioargs.mode == "rb" and isinstance(handle, TextIOBase):
# not added to handles as it does not open/buffer resources
handle = _BytesIOWrapper(
handle,
encoding=ioargs.encoding,
)
elif is_text and (
compression or memory_map or _is_binary_mode(handle, ioargs.mode)
):
if (
not hasattr(handle, "readable")
or not hasattr(handle, "writable")
or not hasattr(handle, "seekable")
):
handle = _IOWrapper(handle)
# error: Argument 1 to "TextIOWrapper" has incompatible type
# "_IOWrapper"; expected "IO[bytes]"
handle = TextIOWrapper(
handle, # type: ignore[arg-type]
encoding=ioargs.encoding,
errors=errors,
newline="",
)
handles.append(handle)
# only marked as wrapped when the caller provided a handle
is_wrapped = not (
isinstance(ioargs.filepath_or_buffer, str) or ioargs.should_close
)
if "r" in ioargs.mode and not hasattr(handle, "read"):
raise TypeError(
"Expected file path name or file-like object, "
f"got {type(ioargs.filepath_or_buffer)} type"
)
handles.reverse() # close the most recently added buffer first
if ioargs.should_close:
assert not isinstance(ioargs.filepath_or_buffer, str)
handles.append(ioargs.filepath_or_buffer)
return IOHandles(
# error: Argument "handle" to "IOHandles" has incompatible type
# "Union[TextIOWrapper, GzipFile, BaseBuffer, typing.IO[bytes],
# typing.IO[Any]]"; expected "pandas._typing.IO[Any]"
handle=handle, # type: ignore[arg-type]
# error: Argument "created_handles" to "IOHandles" has incompatible type
# "List[BaseBuffer]"; expected "List[Union[IO[bytes], IO[str]]]"
created_handles=handles, # type: ignore[arg-type]
is_wrapped=is_wrapped,
compression=ioargs.compression,
)
The provided code snippet includes necessary dependencies for implementing the `to_orc` function. Write a Python function `def to_orc( df: DataFrame, path: FilePath | WriteBuffer[bytes] | None = None, *, engine: Literal["pyarrow"] = "pyarrow", index: bool | None = None, engine_kwargs: dict[str, Any] | None = None, ) -> bytes | None` to solve the following problem:
Write a DataFrame to the ORC format. .. versionadded:: 1.5.0 Parameters ---------- df : DataFrame The dataframe to be written to ORC. Raises NotImplementedError if dtype of one or more columns is category, unsigned integers, intervals, periods or sparse. path : str, file-like object or None, default None If a string, it will be used as Root Directory path when writing a partitioned dataset. By file-like object, we refer to objects with a write() method, such as a file handle (e.g. via builtin open function). If path is None, a bytes object is returned. engine : str, default 'pyarrow' ORC library to use. Pyarrow must be >= 7.0.0. index : bool, optional If ``True``, include the dataframe's index(es) in the file output. If ``False``, they will not be written to the file. If ``None``, similar to ``infer`` the dataframe's index(es) will be saved. However, instead of being saved as values, the RangeIndex will be stored as a range in the metadata so it doesn't require much space and is faster. Other indexes will be included as columns in the file output. engine_kwargs : dict[str, Any] or None, default None Additional keyword arguments passed to :func:`pyarrow.orc.write_table`. Returns ------- bytes if no path argument is provided else None Raises ------ NotImplementedError Dtype of one or more columns is category, unsigned integers, interval, period or sparse. ValueError engine is not pyarrow. Notes ----- * Before using this function you should read the :ref:`user guide about ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`. * This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_ library. * For supported dtypes please refer to `supported ORC features in Arrow <https://arrow.apache.org/docs/cpp/orc.html#data-types>`__. * Currently timezones in datetime columns are not preserved when a dataframe is converted into ORC files.
Here is the function:
def to_orc(
df: DataFrame,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
df : DataFrame
The dataframe to be written to ORC. Raises NotImplementedError
if dtype of one or more columns is category, unsigned integers,
intervals, periods or sparse.
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output. If
``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
Notes
-----
* Before using this function you should read the
:ref:`user guide about ORC <io.orc>` and
:ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
"""
if index is None:
index = df.index.names[0] is not None
if engine_kwargs is None:
engine_kwargs = {}
# If unsupported dtypes are found raise NotImplementedError
# In Pyarrow 9.0.0 this check will no longer be needed
for dtype in df.dtypes:
if (
is_categorical_dtype(dtype)
or is_interval_dtype(dtype)
or is_period_dtype(dtype)
or is_unsigned_integer_dtype(dtype)
):
raise NotImplementedError(
"The dtype of one or more columns is not supported yet."
)
if engine != "pyarrow":
raise ValueError("engine must be 'pyarrow'")
engine = import_optional_dependency(engine, min_version="7.0.0")
orc = import_optional_dependency("pyarrow.orc")
was_none = path is None
if was_none:
path = io.BytesIO()
assert path is not None # For mypy
with get_handle(path, "wb", is_text=False) as handles:
assert isinstance(engine, ModuleType) # For mypy
try:
orc.write_table(
engine.Table.from_pandas(df, preserve_index=index),
handles.handle,
**engine_kwargs,
)
except TypeError as e:
raise NotImplementedError(
"The dtype of one or more columns is not supported yet."
) from e
if was_none:
assert isinstance(path, io.BytesIO) # For mypy
return path.getvalue()
return None | Write a DataFrame to the ORC format. .. versionadded:: 1.5.0 Parameters ---------- df : DataFrame The dataframe to be written to ORC. Raises NotImplementedError if dtype of one or more columns is category, unsigned integers, intervals, periods or sparse. path : str, file-like object or None, default None If a string, it will be used as Root Directory path when writing a partitioned dataset. By file-like object, we refer to objects with a write() method, such as a file handle (e.g. via builtin open function). If path is None, a bytes object is returned. engine : str, default 'pyarrow' ORC library to use. Pyarrow must be >= 7.0.0. index : bool, optional If ``True``, include the dataframe's index(es) in the file output. If ``False``, they will not be written to the file. If ``None``, similar to ``infer`` the dataframe's index(es) will be saved. However, instead of being saved as values, the RangeIndex will be stored as a range in the metadata so it doesn't require much space and is faster. Other indexes will be included as columns in the file output. engine_kwargs : dict[str, Any] or None, default None Additional keyword arguments passed to :func:`pyarrow.orc.write_table`. Returns ------- bytes if no path argument is provided else None Raises ------ NotImplementedError Dtype of one or more columns is category, unsigned integers, interval, period or sparse. ValueError engine is not pyarrow. Notes ----- * Before using this function you should read the :ref:`user guide about ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`. * This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_ library. * For supported dtypes please refer to `supported ORC features in Arrow <https://arrow.apache.org/docs/cpp/orc.html#data-types>`__. * Currently timezones in datetime columns are not preserved when a dataframe is converted into ORC files. |
173,532 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
stata_epoch: Final = datetime.datetime(1960, 1, 1)
class relativedelta(object):
"""
The relativedelta type is designed to be applied to an existing datetime and
can replace specific components of that datetime, or represents an interval
of time.
It is based on the specification of the excellent work done by M.-A. Lemburg
in his
`mx.DateTime <https://www.egenix.com/products/python/mxBase/mxDateTime/>`_ extension.
However, notice that this type does *NOT* implement the same algorithm as
his work. Do *NOT* expect it to behave like mx.DateTime's counterpart.
There are two different ways to build a relativedelta instance. The
first one is passing it two date/datetime classes::
relativedelta(datetime1, datetime2)
The second one is passing it any number of the following keyword arguments::
relativedelta(arg1=x,arg2=y,arg3=z...)
year, month, day, hour, minute, second, microsecond:
Absolute information (argument is singular); adding or subtracting a
relativedelta with absolute information does not perform an arithmetic
operation, but rather REPLACES the corresponding value in the
original datetime with the value(s) in relativedelta.
years, months, weeks, days, hours, minutes, seconds, microseconds:
Relative information, may be negative (argument is plural); adding
or subtracting a relativedelta with relative information performs
the corresponding arithmetic operation on the original datetime value
with the information in the relativedelta.
weekday:
One of the weekday instances (MO, TU, etc) available in the
relativedelta module. These instances may receive a parameter N,
specifying the Nth weekday, which could be positive or negative
(like MO(+1) or MO(-2)). Not specifying it is the same as specifying
+1. You can also use an integer, where 0=MO. This argument is always
relative e.g. if the calculated date is already Monday, using MO(1)
or MO(-1) won't change the day. To effectively make it absolute, use
it in combination with the day argument (e.g. day=1, MO(1) for first
Monday of the month).
leapdays:
Will add given days to the date found, if year is a leap
year, and the date found is post 28 of february.
yearday, nlyearday:
Set the yearday or the non-leap year day (jump leap days).
These are converted to day/month/leapdays information.
There are relative and absolute forms of the keyword
arguments. The plural is relative, and the singular is
absolute. For each argument in the order below, the absolute form
is applied first (by setting each attribute to that value) and
then the relative form (by adding the value to the attribute).
The order of attributes considered when this relativedelta is
added to a datetime is:
1. Year
2. Month
3. Day
4. Hours
5. Minutes
6. Seconds
7. Microseconds
Finally, weekday is applied, using the rule described above.
For example
>>> from datetime import datetime
>>> from dateutil.relativedelta import relativedelta, MO
>>> dt = datetime(2018, 4, 9, 13, 37, 0)
>>> delta = relativedelta(hours=25, day=1, weekday=MO(1))
>>> dt + delta
datetime.datetime(2018, 4, 2, 14, 37)
First, the day is set to 1 (the first of the month), then 25 hours
are added, to get to the 2nd day and 14th hour, finally the
weekday is applied, but since the 2nd is already a Monday there is
no effect.
"""
def __init__(self, dt1=None, dt2=None,
years=0, months=0, days=0, leapdays=0, weeks=0,
hours=0, minutes=0, seconds=0, microseconds=0,
year=None, month=None, day=None, weekday=None,
yearday=None, nlyearday=None,
hour=None, minute=None, second=None, microsecond=None):
if dt1 and dt2:
# datetime is a subclass of date. So both must be date
if not (isinstance(dt1, datetime.date) and
isinstance(dt2, datetime.date)):
raise TypeError("relativedelta only diffs datetime/date")
# We allow two dates, or two datetimes, so we coerce them to be
# of the same type
if (isinstance(dt1, datetime.datetime) !=
isinstance(dt2, datetime.datetime)):
if not isinstance(dt1, datetime.datetime):
dt1 = datetime.datetime.fromordinal(dt1.toordinal())
elif not isinstance(dt2, datetime.datetime):
dt2 = datetime.datetime.fromordinal(dt2.toordinal())
self.years = 0
self.months = 0
self.days = 0
self.leapdays = 0
self.hours = 0
self.minutes = 0
self.seconds = 0
self.microseconds = 0
self.year = None
self.month = None
self.day = None
self.weekday = None
self.hour = None
self.minute = None
self.second = None
self.microsecond = None
self._has_time = 0
# Get year / month delta between the two
months = (dt1.year - dt2.year) * 12 + (dt1.month - dt2.month)
self._set_months(months)
# Remove the year/month delta so the timedelta is just well-defined
# time units (seconds, days and microseconds)
dtm = self.__radd__(dt2)
# If we've overshot our target, make an adjustment
if dt1 < dt2:
compare = operator.gt
increment = 1
else:
compare = operator.lt
increment = -1
while compare(dt1, dtm):
months += increment
self._set_months(months)
dtm = self.__radd__(dt2)
# Get the timedelta between the "months-adjusted" date and dt1
delta = dt1 - dtm
self.seconds = delta.seconds + delta.days * 86400
self.microseconds = delta.microseconds
else:
# Check for non-integer values in integer-only quantities
if any(x is not None and x != int(x) for x in (years, months)):
raise ValueError("Non-integer years and months are "
"ambiguous and not currently supported.")
# Relative information
self.years = int(years)
self.months = int(months)
self.days = days + weeks * 7
self.leapdays = leapdays
self.hours = hours
self.minutes = minutes
self.seconds = seconds
self.microseconds = microseconds
# Absolute information
self.year = year
self.month = month
self.day = day
self.hour = hour
self.minute = minute
self.second = second
self.microsecond = microsecond
if any(x is not None and int(x) != x
for x in (year, month, day, hour,
minute, second, microsecond)):
# For now we'll deprecate floats - later it'll be an error.
warn("Non-integer value passed as absolute information. " +
"This is not a well-defined condition and will raise " +
"errors in future versions.", DeprecationWarning)
if isinstance(weekday, integer_types):
self.weekday = weekdays[weekday]
else:
self.weekday = weekday
yday = 0
if nlyearday:
yday = nlyearday
elif yearday:
yday = yearday
if yearday > 59:
self.leapdays = -1
if yday:
ydayidx = [31, 59, 90, 120, 151, 181, 212,
243, 273, 304, 334, 366]
for idx, ydays in enumerate(ydayidx):
if yday <= ydays:
self.month = idx+1
if idx == 0:
self.day = yday
else:
self.day = yday-ydayidx[idx-1]
break
else:
raise ValueError("invalid year day (%d)" % yday)
self._fix()
def _fix(self):
if abs(self.microseconds) > 999999:
s = _sign(self.microseconds)
div, mod = divmod(self.microseconds * s, 1000000)
self.microseconds = mod * s
self.seconds += div * s
if abs(self.seconds) > 59:
s = _sign(self.seconds)
div, mod = divmod(self.seconds * s, 60)
self.seconds = mod * s
self.minutes += div * s
if abs(self.minutes) > 59:
s = _sign(self.minutes)
div, mod = divmod(self.minutes * s, 60)
self.minutes = mod * s
self.hours += div * s
if abs(self.hours) > 23:
s = _sign(self.hours)
div, mod = divmod(self.hours * s, 24)
self.hours = mod * s
self.days += div * s
if abs(self.months) > 11:
s = _sign(self.months)
div, mod = divmod(self.months * s, 12)
self.months = mod * s
self.years += div * s
if (self.hours or self.minutes or self.seconds or self.microseconds
or self.hour is not None or self.minute is not None or
self.second is not None or self.microsecond is not None):
self._has_time = 1
else:
self._has_time = 0
def weeks(self):
return int(self.days / 7.0)
def weeks(self, value):
self.days = self.days - (self.weeks * 7) + value * 7
def _set_months(self, months):
self.months = months
if abs(self.months) > 11:
s = _sign(self.months)
div, mod = divmod(self.months * s, 12)
self.months = mod * s
self.years = div * s
else:
self.years = 0
def normalized(self):
"""
Return a version of this object represented entirely using integer
values for the relative attributes.
>>> relativedelta(days=1.5, hours=2).normalized()
relativedelta(days=+1, hours=+14)
:return:
Returns a :class:`dateutil.relativedelta.relativedelta` object.
"""
# Cascade remainders down (rounding each to roughly nearest microsecond)
days = int(self.days)
hours_f = round(self.hours + 24 * (self.days - days), 11)
hours = int(hours_f)
minutes_f = round(self.minutes + 60 * (hours_f - hours), 10)
minutes = int(minutes_f)
seconds_f = round(self.seconds + 60 * (minutes_f - minutes), 8)
seconds = int(seconds_f)
microseconds = round(self.microseconds + 1e6 * (seconds_f - seconds))
# Constructor carries overflow back up with call to _fix()
return self.__class__(years=self.years, months=self.months,
days=days, hours=hours, minutes=minutes,
seconds=seconds, microseconds=microseconds,
leapdays=self.leapdays, year=self.year,
month=self.month, day=self.day,
weekday=self.weekday, hour=self.hour,
minute=self.minute, second=self.second,
microsecond=self.microsecond)
def __add__(self, other):
if isinstance(other, relativedelta):
return self.__class__(years=other.years + self.years,
months=other.months + self.months,
days=other.days + self.days,
hours=other.hours + self.hours,
minutes=other.minutes + self.minutes,
seconds=other.seconds + self.seconds,
microseconds=(other.microseconds +
self.microseconds),
leapdays=other.leapdays or self.leapdays,
year=(other.year if other.year is not None
else self.year),
month=(other.month if other.month is not None
else self.month),
day=(other.day if other.day is not None
else self.day),
weekday=(other.weekday if other.weekday is not None
else self.weekday),
hour=(other.hour if other.hour is not None
else self.hour),
minute=(other.minute if other.minute is not None
else self.minute),
second=(other.second if other.second is not None
else self.second),
microsecond=(other.microsecond if other.microsecond
is not None else
self.microsecond))
if isinstance(other, datetime.timedelta):
return self.__class__(years=self.years,
months=self.months,
days=self.days + other.days,
hours=self.hours,
minutes=self.minutes,
seconds=self.seconds + other.seconds,
microseconds=self.microseconds + other.microseconds,
leapdays=self.leapdays,
year=self.year,
month=self.month,
day=self.day,
weekday=self.weekday,
hour=self.hour,
minute=self.minute,
second=self.second,
microsecond=self.microsecond)
if not isinstance(other, datetime.date):
return NotImplemented
elif self._has_time and not isinstance(other, datetime.datetime):
other = datetime.datetime.fromordinal(other.toordinal())
year = (self.year or other.year)+self.years
month = self.month or other.month
if self.months:
assert 1 <= abs(self.months) <= 12
month += self.months
if month > 12:
year += 1
month -= 12
elif month < 1:
year -= 1
month += 12
day = min(calendar.monthrange(year, month)[1],
self.day or other.day)
repl = {"year": year, "month": month, "day": day}
for attr in ["hour", "minute", "second", "microsecond"]:
value = getattr(self, attr)
if value is not None:
repl[attr] = value
days = self.days
if self.leapdays and month > 2 and calendar.isleap(year):
days += self.leapdays
ret = (other.replace(**repl)
+ datetime.timedelta(days=days,
hours=self.hours,
minutes=self.minutes,
seconds=self.seconds,
microseconds=self.microseconds))
if self.weekday:
weekday, nth = self.weekday.weekday, self.weekday.n or 1
jumpdays = (abs(nth) - 1) * 7
if nth > 0:
jumpdays += (7 - ret.weekday() + weekday) % 7
else:
jumpdays += (ret.weekday() - weekday) % 7
jumpdays *= -1
ret += datetime.timedelta(days=jumpdays)
return ret
def __radd__(self, other):
return self.__add__(other)
def __rsub__(self, other):
return self.__neg__().__radd__(other)
def __sub__(self, other):
if not isinstance(other, relativedelta):
return NotImplemented # In case the other object defines __rsub__
return self.__class__(years=self.years - other.years,
months=self.months - other.months,
days=self.days - other.days,
hours=self.hours - other.hours,
minutes=self.minutes - other.minutes,
seconds=self.seconds - other.seconds,
microseconds=self.microseconds - other.microseconds,
leapdays=self.leapdays or other.leapdays,
year=(self.year if self.year is not None
else other.year),
month=(self.month if self.month is not None else
other.month),
day=(self.day if self.day is not None else
other.day),
weekday=(self.weekday if self.weekday is not None else
other.weekday),
hour=(self.hour if self.hour is not None else
other.hour),
minute=(self.minute if self.minute is not None else
other.minute),
second=(self.second if self.second is not None else
other.second),
microsecond=(self.microsecond if self.microsecond
is not None else
other.microsecond))
def __abs__(self):
return self.__class__(years=abs(self.years),
months=abs(self.months),
days=abs(self.days),
hours=abs(self.hours),
minutes=abs(self.minutes),
seconds=abs(self.seconds),
microseconds=abs(self.microseconds),
leapdays=self.leapdays,
year=self.year,
month=self.month,
day=self.day,
weekday=self.weekday,
hour=self.hour,
minute=self.minute,
second=self.second,
microsecond=self.microsecond)
def __neg__(self):
return self.__class__(years=-self.years,
months=-self.months,
days=-self.days,
hours=-self.hours,
minutes=-self.minutes,
seconds=-self.seconds,
microseconds=-self.microseconds,
leapdays=self.leapdays,
year=self.year,
month=self.month,
day=self.day,
weekday=self.weekday,
hour=self.hour,
minute=self.minute,
second=self.second,
microsecond=self.microsecond)
def __bool__(self):
return not (not self.years and
not self.months and
not self.days and
not self.hours and
not self.minutes and
not self.seconds and
not self.microseconds and
not self.leapdays and
self.year is None and
self.month is None and
self.day is None and
self.weekday is None and
self.hour is None and
self.minute is None and
self.second is None and
self.microsecond is None)
# Compatibility with Python 2.x
__nonzero__ = __bool__
def __mul__(self, other):
try:
f = float(other)
except TypeError:
return NotImplemented
return self.__class__(years=int(self.years * f),
months=int(self.months * f),
days=int(self.days * f),
hours=int(self.hours * f),
minutes=int(self.minutes * f),
seconds=int(self.seconds * f),
microseconds=int(self.microseconds * f),
leapdays=self.leapdays,
year=self.year,
month=self.month,
day=self.day,
weekday=self.weekday,
hour=self.hour,
minute=self.minute,
second=self.second,
microsecond=self.microsecond)
__rmul__ = __mul__
def __eq__(self, other):
if not isinstance(other, relativedelta):
return NotImplemented
if self.weekday or other.weekday:
if not self.weekday or not other.weekday:
return False
if self.weekday.weekday != other.weekday.weekday:
return False
n1, n2 = self.weekday.n, other.weekday.n
if n1 != n2 and not ((not n1 or n1 == 1) and (not n2 or n2 == 1)):
return False
return (self.years == other.years and
self.months == other.months and
self.days == other.days and
self.hours == other.hours and
self.minutes == other.minutes and
self.seconds == other.seconds and
self.microseconds == other.microseconds and
self.leapdays == other.leapdays and
self.year == other.year and
self.month == other.month and
self.day == other.day and
self.hour == other.hour and
self.minute == other.minute and
self.second == other.second and
self.microsecond == other.microsecond)
def __hash__(self):
return hash((
self.weekday,
self.years,
self.months,
self.days,
self.hours,
self.minutes,
self.seconds,
self.microseconds,
self.leapdays,
self.year,
self.month,
self.day,
self.hour,
self.minute,
self.second,
self.microsecond,
))
def __ne__(self, other):
return not self.__eq__(other)
def __div__(self, other):
try:
reciprocal = 1 / float(other)
except TypeError:
return NotImplemented
return self.__mul__(reciprocal)
__truediv__ = __div__
def __repr__(self):
l = []
for attr in ["years", "months", "days", "leapdays",
"hours", "minutes", "seconds", "microseconds"]:
value = getattr(self, attr)
if value:
l.append("{attr}={value:+g}".format(attr=attr, value=value))
for attr in ["year", "month", "day", "weekday",
"hour", "minute", "second", "microsecond"]:
value = getattr(self, attr)
if value is not None:
l.append("{attr}={value}".format(attr=attr, value=repr(value)))
return "{classname}({attrs})".format(classname=self.__class__.__name__,
attrs=", ".join(l))
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
class Series(base.IndexOpsMixin, NDFrame): # type: ignore[misc]
"""
One-dimensional ndarray with axis labels (including time series).
Labels need not be unique but must be a hashable type. The object
supports both integer- and label-based indexing and provides a host of
methods for performing operations involving the index. Statistical
methods from ndarray have been overridden to automatically exclude
missing data (currently represented as NaN).
Operations between Series (+, -, /, \\*, \\*\\*) align values based on their
associated index values-- they need not be the same length. The result
index will be the sorted union of the two indexes.
Parameters
----------
data : array-like, Iterable, dict, or scalar value
Contains data stored in Series. If data is a dict, argument order is
maintained.
index : array-like or Index (1d)
Values must be hashable and have the same length as `data`.
Non-unique index values are allowed. Will default to
RangeIndex (0, 1, 2, ..., n) if not provided. If data is dict-like
and index is None, then the keys in the data are used as the index. If the
index is not None, the resulting Series is reindexed with the index values.
dtype : str, numpy.dtype, or ExtensionDtype, optional
Data type for the output Series. If not specified, this will be
inferred from `data`.
See the :ref:`user guide <basics.dtypes>` for more usages.
name : Hashable, default None
The name to give to the Series.
copy : bool, default False
Copy input data. Only affects Series or 1d ndarray input. See examples.
Notes
-----
Please reference the :ref:`User Guide <basics.series>` for more information.
Examples
--------
Constructing Series from a dictionary with an Index specified
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['a', 'b', 'c'])
>>> ser
a 1
b 2
c 3
dtype: int64
The keys of the dictionary match with the Index values, hence the Index
values have no effect.
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['x', 'y', 'z'])
>>> ser
x NaN
y NaN
z NaN
dtype: float64
Note that the Index is first build with the keys from the dictionary.
After this the Series is reindexed with the given Index values, hence we
get all NaN as a result.
Constructing Series from a list with `copy=False`.
>>> r = [1, 2]
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
[1, 2]
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `copy` of
the original data even though `copy=False`, so
the data is unchanged.
Constructing Series from a 1d ndarray with `copy=False`.
>>> r = np.array([1, 2])
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
array([999, 2])
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `view` on
the original data, so
the data is changed as well.
"""
_typ = "series"
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
_name: Hashable
_metadata: list[str] = ["name"]
_internal_names_set = {"index"} | NDFrame._internal_names_set
_accessors = {"dt", "cat", "str", "sparse"}
_hidden_attrs = (
base.IndexOpsMixin._hidden_attrs | NDFrame._hidden_attrs | frozenset([])
)
# Override cache_readonly bc Series is mutable
# error: Incompatible types in assignment (expression has type "property",
# base class "IndexOpsMixin" defined the type as "Callable[[IndexOpsMixin], bool]")
hasnans = property( # type: ignore[assignment]
# error: "Callable[[IndexOpsMixin], bool]" has no attribute "fget"
base.IndexOpsMixin.hasnans.fget, # type: ignore[attr-defined]
doc=base.IndexOpsMixin.hasnans.__doc__,
)
_mgr: SingleManager
div: Callable[[Series, Any], Series]
rdiv: Callable[[Series, Any], Series]
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index=None,
dtype: Dtype | None = None,
name=None,
copy: bool | None = None,
fastpath: bool = False,
) -> None:
if (
isinstance(data, (SingleBlockManager, SingleArrayManager))
and index is None
and dtype is None
and (copy is False or copy is None)
):
if using_copy_on_write():
data = data.copy(deep=False)
# GH#33357 called with just the SingleBlockManager
NDFrame.__init__(self, data)
if fastpath:
# e.g. from _box_col_values, skip validation of name
object.__setattr__(self, "_name", name)
else:
self.name = name
return
if isinstance(data, (ExtensionArray, np.ndarray)):
if copy is not False and using_copy_on_write():
if dtype is None or astype_is_view(data.dtype, pandas_dtype(dtype)):
data = data.copy()
if copy is None:
copy = False
# we are called internally, so short-circuit
if fastpath:
# data is a ndarray, index is defined
if not isinstance(data, (SingleBlockManager, SingleArrayManager)):
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
elif using_copy_on_write() and not copy:
data = data.copy(deep=False)
if copy:
data = data.copy()
# skips validation of the name
object.__setattr__(self, "_name", name)
NDFrame.__init__(self, data)
return
if isinstance(data, SingleBlockManager) and using_copy_on_write() and not copy:
data = data.copy(deep=False)
name = ibase.maybe_extract_name(name, data, type(self))
if index is not None:
index = ensure_index(index)
if dtype is not None:
dtype = self._validate_dtype(dtype)
if data is None:
index = index if index is not None else default_index(0)
if len(index) or dtype is not None:
data = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
data = []
if isinstance(data, MultiIndex):
raise NotImplementedError(
"initializing a Series from a MultiIndex is not supported"
)
refs = None
if isinstance(data, Index):
if dtype is not None:
data = data.astype(dtype, copy=False)
if using_copy_on_write():
refs = data._references
data = data._values
else:
# GH#24096 we need to ensure the index remains immutable
data = data._values.copy()
copy = False
elif isinstance(data, np.ndarray):
if len(data.dtype):
# GH#13296 we are dealing with a compound dtype, which
# should be treated as 2D
raise ValueError(
"Cannot construct a Series from an ndarray with "
"compound dtype. Use DataFrame instead."
)
elif isinstance(data, Series):
if index is None:
index = data.index
data = data._mgr.copy(deep=False)
else:
data = data.reindex(index, copy=copy)
copy = False
data = data._mgr
elif is_dict_like(data):
data, index = self._init_dict(data, index, dtype)
dtype = None
copy = False
elif isinstance(data, (SingleBlockManager, SingleArrayManager)):
if index is None:
index = data.index
elif not data.index.equals(index) or copy:
# GH#19275 SingleBlockManager input should only be called
# internally
raise AssertionError(
"Cannot pass both SingleBlockManager "
"`data` argument and a different "
"`index` argument. `copy` must be False."
)
elif isinstance(data, ExtensionArray):
pass
else:
data = com.maybe_iterable_to_list(data)
if is_list_like(data) and not len(data) and dtype is None:
# GH 29405: Pre-2.0, this defaulted to float.
dtype = np.dtype(object)
if index is None:
if not is_list_like(data):
data = [data]
index = default_index(len(data))
elif is_list_like(data):
com.require_length_match(data, index)
# create/copy the manager
if isinstance(data, (SingleBlockManager, SingleArrayManager)):
if dtype is not None:
data = data.astype(dtype=dtype, errors="ignore", copy=copy)
elif copy:
data = data.copy()
else:
data = sanitize_array(data, index, dtype, copy)
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index, refs=refs)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
NDFrame.__init__(self, data)
self.name = name
self._set_axis(0, index)
def _init_dict(
self, data, index: Index | None = None, dtype: DtypeObj | None = None
):
"""
Derive the "_mgr" and "index" attributes of a new Series from a
dictionary input.
Parameters
----------
data : dict or dict-like
Data used to populate the new Series.
index : Index or None, default None
Index for the new Series: if None, use dict keys.
dtype : np.dtype, ExtensionDtype, or None, default None
The dtype for the new Series: if None, infer from data.
Returns
-------
_data : BlockManager for the new Series
index : index for the new Series
"""
keys: Index | tuple
# Looking for NaN in dict doesn't work ({np.nan : 1}[float('nan')]
# raises KeyError), so we iterate the entire dict, and align
if data:
# GH:34717, issue was using zip to extract key and values from data.
# using generators in effects the performance.
# Below is the new way of extracting the keys and values
keys = tuple(data.keys())
values = list(data.values()) # Generating list of values- faster way
elif index is not None:
# fastpath for Series(data=None). Just use broadcasting a scalar
# instead of reindexing.
if len(index) or dtype is not None:
values = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
values = []
keys = index
else:
keys, values = (), []
# Input is now list-like, so rely on "standard" construction:
s = self._constructor(
values,
index=keys,
dtype=dtype,
)
# Now we just make sure the order is respected, if any
if data and index is not None:
s = s.reindex(index, copy=False)
return s._mgr, s.index
# ----------------------------------------------------------------------
def _constructor(self) -> Callable[..., Series]:
return Series
def _constructor_expanddim(self) -> Callable[..., DataFrame]:
"""
Used when a manipulation result has one higher dimension as the
original, such as Series.to_frame()
"""
from pandas.core.frame import DataFrame
return DataFrame
# types
def _can_hold_na(self) -> bool:
return self._mgr._can_hold_na
# ndarray compatibility
def dtype(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtype
dtype('int64')
"""
return self._mgr.dtype
def dtypes(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtypes
dtype('int64')
"""
# DataFrame compatibility
return self.dtype
def name(self) -> Hashable:
"""
Return the name of the Series.
The name of a Series becomes its index or column name if it is used
to form a DataFrame. It is also used whenever displaying the Series
using the interpreter.
Returns
-------
label (hashable object)
The name of the Series, also the column name if part of a DataFrame.
See Also
--------
Series.rename : Sets the Series name when given a scalar input.
Index.name : Corresponding Index property.
Examples
--------
The Series name can be set initially when calling the constructor.
>>> s = pd.Series([1, 2, 3], dtype=np.int64, name='Numbers')
>>> s
0 1
1 2
2 3
Name: Numbers, dtype: int64
>>> s.name = "Integers"
>>> s
0 1
1 2
2 3
Name: Integers, dtype: int64
The name of a Series within a DataFrame is its column name.
>>> df = pd.DataFrame([[1, 2], [3, 4], [5, 6]],
... columns=["Odd Numbers", "Even Numbers"])
>>> df
Odd Numbers Even Numbers
0 1 2
1 3 4
2 5 6
>>> df["Even Numbers"].name
'Even Numbers'
"""
return self._name
def name(self, value: Hashable) -> None:
validate_all_hashable(value, error_name=f"{type(self).__name__}.name")
object.__setattr__(self, "_name", value)
def values(self):
"""
Return Series as ndarray or ndarray-like depending on the dtype.
.. warning::
We recommend using :attr:`Series.array` or
:meth:`Series.to_numpy`, depending on whether you need
a reference to the underlying data or a NumPy array.
Returns
-------
numpy.ndarray or ndarray-like
See Also
--------
Series.array : Reference to the underlying data.
Series.to_numpy : A NumPy array representing the underlying data.
Examples
--------
>>> pd.Series([1, 2, 3]).values
array([1, 2, 3])
>>> pd.Series(list('aabc')).values
array(['a', 'a', 'b', 'c'], dtype=object)
>>> pd.Series(list('aabc')).astype('category').values
['a', 'a', 'b', 'c']
Categories (3, object): ['a', 'b', 'c']
Timezone aware datetime data is converted to UTC:
>>> pd.Series(pd.date_range('20130101', periods=3,
... tz='US/Eastern')).values
array(['2013-01-01T05:00:00.000000000',
'2013-01-02T05:00:00.000000000',
'2013-01-03T05:00:00.000000000'], dtype='datetime64[ns]')
"""
return self._mgr.external_values()
def _values(self):
"""
Return the internal repr of this data (defined by Block.interval_values).
This are the values as stored in the Block (ndarray or ExtensionArray
depending on the Block class), with datetime64[ns] and timedelta64[ns]
wrapped in ExtensionArrays to match Index._values behavior.
Differs from the public ``.values`` for certain data types, because of
historical backwards compatibility of the public attribute (e.g. period
returns object ndarray and datetimetz a datetime64[ns] ndarray for
``.values`` while it returns an ExtensionArray for ``._values`` in those
cases).
Differs from ``.array`` in that this still returns the numpy array if
the Block is backed by a numpy array (except for datetime64 and
timedelta64 dtypes), while ``.array`` ensures to always return an
ExtensionArray.
Overview:
dtype | values | _values | array |
----------- | ------------- | ------------- | ------------- |
Numeric | ndarray | ndarray | PandasArray |
Category | Categorical | Categorical | Categorical |
dt64[ns] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
dt64[ns tz] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
td64[ns] | ndarray[m8ns] | TimedeltaArray| ndarray[m8ns] |
Period | ndarray[obj] | PeriodArray | PeriodArray |
Nullable | EA | EA | EA |
"""
return self._mgr.internal_values()
def _references(self) -> BlockValuesRefs | None:
if isinstance(self._mgr, SingleArrayManager):
return None
return self._mgr._block.refs
# error: Decorated property not supported
def array(self) -> ExtensionArray:
return self._mgr.array_values()
# ops
def ravel(self, order: str = "C") -> ArrayLike:
"""
Return the flattened underlying data as an ndarray or ExtensionArray.
Returns
-------
numpy.ndarray or ExtensionArray
Flattened data of the Series.
See Also
--------
numpy.ndarray.ravel : Return a flattened array.
"""
arr = self._values.ravel(order=order)
if isinstance(arr, np.ndarray) and using_copy_on_write():
arr.flags.writeable = False
return arr
def __len__(self) -> int:
"""
Return the length of the Series.
"""
return len(self._mgr)
def view(self, dtype: Dtype | None = None) -> Series:
"""
Create a new view of the Series.
This function will return a new Series with a view of the same
underlying values in memory, optionally reinterpreted with a new data
type. The new data type must preserve the same size in bytes as to not
cause index misalignment.
Parameters
----------
dtype : data type
Data type object or one of their string representations.
Returns
-------
Series
A new Series object as a view of the same data in memory.
See Also
--------
numpy.ndarray.view : Equivalent numpy function to create a new view of
the same data in memory.
Notes
-----
Series are instantiated with ``dtype=float64`` by default. While
``numpy.ndarray.view()`` will return a view with the same data type as
the original array, ``Series.view()`` (without specified dtype)
will try using ``float64`` and may fail if the original data type size
in bytes is not the same.
Examples
--------
>>> s = pd.Series([-2, -1, 0, 1, 2], dtype='int8')
>>> s
0 -2
1 -1
2 0
3 1
4 2
dtype: int8
The 8 bit signed integer representation of `-1` is `0b11111111`, but
the same bytes represent 255 if read as an 8 bit unsigned integer:
>>> us = s.view('uint8')
>>> us
0 254
1 255
2 0
3 1
4 2
dtype: uint8
The views share the same underlying values:
>>> us[0] = 128
>>> s
0 -128
1 -1
2 0
3 1
4 2
dtype: int8
"""
# self.array instead of self._values so we piggyback on PandasArray
# implementation
res_values = self.array.view(dtype)
res_ser = self._constructor(res_values, index=self.index, copy=False)
if isinstance(res_ser._mgr, SingleBlockManager) and using_copy_on_write():
blk = res_ser._mgr._block
blk.refs = cast("BlockValuesRefs", self._references)
blk.refs.add_reference(blk) # type: ignore[arg-type]
return res_ser.__finalize__(self, method="view")
# ----------------------------------------------------------------------
# NDArray Compat
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
"""
Return the values as a NumPy array.
Users should not call this directly. Rather, it is invoked by
:func:`numpy.array` and :func:`numpy.asarray`.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to use for the resulting NumPy array. By default,
the dtype is inferred from the data.
Returns
-------
numpy.ndarray
The values in the series converted to a :class:`numpy.ndarray`
with the specified `dtype`.
See Also
--------
array : Create a new array from data.
Series.array : Zero-copy view to the array backing the Series.
Series.to_numpy : Series method for similar behavior.
Examples
--------
>>> ser = pd.Series([1, 2, 3])
>>> np.asarray(ser)
array([1, 2, 3])
For timezone-aware data, the timezones may be retained with
``dtype='object'``
>>> tzser = pd.Series(pd.date_range('2000', periods=2, tz="CET"))
>>> np.asarray(tzser, dtype="object")
array([Timestamp('2000-01-01 00:00:00+0100', tz='CET'),
Timestamp('2000-01-02 00:00:00+0100', tz='CET')],
dtype=object)
Or the values may be localized to UTC and the tzinfo discarded with
``dtype='datetime64[ns]'``
>>> np.asarray(tzser, dtype="datetime64[ns]") # doctest: +ELLIPSIS
array(['1999-12-31T23:00:00.000000000', ...],
dtype='datetime64[ns]')
"""
values = self._values
arr = np.asarray(values, dtype=dtype)
if using_copy_on_write() and astype_is_view(values.dtype, arr.dtype):
arr = arr.view()
arr.flags.writeable = False
return arr
# ----------------------------------------------------------------------
# Unary Methods
# coercion
__float__ = _coerce_method(float)
__int__ = _coerce_method(int)
# ----------------------------------------------------------------------
# indexers
def axes(self) -> list[Index]:
"""
Return a list of the row axis labels.
"""
return [self.index]
# ----------------------------------------------------------------------
# Indexing Methods
def take(self, indices, axis: Axis = 0, **kwargs) -> Series:
nv.validate_take((), kwargs)
indices = ensure_platform_int(indices)
if (
indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_index = self.index.take(indices)
new_values = self._values.take(indices)
result = self._constructor(new_values, index=new_index, fastpath=True)
return result.__finalize__(self, method="take")
def _take_with_is_copy(self, indices, axis: Axis = 0) -> Series:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning). For Series this does the same
as the public take (it never sets `_is_copy`).
See the docstring of `take` for full explanation of the parameters.
"""
return self.take(indices=indices, axis=axis)
def _ixs(self, i: int, axis: AxisInt = 0) -> Any:
"""
Return the i-th value or values in the Series by location.
Parameters
----------
i : int
Returns
-------
scalar (int) or Series (slice, sequence)
"""
return self._values[i]
def _slice(self, slobj: slice | np.ndarray, axis: Axis = 0) -> Series:
# axis kwarg is retained for compat with NDFrame method
# _slice is *always* positional
return self._get_values(slobj)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
if key is Ellipsis:
return self
key_is_scalar = is_scalar(key)
if isinstance(key, (list, tuple)):
key = unpack_1tuple(key)
if is_integer(key) and self.index._should_fallback_to_positional:
return self._values[key]
elif key_is_scalar:
return self._get_value(key)
if is_hashable(key):
# Otherwise index.get_value will raise InvalidIndexError
try:
# For labels that don't resolve as scalars like tuples and frozensets
result = self._get_value(key)
return result
except (KeyError, TypeError, InvalidIndexError):
# InvalidIndexError for e.g. generator
# see test_series_getitem_corner_generator
if isinstance(key, tuple) and isinstance(self.index, MultiIndex):
# We still have the corner case where a tuple is a key
# in the first level of our MultiIndex
return self._get_values_tuple(key)
if is_iterator(key):
key = list(key)
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
return self._get_values(key)
return self._get_with(key)
def _get_with(self, key):
# other: fancy integer or otherwise
if isinstance(key, slice):
# _convert_slice_indexer to determine if this slice is positional
# or label based, and if the latter, convert to positional
slobj = self.index._convert_slice_indexer(key, kind="getitem")
return self._slice(slobj)
elif isinstance(key, ABCDataFrame):
raise TypeError(
"Indexing a Series with DataFrame is not "
"supported, use the appropriate DataFrame column"
)
elif isinstance(key, tuple):
return self._get_values_tuple(key)
elif not is_list_like(key):
# e.g. scalars that aren't recognized by lib.is_scalar, GH#32684
return self.loc[key]
if not isinstance(key, (list, np.ndarray, ExtensionArray, Series, Index)):
key = list(key)
if isinstance(key, Index):
key_type = key.inferred_type
else:
key_type = lib.infer_dtype(key, skipna=False)
# Note: The key_type == "boolean" case should be caught by the
# com.is_bool_indexer check in __getitem__
if key_type == "integer":
# We need to decide whether to treat this as a positional indexer
# (i.e. self.iloc) or label-based (i.e. self.loc)
if not self.index._should_fallback_to_positional:
return self.loc[key]
else:
return self.iloc[key]
# handle the dup indexing case GH#4246
return self.loc[key]
def _get_values_tuple(self, key: tuple):
# mpl hackaround
if com.any_none(*key):
# mpl compat if we look up e.g. ser[:, np.newaxis];
# see tests.series.timeseries.test_mpl_compat_hack
# the asarray is needed to avoid returning a 2D DatetimeArray
result = np.asarray(self._values[key])
disallow_ndim_indexing(result)
return result
if not isinstance(self.index, MultiIndex):
raise KeyError("key of type tuple not found and not a MultiIndex")
# If key is contained, would have returned by now
indexer, new_index = self.index.get_loc_level(key)
new_ser = self._constructor(self._values[indexer], index=new_index, copy=False)
if using_copy_on_write() and isinstance(indexer, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
def _get_values(self, indexer: slice | npt.NDArray[np.bool_]) -> Series:
new_mgr = self._mgr.getitem_mgr(indexer)
return self._constructor(new_mgr).__finalize__(self)
def _get_value(self, label, takeable: bool = False):
"""
Quickly retrieve single value at passed index label.
Parameters
----------
label : object
takeable : interpret the index as indexers, default False
Returns
-------
scalar value
"""
if takeable:
return self._values[label]
# Similar to Index.get_value, but we do not fall back to positional
loc = self.index.get_loc(label)
if is_integer(loc):
return self._values[loc]
if isinstance(self.index, MultiIndex):
mi = self.index
new_values = self._values[loc]
if len(new_values) == 1 and mi.nlevels == 1:
# If more than one level left, we can not return a scalar
return new_values[0]
new_index = mi[loc]
new_index = maybe_droplevels(new_index, label)
new_ser = self._constructor(
new_values, index=new_index, name=self.name, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
else:
return self.iloc[loc]
def __setitem__(self, key, value) -> None:
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
cacher_needs_updating = self._check_is_chained_assignment_possible()
if key is Ellipsis:
key = slice(None)
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
return self._set_values(indexer, value)
try:
self._set_with_engine(key, value)
except KeyError:
# We have a scalar (or for MultiIndex or object-dtype, scalar-like)
# key that is not present in self.index.
if is_integer(key):
if not self.index._should_fallback_to_positional:
# GH#33469
self.loc[key] = value
else:
# positional setter
# can't use _mgr.setitem_inplace yet bc could have *both*
# KeyError and then ValueError, xref GH#45070
self._set_values(key, value)
else:
# GH#12862 adding a new key to the Series
self.loc[key] = value
except (TypeError, ValueError, LossySetitemError):
# The key was OK, but we cannot set the value losslessly
indexer = self.index.get_loc(key)
self._set_values(indexer, value)
except InvalidIndexError as err:
if isinstance(key, tuple) and not isinstance(self.index, MultiIndex):
# cases with MultiIndex don't get here bc they raise KeyError
# e.g. test_basic_getitem_setitem_corner
raise KeyError(
"key of type tuple not found and not a MultiIndex"
) from err
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
if (
is_list_like(value)
and len(value) != len(self)
and not isinstance(value, Series)
and not is_object_dtype(self.dtype)
):
# Series will be reindexed to have matching length inside
# _where call below
# GH#44265
indexer = key.nonzero()[0]
self._set_values(indexer, value)
return
# otherwise with listlike other we interpret series[mask] = other
# as series[mask] = other[mask]
try:
self._where(~key, value, inplace=True)
except InvalidIndexError:
# test_where_dups
self.iloc[key] = value
return
else:
self._set_with(key, value)
if cacher_needs_updating:
self._maybe_update_cacher(inplace=True)
def _set_with_engine(self, key, value) -> None:
loc = self.index.get_loc(key)
# this is equivalent to self._values[key] = value
self._mgr.setitem_inplace(loc, value)
def _set_with(self, key, value) -> None:
# We got here via exception-handling off of InvalidIndexError, so
# key should always be listlike at this point.
assert not isinstance(key, tuple)
if is_iterator(key):
# Without this, the call to infer_dtype will consume the generator
key = list(key)
if not self.index._should_fallback_to_positional:
# Regardless of the key type, we're treating it as labels
self._set_labels(key, value)
else:
# Note: key_type == "boolean" should not occur because that
# should be caught by the is_bool_indexer check in __setitem__
key_type = lib.infer_dtype(key, skipna=False)
if key_type == "integer":
self._set_values(key, value)
else:
self._set_labels(key, value)
def _set_labels(self, key, value) -> None:
key = com.asarray_tuplesafe(key)
indexer: np.ndarray = self.index.get_indexer(key)
mask = indexer == -1
if mask.any():
raise KeyError(f"{key[mask]} not in index")
self._set_values(indexer, value)
def _set_values(self, key, value) -> None:
if isinstance(key, (Index, Series)):
key = key._values
self._mgr = self._mgr.setitem(indexer=key, value=value)
self._maybe_update_cacher()
def _set_value(self, label, value, takeable: bool = False) -> None:
"""
Quickly set single value at passed label.
If label is not contained, a new object is created with the label
placed at the end of the result index.
Parameters
----------
label : object
Partial indexing with MultiIndex not allowed.
value : object
Scalar value.
takeable : interpret the index as indexers, default False
"""
if not takeable:
try:
loc = self.index.get_loc(label)
except KeyError:
# set using a non-recursive method
self.loc[label] = value
return
else:
loc = label
self._set_values(loc, value)
# ----------------------------------------------------------------------
# Lookup Caching
def _is_cached(self) -> bool:
"""Return boolean indicating if self is cached or not."""
return getattr(self, "_cacher", None) is not None
def _get_cacher(self):
"""return my cacher or None"""
cacher = getattr(self, "_cacher", None)
if cacher is not None:
cacher = cacher[1]()
return cacher
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
if hasattr(self, "_cacher"):
del self._cacher
def _set_as_cached(self, item, cacher) -> None:
"""
Set the _cacher attribute on the calling object with a weakref to
cacher.
"""
if using_copy_on_write():
return
self._cacher = (item, weakref.ref(cacher))
def _clear_item_cache(self) -> None:
# no-op for Series
pass
def _check_is_chained_assignment_possible(self) -> bool:
"""
See NDFrame._check_is_chained_assignment_possible.__doc__
"""
if self._is_view and self._is_cached:
ref = self._get_cacher()
if ref is not None and ref._is_mixed_type:
self._check_setitem_copy(t="referent", force=True)
return True
return super()._check_is_chained_assignment_possible()
def _maybe_update_cacher(
self, clear: bool = False, verify_is_copy: bool = True, inplace: bool = False
) -> None:
"""
See NDFrame._maybe_update_cacher.__doc__
"""
# for CoW, we never want to update the parent DataFrame cache
# if the Series changed, but don't keep track of any cacher
if using_copy_on_write():
return
cacher = getattr(self, "_cacher", None)
if cacher is not None:
assert self.ndim == 1
ref: DataFrame = cacher[1]()
# we are trying to reference a dead referent, hence
# a copy
if ref is None:
del self._cacher
elif len(self) == len(ref) and self.name in ref.columns:
# GH#42530 self.name must be in ref.columns
# to ensure column still in dataframe
# otherwise, either self or ref has swapped in new arrays
ref._maybe_cache_changed(cacher[0], self, inplace=inplace)
else:
# GH#33675 we have swapped in a new array, so parent
# reference to self is now invalid
ref._item_cache.pop(cacher[0], None)
super()._maybe_update_cacher(
clear=clear, verify_is_copy=verify_is_copy, inplace=inplace
)
# ----------------------------------------------------------------------
# Unsorted
def _is_mixed_type(self) -> bool:
return False
def repeat(self, repeats: int | Sequence[int], axis: None = None) -> Series:
"""
Repeat elements of a Series.
Returns a new Series where each element of the current Series
is repeated consecutively a given number of times.
Parameters
----------
repeats : int or array of ints
The number of repetitions for each element. This should be a
non-negative integer. Repeating 0 times will return an empty
Series.
axis : None
Unused. Parameter needed for compatibility with DataFrame.
Returns
-------
Series
Newly created Series with repeated elements.
See Also
--------
Index.repeat : Equivalent function for Index.
numpy.repeat : Similar method for :class:`numpy.ndarray`.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c'])
>>> s
0 a
1 b
2 c
dtype: object
>>> s.repeat(2)
0 a
0 a
1 b
1 b
2 c
2 c
dtype: object
>>> s.repeat([1, 2, 3])
0 a
1 b
1 b
2 c
2 c
2 c
dtype: object
"""
nv.validate_repeat((), {"axis": axis})
new_index = self.index.repeat(repeats)
new_values = self._values.repeat(repeats)
return self._constructor(new_values, index=new_index, copy=False).__finalize__(
self, method="repeat"
)
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[False] = ...,
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> DataFrame:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[True],
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> Series:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: bool = ...,
name: Level = ...,
inplace: Literal[True],
allow_duplicates: bool = ...,
) -> None:
...
def reset_index(
self,
level: IndexLabel = None,
*,
drop: bool = False,
name: Level = lib.no_default,
inplace: bool = False,
allow_duplicates: bool = False,
) -> DataFrame | Series | None:
"""
Generate a new DataFrame or Series with the index reset.
This is useful when the index needs to be treated as a column, or
when the index is meaningless and needs to be reset to the default
before another operation.
Parameters
----------
level : int, str, tuple, or list, default optional
For a Series with a MultiIndex, only remove the specified levels
from the index. Removes all levels by default.
drop : bool, default False
Just reset the index, without inserting it as a column in
the new DataFrame.
name : object, optional
The name to use for the column containing the original Series
values. Uses ``self.name`` by default. This argument is ignored
when `drop` is True.
inplace : bool, default False
Modify the Series in place (do not create a new object).
allow_duplicates : bool, default False
Allow duplicate column labels to be created.
.. versionadded:: 1.5.0
Returns
-------
Series or DataFrame or None
When `drop` is False (the default), a DataFrame is returned.
The newly created columns will come first in the DataFrame,
followed by the original Series values.
When `drop` is True, a `Series` is returned.
In either case, if ``inplace=True``, no value is returned.
See Also
--------
DataFrame.reset_index: Analogous function for DataFrame.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4], name='foo',
... index=pd.Index(['a', 'b', 'c', 'd'], name='idx'))
Generate a DataFrame with default index.
>>> s.reset_index()
idx foo
0 a 1
1 b 2
2 c 3
3 d 4
To specify the name of the new column use `name`.
>>> s.reset_index(name='values')
idx values
0 a 1
1 b 2
2 c 3
3 d 4
To generate a new Series with the default set `drop` to True.
>>> s.reset_index(drop=True)
0 1
1 2
2 3
3 4
Name: foo, dtype: int64
The `level` parameter is interesting for Series with a multi-level
index.
>>> arrays = [np.array(['bar', 'bar', 'baz', 'baz']),
... np.array(['one', 'two', 'one', 'two'])]
>>> s2 = pd.Series(
... range(4), name='foo',
... index=pd.MultiIndex.from_arrays(arrays,
... names=['a', 'b']))
To remove a specific level from the Index, use `level`.
>>> s2.reset_index(level='a')
a foo
b
one bar 0
two bar 1
one baz 2
two baz 3
If `level` is not set, all levels are removed from the Index.
>>> s2.reset_index()
a b foo
0 bar one 0
1 bar two 1
2 baz one 2
3 baz two 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if drop:
new_index = default_index(len(self))
if level is not None:
level_list: Sequence[Hashable]
if not isinstance(level, (tuple, list)):
level_list = [level]
else:
level_list = level
level_list = [self.index._get_level_number(lev) for lev in level_list]
if len(level_list) < self.index.nlevels:
new_index = self.index.droplevel(level_list)
if inplace:
self.index = new_index
elif using_copy_on_write():
new_ser = self.copy(deep=False)
new_ser.index = new_index
return new_ser.__finalize__(self, method="reset_index")
else:
return self._constructor(
self._values.copy(), index=new_index, copy=False
).__finalize__(self, method="reset_index")
elif inplace:
raise TypeError(
"Cannot reset_index inplace on a Series to create a DataFrame"
)
else:
if name is lib.no_default:
# For backwards compatibility, keep columns as [0] instead of
# [None] when self.name is None
if self.name is None:
name = 0
else:
name = self.name
df = self.to_frame(name)
return df.reset_index(
level=level, drop=drop, allow_duplicates=allow_duplicates
)
return None
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
"""
Return a string representation for a particular Series.
"""
# pylint: disable=invalid-repr-returned
repr_params = fmt.get_series_repr_params()
return self.to_string(**repr_params)
def to_string(
self,
buf: None = ...,
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> None:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
na_rep: str = "NaN",
float_format: str | None = None,
header: bool = True,
index: bool = True,
length: bool = False,
dtype: bool = False,
name: bool = False,
max_rows: int | None = None,
min_rows: int | None = None,
) -> str | None:
"""
Render a string representation of the Series.
Parameters
----------
buf : StringIO-like, optional
Buffer to write to.
na_rep : str, optional
String representation of NaN to use, default 'NaN'.
float_format : one-parameter function, optional
Formatter function to apply to columns' elements if they are
floats, default None.
header : bool, default True
Add the Series header (index name).
index : bool, optional
Add index (row) labels, default True.
length : bool, default False
Add the Series length.
dtype : bool, default False
Add the Series dtype.
name : bool, default False
Add the Series name if not None.
max_rows : int, optional
Maximum number of rows to show before truncating. If None, show
all.
min_rows : int, optional
The number of rows to display in a truncated repr (when number
of rows is above `max_rows`).
Returns
-------
str or None
String representation of Series if ``buf=None``, otherwise None.
"""
formatter = fmt.SeriesFormatter(
self,
name=name,
length=length,
header=header,
index=index,
dtype=dtype,
na_rep=na_rep,
float_format=float_format,
min_rows=min_rows,
max_rows=max_rows,
)
result = formatter.to_string()
# catch contract violations
if not isinstance(result, str):
raise AssertionError(
"result must be of type str, type "
f"of result is {repr(type(result).__name__)}"
)
if buf is None:
return result
else:
if hasattr(buf, "write"):
buf.write(result)
else:
with open(buf, "w") as f:
f.write(result)
return None
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples=dedent(
"""Examples
--------
>>> s = pd.Series(["elk", "pig", "dog", "quetzal"], name="animal")
>>> print(s.to_markdown())
| | animal |
|---:|:---------|
| 0 | elk |
| 1 | pig |
| 2 | dog |
| 3 | quetzal |
Output markdown with a tabulate option.
>>> print(s.to_markdown(tablefmt="grid"))
+----+----------+
| | animal |
+====+==========+
| 0 | elk |
+----+----------+
| 1 | pig |
+----+----------+
| 2 | dog |
+----+----------+
| 3 | quetzal |
+----+----------+"""
),
)
def to_markdown(
self,
buf: IO[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
"""
Print {klass} in Markdown-friendly format.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
mode : str, optional
Mode in which file is opened, "wt" by default.
index : bool, optional, default True
Add index (row) labels.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
**kwargs
These parameters will be passed to `tabulate \
<https://pypi.org/project/tabulate>`_.
Returns
-------
str
{klass} in Markdown-friendly format.
Notes
-----
Requires the `tabulate <https://pypi.org/project/tabulate>`_ package.
{examples}
"""
return self.to_frame().to_markdown(
buf, mode, index, storage_options=storage_options, **kwargs
)
# ----------------------------------------------------------------------
def items(self) -> Iterable[tuple[Hashable, Any]]:
"""
Lazily iterate over (index, value) tuples.
This method returns an iterable tuple (index, value). This is
convenient if you want to create a lazy iterator.
Returns
-------
iterable
Iterable of tuples containing the (index, value) pairs from a
Series.
See Also
--------
DataFrame.items : Iterate over (column name, Series) pairs.
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series) pairs.
Examples
--------
>>> s = pd.Series(['A', 'B', 'C'])
>>> for index, value in s.items():
... print(f"Index : {index}, Value : {value}")
Index : 0, Value : A
Index : 1, Value : B
Index : 2, Value : C
"""
return zip(iter(self.index), iter(self))
# ----------------------------------------------------------------------
# Misc public methods
def keys(self) -> Index:
"""
Return alias for index.
Returns
-------
Index
Index of the Series.
"""
return self.index
def to_dict(self, into: type[dict] = dict) -> dict:
"""
Convert Series to {label -> value} dict or dict-like object.
Parameters
----------
into : class, default dict
The collections.abc.Mapping subclass to use as the return
object. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
Returns
-------
collections.abc.Mapping
Key-value representation of Series.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.to_dict()
{0: 1, 1: 2, 2: 3, 3: 4}
>>> from collections import OrderedDict, defaultdict
>>> s.to_dict(OrderedDict)
OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
>>> dd = defaultdict(list)
>>> s.to_dict(dd)
defaultdict(<class 'list'>, {0: 1, 1: 2, 2: 3, 3: 4})
"""
# GH16122
into_c = com.standardize_mapping(into)
if is_object_dtype(self) or is_extension_array_dtype(self):
return into_c((k, maybe_box_native(v)) for k, v in self.items())
else:
# Not an object dtype => all types will be the same so let the default
# indexer return native python type
return into_c(self.items())
def to_frame(self, name: Hashable = lib.no_default) -> DataFrame:
"""
Convert Series to DataFrame.
Parameters
----------
name : object, optional
The passed name should substitute for the series name (if it has
one).
Returns
-------
DataFrame
DataFrame representation of Series.
Examples
--------
>>> s = pd.Series(["a", "b", "c"],
... name="vals")
>>> s.to_frame()
vals
0 a
1 b
2 c
"""
columns: Index
if name is lib.no_default:
name = self.name
if name is None:
# default to [0], same as we would get with DataFrame(self)
columns = default_index(1)
else:
columns = Index([name])
else:
columns = Index([name])
mgr = self._mgr.to_2d_mgr(columns)
df = self._constructor_expanddim(mgr)
return df.__finalize__(self, method="to_frame")
def _set_name(self, name, inplace: bool = False) -> Series:
"""
Set the Series name.
Parameters
----------
name : str
inplace : bool
Whether to modify `self` directly or return a copy.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
ser = self if inplace else self.copy()
ser.name = name
return ser
"""
Examples
--------
>>> ser = pd.Series([390., 350., 30., 20.],
... index=['Falcon', 'Falcon', 'Parrot', 'Parrot'], name="Max Speed")
>>> ser
Falcon 390.0
Falcon 350.0
Parrot 30.0
Parrot 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", "b"]).mean()
a 210.0
b 185.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(ser > 100).mean()
Max Speed
False 25.0
True 370.0
Name: Max Speed, dtype: float64
**Grouping by Indexes**
We can groupby different levels of a hierarchical index
using the `level` parameter:
>>> arrays = [['Falcon', 'Falcon', 'Parrot', 'Parrot'],
... ['Captive', 'Wild', 'Captive', 'Wild']]
>>> index = pd.MultiIndex.from_arrays(arrays, names=('Animal', 'Type'))
>>> ser = pd.Series([390., 350., 30., 20.], index=index, name="Max Speed")
>>> ser
Animal Type
Falcon Captive 390.0
Wild 350.0
Parrot Captive 30.0
Wild 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Animal
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level="Type").mean()
Type
Captive 210.0
Wild 185.0
Name: Max Speed, dtype: float64
We can also choose to include `NA` in group keys or not by defining
`dropna` parameter, the default setting is `True`.
>>> ser = pd.Series([1, 2, 3, 3], index=["a", 'a', 'b', np.nan])
>>> ser.groupby(level=0).sum()
a 3
b 3
dtype: int64
>>> ser.groupby(level=0, dropna=False).sum()
a 3
b 3
NaN 3
dtype: int64
>>> arrays = ['Falcon', 'Falcon', 'Parrot', 'Parrot']
>>> ser = pd.Series([390., 350., 30., 20.], index=arrays, name="Max Speed")
>>> ser.groupby(["a", "b", "a", np.nan]).mean()
a 210.0
b 350.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", np.nan], dropna=False).mean()
a 210.0
b 350.0
NaN 20.0
Name: Max Speed, dtype: float64
"""
)
def groupby(
self,
by=None,
axis: Axis = 0,
level: IndexLabel = None,
as_index: bool = True,
sort: bool = True,
group_keys: bool = True,
observed: bool = False,
dropna: bool = True,
) -> SeriesGroupBy:
from pandas.core.groupby.generic import SeriesGroupBy
if level is None and by is None:
raise TypeError("You have to supply one of 'by' and 'level'")
if not as_index:
raise TypeError("as_index=False only valid with DataFrame")
axis = self._get_axis_number(axis)
return SeriesGroupBy(
obj=self,
keys=by,
axis=axis,
level=level,
as_index=as_index,
sort=sort,
group_keys=group_keys,
observed=observed,
dropna=dropna,
)
# ----------------------------------------------------------------------
# Statistics, overridden ndarray methods
# TODO: integrate bottleneck
def count(self):
"""
Return number of non-NA/null observations in the Series.
Returns
-------
int or Series (if level specified)
Number of non-null values in the Series.
See Also
--------
DataFrame.count : Count non-NA cells for each column or row.
Examples
--------
>>> s = pd.Series([0.0, 1.0, np.nan])
>>> s.count()
2
"""
return notna(self._values).sum().astype("int64")
def mode(self, dropna: bool = True) -> Series:
"""
Return the mode(s) of the Series.
The mode is the value that appears most often. There can be multiple modes.
Always returns Series even if only one value is returned.
Parameters
----------
dropna : bool, default True
Don't consider counts of NaN/NaT.
Returns
-------
Series
Modes of the Series in sorted order.
"""
# TODO: Add option for bins like value_counts()
values = self._values
if isinstance(values, np.ndarray):
res_values = algorithms.mode(values, dropna=dropna)
else:
res_values = values._mode(dropna=dropna)
# Ensure index is type stable (should always use int index)
return self._constructor(
res_values, index=range(len(res_values)), name=self.name, copy=False
)
def unique(self) -> ArrayLike: # pylint: disable=useless-parent-delegation
"""
Return unique values of Series object.
Uniques are returned in order of appearance. Hash table-based unique,
therefore does NOT sort.
Returns
-------
ndarray or ExtensionArray
The unique values returned as a NumPy array. See Notes.
See Also
--------
Series.drop_duplicates : Return Series with duplicate values removed.
unique : Top-level unique method for any 1-d array-like object.
Index.unique : Return Index with unique values from an Index object.
Notes
-----
Returns the unique values as a NumPy array. In case of an
extension-array backed Series, a new
:class:`~api.extensions.ExtensionArray` of that type with just
the unique values is returned. This includes
* Categorical
* Period
* Datetime with Timezone
* Datetime without Timezone
* Timedelta
* Interval
* Sparse
* IntegerNA
See Examples section.
Examples
--------
>>> pd.Series([2, 1, 3, 3], name='A').unique()
array([2, 1, 3])
>>> pd.Series([pd.Timestamp('2016-01-01') for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00']
Length: 1, dtype: datetime64[ns]
>>> pd.Series([pd.Timestamp('2016-01-01', tz='US/Eastern')
... for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00-05:00']
Length: 1, dtype: datetime64[ns, US/Eastern]
An Categorical will return categories in the order of
appearance and with the same dtype.
>>> pd.Series(pd.Categorical(list('baabc'))).unique()
['b', 'a', 'c']
Categories (3, object): ['a', 'b', 'c']
>>> pd.Series(pd.Categorical(list('baabc'), categories=list('abc'),
... ordered=True)).unique()
['b', 'a', 'c']
Categories (3, object): ['a' < 'b' < 'c']
"""
return super().unique()
def drop_duplicates(
self,
*,
keep: DropKeep = ...,
inplace: Literal[False] = ...,
ignore_index: bool = ...,
) -> Series:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: Literal[True], ignore_index: bool = ...
) -> None:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: bool = ..., ignore_index: bool = ...
) -> Series | None:
...
def drop_duplicates(
self,
*,
keep: DropKeep = "first",
inplace: bool = False,
ignore_index: bool = False,
) -> Series | None:
"""
Return Series with duplicate values removed.
Parameters
----------
keep : {'first', 'last', ``False``}, default 'first'
Method to handle dropping duplicates:
- 'first' : Drop duplicates except for the first occurrence.
- 'last' : Drop duplicates except for the last occurrence.
- ``False`` : Drop all duplicates.
inplace : bool, default ``False``
If ``True``, performs operation inplace and returns None.
ignore_index : bool, default ``False``
If ``True``, the resulting axis will be labeled 0, 1, …, n - 1.
.. versionadded:: 2.0.0
Returns
-------
Series or None
Series with duplicates dropped or None if ``inplace=True``.
See Also
--------
Index.drop_duplicates : Equivalent method on Index.
DataFrame.drop_duplicates : Equivalent method on DataFrame.
Series.duplicated : Related method on Series, indicating duplicate
Series values.
Series.unique : Return unique values as an array.
Examples
--------
Generate a Series with duplicated entries.
>>> s = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama', 'hippo'],
... name='animal')
>>> s
0 lama
1 cow
2 lama
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
With the 'keep' parameter, the selection behaviour of duplicated values
can be changed. The value 'first' keeps the first occurrence for each
set of duplicated entries. The default value of keep is 'first'.
>>> s.drop_duplicates()
0 lama
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
The value 'last' for parameter 'keep' keeps the last occurrence for
each set of duplicated entries.
>>> s.drop_duplicates(keep='last')
1 cow
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
The value ``False`` for parameter 'keep' discards all sets of
duplicated entries.
>>> s.drop_duplicates(keep=False)
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
"""
inplace = validate_bool_kwarg(inplace, "inplace")
result = super().drop_duplicates(keep=keep)
if ignore_index:
result.index = default_index(len(result))
if inplace:
self._update_inplace(result)
return None
else:
return result
def duplicated(self, keep: DropKeep = "first") -> Series:
"""
Indicate duplicate Series values.
Duplicated values are indicated as ``True`` values in the resulting
Series. Either all duplicates, all except the first or all except the
last occurrence of duplicates can be indicated.
Parameters
----------
keep : {'first', 'last', False}, default 'first'
Method to handle dropping duplicates:
- 'first' : Mark duplicates as ``True`` except for the first
occurrence.
- 'last' : Mark duplicates as ``True`` except for the last
occurrence.
- ``False`` : Mark all duplicates as ``True``.
Returns
-------
Series[bool]
Series indicating whether each value has occurred in the
preceding values.
See Also
--------
Index.duplicated : Equivalent method on pandas.Index.
DataFrame.duplicated : Equivalent method on pandas.DataFrame.
Series.drop_duplicates : Remove duplicate values from Series.
Examples
--------
By default, for each set of duplicated values, the first occurrence is
set on False and all others on True:
>>> animals = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama'])
>>> animals.duplicated()
0 False
1 False
2 True
3 False
4 True
dtype: bool
which is equivalent to
>>> animals.duplicated(keep='first')
0 False
1 False
2 True
3 False
4 True
dtype: bool
By using 'last', the last occurrence of each set of duplicated values
is set on False and all others on True:
>>> animals.duplicated(keep='last')
0 True
1 False
2 True
3 False
4 False
dtype: bool
By setting keep on ``False``, all duplicates are True:
>>> animals.duplicated(keep=False)
0 True
1 False
2 True
3 False
4 True
dtype: bool
"""
res = self._duplicated(keep=keep)
result = self._constructor(res, index=self.index, copy=False)
return result.__finalize__(self, method="duplicated")
def idxmin(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the minimum value.
If multiple values equal the minimum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the minimum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmin : Return indices of the minimum values
along the given axis.
DataFrame.idxmin : Return index of first occurrence of minimum
over requested axis.
Series.idxmax : Return index *label* of the first occurrence
of maximum of values.
Notes
-----
This method is the Series version of ``ndarray.argmin``. This method
returns the label of the minimum, while ``ndarray.argmin`` returns
the position. To get the position, use ``series.values.argmin()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 1],
... index=['A', 'B', 'C', 'D'])
>>> s
A 1.0
B NaN
C 4.0
D 1.0
dtype: float64
>>> s.idxmin()
'A'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmin(skipna=False)
nan
"""
# error: Argument 1 to "argmin" of "IndexOpsMixin" has incompatible type "Union
# [int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmin(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def idxmax(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the maximum value.
If multiple values equal the maximum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the maximum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmax : Return indices of the maximum values
along the given axis.
DataFrame.idxmax : Return index of first occurrence of maximum
over requested axis.
Series.idxmin : Return index *label* of the first occurrence
of minimum of values.
Notes
-----
This method is the Series version of ``ndarray.argmax``. This method
returns the label of the maximum, while ``ndarray.argmax`` returns
the position. To get the position, use ``series.values.argmax()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 3, 4],
... index=['A', 'B', 'C', 'D', 'E'])
>>> s
A 1.0
B NaN
C 4.0
D 3.0
E 4.0
dtype: float64
>>> s.idxmax()
'C'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmax(skipna=False)
nan
"""
# error: Argument 1 to "argmax" of "IndexOpsMixin" has incompatible type
# "Union[int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmax(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def round(self, decimals: int = 0, *args, **kwargs) -> Series:
"""
Round each value in a Series to the given number of decimals.
Parameters
----------
decimals : int, default 0
Number of decimal places to round to. If decimals is negative,
it specifies the number of positions to the left of the decimal point.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Series
Rounded values of the Series.
See Also
--------
numpy.around : Round values of an np.array.
DataFrame.round : Round values of a DataFrame.
Examples
--------
>>> s = pd.Series([0.1, 1.3, 2.7])
>>> s.round()
0 0.0
1 1.0
2 3.0
dtype: float64
"""
nv.validate_round(args, kwargs)
result = self._values.round(decimals)
result = self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="round"
)
return result
def quantile(
self, q: float = ..., interpolation: QuantileInterpolation = ...
) -> float:
...
def quantile(
self,
q: Sequence[float] | AnyArrayLike,
interpolation: QuantileInterpolation = ...,
) -> Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = ...,
interpolation: QuantileInterpolation = ...,
) -> float | Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = 0.5,
interpolation: QuantileInterpolation = "linear",
) -> float | Series:
"""
Return value at the given quantile.
Parameters
----------
q : float or array-like, default 0.5 (50% quantile)
The quantile(s) to compute, which can lie in range: 0 <= q <= 1.
interpolation : {'linear', 'lower', 'higher', 'midpoint', 'nearest'}
This optional parameter specifies the interpolation method to use,
when the desired quantile lies between two data points `i` and `j`:
* linear: `i + (j - i) * fraction`, where `fraction` is the
fractional part of the index surrounded by `i` and `j`.
* lower: `i`.
* higher: `j`.
* nearest: `i` or `j` whichever is nearest.
* midpoint: (`i` + `j`) / 2.
Returns
-------
float or Series
If ``q`` is an array, a Series will be returned where the
index is ``q`` and the values are the quantiles, otherwise
a float will be returned.
See Also
--------
core.window.Rolling.quantile : Calculate the rolling quantile.
numpy.percentile : Returns the q-th percentile(s) of the array elements.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.quantile(.5)
2.5
>>> s.quantile([.25, .5, .75])
0.25 1.75
0.50 2.50
0.75 3.25
dtype: float64
"""
validate_percentile(q)
# We dispatch to DataFrame so that core.internals only has to worry
# about 2D cases.
df = self.to_frame()
result = df.quantile(q=q, interpolation=interpolation, numeric_only=False)
if result.ndim == 2:
result = result.iloc[:, 0]
if is_list_like(q):
result.name = self.name
idx = Index(q, dtype=np.float64)
return self._constructor(result, index=idx, name=self.name)
else:
# scalar
return result.iloc[0]
def corr(
self,
other: Series,
method: CorrelationMethod = "pearson",
min_periods: int | None = None,
) -> float:
"""
Compute correlation with `other` Series, excluding missing values.
The two `Series` objects are not required to be the same length and will be
aligned internally before the correlation function is applied.
Parameters
----------
other : Series
Series with which to compute the correlation.
method : {'pearson', 'kendall', 'spearman'} or callable
Method used to compute correlation:
- pearson : Standard correlation coefficient
- kendall : Kendall Tau correlation coefficient
- spearman : Spearman rank correlation
- callable: Callable with input two 1d ndarrays and returning a float.
.. warning::
Note that the returned matrix from corr will have 1 along the
diagonals and will be symmetric regardless of the callable's
behavior.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
Returns
-------
float
Correlation with other.
See Also
--------
DataFrame.corr : Compute pairwise correlation between columns.
DataFrame.corrwith : Compute pairwise correlation with another
DataFrame or Series.
Notes
-----
Pearson, Kendall and Spearman correlation are currently computed using pairwise complete observations.
* `Pearson correlation coefficient <https://en.wikipedia.org/wiki/Pearson_correlation_coefficient>`_
* `Kendall rank correlation coefficient <https://en.wikipedia.org/wiki/Kendall_rank_correlation_coefficient>`_
* `Spearman's rank correlation coefficient <https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient>`_
Examples
--------
>>> def histogram_intersection(a, b):
... v = np.minimum(a, b).sum().round(decimals=1)
... return v
>>> s1 = pd.Series([.2, .0, .6, .2])
>>> s2 = pd.Series([.3, .6, .0, .1])
>>> s1.corr(s2, method=histogram_intersection)
0.3
""" # noqa:E501
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
if method in ["pearson", "spearman", "kendall"] or callable(method):
return nanops.nancorr(
this.values, other.values, method=method, min_periods=min_periods
)
raise ValueError(
"method must be either 'pearson', "
"'spearman', 'kendall', or a callable, "
f"'{method}' was supplied"
)
def cov(
self,
other: Series,
min_periods: int | None = None,
ddof: int | None = 1,
) -> float:
"""
Compute covariance with Series, excluding missing values.
The two `Series` objects are not required to be the same length and
will be aligned internally before the covariance is calculated.
Parameters
----------
other : Series
Series with which to compute the covariance.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
ddof : int, default 1
Delta degrees of freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.
.. versionadded:: 1.1.0
Returns
-------
float
Covariance between Series and other normalized by N-1
(unbiased estimator).
See Also
--------
DataFrame.cov : Compute pairwise covariance of columns.
Examples
--------
>>> s1 = pd.Series([0.90010907, 0.13484424, 0.62036035])
>>> s2 = pd.Series([0.12528585, 0.26962463, 0.51111198])
>>> s1.cov(s2)
-0.01685762652715874
"""
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
return nanops.nancov(
this.values, other.values, min_periods=min_periods, ddof=ddof
)
klass="Series",
extra_params="",
other_klass="DataFrame",
examples=dedent(
"""
Difference with previous row
>>> s = pd.Series([1, 1, 2, 3, 5, 8])
>>> s.diff()
0 NaN
1 0.0
2 1.0
3 1.0
4 2.0
5 3.0
dtype: float64
Difference with 3rd previous row
>>> s.diff(periods=3)
0 NaN
1 NaN
2 NaN
3 2.0
4 4.0
5 6.0
dtype: float64
Difference with following row
>>> s.diff(periods=-1)
0 0.0
1 -1.0
2 -1.0
3 -2.0
4 -3.0
5 NaN
dtype: float64
Overflow in input dtype
>>> s = pd.Series([1, 0], dtype=np.uint8)
>>> s.diff()
0 NaN
1 255.0
dtype: float64"""
),
)
def diff(self, periods: int = 1) -> Series:
"""
First discrete difference of element.
Calculates the difference of a {klass} element compared with another
element in the {klass} (default is element in previous row).
Parameters
----------
periods : int, default 1
Periods to shift for calculating difference, accepts negative
values.
{extra_params}
Returns
-------
{klass}
First differences of the Series.
See Also
--------
{klass}.pct_change: Percent change over given number of periods.
{klass}.shift: Shift index by desired number of periods with an
optional time freq.
{other_klass}.diff: First discrete difference of object.
Notes
-----
For boolean dtypes, this uses :meth:`operator.xor` rather than
:meth:`operator.sub`.
The result is calculated according to current dtype in {klass},
however dtype of the result is always float64.
Examples
--------
{examples}
"""
result = algorithms.diff(self._values, periods)
return self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="diff"
)
def autocorr(self, lag: int = 1) -> float:
"""
Compute the lag-N autocorrelation.
This method computes the Pearson correlation between
the Series and its shifted self.
Parameters
----------
lag : int, default 1
Number of lags to apply before performing autocorrelation.
Returns
-------
float
The Pearson correlation between self and self.shift(lag).
See Also
--------
Series.corr : Compute the correlation between two Series.
Series.shift : Shift index by desired number of periods.
DataFrame.corr : Compute pairwise correlation of columns.
DataFrame.corrwith : Compute pairwise correlation between rows or
columns of two DataFrame objects.
Notes
-----
If the Pearson correlation is not well defined return 'NaN'.
Examples
--------
>>> s = pd.Series([0.25, 0.5, 0.2, -0.05])
>>> s.autocorr() # doctest: +ELLIPSIS
0.10355...
>>> s.autocorr(lag=2) # doctest: +ELLIPSIS
-0.99999...
If the Pearson correlation is not well defined, then 'NaN' is returned.
>>> s = pd.Series([1, 0, 0, 0])
>>> s.autocorr()
nan
"""
return self.corr(self.shift(lag))
def dot(self, other: AnyArrayLike) -> Series | np.ndarray:
"""
Compute the dot product between the Series and the columns of other.
This method computes the dot product between the Series and another
one, or the Series and each columns of a DataFrame, or the Series and
each columns of an array.
It can also be called using `self @ other` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the dot product with its columns.
Returns
-------
scalar, Series or numpy.ndarray
Return the dot product of the Series and other if other is a
Series, the Series of the dot product of Series and each rows of
other if other is a DataFrame or a numpy.ndarray between the Series
and each columns of the numpy array.
See Also
--------
DataFrame.dot: Compute the matrix product with the DataFrame.
Series.mul: Multiplication of series and other, element-wise.
Notes
-----
The Series and other has to share the same index if other is a Series
or a DataFrame.
Examples
--------
>>> s = pd.Series([0, 1, 2, 3])
>>> other = pd.Series([-1, 2, -3, 4])
>>> s.dot(other)
8
>>> s @ other
8
>>> df = pd.DataFrame([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(df)
0 24
1 14
dtype: int64
>>> arr = np.array([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(arr)
array([24, 14])
"""
if isinstance(other, (Series, ABCDataFrame)):
common = self.index.union(other.index)
if len(common) > len(self.index) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(index=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right.values
else:
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[0] != rvals.shape[0]:
raise Exception(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, ABCDataFrame):
return self._constructor(
np.dot(lvals, rvals), index=other.columns, copy=False
).__finalize__(self, method="dot")
elif isinstance(other, Series):
return np.dot(lvals, rvals)
elif isinstance(rvals, np.ndarray):
return np.dot(lvals, rvals)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(np.transpose(other))
# Signature of "searchsorted" incompatible with supertype "IndexOpsMixin"
def searchsorted( # type: ignore[override]
self,
value: NumpyValueArrayLike | ExtensionArray,
side: Literal["left", "right"] = "left",
sorter: NumpySorter = None,
) -> npt.NDArray[np.intp] | np.intp:
return base.IndexOpsMixin.searchsorted(self, value, side=side, sorter=sorter)
# -------------------------------------------------------------------
# Combination
def _append(
self, to_append, ignore_index: bool = False, verify_integrity: bool = False
):
from pandas.core.reshape.concat import concat
if isinstance(to_append, (list, tuple)):
to_concat = [self]
to_concat.extend(to_append)
else:
to_concat = [self, to_append]
if any(isinstance(x, (ABCDataFrame,)) for x in to_concat[1:]):
msg = "to_append should be a Series or list/tuple of Series, got DataFrame"
raise TypeError(msg)
return concat(
to_concat, ignore_index=ignore_index, verify_integrity=verify_integrity
)
def _binop(self, other: Series, func, level=None, fill_value=None):
"""
Perform generic binary operation with optional fill value.
Parameters
----------
other : Series
func : binary operator
fill_value : float or object
Value to substitute for NA/null values. If both Series are NA in a
location, the result will be NA regardless of the passed fill value.
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
Returns
-------
Series
"""
if not isinstance(other, Series):
raise AssertionError("Other operand must be Series")
this = self
if not self.index.equals(other.index):
this, other = self.align(other, level=level, join="outer", copy=False)
this_vals, other_vals = ops.fill_binop(this._values, other._values, fill_value)
with np.errstate(all="ignore"):
result = func(this_vals, other_vals)
name = ops.get_op_result_name(self, other)
return this._construct_result(result, name)
def _construct_result(
self, result: ArrayLike | tuple[ArrayLike, ArrayLike], name: Hashable
) -> Series | tuple[Series, Series]:
"""
Construct an appropriately-labelled Series from the result of an op.
Parameters
----------
result : ndarray or ExtensionArray
name : Label
Returns
-------
Series
In the case of __divmod__ or __rdivmod__, a 2-tuple of Series.
"""
if isinstance(result, tuple):
# produced by divmod or rdivmod
res1 = self._construct_result(result[0], name=name)
res2 = self._construct_result(result[1], name=name)
# GH#33427 assertions to keep mypy happy
assert isinstance(res1, Series)
assert isinstance(res2, Series)
return (res1, res2)
# TODO: result should always be ArrayLike, but this fails for some
# JSONArray tests
dtype = getattr(result, "dtype", None)
out = self._constructor(result, index=self.index, dtype=dtype)
out = out.__finalize__(self)
# Set the result's name after __finalize__ is called because __finalize__
# would set it back to self.name
out.name = name
return out
_shared_docs["compare"],
"""
Returns
-------
Series or DataFrame
If axis is 0 or 'index' the result will be a Series.
The resulting index will be a MultiIndex with 'self' and 'other'
stacked alternately at the inner level.
If axis is 1 or 'columns' the result will be a DataFrame.
It will have two columns namely 'self' and 'other'.
See Also
--------
DataFrame.compare : Compare with another DataFrame and show differences.
Notes
-----
Matching NaNs will not appear as a difference.
Examples
--------
>>> s1 = pd.Series(["a", "b", "c", "d", "e"])
>>> s2 = pd.Series(["a", "a", "c", "b", "e"])
Align the differences on columns
>>> s1.compare(s2)
self other
1 b a
3 d b
Stack the differences on indices
>>> s1.compare(s2, align_axis=0)
1 self b
other a
3 self d
other b
dtype: object
Keep all original rows
>>> s1.compare(s2, keep_shape=True)
self other
0 NaN NaN
1 b a
2 NaN NaN
3 d b
4 NaN NaN
Keep all original rows and also all original values
>>> s1.compare(s2, keep_shape=True, keep_equal=True)
self other
0 a a
1 b a
2 c c
3 d b
4 e e
""",
klass=_shared_doc_kwargs["klass"],
)
def compare(
self,
other: Series,
align_axis: Axis = 1,
keep_shape: bool = False,
keep_equal: bool = False,
result_names: Suffixes = ("self", "other"),
) -> DataFrame | Series:
return super().compare(
other=other,
align_axis=align_axis,
keep_shape=keep_shape,
keep_equal=keep_equal,
result_names=result_names,
)
def combine(
self,
other: Series | Hashable,
func: Callable[[Hashable, Hashable], Hashable],
fill_value: Hashable = None,
) -> Series:
"""
Combine the Series with a Series or scalar according to `func`.
Combine the Series and `other` using `func` to perform elementwise
selection for combined Series.
`fill_value` is assumed when value is missing at some index
from one of the two objects being combined.
Parameters
----------
other : Series or scalar
The value(s) to be combined with the `Series`.
func : function
Function that takes two scalars as inputs and returns an element.
fill_value : scalar, optional
The value to assume when an index is missing from
one Series or the other. The default specifies to use the
appropriate NaN value for the underlying dtype of the Series.
Returns
-------
Series
The result of combining the Series with the other object.
See Also
--------
Series.combine_first : Combine Series values, choosing the calling
Series' values first.
Examples
--------
Consider 2 Datasets ``s1`` and ``s2`` containing
highest clocked speeds of different birds.
>>> s1 = pd.Series({'falcon': 330.0, 'eagle': 160.0})
>>> s1
falcon 330.0
eagle 160.0
dtype: float64
>>> s2 = pd.Series({'falcon': 345.0, 'eagle': 200.0, 'duck': 30.0})
>>> s2
falcon 345.0
eagle 200.0
duck 30.0
dtype: float64
Now, to combine the two datasets and view the highest speeds
of the birds across the two datasets
>>> s1.combine(s2, max)
duck NaN
eagle 200.0
falcon 345.0
dtype: float64
In the previous example, the resulting value for duck is missing,
because the maximum of a NaN and a float is a NaN.
So, in the example, we set ``fill_value=0``,
so the maximum value returned will be the value from some dataset.
>>> s1.combine(s2, max, fill_value=0)
duck 30.0
eagle 200.0
falcon 345.0
dtype: float64
"""
if fill_value is None:
fill_value = na_value_for_dtype(self.dtype, compat=False)
if isinstance(other, Series):
# If other is a Series, result is based on union of Series,
# so do this element by element
new_index = self.index.union(other.index)
new_name = ops.get_op_result_name(self, other)
new_values = np.empty(len(new_index), dtype=object)
for i, idx in enumerate(new_index):
lv = self.get(idx, fill_value)
rv = other.get(idx, fill_value)
with np.errstate(all="ignore"):
new_values[i] = func(lv, rv)
else:
# Assume that other is a scalar, so apply the function for
# each element in the Series
new_index = self.index
new_values = np.empty(len(new_index), dtype=object)
with np.errstate(all="ignore"):
new_values[:] = [func(lv, other) for lv in self._values]
new_name = self.name
# try_float=False is to match agg_series
npvalues = lib.maybe_convert_objects(new_values, try_float=False)
res_values = maybe_cast_pointwise_result(npvalues, self.dtype, same_dtype=False)
return self._constructor(res_values, index=new_index, name=new_name, copy=False)
def combine_first(self, other) -> Series:
"""
Update null elements with value in the same location in 'other'.
Combine two Series objects by filling null values in one Series with
non-null values from the other Series. Result index will be the union
of the two indexes.
Parameters
----------
other : Series
The value(s) to be used for filling null values.
Returns
-------
Series
The result of combining the provided Series with the other object.
See Also
--------
Series.combine : Perform element-wise operation on two Series
using a given function.
Examples
--------
>>> s1 = pd.Series([1, np.nan])
>>> s2 = pd.Series([3, 4, 5])
>>> s1.combine_first(s2)
0 1.0
1 4.0
2 5.0
dtype: float64
Null values still persist if the location of that null value
does not exist in `other`
>>> s1 = pd.Series({'falcon': np.nan, 'eagle': 160.0})
>>> s2 = pd.Series({'eagle': 200.0, 'duck': 30.0})
>>> s1.combine_first(s2)
duck 30.0
eagle 160.0
falcon NaN
dtype: float64
"""
new_index = self.index.union(other.index)
this = self.reindex(new_index, copy=False)
other = other.reindex(new_index, copy=False)
if this.dtype.kind == "M" and other.dtype.kind != "M":
other = to_datetime(other)
return this.where(notna(this), other)
def update(self, other: Series | Sequence | Mapping) -> None:
"""
Modify Series in place using values from passed Series.
Uses non-NA values from passed Series to make updates. Aligns
on index.
Parameters
----------
other : Series, or object coercible into Series
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6]))
>>> s
0 4
1 5
2 6
dtype: int64
>>> s = pd.Series(['a', 'b', 'c'])
>>> s.update(pd.Series(['d', 'e'], index=[0, 2]))
>>> s
0 d
1 b
2 e
dtype: object
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6, 7, 8]))
>>> s
0 4
1 5
2 6
dtype: int64
If ``other`` contains NaNs the corresponding values are not updated
in the original Series.
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, np.nan, 6]))
>>> s
0 4
1 2
2 6
dtype: int64
``other`` can also be a non-Series object type
that is coercible into a Series
>>> s = pd.Series([1, 2, 3])
>>> s.update([4, np.nan, 6])
>>> s
0 4
1 2
2 6
dtype: int64
>>> s = pd.Series([1, 2, 3])
>>> s.update({1: 9})
>>> s
0 1
1 9
2 3
dtype: int64
"""
if not isinstance(other, Series):
other = Series(other)
other = other.reindex_like(self)
mask = notna(other)
self._mgr = self._mgr.putmask(mask=mask, new=other)
self._maybe_update_cacher()
# ----------------------------------------------------------------------
# Reindexing, sorting
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> Series:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self,
*,
axis: Axis = 0,
ascending: bool | int | Sequence[bool] | Sequence[int] = True,
inplace: bool = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool = False,
key: ValueKeyFunc = None,
) -> Series | None:
"""
Sort by the values.
Sort a Series in ascending or descending order by some
criterion.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
ascending : bool or list of bools, default True
If True, sort values in ascending order, otherwise descending.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
na_position : {'first' or 'last'}, default 'last'
Argument 'first' puts NaNs at the beginning, 'last' puts NaNs at
the end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the series values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return an array-like.
.. versionadded:: 1.1.0
Returns
-------
Series or None
Series ordered by values or None if ``inplace=True``.
See Also
--------
Series.sort_index : Sort by the Series indices.
DataFrame.sort_values : Sort DataFrame by the values along either axis.
DataFrame.sort_index : Sort DataFrame by indices.
Examples
--------
>>> s = pd.Series([np.nan, 1, 3, 10, 5])
>>> s
0 NaN
1 1.0
2 3.0
3 10.0
4 5.0
dtype: float64
Sort values ascending order (default behaviour)
>>> s.sort_values(ascending=True)
1 1.0
2 3.0
4 5.0
3 10.0
0 NaN
dtype: float64
Sort values descending order
>>> s.sort_values(ascending=False)
3 10.0
4 5.0
2 3.0
1 1.0
0 NaN
dtype: float64
Sort values putting NAs first
>>> s.sort_values(na_position='first')
0 NaN
1 1.0
2 3.0
4 5.0
3 10.0
dtype: float64
Sort a series of strings
>>> s = pd.Series(['z', 'b', 'd', 'a', 'c'])
>>> s
0 z
1 b
2 d
3 a
4 c
dtype: object
>>> s.sort_values()
3 a
1 b
4 c
2 d
0 z
dtype: object
Sort using a key function. Your `key` function will be
given the ``Series`` of values and should return an array-like.
>>> s = pd.Series(['a', 'B', 'c', 'D', 'e'])
>>> s.sort_values()
1 B
3 D
0 a
2 c
4 e
dtype: object
>>> s.sort_values(key=lambda x: x.str.lower())
0 a
1 B
2 c
3 D
4 e
dtype: object
NumPy ufuncs work well here. For example, we can
sort by the ``sin`` of the value
>>> s = pd.Series([-4, -2, 0, 2, 4])
>>> s.sort_values(key=np.sin)
1 -2
4 4
2 0
0 -4
3 2
dtype: int64
More complicated user-defined functions can be used,
as long as they expect a Series and return an array-like
>>> s.sort_values(key=lambda x: (np.tan(x.cumsum())))
0 -4
3 2
4 4
1 -2
2 0
dtype: int64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
# Validate the axis parameter
self._get_axis_number(axis)
# GH 5856/5853
if inplace and self._is_cached:
raise ValueError(
"This Series is a view of some other array, to "
"sort in-place you must create a copy"
)
if is_list_like(ascending):
ascending = cast(Sequence[Union[bool, int]], ascending)
if len(ascending) != 1:
raise ValueError(
f"Length of ascending ({len(ascending)}) must be 1 for Series"
)
ascending = ascending[0]
ascending = validate_ascending(ascending)
if na_position not in ["first", "last"]:
raise ValueError(f"invalid na_position: {na_position}")
# GH 35922. Make sorting stable by leveraging nargsort
values_to_sort = ensure_key_mapped(self, key)._values if key else self._values
sorted_index = nargsort(values_to_sort, kind, bool(ascending), na_position)
if is_range_indexer(sorted_index, len(sorted_index)):
if inplace:
return self._update_inplace(self)
return self.copy(deep=None)
result = self._constructor(
self._values[sorted_index], index=self.index[sorted_index], copy=False
)
if ignore_index:
result.index = default_index(len(sorted_index))
if not inplace:
return result.__finalize__(self, method="sort_values")
self._update_inplace(result)
return None
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: bool = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series | None:
...
def sort_index(
self,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool | Sequence[bool] = True,
inplace: bool = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool = True,
ignore_index: bool = False,
key: IndexKeyFunc = None,
) -> Series | None:
"""
Sort Series by index labels.
Returns a new Series sorted by label if `inplace` argument is
``False``, otherwise updates the original series and returns None.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
level : int, optional
If not None, sort on values in specified index level(s).
ascending : bool or list-like of bools, default True
Sort ascending vs. descending. When the index is a MultiIndex the
sort direction can be controlled for each level individually.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
If 'first' puts NaNs at the beginning, 'last' puts NaNs at the end.
Not implemented for MultiIndex.
sort_remaining : bool, default True
If True and sorting by level and index is multilevel, sort by other
levels too (in order) after sorting by specified level.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the index values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect an
``Index`` and return an ``Index`` of the same shape.
.. versionadded:: 1.1.0
Returns
-------
Series or None
The original Series sorted by the labels or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index: Sort DataFrame by the index.
DataFrame.sort_values: Sort DataFrame by the value.
Series.sort_values : Sort Series by the value.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, 4])
>>> s.sort_index()
1 c
2 b
3 a
4 d
dtype: object
Sort Descending
>>> s.sort_index(ascending=False)
4 d
3 a
2 b
1 c
dtype: object
By default NaNs are put at the end, but use `na_position` to place
them at the beginning
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, np.nan])
>>> s.sort_index(na_position='first')
NaN d
1.0 c
2.0 b
3.0 a
dtype: object
Specify index level to sort
>>> arrays = [np.array(['qux', 'qux', 'foo', 'foo',
... 'baz', 'baz', 'bar', 'bar']),
... np.array(['two', 'one', 'two', 'one',
... 'two', 'one', 'two', 'one'])]
>>> s = pd.Series([1, 2, 3, 4, 5, 6, 7, 8], index=arrays)
>>> s.sort_index(level=1)
bar one 8
baz one 6
foo one 4
qux one 2
bar two 7
baz two 5
foo two 3
qux two 1
dtype: int64
Does not sort by remaining levels when sorting by levels
>>> s.sort_index(level=1, sort_remaining=False)
qux one 2
foo one 4
baz one 6
bar one 8
qux two 1
foo two 3
baz two 5
bar two 7
dtype: int64
Apply a key function before sorting
>>> s = pd.Series([1, 2, 3, 4], index=['A', 'b', 'C', 'd'])
>>> s.sort_index(key=lambda x : x.str.lower())
A 1
b 2
C 3
d 4
dtype: int64
"""
return super().sort_index(
axis=axis,
level=level,
ascending=ascending,
inplace=inplace,
kind=kind,
na_position=na_position,
sort_remaining=sort_remaining,
ignore_index=ignore_index,
key=key,
)
def argsort(
self,
axis: Axis = 0,
kind: SortKind = "quicksort",
order: None = None,
) -> Series:
"""
Return the integer indices that would sort the Series values.
Override ndarray.argsort. Argsorts the value, omitting NA/null values,
and places the result in the same locations as the non-NA values.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
kind : {'mergesort', 'quicksort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
order : None
Has no effect but is accepted for compatibility with numpy.
Returns
-------
Series[np.intp]
Positions of values within the sort order with -1 indicating
nan values.
See Also
--------
numpy.ndarray.argsort : Returns the indices that would sort this array.
"""
values = self._values
mask = isna(values)
if mask.any():
result = np.full(len(self), -1, dtype=np.intp)
notmask = ~mask
result[notmask] = np.argsort(values[notmask], kind=kind)
else:
result = np.argsort(values, kind=kind)
res = self._constructor(
result, index=self.index, name=self.name, dtype=np.intp, copy=False
)
return res.__finalize__(self, method="argsort")
def nlargest(
self, n: int = 5, keep: Literal["first", "last", "all"] = "first"
) -> Series:
"""
Return the largest `n` elements.
Parameters
----------
n : int, default 5
Return this many descending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` largest values in the Series, sorted in decreasing order.
See Also
--------
Series.nsmallest: Get the `n` smallest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values(ascending=False).head(n)`` for small `n`
relative to the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Malta": 434000, "Maldives": 434000,
... "Brunei": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Malta 434000
Maldives 434000
Brunei 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` largest elements where ``n=5`` by default.
>>> s.nlargest()
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3``. Default `keep` value is 'first'
so Malta will be kept.
>>> s.nlargest(3)
France 65000000
Italy 59000000
Malta 434000
dtype: int64
The `n` largest elements where ``n=3`` and keeping the last duplicates.
Brunei will be kept since it is the last with value 434000 based on
the index order.
>>> s.nlargest(3, keep='last')
France 65000000
Italy 59000000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has five elements due to the three duplicates.
>>> s.nlargest(3, keep='all')
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nlargest()
def nsmallest(self, n: int = 5, keep: str = "first") -> Series:
"""
Return the smallest `n` elements.
Parameters
----------
n : int, default 5
Return this many ascending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` smallest values in the Series, sorted in increasing order.
See Also
--------
Series.nlargest: Get the `n` largest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values().head(n)`` for small `n` relative to
the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Brunei": 434000, "Malta": 434000,
... "Maldives": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Brunei 434000
Malta 434000
Maldives 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` smallest elements where ``n=5`` by default.
>>> s.nsmallest()
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
Iceland 337000
dtype: int64
The `n` smallest elements where ``n=3``. Default `keep` value is
'first' so Nauru and Tuvalu will be kept.
>>> s.nsmallest(3)
Montserrat 5200
Nauru 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` and keeping the last
duplicates. Anguilla and Tuvalu will be kept since they are the last
with value 11300 based on the index order.
>>> s.nsmallest(3, keep='last')
Montserrat 5200
Anguilla 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has four elements due to the three duplicates.
>>> s.nsmallest(3, keep='all')
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nsmallest()
klass=_shared_doc_kwargs["klass"],
extra_params=dedent(
"""copy : bool, default True
Whether to copy underlying data."""
),
examples=dedent(
"""\
Examples
--------
>>> s = pd.Series(
... ["A", "B", "A", "C"],
... index=[
... ["Final exam", "Final exam", "Coursework", "Coursework"],
... ["History", "Geography", "History", "Geography"],
... ["January", "February", "March", "April"],
... ],
... )
>>> s
Final exam History January A
Geography February B
Coursework History March A
Geography April C
dtype: object
In the following example, we will swap the levels of the indices.
Here, we will swap the levels column-wise, but levels can be swapped row-wise
in a similar manner. Note that column-wise is the default behaviour.
By not supplying any arguments for i and j, we swap the last and second to
last indices.
>>> s.swaplevel()
Final exam January History A
February Geography B
Coursework March History A
April Geography C
dtype: object
By supplying one argument, we can choose which index to swap the last
index with. We can for example swap the first index with the last one as
follows.
>>> s.swaplevel(0)
January History Final exam A
February Geography Final exam B
March History Coursework A
April Geography Coursework C
dtype: object
We can also define explicitly which indices we want to swap by supplying values
for both i and j. Here, we for example swap the first and second indices.
>>> s.swaplevel(0, 1)
History Final exam January A
Geography Final exam February B
History Coursework March A
Geography Coursework April C
dtype: object"""
),
)
def swaplevel(
self, i: Level = -2, j: Level = -1, copy: bool | None = None
) -> Series:
"""
Swap levels i and j in a :class:`MultiIndex`.
Default is to swap the two innermost levels of the index.
Parameters
----------
i, j : int or str
Levels of the indices to be swapped. Can pass level name as string.
{extra_params}
Returns
-------
{klass}
{klass} with levels swapped in MultiIndex.
{examples}
"""
assert isinstance(self.index, MultiIndex)
result = self.copy(deep=copy and not using_copy_on_write())
result.index = self.index.swaplevel(i, j)
return result
def reorder_levels(self, order: Sequence[Level]) -> Series:
"""
Rearrange index levels using input order.
May not drop or duplicate levels.
Parameters
----------
order : list of int representing new level order
Reference level by number or key.
Returns
-------
type of caller (new object)
"""
if not isinstance(self.index, MultiIndex): # pragma: no cover
raise Exception("Can only reorder levels on a hierarchical axis.")
result = self.copy(deep=None)
assert isinstance(result.index, MultiIndex)
result.index = result.index.reorder_levels(order)
return result
def explode(self, ignore_index: bool = False) -> Series:
"""
Transform each element of a list-like to a row.
Parameters
----------
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.1.0
Returns
-------
Series
Exploded lists to rows; index will be duplicated for these rows.
See Also
--------
Series.str.split : Split string values on specified separator.
Series.unstack : Unstack, a.k.a. pivot, Series with MultiIndex
to produce DataFrame.
DataFrame.melt : Unpivot a DataFrame from wide format to long format.
DataFrame.explode : Explode a DataFrame from list-like
columns to long format.
Notes
-----
This routine will explode list-likes including lists, tuples, sets,
Series, and np.ndarray. The result dtype of the subset rows will
be object. Scalars will be returned unchanged, and empty list-likes will
result in a np.nan for that row. In addition, the ordering of elements in
the output will be non-deterministic when exploding sets.
Reference :ref:`the user guide <reshaping.explode>` for more examples.
Examples
--------
>>> s = pd.Series([[1, 2, 3], 'foo', [], [3, 4]])
>>> s
0 [1, 2, 3]
1 foo
2 []
3 [3, 4]
dtype: object
>>> s.explode()
0 1
0 2
0 3
1 foo
2 NaN
3 3
3 4
dtype: object
"""
if not len(self) or not is_object_dtype(self):
result = self.copy()
return result.reset_index(drop=True) if ignore_index else result
values, counts = reshape.explode(np.asarray(self._values))
if ignore_index:
index = default_index(len(values))
else:
index = self.index.repeat(counts)
return self._constructor(values, index=index, name=self.name, copy=False)
def unstack(self, level: IndexLabel = -1, fill_value: Hashable = None) -> DataFrame:
"""
Unstack, also known as pivot, Series with MultiIndex to produce DataFrame.
Parameters
----------
level : int, str, or list of these, default last level
Level(s) to unstack, can pass level name.
fill_value : scalar value, default None
Value to use when replacing NaN values.
Returns
-------
DataFrame
Unstacked Series.
Notes
-----
Reference :ref:`the user guide <reshaping.stacking>` for more examples.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4],
... index=pd.MultiIndex.from_product([['one', 'two'],
... ['a', 'b']]))
>>> s
one a 1
b 2
two a 3
b 4
dtype: int64
>>> s.unstack(level=-1)
a b
one 1 2
two 3 4
>>> s.unstack(level=0)
one two
a 1 3
b 2 4
"""
from pandas.core.reshape.reshape import unstack
return unstack(self, level, fill_value)
# ----------------------------------------------------------------------
# function application
def map(
self,
arg: Callable | Mapping | Series,
na_action: Literal["ignore"] | None = None,
) -> Series:
"""
Map values of Series according to an input mapping or function.
Used for substituting each value in a Series with another value,
that may be derived from a function, a ``dict`` or
a :class:`Series`.
Parameters
----------
arg : function, collections.abc.Mapping subclass or Series
Mapping correspondence.
na_action : {None, 'ignore'}, default None
If 'ignore', propagate NaN values, without passing them to the
mapping correspondence.
Returns
-------
Series
Same index as caller.
See Also
--------
Series.apply : For applying more complex functions on a Series.
DataFrame.apply : Apply a function row-/column-wise.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Notes
-----
When ``arg`` is a dictionary, values in Series that are not in the
dictionary (as keys) are converted to ``NaN``. However, if the
dictionary is a ``dict`` subclass that defines ``__missing__`` (i.e.
provides a method for default values), then this default is used
rather than ``NaN``.
Examples
--------
>>> s = pd.Series(['cat', 'dog', np.nan, 'rabbit'])
>>> s
0 cat
1 dog
2 NaN
3 rabbit
dtype: object
``map`` accepts a ``dict`` or a ``Series``. Values that are not found
in the ``dict`` are converted to ``NaN``, unless the dict has a default
value (e.g. ``defaultdict``):
>>> s.map({'cat': 'kitten', 'dog': 'puppy'})
0 kitten
1 puppy
2 NaN
3 NaN
dtype: object
It also accepts a function:
>>> s.map('I am a {}'.format)
0 I am a cat
1 I am a dog
2 I am a nan
3 I am a rabbit
dtype: object
To avoid applying the function to missing values (and keep them as
``NaN``) ``na_action='ignore'`` can be used:
>>> s.map('I am a {}'.format, na_action='ignore')
0 I am a cat
1 I am a dog
2 NaN
3 I am a rabbit
dtype: object
"""
new_values = self._map_values(arg, na_action=na_action)
return self._constructor(new_values, index=self.index, copy=False).__finalize__(
self, method="map"
)
def _gotitem(self, key, ndim, subset=None) -> Series:
"""
Sub-classes to define. Return a sliced object.
Parameters
----------
key : string / list of selections
ndim : {1, 2}
Requested ndim of result.
subset : object, default None
Subset to act on.
"""
return self
_agg_see_also_doc = dedent(
"""
See Also
--------
Series.apply : Invoke function on a Series.
Series.transform : Transform function producing a Series with like indexes.
"""
)
_agg_examples_doc = dedent(
"""
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.agg('min')
1
>>> s.agg(['min', 'max'])
min 1
max 4
dtype: int64
"""
)
_shared_docs["aggregate"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
see_also=_agg_see_also_doc,
examples=_agg_examples_doc,
)
def aggregate(self, func=None, axis: Axis = 0, *args, **kwargs):
# Validate the axis parameter
self._get_axis_number(axis)
# if func is None, will switch to user-provided "named aggregation" kwargs
if func is None:
func = dict(kwargs.items())
op = SeriesApply(self, func, convert_dtype=False, args=args, kwargs=kwargs)
result = op.agg()
return result
agg = aggregate
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: None = ...,
**kwargs,
) -> bool:
...
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: Level,
**kwargs,
) -> Series | bool:
...
# error: Missing return statement
def any( # type: ignore[empty-body]
self,
axis: Axis = 0,
bool_only: bool | None = None,
skipna: bool = True,
level: Level | None = None,
**kwargs,
) -> Series | bool:
...
_shared_docs["transform"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
)
def transform(
self, func: AggFuncType, axis: Axis = 0, *args, **kwargs
) -> DataFrame | Series:
# Validate axis argument
self._get_axis_number(axis)
result = SeriesApply(
self, func=func, convert_dtype=True, args=args, kwargs=kwargs
).transform()
return result
def apply(
self,
func: AggFuncType,
convert_dtype: bool = True,
args: tuple[Any, ...] = (),
**kwargs,
) -> DataFrame | Series:
"""
Invoke function on values of Series.
Can be ufunc (a NumPy function that applies to the entire Series)
or a Python function that only works on single values.
Parameters
----------
func : function
Python function or NumPy ufunc to apply.
convert_dtype : bool, default True
Try to find better dtype for elementwise function results. If
False, leave as dtype=object. Note that the dtype is always
preserved for some extension array dtypes, such as Categorical.
args : tuple
Positional arguments passed to func after the series value.
**kwargs
Additional keyword arguments passed to func.
Returns
-------
Series or DataFrame
If func returns a Series object the result will be a DataFrame.
See Also
--------
Series.map: For element-wise operations.
Series.agg: Only perform aggregating type operations.
Series.transform: Only perform transforming type operations.
Notes
-----
Functions that mutate the passed object can produce unexpected
behavior or errors and are not supported. See :ref:`gotchas.udf-mutation`
for more details.
Examples
--------
Create a series with typical summer temperatures for each city.
>>> s = pd.Series([20, 21, 12],
... index=['London', 'New York', 'Helsinki'])
>>> s
London 20
New York 21
Helsinki 12
dtype: int64
Square the values by defining a function and passing it as an
argument to ``apply()``.
>>> def square(x):
... return x ** 2
>>> s.apply(square)
London 400
New York 441
Helsinki 144
dtype: int64
Square the values by passing an anonymous function as an
argument to ``apply()``.
>>> s.apply(lambda x: x ** 2)
London 400
New York 441
Helsinki 144
dtype: int64
Define a custom function that needs additional positional
arguments and pass these additional arguments using the
``args`` keyword.
>>> def subtract_custom_value(x, custom_value):
... return x - custom_value
>>> s.apply(subtract_custom_value, args=(5,))
London 15
New York 16
Helsinki 7
dtype: int64
Define a custom function that takes keyword arguments
and pass these arguments to ``apply``.
>>> def add_custom_values(x, **kwargs):
... for month in kwargs:
... x += kwargs[month]
... return x
>>> s.apply(add_custom_values, june=30, july=20, august=25)
London 95
New York 96
Helsinki 87
dtype: int64
Use a function from the Numpy library.
>>> s.apply(np.log)
London 2.995732
New York 3.044522
Helsinki 2.484907
dtype: float64
"""
return SeriesApply(self, func, convert_dtype, args, kwargs).apply()
def _reduce(
self,
op,
name: str,
*,
axis: Axis = 0,
skipna: bool = True,
numeric_only: bool = False,
filter_type=None,
**kwds,
):
"""
Perform a reduction operation.
If we have an ndarray as a value, then simply perform the operation,
otherwise delegate to the object.
"""
delegate = self._values
if axis is not None:
self._get_axis_number(axis)
if isinstance(delegate, ExtensionArray):
# dispatch to ExtensionArray interface
return delegate._reduce(name, skipna=skipna, **kwds)
else:
# dispatch to numpy arrays
if numeric_only and not is_numeric_dtype(self.dtype):
kwd_name = "numeric_only"
if name in ["any", "all"]:
kwd_name = "bool_only"
# GH#47500 - change to TypeError to match other methods
raise TypeError(
f"Series.{name} does not allow {kwd_name}={numeric_only} "
"with non-numeric dtypes."
)
with np.errstate(all="ignore"):
return op(delegate, skipna=skipna, **kwds)
def _reindex_indexer(
self,
new_index: Index | None,
indexer: npt.NDArray[np.intp] | None,
copy: bool | None,
) -> Series:
# Note: new_index is None iff indexer is None
# if not None, indexer is np.intp
if indexer is None and (
new_index is None or new_index.names == self.index.names
):
if using_copy_on_write():
return self.copy(deep=copy)
if copy or copy is None:
return self.copy(deep=copy)
return self
new_values = algorithms.take_nd(
self._values, indexer, allow_fill=True, fill_value=None
)
return self._constructor(new_values, index=new_index, copy=False)
def _needs_reindex_multi(self, axes, method, level) -> bool:
"""
Check if we do need a multi reindex; this is for compat with
higher dims.
"""
return False
# error: Cannot determine type of 'align'
NDFrame.align, # type: ignore[has-type]
klass=_shared_doc_kwargs["klass"],
axes_single_arg=_shared_doc_kwargs["axes_single_arg"],
)
def align(
self,
other: Series,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> Series:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[True],
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> None:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[False] = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: bool = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series | None:
...
def rename(
self,
index: Renamer | Hashable | None = None,
*,
axis: Axis | None = None,
copy: bool = True,
inplace: bool = False,
level: Level | None = None,
errors: IgnoreRaise = "ignore",
) -> Series | None:
"""
Alter Series index labels or name.
Function / dict values must be unique (1-to-1). Labels not contained in
a dict / Series will be left as-is. Extra labels listed don't throw an
error.
Alternatively, change ``Series.name`` with a scalar value.
See the :ref:`user guide <basics.rename>` for more.
Parameters
----------
index : scalar, hashable sequence, dict-like or function optional
Functions or dict-like are transformations to apply to
the index.
Scalar or hashable sequence-like will alter the ``Series.name``
attribute.
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
copy : bool, default True
Also copy underlying data.
inplace : bool, default False
Whether to return a new Series. If True the value of copy is ignored.
level : int or level name, default None
In case of MultiIndex, only rename labels in the specified level.
errors : {'ignore', 'raise'}, default 'ignore'
If 'raise', raise `KeyError` when a `dict-like mapper` or
`index` contains labels that are not present in the index being transformed.
If 'ignore', existing keys will be renamed and extra keys will be ignored.
Returns
-------
Series or None
Series with index labels or name altered or None if ``inplace=True``.
See Also
--------
DataFrame.rename : Corresponding DataFrame method.
Series.rename_axis : Set the name of the axis.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.rename("my_name") # scalar, changes Series.name
0 1
1 2
2 3
Name: my_name, dtype: int64
>>> s.rename(lambda x: x ** 2) # function, changes labels
0 1
1 2
4 3
dtype: int64
>>> s.rename({1: 3, 2: 5}) # mapping, changes labels
0 1
3 2
5 3
dtype: int64
"""
if axis is not None:
# Make sure we raise if an invalid 'axis' is passed.
axis = self._get_axis_number(axis)
if callable(index) or is_dict_like(index):
# error: Argument 1 to "_rename" of "NDFrame" has incompatible
# type "Union[Union[Mapping[Any, Hashable], Callable[[Any],
# Hashable]], Hashable, None]"; expected "Union[Mapping[Any,
# Hashable], Callable[[Any], Hashable], None]"
return super()._rename(
index, # type: ignore[arg-type]
copy=copy,
inplace=inplace,
level=level,
errors=errors,
)
else:
return self._set_name(index, inplace=inplace)
"""
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.set_axis(['a', 'b', 'c'], axis=0)
a 1
b 2
c 3
dtype: int64
"""
)
**_shared_doc_kwargs,
extended_summary_sub="",
axis_description_sub="",
see_also_sub="",
)
)
)
# error: Cannot determine type of 'shift'
# ----------------------------------------------------------------------
# Convert to types that support pd.NA
# error: Cannot determine type of 'isna'
# error: Return type "Series" of "isna" incompatible with return type "ndarray
# [Any, dtype[bool_]]" in supertype "IndexOpsMixin"
# error: Cannot determine type of 'isna'
# error: Cannot determine type of 'notna'
# error: Cannot determine type of 'notna'
# ----------------------------------------------------------------------
# Time series-oriented methods
# error: Cannot determine type of 'asfreq'
# error: Cannot determine type of 'resample'
# ----------------------------------------------------------------------
# Add index
# ----------------------------------------------------------------------
# Accessor Methods
# ----------------------------------------------------------------------
# ----------------------------------------------------------------------
# Add plotting methods to Series
# ----------------------------------------------------------------------
# Template-Based Arithmetic/Comparison Methods
Series
The provided code snippet includes necessary dependencies for implementing the `_stata_elapsed_date_to_datetime_vec` function. Write a Python function `def _stata_elapsed_date_to_datetime_vec(dates, fmt) -> Series` to solve the following problem:
Convert from SIF to datetime. https://www.stata.com/help.cgi?datetime Parameters ---------- dates : Series The Stata Internal Format date to convert to datetime according to fmt fmt : str The format to convert to. Can be, tc, td, tw, tm, tq, th, ty Returns Returns ------- converted : Series The converted dates Examples -------- >>> dates = pd.Series([52]) >>> _stata_elapsed_date_to_datetime_vec(dates , "%tw") 0 1961-01-01 dtype: datetime64[ns] Notes ----- datetime/c - tc milliseconds since 01jan1960 00:00:00.000, assuming 86,400 s/day datetime/C - tC - NOT IMPLEMENTED milliseconds since 01jan1960 00:00:00.000, adjusted for leap seconds date - td days since 01jan1960 (01jan1960 = 0) weekly date - tw weeks since 1960w1 This assumes 52 weeks in a year, then adds 7 * remainder of the weeks. The datetime value is the start of the week in terms of days in the year, not ISO calendar weeks. monthly date - tm months since 1960m1 quarterly date - tq quarters since 1960q1 half-yearly date - th half-years since 1960h1 yearly date - ty years since 0000
Here is the function:
def _stata_elapsed_date_to_datetime_vec(dates, fmt) -> Series:
"""
Convert from SIF to datetime. https://www.stata.com/help.cgi?datetime
Parameters
----------
dates : Series
The Stata Internal Format date to convert to datetime according to fmt
fmt : str
The format to convert to. Can be, tc, td, tw, tm, tq, th, ty
Returns
Returns
-------
converted : Series
The converted dates
Examples
--------
>>> dates = pd.Series([52])
>>> _stata_elapsed_date_to_datetime_vec(dates , "%tw")
0 1961-01-01
dtype: datetime64[ns]
Notes
-----
datetime/c - tc
milliseconds since 01jan1960 00:00:00.000, assuming 86,400 s/day
datetime/C - tC - NOT IMPLEMENTED
milliseconds since 01jan1960 00:00:00.000, adjusted for leap seconds
date - td
days since 01jan1960 (01jan1960 = 0)
weekly date - tw
weeks since 1960w1
This assumes 52 weeks in a year, then adds 7 * remainder of the weeks.
The datetime value is the start of the week in terms of days in the
year, not ISO calendar weeks.
monthly date - tm
months since 1960m1
quarterly date - tq
quarters since 1960q1
half-yearly date - th
half-years since 1960h1 yearly
date - ty
years since 0000
"""
MIN_YEAR, MAX_YEAR = Timestamp.min.year, Timestamp.max.year
MAX_DAY_DELTA = (Timestamp.max - datetime.datetime(1960, 1, 1)).days
MIN_DAY_DELTA = (Timestamp.min - datetime.datetime(1960, 1, 1)).days
MIN_MS_DELTA = MIN_DAY_DELTA * 24 * 3600 * 1000
MAX_MS_DELTA = MAX_DAY_DELTA * 24 * 3600 * 1000
def convert_year_month_safe(year, month) -> Series:
"""
Convert year and month to datetimes, using pandas vectorized versions
when the date range falls within the range supported by pandas.
Otherwise it falls back to a slower but more robust method
using datetime.
"""
if year.max() < MAX_YEAR and year.min() > MIN_YEAR:
return to_datetime(100 * year + month, format="%Y%m")
else:
index = getattr(year, "index", None)
return Series(
[datetime.datetime(y, m, 1) for y, m in zip(year, month)], index=index
)
def convert_year_days_safe(year, days) -> Series:
"""
Converts year (e.g. 1999) and days since the start of the year to a
datetime or datetime64 Series
"""
if year.max() < (MAX_YEAR - 1) and year.min() > MIN_YEAR:
return to_datetime(year, format="%Y") + to_timedelta(days, unit="d")
else:
index = getattr(year, "index", None)
value = [
datetime.datetime(y, 1, 1) + relativedelta(days=int(d))
for y, d in zip(year, days)
]
return Series(value, index=index)
def convert_delta_safe(base, deltas, unit) -> Series:
"""
Convert base dates and deltas to datetimes, using pandas vectorized
versions if the deltas satisfy restrictions required to be expressed
as dates in pandas.
"""
index = getattr(deltas, "index", None)
if unit == "d":
if deltas.max() > MAX_DAY_DELTA or deltas.min() < MIN_DAY_DELTA:
values = [base + relativedelta(days=int(d)) for d in deltas]
return Series(values, index=index)
elif unit == "ms":
if deltas.max() > MAX_MS_DELTA or deltas.min() < MIN_MS_DELTA:
values = [
base + relativedelta(microseconds=(int(d) * 1000)) for d in deltas
]
return Series(values, index=index)
else:
raise ValueError("format not understood")
base = to_datetime(base)
deltas = to_timedelta(deltas, unit=unit)
return base + deltas
# TODO(non-nano): If/when pandas supports more than datetime64[ns], this
# should be improved to use correct range, e.g. datetime[Y] for yearly
bad_locs = np.isnan(dates)
has_bad_values = False
if bad_locs.any():
has_bad_values = True
# reset cache to avoid SettingWithCopy checks (we own the DataFrame and the
# `dates` Series is used to overwrite itself in the DataFramae)
dates._reset_cacher()
dates[bad_locs] = 1.0 # Replace with NaT
dates = dates.astype(np.int64)
if fmt.startswith(("%tc", "tc")): # Delta ms relative to base
base = stata_epoch
ms = dates
conv_dates = convert_delta_safe(base, ms, "ms")
elif fmt.startswith(("%tC", "tC")):
warnings.warn(
"Encountered %tC format. Leaving in Stata Internal Format.",
stacklevel=find_stack_level(),
)
conv_dates = Series(dates, dtype=object)
if has_bad_values:
conv_dates[bad_locs] = NaT
return conv_dates
# Delta days relative to base
elif fmt.startswith(("%td", "td", "%d", "d")):
base = stata_epoch
days = dates
conv_dates = convert_delta_safe(base, days, "d")
# does not count leap days - 7 days is a week.
# 52nd week may have more than 7 days
elif fmt.startswith(("%tw", "tw")):
year = stata_epoch.year + dates // 52
days = (dates % 52) * 7
conv_dates = convert_year_days_safe(year, days)
elif fmt.startswith(("%tm", "tm")): # Delta months relative to base
year = stata_epoch.year + dates // 12
month = (dates % 12) + 1
conv_dates = convert_year_month_safe(year, month)
elif fmt.startswith(("%tq", "tq")): # Delta quarters relative to base
year = stata_epoch.year + dates // 4
quarter_month = (dates % 4) * 3 + 1
conv_dates = convert_year_month_safe(year, quarter_month)
elif fmt.startswith(("%th", "th")): # Delta half-years relative to base
year = stata_epoch.year + dates // 2
month = (dates % 2) * 6 + 1
conv_dates = convert_year_month_safe(year, month)
elif fmt.startswith(("%ty", "ty")): # Years -- not delta
year = dates
first_month = np.ones_like(dates)
conv_dates = convert_year_month_safe(year, first_month)
else:
raise ValueError(f"Date fmt {fmt} not understood")
if has_bad_values: # Restore NaT for bad values
conv_dates[bad_locs] = NaT
return conv_dates | Convert from SIF to datetime. https://www.stata.com/help.cgi?datetime Parameters ---------- dates : Series The Stata Internal Format date to convert to datetime according to fmt fmt : str The format to convert to. Can be, tc, td, tw, tm, tq, th, ty Returns Returns ------- converted : Series The converted dates Examples -------- >>> dates = pd.Series([52]) >>> _stata_elapsed_date_to_datetime_vec(dates , "%tw") 0 1961-01-01 dtype: datetime64[ns] Notes ----- datetime/c - tc milliseconds since 01jan1960 00:00:00.000, assuming 86,400 s/day datetime/C - tC - NOT IMPLEMENTED milliseconds since 01jan1960 00:00:00.000, adjusted for leap seconds date - td days since 01jan1960 (01jan1960 = 0) weekly date - tw weeks since 1960w1 This assumes 52 weeks in a year, then adds 7 * remainder of the weeks. The datetime value is the start of the week in terms of days in the year, not ISO calendar weeks. monthly date - tm months since 1960m1 quarterly date - tq quarters since 1960q1 half-yearly date - th half-years since 1960h1 yearly date - ty years since 0000 |
173,533 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
stata_epoch: Final = datetime.datetime(1960, 1, 1)
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
def is_datetime64_dtype(arr_or_dtype) -> bool:
"""
Check whether an array-like or dtype is of the datetime64 dtype.
Parameters
----------
arr_or_dtype : array-like or dtype
The array-like or dtype to check.
Returns
-------
boolean
Whether or not the array-like or dtype is of the datetime64 dtype.
Examples
--------
>>> from pandas.api.types import is_datetime64_dtype
>>> is_datetime64_dtype(object)
False
>>> is_datetime64_dtype(np.datetime64)
True
>>> is_datetime64_dtype(np.array([], dtype=int))
False
>>> is_datetime64_dtype(np.array([], dtype=np.datetime64))
True
>>> is_datetime64_dtype([1, 2, 3])
False
"""
if isinstance(arr_or_dtype, np.dtype):
# GH#33400 fastpath for dtype object
return arr_or_dtype.kind == "M"
return _is_dtype_type(arr_or_dtype, classes(np.datetime64))
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
class Series(base.IndexOpsMixin, NDFrame): # type: ignore[misc]
"""
One-dimensional ndarray with axis labels (including time series).
Labels need not be unique but must be a hashable type. The object
supports both integer- and label-based indexing and provides a host of
methods for performing operations involving the index. Statistical
methods from ndarray have been overridden to automatically exclude
missing data (currently represented as NaN).
Operations between Series (+, -, /, \\*, \\*\\*) align values based on their
associated index values-- they need not be the same length. The result
index will be the sorted union of the two indexes.
Parameters
----------
data : array-like, Iterable, dict, or scalar value
Contains data stored in Series. If data is a dict, argument order is
maintained.
index : array-like or Index (1d)
Values must be hashable and have the same length as `data`.
Non-unique index values are allowed. Will default to
RangeIndex (0, 1, 2, ..., n) if not provided. If data is dict-like
and index is None, then the keys in the data are used as the index. If the
index is not None, the resulting Series is reindexed with the index values.
dtype : str, numpy.dtype, or ExtensionDtype, optional
Data type for the output Series. If not specified, this will be
inferred from `data`.
See the :ref:`user guide <basics.dtypes>` for more usages.
name : Hashable, default None
The name to give to the Series.
copy : bool, default False
Copy input data. Only affects Series or 1d ndarray input. See examples.
Notes
-----
Please reference the :ref:`User Guide <basics.series>` for more information.
Examples
--------
Constructing Series from a dictionary with an Index specified
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['a', 'b', 'c'])
>>> ser
a 1
b 2
c 3
dtype: int64
The keys of the dictionary match with the Index values, hence the Index
values have no effect.
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['x', 'y', 'z'])
>>> ser
x NaN
y NaN
z NaN
dtype: float64
Note that the Index is first build with the keys from the dictionary.
After this the Series is reindexed with the given Index values, hence we
get all NaN as a result.
Constructing Series from a list with `copy=False`.
>>> r = [1, 2]
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
[1, 2]
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `copy` of
the original data even though `copy=False`, so
the data is unchanged.
Constructing Series from a 1d ndarray with `copy=False`.
>>> r = np.array([1, 2])
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
array([999, 2])
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `view` on
the original data, so
the data is changed as well.
"""
_typ = "series"
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
_name: Hashable
_metadata: list[str] = ["name"]
_internal_names_set = {"index"} | NDFrame._internal_names_set
_accessors = {"dt", "cat", "str", "sparse"}
_hidden_attrs = (
base.IndexOpsMixin._hidden_attrs | NDFrame._hidden_attrs | frozenset([])
)
# Override cache_readonly bc Series is mutable
# error: Incompatible types in assignment (expression has type "property",
# base class "IndexOpsMixin" defined the type as "Callable[[IndexOpsMixin], bool]")
hasnans = property( # type: ignore[assignment]
# error: "Callable[[IndexOpsMixin], bool]" has no attribute "fget"
base.IndexOpsMixin.hasnans.fget, # type: ignore[attr-defined]
doc=base.IndexOpsMixin.hasnans.__doc__,
)
_mgr: SingleManager
div: Callable[[Series, Any], Series]
rdiv: Callable[[Series, Any], Series]
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index=None,
dtype: Dtype | None = None,
name=None,
copy: bool | None = None,
fastpath: bool = False,
) -> None:
if (
isinstance(data, (SingleBlockManager, SingleArrayManager))
and index is None
and dtype is None
and (copy is False or copy is None)
):
if using_copy_on_write():
data = data.copy(deep=False)
# GH#33357 called with just the SingleBlockManager
NDFrame.__init__(self, data)
if fastpath:
# e.g. from _box_col_values, skip validation of name
object.__setattr__(self, "_name", name)
else:
self.name = name
return
if isinstance(data, (ExtensionArray, np.ndarray)):
if copy is not False and using_copy_on_write():
if dtype is None or astype_is_view(data.dtype, pandas_dtype(dtype)):
data = data.copy()
if copy is None:
copy = False
# we are called internally, so short-circuit
if fastpath:
# data is a ndarray, index is defined
if not isinstance(data, (SingleBlockManager, SingleArrayManager)):
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
elif using_copy_on_write() and not copy:
data = data.copy(deep=False)
if copy:
data = data.copy()
# skips validation of the name
object.__setattr__(self, "_name", name)
NDFrame.__init__(self, data)
return
if isinstance(data, SingleBlockManager) and using_copy_on_write() and not copy:
data = data.copy(deep=False)
name = ibase.maybe_extract_name(name, data, type(self))
if index is not None:
index = ensure_index(index)
if dtype is not None:
dtype = self._validate_dtype(dtype)
if data is None:
index = index if index is not None else default_index(0)
if len(index) or dtype is not None:
data = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
data = []
if isinstance(data, MultiIndex):
raise NotImplementedError(
"initializing a Series from a MultiIndex is not supported"
)
refs = None
if isinstance(data, Index):
if dtype is not None:
data = data.astype(dtype, copy=False)
if using_copy_on_write():
refs = data._references
data = data._values
else:
# GH#24096 we need to ensure the index remains immutable
data = data._values.copy()
copy = False
elif isinstance(data, np.ndarray):
if len(data.dtype):
# GH#13296 we are dealing with a compound dtype, which
# should be treated as 2D
raise ValueError(
"Cannot construct a Series from an ndarray with "
"compound dtype. Use DataFrame instead."
)
elif isinstance(data, Series):
if index is None:
index = data.index
data = data._mgr.copy(deep=False)
else:
data = data.reindex(index, copy=copy)
copy = False
data = data._mgr
elif is_dict_like(data):
data, index = self._init_dict(data, index, dtype)
dtype = None
copy = False
elif isinstance(data, (SingleBlockManager, SingleArrayManager)):
if index is None:
index = data.index
elif not data.index.equals(index) or copy:
# GH#19275 SingleBlockManager input should only be called
# internally
raise AssertionError(
"Cannot pass both SingleBlockManager "
"`data` argument and a different "
"`index` argument. `copy` must be False."
)
elif isinstance(data, ExtensionArray):
pass
else:
data = com.maybe_iterable_to_list(data)
if is_list_like(data) and not len(data) and dtype is None:
# GH 29405: Pre-2.0, this defaulted to float.
dtype = np.dtype(object)
if index is None:
if not is_list_like(data):
data = [data]
index = default_index(len(data))
elif is_list_like(data):
com.require_length_match(data, index)
# create/copy the manager
if isinstance(data, (SingleBlockManager, SingleArrayManager)):
if dtype is not None:
data = data.astype(dtype=dtype, errors="ignore", copy=copy)
elif copy:
data = data.copy()
else:
data = sanitize_array(data, index, dtype, copy)
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index, refs=refs)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
NDFrame.__init__(self, data)
self.name = name
self._set_axis(0, index)
def _init_dict(
self, data, index: Index | None = None, dtype: DtypeObj | None = None
):
"""
Derive the "_mgr" and "index" attributes of a new Series from a
dictionary input.
Parameters
----------
data : dict or dict-like
Data used to populate the new Series.
index : Index or None, default None
Index for the new Series: if None, use dict keys.
dtype : np.dtype, ExtensionDtype, or None, default None
The dtype for the new Series: if None, infer from data.
Returns
-------
_data : BlockManager for the new Series
index : index for the new Series
"""
keys: Index | tuple
# Looking for NaN in dict doesn't work ({np.nan : 1}[float('nan')]
# raises KeyError), so we iterate the entire dict, and align
if data:
# GH:34717, issue was using zip to extract key and values from data.
# using generators in effects the performance.
# Below is the new way of extracting the keys and values
keys = tuple(data.keys())
values = list(data.values()) # Generating list of values- faster way
elif index is not None:
# fastpath for Series(data=None). Just use broadcasting a scalar
# instead of reindexing.
if len(index) or dtype is not None:
values = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
values = []
keys = index
else:
keys, values = (), []
# Input is now list-like, so rely on "standard" construction:
s = self._constructor(
values,
index=keys,
dtype=dtype,
)
# Now we just make sure the order is respected, if any
if data and index is not None:
s = s.reindex(index, copy=False)
return s._mgr, s.index
# ----------------------------------------------------------------------
def _constructor(self) -> Callable[..., Series]:
return Series
def _constructor_expanddim(self) -> Callable[..., DataFrame]:
"""
Used when a manipulation result has one higher dimension as the
original, such as Series.to_frame()
"""
from pandas.core.frame import DataFrame
return DataFrame
# types
def _can_hold_na(self) -> bool:
return self._mgr._can_hold_na
# ndarray compatibility
def dtype(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtype
dtype('int64')
"""
return self._mgr.dtype
def dtypes(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtypes
dtype('int64')
"""
# DataFrame compatibility
return self.dtype
def name(self) -> Hashable:
"""
Return the name of the Series.
The name of a Series becomes its index or column name if it is used
to form a DataFrame. It is also used whenever displaying the Series
using the interpreter.
Returns
-------
label (hashable object)
The name of the Series, also the column name if part of a DataFrame.
See Also
--------
Series.rename : Sets the Series name when given a scalar input.
Index.name : Corresponding Index property.
Examples
--------
The Series name can be set initially when calling the constructor.
>>> s = pd.Series([1, 2, 3], dtype=np.int64, name='Numbers')
>>> s
0 1
1 2
2 3
Name: Numbers, dtype: int64
>>> s.name = "Integers"
>>> s
0 1
1 2
2 3
Name: Integers, dtype: int64
The name of a Series within a DataFrame is its column name.
>>> df = pd.DataFrame([[1, 2], [3, 4], [5, 6]],
... columns=["Odd Numbers", "Even Numbers"])
>>> df
Odd Numbers Even Numbers
0 1 2
1 3 4
2 5 6
>>> df["Even Numbers"].name
'Even Numbers'
"""
return self._name
def name(self, value: Hashable) -> None:
validate_all_hashable(value, error_name=f"{type(self).__name__}.name")
object.__setattr__(self, "_name", value)
def values(self):
"""
Return Series as ndarray or ndarray-like depending on the dtype.
.. warning::
We recommend using :attr:`Series.array` or
:meth:`Series.to_numpy`, depending on whether you need
a reference to the underlying data or a NumPy array.
Returns
-------
numpy.ndarray or ndarray-like
See Also
--------
Series.array : Reference to the underlying data.
Series.to_numpy : A NumPy array representing the underlying data.
Examples
--------
>>> pd.Series([1, 2, 3]).values
array([1, 2, 3])
>>> pd.Series(list('aabc')).values
array(['a', 'a', 'b', 'c'], dtype=object)
>>> pd.Series(list('aabc')).astype('category').values
['a', 'a', 'b', 'c']
Categories (3, object): ['a', 'b', 'c']
Timezone aware datetime data is converted to UTC:
>>> pd.Series(pd.date_range('20130101', periods=3,
... tz='US/Eastern')).values
array(['2013-01-01T05:00:00.000000000',
'2013-01-02T05:00:00.000000000',
'2013-01-03T05:00:00.000000000'], dtype='datetime64[ns]')
"""
return self._mgr.external_values()
def _values(self):
"""
Return the internal repr of this data (defined by Block.interval_values).
This are the values as stored in the Block (ndarray or ExtensionArray
depending on the Block class), with datetime64[ns] and timedelta64[ns]
wrapped in ExtensionArrays to match Index._values behavior.
Differs from the public ``.values`` for certain data types, because of
historical backwards compatibility of the public attribute (e.g. period
returns object ndarray and datetimetz a datetime64[ns] ndarray for
``.values`` while it returns an ExtensionArray for ``._values`` in those
cases).
Differs from ``.array`` in that this still returns the numpy array if
the Block is backed by a numpy array (except for datetime64 and
timedelta64 dtypes), while ``.array`` ensures to always return an
ExtensionArray.
Overview:
dtype | values | _values | array |
----------- | ------------- | ------------- | ------------- |
Numeric | ndarray | ndarray | PandasArray |
Category | Categorical | Categorical | Categorical |
dt64[ns] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
dt64[ns tz] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
td64[ns] | ndarray[m8ns] | TimedeltaArray| ndarray[m8ns] |
Period | ndarray[obj] | PeriodArray | PeriodArray |
Nullable | EA | EA | EA |
"""
return self._mgr.internal_values()
def _references(self) -> BlockValuesRefs | None:
if isinstance(self._mgr, SingleArrayManager):
return None
return self._mgr._block.refs
# error: Decorated property not supported
def array(self) -> ExtensionArray:
return self._mgr.array_values()
# ops
def ravel(self, order: str = "C") -> ArrayLike:
"""
Return the flattened underlying data as an ndarray or ExtensionArray.
Returns
-------
numpy.ndarray or ExtensionArray
Flattened data of the Series.
See Also
--------
numpy.ndarray.ravel : Return a flattened array.
"""
arr = self._values.ravel(order=order)
if isinstance(arr, np.ndarray) and using_copy_on_write():
arr.flags.writeable = False
return arr
def __len__(self) -> int:
"""
Return the length of the Series.
"""
return len(self._mgr)
def view(self, dtype: Dtype | None = None) -> Series:
"""
Create a new view of the Series.
This function will return a new Series with a view of the same
underlying values in memory, optionally reinterpreted with a new data
type. The new data type must preserve the same size in bytes as to not
cause index misalignment.
Parameters
----------
dtype : data type
Data type object or one of their string representations.
Returns
-------
Series
A new Series object as a view of the same data in memory.
See Also
--------
numpy.ndarray.view : Equivalent numpy function to create a new view of
the same data in memory.
Notes
-----
Series are instantiated with ``dtype=float64`` by default. While
``numpy.ndarray.view()`` will return a view with the same data type as
the original array, ``Series.view()`` (without specified dtype)
will try using ``float64`` and may fail if the original data type size
in bytes is not the same.
Examples
--------
>>> s = pd.Series([-2, -1, 0, 1, 2], dtype='int8')
>>> s
0 -2
1 -1
2 0
3 1
4 2
dtype: int8
The 8 bit signed integer representation of `-1` is `0b11111111`, but
the same bytes represent 255 if read as an 8 bit unsigned integer:
>>> us = s.view('uint8')
>>> us
0 254
1 255
2 0
3 1
4 2
dtype: uint8
The views share the same underlying values:
>>> us[0] = 128
>>> s
0 -128
1 -1
2 0
3 1
4 2
dtype: int8
"""
# self.array instead of self._values so we piggyback on PandasArray
# implementation
res_values = self.array.view(dtype)
res_ser = self._constructor(res_values, index=self.index, copy=False)
if isinstance(res_ser._mgr, SingleBlockManager) and using_copy_on_write():
blk = res_ser._mgr._block
blk.refs = cast("BlockValuesRefs", self._references)
blk.refs.add_reference(blk) # type: ignore[arg-type]
return res_ser.__finalize__(self, method="view")
# ----------------------------------------------------------------------
# NDArray Compat
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
"""
Return the values as a NumPy array.
Users should not call this directly. Rather, it is invoked by
:func:`numpy.array` and :func:`numpy.asarray`.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to use for the resulting NumPy array. By default,
the dtype is inferred from the data.
Returns
-------
numpy.ndarray
The values in the series converted to a :class:`numpy.ndarray`
with the specified `dtype`.
See Also
--------
array : Create a new array from data.
Series.array : Zero-copy view to the array backing the Series.
Series.to_numpy : Series method for similar behavior.
Examples
--------
>>> ser = pd.Series([1, 2, 3])
>>> np.asarray(ser)
array([1, 2, 3])
For timezone-aware data, the timezones may be retained with
``dtype='object'``
>>> tzser = pd.Series(pd.date_range('2000', periods=2, tz="CET"))
>>> np.asarray(tzser, dtype="object")
array([Timestamp('2000-01-01 00:00:00+0100', tz='CET'),
Timestamp('2000-01-02 00:00:00+0100', tz='CET')],
dtype=object)
Or the values may be localized to UTC and the tzinfo discarded with
``dtype='datetime64[ns]'``
>>> np.asarray(tzser, dtype="datetime64[ns]") # doctest: +ELLIPSIS
array(['1999-12-31T23:00:00.000000000', ...],
dtype='datetime64[ns]')
"""
values = self._values
arr = np.asarray(values, dtype=dtype)
if using_copy_on_write() and astype_is_view(values.dtype, arr.dtype):
arr = arr.view()
arr.flags.writeable = False
return arr
# ----------------------------------------------------------------------
# Unary Methods
# coercion
__float__ = _coerce_method(float)
__int__ = _coerce_method(int)
# ----------------------------------------------------------------------
# indexers
def axes(self) -> list[Index]:
"""
Return a list of the row axis labels.
"""
return [self.index]
# ----------------------------------------------------------------------
# Indexing Methods
def take(self, indices, axis: Axis = 0, **kwargs) -> Series:
nv.validate_take((), kwargs)
indices = ensure_platform_int(indices)
if (
indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_index = self.index.take(indices)
new_values = self._values.take(indices)
result = self._constructor(new_values, index=new_index, fastpath=True)
return result.__finalize__(self, method="take")
def _take_with_is_copy(self, indices, axis: Axis = 0) -> Series:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning). For Series this does the same
as the public take (it never sets `_is_copy`).
See the docstring of `take` for full explanation of the parameters.
"""
return self.take(indices=indices, axis=axis)
def _ixs(self, i: int, axis: AxisInt = 0) -> Any:
"""
Return the i-th value or values in the Series by location.
Parameters
----------
i : int
Returns
-------
scalar (int) or Series (slice, sequence)
"""
return self._values[i]
def _slice(self, slobj: slice | np.ndarray, axis: Axis = 0) -> Series:
# axis kwarg is retained for compat with NDFrame method
# _slice is *always* positional
return self._get_values(slobj)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
if key is Ellipsis:
return self
key_is_scalar = is_scalar(key)
if isinstance(key, (list, tuple)):
key = unpack_1tuple(key)
if is_integer(key) and self.index._should_fallback_to_positional:
return self._values[key]
elif key_is_scalar:
return self._get_value(key)
if is_hashable(key):
# Otherwise index.get_value will raise InvalidIndexError
try:
# For labels that don't resolve as scalars like tuples and frozensets
result = self._get_value(key)
return result
except (KeyError, TypeError, InvalidIndexError):
# InvalidIndexError for e.g. generator
# see test_series_getitem_corner_generator
if isinstance(key, tuple) and isinstance(self.index, MultiIndex):
# We still have the corner case where a tuple is a key
# in the first level of our MultiIndex
return self._get_values_tuple(key)
if is_iterator(key):
key = list(key)
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
return self._get_values(key)
return self._get_with(key)
def _get_with(self, key):
# other: fancy integer or otherwise
if isinstance(key, slice):
# _convert_slice_indexer to determine if this slice is positional
# or label based, and if the latter, convert to positional
slobj = self.index._convert_slice_indexer(key, kind="getitem")
return self._slice(slobj)
elif isinstance(key, ABCDataFrame):
raise TypeError(
"Indexing a Series with DataFrame is not "
"supported, use the appropriate DataFrame column"
)
elif isinstance(key, tuple):
return self._get_values_tuple(key)
elif not is_list_like(key):
# e.g. scalars that aren't recognized by lib.is_scalar, GH#32684
return self.loc[key]
if not isinstance(key, (list, np.ndarray, ExtensionArray, Series, Index)):
key = list(key)
if isinstance(key, Index):
key_type = key.inferred_type
else:
key_type = lib.infer_dtype(key, skipna=False)
# Note: The key_type == "boolean" case should be caught by the
# com.is_bool_indexer check in __getitem__
if key_type == "integer":
# We need to decide whether to treat this as a positional indexer
# (i.e. self.iloc) or label-based (i.e. self.loc)
if not self.index._should_fallback_to_positional:
return self.loc[key]
else:
return self.iloc[key]
# handle the dup indexing case GH#4246
return self.loc[key]
def _get_values_tuple(self, key: tuple):
# mpl hackaround
if com.any_none(*key):
# mpl compat if we look up e.g. ser[:, np.newaxis];
# see tests.series.timeseries.test_mpl_compat_hack
# the asarray is needed to avoid returning a 2D DatetimeArray
result = np.asarray(self._values[key])
disallow_ndim_indexing(result)
return result
if not isinstance(self.index, MultiIndex):
raise KeyError("key of type tuple not found and not a MultiIndex")
# If key is contained, would have returned by now
indexer, new_index = self.index.get_loc_level(key)
new_ser = self._constructor(self._values[indexer], index=new_index, copy=False)
if using_copy_on_write() and isinstance(indexer, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
def _get_values(self, indexer: slice | npt.NDArray[np.bool_]) -> Series:
new_mgr = self._mgr.getitem_mgr(indexer)
return self._constructor(new_mgr).__finalize__(self)
def _get_value(self, label, takeable: bool = False):
"""
Quickly retrieve single value at passed index label.
Parameters
----------
label : object
takeable : interpret the index as indexers, default False
Returns
-------
scalar value
"""
if takeable:
return self._values[label]
# Similar to Index.get_value, but we do not fall back to positional
loc = self.index.get_loc(label)
if is_integer(loc):
return self._values[loc]
if isinstance(self.index, MultiIndex):
mi = self.index
new_values = self._values[loc]
if len(new_values) == 1 and mi.nlevels == 1:
# If more than one level left, we can not return a scalar
return new_values[0]
new_index = mi[loc]
new_index = maybe_droplevels(new_index, label)
new_ser = self._constructor(
new_values, index=new_index, name=self.name, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
else:
return self.iloc[loc]
def __setitem__(self, key, value) -> None:
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
cacher_needs_updating = self._check_is_chained_assignment_possible()
if key is Ellipsis:
key = slice(None)
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
return self._set_values(indexer, value)
try:
self._set_with_engine(key, value)
except KeyError:
# We have a scalar (or for MultiIndex or object-dtype, scalar-like)
# key that is not present in self.index.
if is_integer(key):
if not self.index._should_fallback_to_positional:
# GH#33469
self.loc[key] = value
else:
# positional setter
# can't use _mgr.setitem_inplace yet bc could have *both*
# KeyError and then ValueError, xref GH#45070
self._set_values(key, value)
else:
# GH#12862 adding a new key to the Series
self.loc[key] = value
except (TypeError, ValueError, LossySetitemError):
# The key was OK, but we cannot set the value losslessly
indexer = self.index.get_loc(key)
self._set_values(indexer, value)
except InvalidIndexError as err:
if isinstance(key, tuple) and not isinstance(self.index, MultiIndex):
# cases with MultiIndex don't get here bc they raise KeyError
# e.g. test_basic_getitem_setitem_corner
raise KeyError(
"key of type tuple not found and not a MultiIndex"
) from err
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
if (
is_list_like(value)
and len(value) != len(self)
and not isinstance(value, Series)
and not is_object_dtype(self.dtype)
):
# Series will be reindexed to have matching length inside
# _where call below
# GH#44265
indexer = key.nonzero()[0]
self._set_values(indexer, value)
return
# otherwise with listlike other we interpret series[mask] = other
# as series[mask] = other[mask]
try:
self._where(~key, value, inplace=True)
except InvalidIndexError:
# test_where_dups
self.iloc[key] = value
return
else:
self._set_with(key, value)
if cacher_needs_updating:
self._maybe_update_cacher(inplace=True)
def _set_with_engine(self, key, value) -> None:
loc = self.index.get_loc(key)
# this is equivalent to self._values[key] = value
self._mgr.setitem_inplace(loc, value)
def _set_with(self, key, value) -> None:
# We got here via exception-handling off of InvalidIndexError, so
# key should always be listlike at this point.
assert not isinstance(key, tuple)
if is_iterator(key):
# Without this, the call to infer_dtype will consume the generator
key = list(key)
if not self.index._should_fallback_to_positional:
# Regardless of the key type, we're treating it as labels
self._set_labels(key, value)
else:
# Note: key_type == "boolean" should not occur because that
# should be caught by the is_bool_indexer check in __setitem__
key_type = lib.infer_dtype(key, skipna=False)
if key_type == "integer":
self._set_values(key, value)
else:
self._set_labels(key, value)
def _set_labels(self, key, value) -> None:
key = com.asarray_tuplesafe(key)
indexer: np.ndarray = self.index.get_indexer(key)
mask = indexer == -1
if mask.any():
raise KeyError(f"{key[mask]} not in index")
self._set_values(indexer, value)
def _set_values(self, key, value) -> None:
if isinstance(key, (Index, Series)):
key = key._values
self._mgr = self._mgr.setitem(indexer=key, value=value)
self._maybe_update_cacher()
def _set_value(self, label, value, takeable: bool = False) -> None:
"""
Quickly set single value at passed label.
If label is not contained, a new object is created with the label
placed at the end of the result index.
Parameters
----------
label : object
Partial indexing with MultiIndex not allowed.
value : object
Scalar value.
takeable : interpret the index as indexers, default False
"""
if not takeable:
try:
loc = self.index.get_loc(label)
except KeyError:
# set using a non-recursive method
self.loc[label] = value
return
else:
loc = label
self._set_values(loc, value)
# ----------------------------------------------------------------------
# Lookup Caching
def _is_cached(self) -> bool:
"""Return boolean indicating if self is cached or not."""
return getattr(self, "_cacher", None) is not None
def _get_cacher(self):
"""return my cacher or None"""
cacher = getattr(self, "_cacher", None)
if cacher is not None:
cacher = cacher[1]()
return cacher
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
if hasattr(self, "_cacher"):
del self._cacher
def _set_as_cached(self, item, cacher) -> None:
"""
Set the _cacher attribute on the calling object with a weakref to
cacher.
"""
if using_copy_on_write():
return
self._cacher = (item, weakref.ref(cacher))
def _clear_item_cache(self) -> None:
# no-op for Series
pass
def _check_is_chained_assignment_possible(self) -> bool:
"""
See NDFrame._check_is_chained_assignment_possible.__doc__
"""
if self._is_view and self._is_cached:
ref = self._get_cacher()
if ref is not None and ref._is_mixed_type:
self._check_setitem_copy(t="referent", force=True)
return True
return super()._check_is_chained_assignment_possible()
def _maybe_update_cacher(
self, clear: bool = False, verify_is_copy: bool = True, inplace: bool = False
) -> None:
"""
See NDFrame._maybe_update_cacher.__doc__
"""
# for CoW, we never want to update the parent DataFrame cache
# if the Series changed, but don't keep track of any cacher
if using_copy_on_write():
return
cacher = getattr(self, "_cacher", None)
if cacher is not None:
assert self.ndim == 1
ref: DataFrame = cacher[1]()
# we are trying to reference a dead referent, hence
# a copy
if ref is None:
del self._cacher
elif len(self) == len(ref) and self.name in ref.columns:
# GH#42530 self.name must be in ref.columns
# to ensure column still in dataframe
# otherwise, either self or ref has swapped in new arrays
ref._maybe_cache_changed(cacher[0], self, inplace=inplace)
else:
# GH#33675 we have swapped in a new array, so parent
# reference to self is now invalid
ref._item_cache.pop(cacher[0], None)
super()._maybe_update_cacher(
clear=clear, verify_is_copy=verify_is_copy, inplace=inplace
)
# ----------------------------------------------------------------------
# Unsorted
def _is_mixed_type(self) -> bool:
return False
def repeat(self, repeats: int | Sequence[int], axis: None = None) -> Series:
"""
Repeat elements of a Series.
Returns a new Series where each element of the current Series
is repeated consecutively a given number of times.
Parameters
----------
repeats : int or array of ints
The number of repetitions for each element. This should be a
non-negative integer. Repeating 0 times will return an empty
Series.
axis : None
Unused. Parameter needed for compatibility with DataFrame.
Returns
-------
Series
Newly created Series with repeated elements.
See Also
--------
Index.repeat : Equivalent function for Index.
numpy.repeat : Similar method for :class:`numpy.ndarray`.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c'])
>>> s
0 a
1 b
2 c
dtype: object
>>> s.repeat(2)
0 a
0 a
1 b
1 b
2 c
2 c
dtype: object
>>> s.repeat([1, 2, 3])
0 a
1 b
1 b
2 c
2 c
2 c
dtype: object
"""
nv.validate_repeat((), {"axis": axis})
new_index = self.index.repeat(repeats)
new_values = self._values.repeat(repeats)
return self._constructor(new_values, index=new_index, copy=False).__finalize__(
self, method="repeat"
)
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[False] = ...,
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> DataFrame:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[True],
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> Series:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: bool = ...,
name: Level = ...,
inplace: Literal[True],
allow_duplicates: bool = ...,
) -> None:
...
def reset_index(
self,
level: IndexLabel = None,
*,
drop: bool = False,
name: Level = lib.no_default,
inplace: bool = False,
allow_duplicates: bool = False,
) -> DataFrame | Series | None:
"""
Generate a new DataFrame or Series with the index reset.
This is useful when the index needs to be treated as a column, or
when the index is meaningless and needs to be reset to the default
before another operation.
Parameters
----------
level : int, str, tuple, or list, default optional
For a Series with a MultiIndex, only remove the specified levels
from the index. Removes all levels by default.
drop : bool, default False
Just reset the index, without inserting it as a column in
the new DataFrame.
name : object, optional
The name to use for the column containing the original Series
values. Uses ``self.name`` by default. This argument is ignored
when `drop` is True.
inplace : bool, default False
Modify the Series in place (do not create a new object).
allow_duplicates : bool, default False
Allow duplicate column labels to be created.
.. versionadded:: 1.5.0
Returns
-------
Series or DataFrame or None
When `drop` is False (the default), a DataFrame is returned.
The newly created columns will come first in the DataFrame,
followed by the original Series values.
When `drop` is True, a `Series` is returned.
In either case, if ``inplace=True``, no value is returned.
See Also
--------
DataFrame.reset_index: Analogous function for DataFrame.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4], name='foo',
... index=pd.Index(['a', 'b', 'c', 'd'], name='idx'))
Generate a DataFrame with default index.
>>> s.reset_index()
idx foo
0 a 1
1 b 2
2 c 3
3 d 4
To specify the name of the new column use `name`.
>>> s.reset_index(name='values')
idx values
0 a 1
1 b 2
2 c 3
3 d 4
To generate a new Series with the default set `drop` to True.
>>> s.reset_index(drop=True)
0 1
1 2
2 3
3 4
Name: foo, dtype: int64
The `level` parameter is interesting for Series with a multi-level
index.
>>> arrays = [np.array(['bar', 'bar', 'baz', 'baz']),
... np.array(['one', 'two', 'one', 'two'])]
>>> s2 = pd.Series(
... range(4), name='foo',
... index=pd.MultiIndex.from_arrays(arrays,
... names=['a', 'b']))
To remove a specific level from the Index, use `level`.
>>> s2.reset_index(level='a')
a foo
b
one bar 0
two bar 1
one baz 2
two baz 3
If `level` is not set, all levels are removed from the Index.
>>> s2.reset_index()
a b foo
0 bar one 0
1 bar two 1
2 baz one 2
3 baz two 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if drop:
new_index = default_index(len(self))
if level is not None:
level_list: Sequence[Hashable]
if not isinstance(level, (tuple, list)):
level_list = [level]
else:
level_list = level
level_list = [self.index._get_level_number(lev) for lev in level_list]
if len(level_list) < self.index.nlevels:
new_index = self.index.droplevel(level_list)
if inplace:
self.index = new_index
elif using_copy_on_write():
new_ser = self.copy(deep=False)
new_ser.index = new_index
return new_ser.__finalize__(self, method="reset_index")
else:
return self._constructor(
self._values.copy(), index=new_index, copy=False
).__finalize__(self, method="reset_index")
elif inplace:
raise TypeError(
"Cannot reset_index inplace on a Series to create a DataFrame"
)
else:
if name is lib.no_default:
# For backwards compatibility, keep columns as [0] instead of
# [None] when self.name is None
if self.name is None:
name = 0
else:
name = self.name
df = self.to_frame(name)
return df.reset_index(
level=level, drop=drop, allow_duplicates=allow_duplicates
)
return None
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
"""
Return a string representation for a particular Series.
"""
# pylint: disable=invalid-repr-returned
repr_params = fmt.get_series_repr_params()
return self.to_string(**repr_params)
def to_string(
self,
buf: None = ...,
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> None:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
na_rep: str = "NaN",
float_format: str | None = None,
header: bool = True,
index: bool = True,
length: bool = False,
dtype: bool = False,
name: bool = False,
max_rows: int | None = None,
min_rows: int | None = None,
) -> str | None:
"""
Render a string representation of the Series.
Parameters
----------
buf : StringIO-like, optional
Buffer to write to.
na_rep : str, optional
String representation of NaN to use, default 'NaN'.
float_format : one-parameter function, optional
Formatter function to apply to columns' elements if they are
floats, default None.
header : bool, default True
Add the Series header (index name).
index : bool, optional
Add index (row) labels, default True.
length : bool, default False
Add the Series length.
dtype : bool, default False
Add the Series dtype.
name : bool, default False
Add the Series name if not None.
max_rows : int, optional
Maximum number of rows to show before truncating. If None, show
all.
min_rows : int, optional
The number of rows to display in a truncated repr (when number
of rows is above `max_rows`).
Returns
-------
str or None
String representation of Series if ``buf=None``, otherwise None.
"""
formatter = fmt.SeriesFormatter(
self,
name=name,
length=length,
header=header,
index=index,
dtype=dtype,
na_rep=na_rep,
float_format=float_format,
min_rows=min_rows,
max_rows=max_rows,
)
result = formatter.to_string()
# catch contract violations
if not isinstance(result, str):
raise AssertionError(
"result must be of type str, type "
f"of result is {repr(type(result).__name__)}"
)
if buf is None:
return result
else:
if hasattr(buf, "write"):
buf.write(result)
else:
with open(buf, "w") as f:
f.write(result)
return None
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples=dedent(
"""Examples
--------
>>> s = pd.Series(["elk", "pig", "dog", "quetzal"], name="animal")
>>> print(s.to_markdown())
| | animal |
|---:|:---------|
| 0 | elk |
| 1 | pig |
| 2 | dog |
| 3 | quetzal |
Output markdown with a tabulate option.
>>> print(s.to_markdown(tablefmt="grid"))
+----+----------+
| | animal |
+====+==========+
| 0 | elk |
+----+----------+
| 1 | pig |
+----+----------+
| 2 | dog |
+----+----------+
| 3 | quetzal |
+----+----------+"""
),
)
def to_markdown(
self,
buf: IO[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
"""
Print {klass} in Markdown-friendly format.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
mode : str, optional
Mode in which file is opened, "wt" by default.
index : bool, optional, default True
Add index (row) labels.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
**kwargs
These parameters will be passed to `tabulate \
<https://pypi.org/project/tabulate>`_.
Returns
-------
str
{klass} in Markdown-friendly format.
Notes
-----
Requires the `tabulate <https://pypi.org/project/tabulate>`_ package.
{examples}
"""
return self.to_frame().to_markdown(
buf, mode, index, storage_options=storage_options, **kwargs
)
# ----------------------------------------------------------------------
def items(self) -> Iterable[tuple[Hashable, Any]]:
"""
Lazily iterate over (index, value) tuples.
This method returns an iterable tuple (index, value). This is
convenient if you want to create a lazy iterator.
Returns
-------
iterable
Iterable of tuples containing the (index, value) pairs from a
Series.
See Also
--------
DataFrame.items : Iterate over (column name, Series) pairs.
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series) pairs.
Examples
--------
>>> s = pd.Series(['A', 'B', 'C'])
>>> for index, value in s.items():
... print(f"Index : {index}, Value : {value}")
Index : 0, Value : A
Index : 1, Value : B
Index : 2, Value : C
"""
return zip(iter(self.index), iter(self))
# ----------------------------------------------------------------------
# Misc public methods
def keys(self) -> Index:
"""
Return alias for index.
Returns
-------
Index
Index of the Series.
"""
return self.index
def to_dict(self, into: type[dict] = dict) -> dict:
"""
Convert Series to {label -> value} dict or dict-like object.
Parameters
----------
into : class, default dict
The collections.abc.Mapping subclass to use as the return
object. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
Returns
-------
collections.abc.Mapping
Key-value representation of Series.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.to_dict()
{0: 1, 1: 2, 2: 3, 3: 4}
>>> from collections import OrderedDict, defaultdict
>>> s.to_dict(OrderedDict)
OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
>>> dd = defaultdict(list)
>>> s.to_dict(dd)
defaultdict(<class 'list'>, {0: 1, 1: 2, 2: 3, 3: 4})
"""
# GH16122
into_c = com.standardize_mapping(into)
if is_object_dtype(self) or is_extension_array_dtype(self):
return into_c((k, maybe_box_native(v)) for k, v in self.items())
else:
# Not an object dtype => all types will be the same so let the default
# indexer return native python type
return into_c(self.items())
def to_frame(self, name: Hashable = lib.no_default) -> DataFrame:
"""
Convert Series to DataFrame.
Parameters
----------
name : object, optional
The passed name should substitute for the series name (if it has
one).
Returns
-------
DataFrame
DataFrame representation of Series.
Examples
--------
>>> s = pd.Series(["a", "b", "c"],
... name="vals")
>>> s.to_frame()
vals
0 a
1 b
2 c
"""
columns: Index
if name is lib.no_default:
name = self.name
if name is None:
# default to [0], same as we would get with DataFrame(self)
columns = default_index(1)
else:
columns = Index([name])
else:
columns = Index([name])
mgr = self._mgr.to_2d_mgr(columns)
df = self._constructor_expanddim(mgr)
return df.__finalize__(self, method="to_frame")
def _set_name(self, name, inplace: bool = False) -> Series:
"""
Set the Series name.
Parameters
----------
name : str
inplace : bool
Whether to modify `self` directly or return a copy.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
ser = self if inplace else self.copy()
ser.name = name
return ser
"""
Examples
--------
>>> ser = pd.Series([390., 350., 30., 20.],
... index=['Falcon', 'Falcon', 'Parrot', 'Parrot'], name="Max Speed")
>>> ser
Falcon 390.0
Falcon 350.0
Parrot 30.0
Parrot 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", "b"]).mean()
a 210.0
b 185.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(ser > 100).mean()
Max Speed
False 25.0
True 370.0
Name: Max Speed, dtype: float64
**Grouping by Indexes**
We can groupby different levels of a hierarchical index
using the `level` parameter:
>>> arrays = [['Falcon', 'Falcon', 'Parrot', 'Parrot'],
... ['Captive', 'Wild', 'Captive', 'Wild']]
>>> index = pd.MultiIndex.from_arrays(arrays, names=('Animal', 'Type'))
>>> ser = pd.Series([390., 350., 30., 20.], index=index, name="Max Speed")
>>> ser
Animal Type
Falcon Captive 390.0
Wild 350.0
Parrot Captive 30.0
Wild 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Animal
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level="Type").mean()
Type
Captive 210.0
Wild 185.0
Name: Max Speed, dtype: float64
We can also choose to include `NA` in group keys or not by defining
`dropna` parameter, the default setting is `True`.
>>> ser = pd.Series([1, 2, 3, 3], index=["a", 'a', 'b', np.nan])
>>> ser.groupby(level=0).sum()
a 3
b 3
dtype: int64
>>> ser.groupby(level=0, dropna=False).sum()
a 3
b 3
NaN 3
dtype: int64
>>> arrays = ['Falcon', 'Falcon', 'Parrot', 'Parrot']
>>> ser = pd.Series([390., 350., 30., 20.], index=arrays, name="Max Speed")
>>> ser.groupby(["a", "b", "a", np.nan]).mean()
a 210.0
b 350.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", np.nan], dropna=False).mean()
a 210.0
b 350.0
NaN 20.0
Name: Max Speed, dtype: float64
"""
)
def groupby(
self,
by=None,
axis: Axis = 0,
level: IndexLabel = None,
as_index: bool = True,
sort: bool = True,
group_keys: bool = True,
observed: bool = False,
dropna: bool = True,
) -> SeriesGroupBy:
from pandas.core.groupby.generic import SeriesGroupBy
if level is None and by is None:
raise TypeError("You have to supply one of 'by' and 'level'")
if not as_index:
raise TypeError("as_index=False only valid with DataFrame")
axis = self._get_axis_number(axis)
return SeriesGroupBy(
obj=self,
keys=by,
axis=axis,
level=level,
as_index=as_index,
sort=sort,
group_keys=group_keys,
observed=observed,
dropna=dropna,
)
# ----------------------------------------------------------------------
# Statistics, overridden ndarray methods
# TODO: integrate bottleneck
def count(self):
"""
Return number of non-NA/null observations in the Series.
Returns
-------
int or Series (if level specified)
Number of non-null values in the Series.
See Also
--------
DataFrame.count : Count non-NA cells for each column or row.
Examples
--------
>>> s = pd.Series([0.0, 1.0, np.nan])
>>> s.count()
2
"""
return notna(self._values).sum().astype("int64")
def mode(self, dropna: bool = True) -> Series:
"""
Return the mode(s) of the Series.
The mode is the value that appears most often. There can be multiple modes.
Always returns Series even if only one value is returned.
Parameters
----------
dropna : bool, default True
Don't consider counts of NaN/NaT.
Returns
-------
Series
Modes of the Series in sorted order.
"""
# TODO: Add option for bins like value_counts()
values = self._values
if isinstance(values, np.ndarray):
res_values = algorithms.mode(values, dropna=dropna)
else:
res_values = values._mode(dropna=dropna)
# Ensure index is type stable (should always use int index)
return self._constructor(
res_values, index=range(len(res_values)), name=self.name, copy=False
)
def unique(self) -> ArrayLike: # pylint: disable=useless-parent-delegation
"""
Return unique values of Series object.
Uniques are returned in order of appearance. Hash table-based unique,
therefore does NOT sort.
Returns
-------
ndarray or ExtensionArray
The unique values returned as a NumPy array. See Notes.
See Also
--------
Series.drop_duplicates : Return Series with duplicate values removed.
unique : Top-level unique method for any 1-d array-like object.
Index.unique : Return Index with unique values from an Index object.
Notes
-----
Returns the unique values as a NumPy array. In case of an
extension-array backed Series, a new
:class:`~api.extensions.ExtensionArray` of that type with just
the unique values is returned. This includes
* Categorical
* Period
* Datetime with Timezone
* Datetime without Timezone
* Timedelta
* Interval
* Sparse
* IntegerNA
See Examples section.
Examples
--------
>>> pd.Series([2, 1, 3, 3], name='A').unique()
array([2, 1, 3])
>>> pd.Series([pd.Timestamp('2016-01-01') for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00']
Length: 1, dtype: datetime64[ns]
>>> pd.Series([pd.Timestamp('2016-01-01', tz='US/Eastern')
... for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00-05:00']
Length: 1, dtype: datetime64[ns, US/Eastern]
An Categorical will return categories in the order of
appearance and with the same dtype.
>>> pd.Series(pd.Categorical(list('baabc'))).unique()
['b', 'a', 'c']
Categories (3, object): ['a', 'b', 'c']
>>> pd.Series(pd.Categorical(list('baabc'), categories=list('abc'),
... ordered=True)).unique()
['b', 'a', 'c']
Categories (3, object): ['a' < 'b' < 'c']
"""
return super().unique()
def drop_duplicates(
self,
*,
keep: DropKeep = ...,
inplace: Literal[False] = ...,
ignore_index: bool = ...,
) -> Series:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: Literal[True], ignore_index: bool = ...
) -> None:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: bool = ..., ignore_index: bool = ...
) -> Series | None:
...
def drop_duplicates(
self,
*,
keep: DropKeep = "first",
inplace: bool = False,
ignore_index: bool = False,
) -> Series | None:
"""
Return Series with duplicate values removed.
Parameters
----------
keep : {'first', 'last', ``False``}, default 'first'
Method to handle dropping duplicates:
- 'first' : Drop duplicates except for the first occurrence.
- 'last' : Drop duplicates except for the last occurrence.
- ``False`` : Drop all duplicates.
inplace : bool, default ``False``
If ``True``, performs operation inplace and returns None.
ignore_index : bool, default ``False``
If ``True``, the resulting axis will be labeled 0, 1, …, n - 1.
.. versionadded:: 2.0.0
Returns
-------
Series or None
Series with duplicates dropped or None if ``inplace=True``.
See Also
--------
Index.drop_duplicates : Equivalent method on Index.
DataFrame.drop_duplicates : Equivalent method on DataFrame.
Series.duplicated : Related method on Series, indicating duplicate
Series values.
Series.unique : Return unique values as an array.
Examples
--------
Generate a Series with duplicated entries.
>>> s = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama', 'hippo'],
... name='animal')
>>> s
0 lama
1 cow
2 lama
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
With the 'keep' parameter, the selection behaviour of duplicated values
can be changed. The value 'first' keeps the first occurrence for each
set of duplicated entries. The default value of keep is 'first'.
>>> s.drop_duplicates()
0 lama
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
The value 'last' for parameter 'keep' keeps the last occurrence for
each set of duplicated entries.
>>> s.drop_duplicates(keep='last')
1 cow
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
The value ``False`` for parameter 'keep' discards all sets of
duplicated entries.
>>> s.drop_duplicates(keep=False)
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
"""
inplace = validate_bool_kwarg(inplace, "inplace")
result = super().drop_duplicates(keep=keep)
if ignore_index:
result.index = default_index(len(result))
if inplace:
self._update_inplace(result)
return None
else:
return result
def duplicated(self, keep: DropKeep = "first") -> Series:
"""
Indicate duplicate Series values.
Duplicated values are indicated as ``True`` values in the resulting
Series. Either all duplicates, all except the first or all except the
last occurrence of duplicates can be indicated.
Parameters
----------
keep : {'first', 'last', False}, default 'first'
Method to handle dropping duplicates:
- 'first' : Mark duplicates as ``True`` except for the first
occurrence.
- 'last' : Mark duplicates as ``True`` except for the last
occurrence.
- ``False`` : Mark all duplicates as ``True``.
Returns
-------
Series[bool]
Series indicating whether each value has occurred in the
preceding values.
See Also
--------
Index.duplicated : Equivalent method on pandas.Index.
DataFrame.duplicated : Equivalent method on pandas.DataFrame.
Series.drop_duplicates : Remove duplicate values from Series.
Examples
--------
By default, for each set of duplicated values, the first occurrence is
set on False and all others on True:
>>> animals = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama'])
>>> animals.duplicated()
0 False
1 False
2 True
3 False
4 True
dtype: bool
which is equivalent to
>>> animals.duplicated(keep='first')
0 False
1 False
2 True
3 False
4 True
dtype: bool
By using 'last', the last occurrence of each set of duplicated values
is set on False and all others on True:
>>> animals.duplicated(keep='last')
0 True
1 False
2 True
3 False
4 False
dtype: bool
By setting keep on ``False``, all duplicates are True:
>>> animals.duplicated(keep=False)
0 True
1 False
2 True
3 False
4 True
dtype: bool
"""
res = self._duplicated(keep=keep)
result = self._constructor(res, index=self.index, copy=False)
return result.__finalize__(self, method="duplicated")
def idxmin(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the minimum value.
If multiple values equal the minimum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the minimum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmin : Return indices of the minimum values
along the given axis.
DataFrame.idxmin : Return index of first occurrence of minimum
over requested axis.
Series.idxmax : Return index *label* of the first occurrence
of maximum of values.
Notes
-----
This method is the Series version of ``ndarray.argmin``. This method
returns the label of the minimum, while ``ndarray.argmin`` returns
the position. To get the position, use ``series.values.argmin()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 1],
... index=['A', 'B', 'C', 'D'])
>>> s
A 1.0
B NaN
C 4.0
D 1.0
dtype: float64
>>> s.idxmin()
'A'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmin(skipna=False)
nan
"""
# error: Argument 1 to "argmin" of "IndexOpsMixin" has incompatible type "Union
# [int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmin(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def idxmax(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the maximum value.
If multiple values equal the maximum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the maximum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmax : Return indices of the maximum values
along the given axis.
DataFrame.idxmax : Return index of first occurrence of maximum
over requested axis.
Series.idxmin : Return index *label* of the first occurrence
of minimum of values.
Notes
-----
This method is the Series version of ``ndarray.argmax``. This method
returns the label of the maximum, while ``ndarray.argmax`` returns
the position. To get the position, use ``series.values.argmax()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 3, 4],
... index=['A', 'B', 'C', 'D', 'E'])
>>> s
A 1.0
B NaN
C 4.0
D 3.0
E 4.0
dtype: float64
>>> s.idxmax()
'C'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmax(skipna=False)
nan
"""
# error: Argument 1 to "argmax" of "IndexOpsMixin" has incompatible type
# "Union[int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmax(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def round(self, decimals: int = 0, *args, **kwargs) -> Series:
"""
Round each value in a Series to the given number of decimals.
Parameters
----------
decimals : int, default 0
Number of decimal places to round to. If decimals is negative,
it specifies the number of positions to the left of the decimal point.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Series
Rounded values of the Series.
See Also
--------
numpy.around : Round values of an np.array.
DataFrame.round : Round values of a DataFrame.
Examples
--------
>>> s = pd.Series([0.1, 1.3, 2.7])
>>> s.round()
0 0.0
1 1.0
2 3.0
dtype: float64
"""
nv.validate_round(args, kwargs)
result = self._values.round(decimals)
result = self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="round"
)
return result
def quantile(
self, q: float = ..., interpolation: QuantileInterpolation = ...
) -> float:
...
def quantile(
self,
q: Sequence[float] | AnyArrayLike,
interpolation: QuantileInterpolation = ...,
) -> Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = ...,
interpolation: QuantileInterpolation = ...,
) -> float | Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = 0.5,
interpolation: QuantileInterpolation = "linear",
) -> float | Series:
"""
Return value at the given quantile.
Parameters
----------
q : float or array-like, default 0.5 (50% quantile)
The quantile(s) to compute, which can lie in range: 0 <= q <= 1.
interpolation : {'linear', 'lower', 'higher', 'midpoint', 'nearest'}
This optional parameter specifies the interpolation method to use,
when the desired quantile lies between two data points `i` and `j`:
* linear: `i + (j - i) * fraction`, where `fraction` is the
fractional part of the index surrounded by `i` and `j`.
* lower: `i`.
* higher: `j`.
* nearest: `i` or `j` whichever is nearest.
* midpoint: (`i` + `j`) / 2.
Returns
-------
float or Series
If ``q`` is an array, a Series will be returned where the
index is ``q`` and the values are the quantiles, otherwise
a float will be returned.
See Also
--------
core.window.Rolling.quantile : Calculate the rolling quantile.
numpy.percentile : Returns the q-th percentile(s) of the array elements.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.quantile(.5)
2.5
>>> s.quantile([.25, .5, .75])
0.25 1.75
0.50 2.50
0.75 3.25
dtype: float64
"""
validate_percentile(q)
# We dispatch to DataFrame so that core.internals only has to worry
# about 2D cases.
df = self.to_frame()
result = df.quantile(q=q, interpolation=interpolation, numeric_only=False)
if result.ndim == 2:
result = result.iloc[:, 0]
if is_list_like(q):
result.name = self.name
idx = Index(q, dtype=np.float64)
return self._constructor(result, index=idx, name=self.name)
else:
# scalar
return result.iloc[0]
def corr(
self,
other: Series,
method: CorrelationMethod = "pearson",
min_periods: int | None = None,
) -> float:
"""
Compute correlation with `other` Series, excluding missing values.
The two `Series` objects are not required to be the same length and will be
aligned internally before the correlation function is applied.
Parameters
----------
other : Series
Series with which to compute the correlation.
method : {'pearson', 'kendall', 'spearman'} or callable
Method used to compute correlation:
- pearson : Standard correlation coefficient
- kendall : Kendall Tau correlation coefficient
- spearman : Spearman rank correlation
- callable: Callable with input two 1d ndarrays and returning a float.
.. warning::
Note that the returned matrix from corr will have 1 along the
diagonals and will be symmetric regardless of the callable's
behavior.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
Returns
-------
float
Correlation with other.
See Also
--------
DataFrame.corr : Compute pairwise correlation between columns.
DataFrame.corrwith : Compute pairwise correlation with another
DataFrame or Series.
Notes
-----
Pearson, Kendall and Spearman correlation are currently computed using pairwise complete observations.
* `Pearson correlation coefficient <https://en.wikipedia.org/wiki/Pearson_correlation_coefficient>`_
* `Kendall rank correlation coefficient <https://en.wikipedia.org/wiki/Kendall_rank_correlation_coefficient>`_
* `Spearman's rank correlation coefficient <https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient>`_
Examples
--------
>>> def histogram_intersection(a, b):
... v = np.minimum(a, b).sum().round(decimals=1)
... return v
>>> s1 = pd.Series([.2, .0, .6, .2])
>>> s2 = pd.Series([.3, .6, .0, .1])
>>> s1.corr(s2, method=histogram_intersection)
0.3
""" # noqa:E501
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
if method in ["pearson", "spearman", "kendall"] or callable(method):
return nanops.nancorr(
this.values, other.values, method=method, min_periods=min_periods
)
raise ValueError(
"method must be either 'pearson', "
"'spearman', 'kendall', or a callable, "
f"'{method}' was supplied"
)
def cov(
self,
other: Series,
min_periods: int | None = None,
ddof: int | None = 1,
) -> float:
"""
Compute covariance with Series, excluding missing values.
The two `Series` objects are not required to be the same length and
will be aligned internally before the covariance is calculated.
Parameters
----------
other : Series
Series with which to compute the covariance.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
ddof : int, default 1
Delta degrees of freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.
.. versionadded:: 1.1.0
Returns
-------
float
Covariance between Series and other normalized by N-1
(unbiased estimator).
See Also
--------
DataFrame.cov : Compute pairwise covariance of columns.
Examples
--------
>>> s1 = pd.Series([0.90010907, 0.13484424, 0.62036035])
>>> s2 = pd.Series([0.12528585, 0.26962463, 0.51111198])
>>> s1.cov(s2)
-0.01685762652715874
"""
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
return nanops.nancov(
this.values, other.values, min_periods=min_periods, ddof=ddof
)
klass="Series",
extra_params="",
other_klass="DataFrame",
examples=dedent(
"""
Difference with previous row
>>> s = pd.Series([1, 1, 2, 3, 5, 8])
>>> s.diff()
0 NaN
1 0.0
2 1.0
3 1.0
4 2.0
5 3.0
dtype: float64
Difference with 3rd previous row
>>> s.diff(periods=3)
0 NaN
1 NaN
2 NaN
3 2.0
4 4.0
5 6.0
dtype: float64
Difference with following row
>>> s.diff(periods=-1)
0 0.0
1 -1.0
2 -1.0
3 -2.0
4 -3.0
5 NaN
dtype: float64
Overflow in input dtype
>>> s = pd.Series([1, 0], dtype=np.uint8)
>>> s.diff()
0 NaN
1 255.0
dtype: float64"""
),
)
def diff(self, periods: int = 1) -> Series:
"""
First discrete difference of element.
Calculates the difference of a {klass} element compared with another
element in the {klass} (default is element in previous row).
Parameters
----------
periods : int, default 1
Periods to shift for calculating difference, accepts negative
values.
{extra_params}
Returns
-------
{klass}
First differences of the Series.
See Also
--------
{klass}.pct_change: Percent change over given number of periods.
{klass}.shift: Shift index by desired number of periods with an
optional time freq.
{other_klass}.diff: First discrete difference of object.
Notes
-----
For boolean dtypes, this uses :meth:`operator.xor` rather than
:meth:`operator.sub`.
The result is calculated according to current dtype in {klass},
however dtype of the result is always float64.
Examples
--------
{examples}
"""
result = algorithms.diff(self._values, periods)
return self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="diff"
)
def autocorr(self, lag: int = 1) -> float:
"""
Compute the lag-N autocorrelation.
This method computes the Pearson correlation between
the Series and its shifted self.
Parameters
----------
lag : int, default 1
Number of lags to apply before performing autocorrelation.
Returns
-------
float
The Pearson correlation between self and self.shift(lag).
See Also
--------
Series.corr : Compute the correlation between two Series.
Series.shift : Shift index by desired number of periods.
DataFrame.corr : Compute pairwise correlation of columns.
DataFrame.corrwith : Compute pairwise correlation between rows or
columns of two DataFrame objects.
Notes
-----
If the Pearson correlation is not well defined return 'NaN'.
Examples
--------
>>> s = pd.Series([0.25, 0.5, 0.2, -0.05])
>>> s.autocorr() # doctest: +ELLIPSIS
0.10355...
>>> s.autocorr(lag=2) # doctest: +ELLIPSIS
-0.99999...
If the Pearson correlation is not well defined, then 'NaN' is returned.
>>> s = pd.Series([1, 0, 0, 0])
>>> s.autocorr()
nan
"""
return self.corr(self.shift(lag))
def dot(self, other: AnyArrayLike) -> Series | np.ndarray:
"""
Compute the dot product between the Series and the columns of other.
This method computes the dot product between the Series and another
one, or the Series and each columns of a DataFrame, or the Series and
each columns of an array.
It can also be called using `self @ other` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the dot product with its columns.
Returns
-------
scalar, Series or numpy.ndarray
Return the dot product of the Series and other if other is a
Series, the Series of the dot product of Series and each rows of
other if other is a DataFrame or a numpy.ndarray between the Series
and each columns of the numpy array.
See Also
--------
DataFrame.dot: Compute the matrix product with the DataFrame.
Series.mul: Multiplication of series and other, element-wise.
Notes
-----
The Series and other has to share the same index if other is a Series
or a DataFrame.
Examples
--------
>>> s = pd.Series([0, 1, 2, 3])
>>> other = pd.Series([-1, 2, -3, 4])
>>> s.dot(other)
8
>>> s @ other
8
>>> df = pd.DataFrame([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(df)
0 24
1 14
dtype: int64
>>> arr = np.array([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(arr)
array([24, 14])
"""
if isinstance(other, (Series, ABCDataFrame)):
common = self.index.union(other.index)
if len(common) > len(self.index) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(index=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right.values
else:
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[0] != rvals.shape[0]:
raise Exception(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, ABCDataFrame):
return self._constructor(
np.dot(lvals, rvals), index=other.columns, copy=False
).__finalize__(self, method="dot")
elif isinstance(other, Series):
return np.dot(lvals, rvals)
elif isinstance(rvals, np.ndarray):
return np.dot(lvals, rvals)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(np.transpose(other))
# Signature of "searchsorted" incompatible with supertype "IndexOpsMixin"
def searchsorted( # type: ignore[override]
self,
value: NumpyValueArrayLike | ExtensionArray,
side: Literal["left", "right"] = "left",
sorter: NumpySorter = None,
) -> npt.NDArray[np.intp] | np.intp:
return base.IndexOpsMixin.searchsorted(self, value, side=side, sorter=sorter)
# -------------------------------------------------------------------
# Combination
def _append(
self, to_append, ignore_index: bool = False, verify_integrity: bool = False
):
from pandas.core.reshape.concat import concat
if isinstance(to_append, (list, tuple)):
to_concat = [self]
to_concat.extend(to_append)
else:
to_concat = [self, to_append]
if any(isinstance(x, (ABCDataFrame,)) for x in to_concat[1:]):
msg = "to_append should be a Series or list/tuple of Series, got DataFrame"
raise TypeError(msg)
return concat(
to_concat, ignore_index=ignore_index, verify_integrity=verify_integrity
)
def _binop(self, other: Series, func, level=None, fill_value=None):
"""
Perform generic binary operation with optional fill value.
Parameters
----------
other : Series
func : binary operator
fill_value : float or object
Value to substitute for NA/null values. If both Series are NA in a
location, the result will be NA regardless of the passed fill value.
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
Returns
-------
Series
"""
if not isinstance(other, Series):
raise AssertionError("Other operand must be Series")
this = self
if not self.index.equals(other.index):
this, other = self.align(other, level=level, join="outer", copy=False)
this_vals, other_vals = ops.fill_binop(this._values, other._values, fill_value)
with np.errstate(all="ignore"):
result = func(this_vals, other_vals)
name = ops.get_op_result_name(self, other)
return this._construct_result(result, name)
def _construct_result(
self, result: ArrayLike | tuple[ArrayLike, ArrayLike], name: Hashable
) -> Series | tuple[Series, Series]:
"""
Construct an appropriately-labelled Series from the result of an op.
Parameters
----------
result : ndarray or ExtensionArray
name : Label
Returns
-------
Series
In the case of __divmod__ or __rdivmod__, a 2-tuple of Series.
"""
if isinstance(result, tuple):
# produced by divmod or rdivmod
res1 = self._construct_result(result[0], name=name)
res2 = self._construct_result(result[1], name=name)
# GH#33427 assertions to keep mypy happy
assert isinstance(res1, Series)
assert isinstance(res2, Series)
return (res1, res2)
# TODO: result should always be ArrayLike, but this fails for some
# JSONArray tests
dtype = getattr(result, "dtype", None)
out = self._constructor(result, index=self.index, dtype=dtype)
out = out.__finalize__(self)
# Set the result's name after __finalize__ is called because __finalize__
# would set it back to self.name
out.name = name
return out
_shared_docs["compare"],
"""
Returns
-------
Series or DataFrame
If axis is 0 or 'index' the result will be a Series.
The resulting index will be a MultiIndex with 'self' and 'other'
stacked alternately at the inner level.
If axis is 1 or 'columns' the result will be a DataFrame.
It will have two columns namely 'self' and 'other'.
See Also
--------
DataFrame.compare : Compare with another DataFrame and show differences.
Notes
-----
Matching NaNs will not appear as a difference.
Examples
--------
>>> s1 = pd.Series(["a", "b", "c", "d", "e"])
>>> s2 = pd.Series(["a", "a", "c", "b", "e"])
Align the differences on columns
>>> s1.compare(s2)
self other
1 b a
3 d b
Stack the differences on indices
>>> s1.compare(s2, align_axis=0)
1 self b
other a
3 self d
other b
dtype: object
Keep all original rows
>>> s1.compare(s2, keep_shape=True)
self other
0 NaN NaN
1 b a
2 NaN NaN
3 d b
4 NaN NaN
Keep all original rows and also all original values
>>> s1.compare(s2, keep_shape=True, keep_equal=True)
self other
0 a a
1 b a
2 c c
3 d b
4 e e
""",
klass=_shared_doc_kwargs["klass"],
)
def compare(
self,
other: Series,
align_axis: Axis = 1,
keep_shape: bool = False,
keep_equal: bool = False,
result_names: Suffixes = ("self", "other"),
) -> DataFrame | Series:
return super().compare(
other=other,
align_axis=align_axis,
keep_shape=keep_shape,
keep_equal=keep_equal,
result_names=result_names,
)
def combine(
self,
other: Series | Hashable,
func: Callable[[Hashable, Hashable], Hashable],
fill_value: Hashable = None,
) -> Series:
"""
Combine the Series with a Series or scalar according to `func`.
Combine the Series and `other` using `func` to perform elementwise
selection for combined Series.
`fill_value` is assumed when value is missing at some index
from one of the two objects being combined.
Parameters
----------
other : Series or scalar
The value(s) to be combined with the `Series`.
func : function
Function that takes two scalars as inputs and returns an element.
fill_value : scalar, optional
The value to assume when an index is missing from
one Series or the other. The default specifies to use the
appropriate NaN value for the underlying dtype of the Series.
Returns
-------
Series
The result of combining the Series with the other object.
See Also
--------
Series.combine_first : Combine Series values, choosing the calling
Series' values first.
Examples
--------
Consider 2 Datasets ``s1`` and ``s2`` containing
highest clocked speeds of different birds.
>>> s1 = pd.Series({'falcon': 330.0, 'eagle': 160.0})
>>> s1
falcon 330.0
eagle 160.0
dtype: float64
>>> s2 = pd.Series({'falcon': 345.0, 'eagle': 200.0, 'duck': 30.0})
>>> s2
falcon 345.0
eagle 200.0
duck 30.0
dtype: float64
Now, to combine the two datasets and view the highest speeds
of the birds across the two datasets
>>> s1.combine(s2, max)
duck NaN
eagle 200.0
falcon 345.0
dtype: float64
In the previous example, the resulting value for duck is missing,
because the maximum of a NaN and a float is a NaN.
So, in the example, we set ``fill_value=0``,
so the maximum value returned will be the value from some dataset.
>>> s1.combine(s2, max, fill_value=0)
duck 30.0
eagle 200.0
falcon 345.0
dtype: float64
"""
if fill_value is None:
fill_value = na_value_for_dtype(self.dtype, compat=False)
if isinstance(other, Series):
# If other is a Series, result is based on union of Series,
# so do this element by element
new_index = self.index.union(other.index)
new_name = ops.get_op_result_name(self, other)
new_values = np.empty(len(new_index), dtype=object)
for i, idx in enumerate(new_index):
lv = self.get(idx, fill_value)
rv = other.get(idx, fill_value)
with np.errstate(all="ignore"):
new_values[i] = func(lv, rv)
else:
# Assume that other is a scalar, so apply the function for
# each element in the Series
new_index = self.index
new_values = np.empty(len(new_index), dtype=object)
with np.errstate(all="ignore"):
new_values[:] = [func(lv, other) for lv in self._values]
new_name = self.name
# try_float=False is to match agg_series
npvalues = lib.maybe_convert_objects(new_values, try_float=False)
res_values = maybe_cast_pointwise_result(npvalues, self.dtype, same_dtype=False)
return self._constructor(res_values, index=new_index, name=new_name, copy=False)
def combine_first(self, other) -> Series:
"""
Update null elements with value in the same location in 'other'.
Combine two Series objects by filling null values in one Series with
non-null values from the other Series. Result index will be the union
of the two indexes.
Parameters
----------
other : Series
The value(s) to be used for filling null values.
Returns
-------
Series
The result of combining the provided Series with the other object.
See Also
--------
Series.combine : Perform element-wise operation on two Series
using a given function.
Examples
--------
>>> s1 = pd.Series([1, np.nan])
>>> s2 = pd.Series([3, 4, 5])
>>> s1.combine_first(s2)
0 1.0
1 4.0
2 5.0
dtype: float64
Null values still persist if the location of that null value
does not exist in `other`
>>> s1 = pd.Series({'falcon': np.nan, 'eagle': 160.0})
>>> s2 = pd.Series({'eagle': 200.0, 'duck': 30.0})
>>> s1.combine_first(s2)
duck 30.0
eagle 160.0
falcon NaN
dtype: float64
"""
new_index = self.index.union(other.index)
this = self.reindex(new_index, copy=False)
other = other.reindex(new_index, copy=False)
if this.dtype.kind == "M" and other.dtype.kind != "M":
other = to_datetime(other)
return this.where(notna(this), other)
def update(self, other: Series | Sequence | Mapping) -> None:
"""
Modify Series in place using values from passed Series.
Uses non-NA values from passed Series to make updates. Aligns
on index.
Parameters
----------
other : Series, or object coercible into Series
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6]))
>>> s
0 4
1 5
2 6
dtype: int64
>>> s = pd.Series(['a', 'b', 'c'])
>>> s.update(pd.Series(['d', 'e'], index=[0, 2]))
>>> s
0 d
1 b
2 e
dtype: object
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6, 7, 8]))
>>> s
0 4
1 5
2 6
dtype: int64
If ``other`` contains NaNs the corresponding values are not updated
in the original Series.
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, np.nan, 6]))
>>> s
0 4
1 2
2 6
dtype: int64
``other`` can also be a non-Series object type
that is coercible into a Series
>>> s = pd.Series([1, 2, 3])
>>> s.update([4, np.nan, 6])
>>> s
0 4
1 2
2 6
dtype: int64
>>> s = pd.Series([1, 2, 3])
>>> s.update({1: 9})
>>> s
0 1
1 9
2 3
dtype: int64
"""
if not isinstance(other, Series):
other = Series(other)
other = other.reindex_like(self)
mask = notna(other)
self._mgr = self._mgr.putmask(mask=mask, new=other)
self._maybe_update_cacher()
# ----------------------------------------------------------------------
# Reindexing, sorting
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> Series:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self,
*,
axis: Axis = 0,
ascending: bool | int | Sequence[bool] | Sequence[int] = True,
inplace: bool = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool = False,
key: ValueKeyFunc = None,
) -> Series | None:
"""
Sort by the values.
Sort a Series in ascending or descending order by some
criterion.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
ascending : bool or list of bools, default True
If True, sort values in ascending order, otherwise descending.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
na_position : {'first' or 'last'}, default 'last'
Argument 'first' puts NaNs at the beginning, 'last' puts NaNs at
the end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the series values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return an array-like.
.. versionadded:: 1.1.0
Returns
-------
Series or None
Series ordered by values or None if ``inplace=True``.
See Also
--------
Series.sort_index : Sort by the Series indices.
DataFrame.sort_values : Sort DataFrame by the values along either axis.
DataFrame.sort_index : Sort DataFrame by indices.
Examples
--------
>>> s = pd.Series([np.nan, 1, 3, 10, 5])
>>> s
0 NaN
1 1.0
2 3.0
3 10.0
4 5.0
dtype: float64
Sort values ascending order (default behaviour)
>>> s.sort_values(ascending=True)
1 1.0
2 3.0
4 5.0
3 10.0
0 NaN
dtype: float64
Sort values descending order
>>> s.sort_values(ascending=False)
3 10.0
4 5.0
2 3.0
1 1.0
0 NaN
dtype: float64
Sort values putting NAs first
>>> s.sort_values(na_position='first')
0 NaN
1 1.0
2 3.0
4 5.0
3 10.0
dtype: float64
Sort a series of strings
>>> s = pd.Series(['z', 'b', 'd', 'a', 'c'])
>>> s
0 z
1 b
2 d
3 a
4 c
dtype: object
>>> s.sort_values()
3 a
1 b
4 c
2 d
0 z
dtype: object
Sort using a key function. Your `key` function will be
given the ``Series`` of values and should return an array-like.
>>> s = pd.Series(['a', 'B', 'c', 'D', 'e'])
>>> s.sort_values()
1 B
3 D
0 a
2 c
4 e
dtype: object
>>> s.sort_values(key=lambda x: x.str.lower())
0 a
1 B
2 c
3 D
4 e
dtype: object
NumPy ufuncs work well here. For example, we can
sort by the ``sin`` of the value
>>> s = pd.Series([-4, -2, 0, 2, 4])
>>> s.sort_values(key=np.sin)
1 -2
4 4
2 0
0 -4
3 2
dtype: int64
More complicated user-defined functions can be used,
as long as they expect a Series and return an array-like
>>> s.sort_values(key=lambda x: (np.tan(x.cumsum())))
0 -4
3 2
4 4
1 -2
2 0
dtype: int64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
# Validate the axis parameter
self._get_axis_number(axis)
# GH 5856/5853
if inplace and self._is_cached:
raise ValueError(
"This Series is a view of some other array, to "
"sort in-place you must create a copy"
)
if is_list_like(ascending):
ascending = cast(Sequence[Union[bool, int]], ascending)
if len(ascending) != 1:
raise ValueError(
f"Length of ascending ({len(ascending)}) must be 1 for Series"
)
ascending = ascending[0]
ascending = validate_ascending(ascending)
if na_position not in ["first", "last"]:
raise ValueError(f"invalid na_position: {na_position}")
# GH 35922. Make sorting stable by leveraging nargsort
values_to_sort = ensure_key_mapped(self, key)._values if key else self._values
sorted_index = nargsort(values_to_sort, kind, bool(ascending), na_position)
if is_range_indexer(sorted_index, len(sorted_index)):
if inplace:
return self._update_inplace(self)
return self.copy(deep=None)
result = self._constructor(
self._values[sorted_index], index=self.index[sorted_index], copy=False
)
if ignore_index:
result.index = default_index(len(sorted_index))
if not inplace:
return result.__finalize__(self, method="sort_values")
self._update_inplace(result)
return None
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: bool = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series | None:
...
def sort_index(
self,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool | Sequence[bool] = True,
inplace: bool = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool = True,
ignore_index: bool = False,
key: IndexKeyFunc = None,
) -> Series | None:
"""
Sort Series by index labels.
Returns a new Series sorted by label if `inplace` argument is
``False``, otherwise updates the original series and returns None.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
level : int, optional
If not None, sort on values in specified index level(s).
ascending : bool or list-like of bools, default True
Sort ascending vs. descending. When the index is a MultiIndex the
sort direction can be controlled for each level individually.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
If 'first' puts NaNs at the beginning, 'last' puts NaNs at the end.
Not implemented for MultiIndex.
sort_remaining : bool, default True
If True and sorting by level and index is multilevel, sort by other
levels too (in order) after sorting by specified level.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the index values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect an
``Index`` and return an ``Index`` of the same shape.
.. versionadded:: 1.1.0
Returns
-------
Series or None
The original Series sorted by the labels or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index: Sort DataFrame by the index.
DataFrame.sort_values: Sort DataFrame by the value.
Series.sort_values : Sort Series by the value.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, 4])
>>> s.sort_index()
1 c
2 b
3 a
4 d
dtype: object
Sort Descending
>>> s.sort_index(ascending=False)
4 d
3 a
2 b
1 c
dtype: object
By default NaNs are put at the end, but use `na_position` to place
them at the beginning
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, np.nan])
>>> s.sort_index(na_position='first')
NaN d
1.0 c
2.0 b
3.0 a
dtype: object
Specify index level to sort
>>> arrays = [np.array(['qux', 'qux', 'foo', 'foo',
... 'baz', 'baz', 'bar', 'bar']),
... np.array(['two', 'one', 'two', 'one',
... 'two', 'one', 'two', 'one'])]
>>> s = pd.Series([1, 2, 3, 4, 5, 6, 7, 8], index=arrays)
>>> s.sort_index(level=1)
bar one 8
baz one 6
foo one 4
qux one 2
bar two 7
baz two 5
foo two 3
qux two 1
dtype: int64
Does not sort by remaining levels when sorting by levels
>>> s.sort_index(level=1, sort_remaining=False)
qux one 2
foo one 4
baz one 6
bar one 8
qux two 1
foo two 3
baz two 5
bar two 7
dtype: int64
Apply a key function before sorting
>>> s = pd.Series([1, 2, 3, 4], index=['A', 'b', 'C', 'd'])
>>> s.sort_index(key=lambda x : x.str.lower())
A 1
b 2
C 3
d 4
dtype: int64
"""
return super().sort_index(
axis=axis,
level=level,
ascending=ascending,
inplace=inplace,
kind=kind,
na_position=na_position,
sort_remaining=sort_remaining,
ignore_index=ignore_index,
key=key,
)
def argsort(
self,
axis: Axis = 0,
kind: SortKind = "quicksort",
order: None = None,
) -> Series:
"""
Return the integer indices that would sort the Series values.
Override ndarray.argsort. Argsorts the value, omitting NA/null values,
and places the result in the same locations as the non-NA values.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
kind : {'mergesort', 'quicksort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
order : None
Has no effect but is accepted for compatibility with numpy.
Returns
-------
Series[np.intp]
Positions of values within the sort order with -1 indicating
nan values.
See Also
--------
numpy.ndarray.argsort : Returns the indices that would sort this array.
"""
values = self._values
mask = isna(values)
if mask.any():
result = np.full(len(self), -1, dtype=np.intp)
notmask = ~mask
result[notmask] = np.argsort(values[notmask], kind=kind)
else:
result = np.argsort(values, kind=kind)
res = self._constructor(
result, index=self.index, name=self.name, dtype=np.intp, copy=False
)
return res.__finalize__(self, method="argsort")
def nlargest(
self, n: int = 5, keep: Literal["first", "last", "all"] = "first"
) -> Series:
"""
Return the largest `n` elements.
Parameters
----------
n : int, default 5
Return this many descending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` largest values in the Series, sorted in decreasing order.
See Also
--------
Series.nsmallest: Get the `n` smallest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values(ascending=False).head(n)`` for small `n`
relative to the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Malta": 434000, "Maldives": 434000,
... "Brunei": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Malta 434000
Maldives 434000
Brunei 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` largest elements where ``n=5`` by default.
>>> s.nlargest()
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3``. Default `keep` value is 'first'
so Malta will be kept.
>>> s.nlargest(3)
France 65000000
Italy 59000000
Malta 434000
dtype: int64
The `n` largest elements where ``n=3`` and keeping the last duplicates.
Brunei will be kept since it is the last with value 434000 based on
the index order.
>>> s.nlargest(3, keep='last')
France 65000000
Italy 59000000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has five elements due to the three duplicates.
>>> s.nlargest(3, keep='all')
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nlargest()
def nsmallest(self, n: int = 5, keep: str = "first") -> Series:
"""
Return the smallest `n` elements.
Parameters
----------
n : int, default 5
Return this many ascending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` smallest values in the Series, sorted in increasing order.
See Also
--------
Series.nlargest: Get the `n` largest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values().head(n)`` for small `n` relative to
the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Brunei": 434000, "Malta": 434000,
... "Maldives": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Brunei 434000
Malta 434000
Maldives 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` smallest elements where ``n=5`` by default.
>>> s.nsmallest()
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
Iceland 337000
dtype: int64
The `n` smallest elements where ``n=3``. Default `keep` value is
'first' so Nauru and Tuvalu will be kept.
>>> s.nsmallest(3)
Montserrat 5200
Nauru 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` and keeping the last
duplicates. Anguilla and Tuvalu will be kept since they are the last
with value 11300 based on the index order.
>>> s.nsmallest(3, keep='last')
Montserrat 5200
Anguilla 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has four elements due to the three duplicates.
>>> s.nsmallest(3, keep='all')
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nsmallest()
klass=_shared_doc_kwargs["klass"],
extra_params=dedent(
"""copy : bool, default True
Whether to copy underlying data."""
),
examples=dedent(
"""\
Examples
--------
>>> s = pd.Series(
... ["A", "B", "A", "C"],
... index=[
... ["Final exam", "Final exam", "Coursework", "Coursework"],
... ["History", "Geography", "History", "Geography"],
... ["January", "February", "March", "April"],
... ],
... )
>>> s
Final exam History January A
Geography February B
Coursework History March A
Geography April C
dtype: object
In the following example, we will swap the levels of the indices.
Here, we will swap the levels column-wise, but levels can be swapped row-wise
in a similar manner. Note that column-wise is the default behaviour.
By not supplying any arguments for i and j, we swap the last and second to
last indices.
>>> s.swaplevel()
Final exam January History A
February Geography B
Coursework March History A
April Geography C
dtype: object
By supplying one argument, we can choose which index to swap the last
index with. We can for example swap the first index with the last one as
follows.
>>> s.swaplevel(0)
January History Final exam A
February Geography Final exam B
March History Coursework A
April Geography Coursework C
dtype: object
We can also define explicitly which indices we want to swap by supplying values
for both i and j. Here, we for example swap the first and second indices.
>>> s.swaplevel(0, 1)
History Final exam January A
Geography Final exam February B
History Coursework March A
Geography Coursework April C
dtype: object"""
),
)
def swaplevel(
self, i: Level = -2, j: Level = -1, copy: bool | None = None
) -> Series:
"""
Swap levels i and j in a :class:`MultiIndex`.
Default is to swap the two innermost levels of the index.
Parameters
----------
i, j : int or str
Levels of the indices to be swapped. Can pass level name as string.
{extra_params}
Returns
-------
{klass}
{klass} with levels swapped in MultiIndex.
{examples}
"""
assert isinstance(self.index, MultiIndex)
result = self.copy(deep=copy and not using_copy_on_write())
result.index = self.index.swaplevel(i, j)
return result
def reorder_levels(self, order: Sequence[Level]) -> Series:
"""
Rearrange index levels using input order.
May not drop or duplicate levels.
Parameters
----------
order : list of int representing new level order
Reference level by number or key.
Returns
-------
type of caller (new object)
"""
if not isinstance(self.index, MultiIndex): # pragma: no cover
raise Exception("Can only reorder levels on a hierarchical axis.")
result = self.copy(deep=None)
assert isinstance(result.index, MultiIndex)
result.index = result.index.reorder_levels(order)
return result
def explode(self, ignore_index: bool = False) -> Series:
"""
Transform each element of a list-like to a row.
Parameters
----------
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.1.0
Returns
-------
Series
Exploded lists to rows; index will be duplicated for these rows.
See Also
--------
Series.str.split : Split string values on specified separator.
Series.unstack : Unstack, a.k.a. pivot, Series with MultiIndex
to produce DataFrame.
DataFrame.melt : Unpivot a DataFrame from wide format to long format.
DataFrame.explode : Explode a DataFrame from list-like
columns to long format.
Notes
-----
This routine will explode list-likes including lists, tuples, sets,
Series, and np.ndarray. The result dtype of the subset rows will
be object. Scalars will be returned unchanged, and empty list-likes will
result in a np.nan for that row. In addition, the ordering of elements in
the output will be non-deterministic when exploding sets.
Reference :ref:`the user guide <reshaping.explode>` for more examples.
Examples
--------
>>> s = pd.Series([[1, 2, 3], 'foo', [], [3, 4]])
>>> s
0 [1, 2, 3]
1 foo
2 []
3 [3, 4]
dtype: object
>>> s.explode()
0 1
0 2
0 3
1 foo
2 NaN
3 3
3 4
dtype: object
"""
if not len(self) or not is_object_dtype(self):
result = self.copy()
return result.reset_index(drop=True) if ignore_index else result
values, counts = reshape.explode(np.asarray(self._values))
if ignore_index:
index = default_index(len(values))
else:
index = self.index.repeat(counts)
return self._constructor(values, index=index, name=self.name, copy=False)
def unstack(self, level: IndexLabel = -1, fill_value: Hashable = None) -> DataFrame:
"""
Unstack, also known as pivot, Series with MultiIndex to produce DataFrame.
Parameters
----------
level : int, str, or list of these, default last level
Level(s) to unstack, can pass level name.
fill_value : scalar value, default None
Value to use when replacing NaN values.
Returns
-------
DataFrame
Unstacked Series.
Notes
-----
Reference :ref:`the user guide <reshaping.stacking>` for more examples.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4],
... index=pd.MultiIndex.from_product([['one', 'two'],
... ['a', 'b']]))
>>> s
one a 1
b 2
two a 3
b 4
dtype: int64
>>> s.unstack(level=-1)
a b
one 1 2
two 3 4
>>> s.unstack(level=0)
one two
a 1 3
b 2 4
"""
from pandas.core.reshape.reshape import unstack
return unstack(self, level, fill_value)
# ----------------------------------------------------------------------
# function application
def map(
self,
arg: Callable | Mapping | Series,
na_action: Literal["ignore"] | None = None,
) -> Series:
"""
Map values of Series according to an input mapping or function.
Used for substituting each value in a Series with another value,
that may be derived from a function, a ``dict`` or
a :class:`Series`.
Parameters
----------
arg : function, collections.abc.Mapping subclass or Series
Mapping correspondence.
na_action : {None, 'ignore'}, default None
If 'ignore', propagate NaN values, without passing them to the
mapping correspondence.
Returns
-------
Series
Same index as caller.
See Also
--------
Series.apply : For applying more complex functions on a Series.
DataFrame.apply : Apply a function row-/column-wise.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Notes
-----
When ``arg`` is a dictionary, values in Series that are not in the
dictionary (as keys) are converted to ``NaN``. However, if the
dictionary is a ``dict`` subclass that defines ``__missing__`` (i.e.
provides a method for default values), then this default is used
rather than ``NaN``.
Examples
--------
>>> s = pd.Series(['cat', 'dog', np.nan, 'rabbit'])
>>> s
0 cat
1 dog
2 NaN
3 rabbit
dtype: object
``map`` accepts a ``dict`` or a ``Series``. Values that are not found
in the ``dict`` are converted to ``NaN``, unless the dict has a default
value (e.g. ``defaultdict``):
>>> s.map({'cat': 'kitten', 'dog': 'puppy'})
0 kitten
1 puppy
2 NaN
3 NaN
dtype: object
It also accepts a function:
>>> s.map('I am a {}'.format)
0 I am a cat
1 I am a dog
2 I am a nan
3 I am a rabbit
dtype: object
To avoid applying the function to missing values (and keep them as
``NaN``) ``na_action='ignore'`` can be used:
>>> s.map('I am a {}'.format, na_action='ignore')
0 I am a cat
1 I am a dog
2 NaN
3 I am a rabbit
dtype: object
"""
new_values = self._map_values(arg, na_action=na_action)
return self._constructor(new_values, index=self.index, copy=False).__finalize__(
self, method="map"
)
def _gotitem(self, key, ndim, subset=None) -> Series:
"""
Sub-classes to define. Return a sliced object.
Parameters
----------
key : string / list of selections
ndim : {1, 2}
Requested ndim of result.
subset : object, default None
Subset to act on.
"""
return self
_agg_see_also_doc = dedent(
"""
See Also
--------
Series.apply : Invoke function on a Series.
Series.transform : Transform function producing a Series with like indexes.
"""
)
_agg_examples_doc = dedent(
"""
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.agg('min')
1
>>> s.agg(['min', 'max'])
min 1
max 4
dtype: int64
"""
)
_shared_docs["aggregate"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
see_also=_agg_see_also_doc,
examples=_agg_examples_doc,
)
def aggregate(self, func=None, axis: Axis = 0, *args, **kwargs):
# Validate the axis parameter
self._get_axis_number(axis)
# if func is None, will switch to user-provided "named aggregation" kwargs
if func is None:
func = dict(kwargs.items())
op = SeriesApply(self, func, convert_dtype=False, args=args, kwargs=kwargs)
result = op.agg()
return result
agg = aggregate
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: None = ...,
**kwargs,
) -> bool:
...
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: Level,
**kwargs,
) -> Series | bool:
...
# error: Missing return statement
def any( # type: ignore[empty-body]
self,
axis: Axis = 0,
bool_only: bool | None = None,
skipna: bool = True,
level: Level | None = None,
**kwargs,
) -> Series | bool:
...
_shared_docs["transform"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
)
def transform(
self, func: AggFuncType, axis: Axis = 0, *args, **kwargs
) -> DataFrame | Series:
# Validate axis argument
self._get_axis_number(axis)
result = SeriesApply(
self, func=func, convert_dtype=True, args=args, kwargs=kwargs
).transform()
return result
def apply(
self,
func: AggFuncType,
convert_dtype: bool = True,
args: tuple[Any, ...] = (),
**kwargs,
) -> DataFrame | Series:
"""
Invoke function on values of Series.
Can be ufunc (a NumPy function that applies to the entire Series)
or a Python function that only works on single values.
Parameters
----------
func : function
Python function or NumPy ufunc to apply.
convert_dtype : bool, default True
Try to find better dtype for elementwise function results. If
False, leave as dtype=object. Note that the dtype is always
preserved for some extension array dtypes, such as Categorical.
args : tuple
Positional arguments passed to func after the series value.
**kwargs
Additional keyword arguments passed to func.
Returns
-------
Series or DataFrame
If func returns a Series object the result will be a DataFrame.
See Also
--------
Series.map: For element-wise operations.
Series.agg: Only perform aggregating type operations.
Series.transform: Only perform transforming type operations.
Notes
-----
Functions that mutate the passed object can produce unexpected
behavior or errors and are not supported. See :ref:`gotchas.udf-mutation`
for more details.
Examples
--------
Create a series with typical summer temperatures for each city.
>>> s = pd.Series([20, 21, 12],
... index=['London', 'New York', 'Helsinki'])
>>> s
London 20
New York 21
Helsinki 12
dtype: int64
Square the values by defining a function and passing it as an
argument to ``apply()``.
>>> def square(x):
... return x ** 2
>>> s.apply(square)
London 400
New York 441
Helsinki 144
dtype: int64
Square the values by passing an anonymous function as an
argument to ``apply()``.
>>> s.apply(lambda x: x ** 2)
London 400
New York 441
Helsinki 144
dtype: int64
Define a custom function that needs additional positional
arguments and pass these additional arguments using the
``args`` keyword.
>>> def subtract_custom_value(x, custom_value):
... return x - custom_value
>>> s.apply(subtract_custom_value, args=(5,))
London 15
New York 16
Helsinki 7
dtype: int64
Define a custom function that takes keyword arguments
and pass these arguments to ``apply``.
>>> def add_custom_values(x, **kwargs):
... for month in kwargs:
... x += kwargs[month]
... return x
>>> s.apply(add_custom_values, june=30, july=20, august=25)
London 95
New York 96
Helsinki 87
dtype: int64
Use a function from the Numpy library.
>>> s.apply(np.log)
London 2.995732
New York 3.044522
Helsinki 2.484907
dtype: float64
"""
return SeriesApply(self, func, convert_dtype, args, kwargs).apply()
def _reduce(
self,
op,
name: str,
*,
axis: Axis = 0,
skipna: bool = True,
numeric_only: bool = False,
filter_type=None,
**kwds,
):
"""
Perform a reduction operation.
If we have an ndarray as a value, then simply perform the operation,
otherwise delegate to the object.
"""
delegate = self._values
if axis is not None:
self._get_axis_number(axis)
if isinstance(delegate, ExtensionArray):
# dispatch to ExtensionArray interface
return delegate._reduce(name, skipna=skipna, **kwds)
else:
# dispatch to numpy arrays
if numeric_only and not is_numeric_dtype(self.dtype):
kwd_name = "numeric_only"
if name in ["any", "all"]:
kwd_name = "bool_only"
# GH#47500 - change to TypeError to match other methods
raise TypeError(
f"Series.{name} does not allow {kwd_name}={numeric_only} "
"with non-numeric dtypes."
)
with np.errstate(all="ignore"):
return op(delegate, skipna=skipna, **kwds)
def _reindex_indexer(
self,
new_index: Index | None,
indexer: npt.NDArray[np.intp] | None,
copy: bool | None,
) -> Series:
# Note: new_index is None iff indexer is None
# if not None, indexer is np.intp
if indexer is None and (
new_index is None or new_index.names == self.index.names
):
if using_copy_on_write():
return self.copy(deep=copy)
if copy or copy is None:
return self.copy(deep=copy)
return self
new_values = algorithms.take_nd(
self._values, indexer, allow_fill=True, fill_value=None
)
return self._constructor(new_values, index=new_index, copy=False)
def _needs_reindex_multi(self, axes, method, level) -> bool:
"""
Check if we do need a multi reindex; this is for compat with
higher dims.
"""
return False
# error: Cannot determine type of 'align'
NDFrame.align, # type: ignore[has-type]
klass=_shared_doc_kwargs["klass"],
axes_single_arg=_shared_doc_kwargs["axes_single_arg"],
)
def align(
self,
other: Series,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> Series:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[True],
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> None:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[False] = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: bool = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series | None:
...
def rename(
self,
index: Renamer | Hashable | None = None,
*,
axis: Axis | None = None,
copy: bool = True,
inplace: bool = False,
level: Level | None = None,
errors: IgnoreRaise = "ignore",
) -> Series | None:
"""
Alter Series index labels or name.
Function / dict values must be unique (1-to-1). Labels not contained in
a dict / Series will be left as-is. Extra labels listed don't throw an
error.
Alternatively, change ``Series.name`` with a scalar value.
See the :ref:`user guide <basics.rename>` for more.
Parameters
----------
index : scalar, hashable sequence, dict-like or function optional
Functions or dict-like are transformations to apply to
the index.
Scalar or hashable sequence-like will alter the ``Series.name``
attribute.
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
copy : bool, default True
Also copy underlying data.
inplace : bool, default False
Whether to return a new Series. If True the value of copy is ignored.
level : int or level name, default None
In case of MultiIndex, only rename labels in the specified level.
errors : {'ignore', 'raise'}, default 'ignore'
If 'raise', raise `KeyError` when a `dict-like mapper` or
`index` contains labels that are not present in the index being transformed.
If 'ignore', existing keys will be renamed and extra keys will be ignored.
Returns
-------
Series or None
Series with index labels or name altered or None if ``inplace=True``.
See Also
--------
DataFrame.rename : Corresponding DataFrame method.
Series.rename_axis : Set the name of the axis.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.rename("my_name") # scalar, changes Series.name
0 1
1 2
2 3
Name: my_name, dtype: int64
>>> s.rename(lambda x: x ** 2) # function, changes labels
0 1
1 2
4 3
dtype: int64
>>> s.rename({1: 3, 2: 5}) # mapping, changes labels
0 1
3 2
5 3
dtype: int64
"""
if axis is not None:
# Make sure we raise if an invalid 'axis' is passed.
axis = self._get_axis_number(axis)
if callable(index) or is_dict_like(index):
# error: Argument 1 to "_rename" of "NDFrame" has incompatible
# type "Union[Union[Mapping[Any, Hashable], Callable[[Any],
# Hashable]], Hashable, None]"; expected "Union[Mapping[Any,
# Hashable], Callable[[Any], Hashable], None]"
return super()._rename(
index, # type: ignore[arg-type]
copy=copy,
inplace=inplace,
level=level,
errors=errors,
)
else:
return self._set_name(index, inplace=inplace)
"""
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.set_axis(['a', 'b', 'c'], axis=0)
a 1
b 2
c 3
dtype: int64
"""
)
**_shared_doc_kwargs,
extended_summary_sub="",
axis_description_sub="",
see_also_sub="",
)
)
)
# error: Cannot determine type of 'shift'
# ----------------------------------------------------------------------
# Convert to types that support pd.NA
# error: Cannot determine type of 'isna'
# error: Return type "Series" of "isna" incompatible with return type "ndarray
# [Any, dtype[bool_]]" in supertype "IndexOpsMixin"
# error: Cannot determine type of 'isna'
# error: Cannot determine type of 'notna'
# error: Cannot determine type of 'notna'
# ----------------------------------------------------------------------
# Time series-oriented methods
# error: Cannot determine type of 'asfreq'
# error: Cannot determine type of 'resample'
# ----------------------------------------------------------------------
# Add index
# ----------------------------------------------------------------------
# Accessor Methods
# ----------------------------------------------------------------------
# ----------------------------------------------------------------------
# Add plotting methods to Series
# ----------------------------------------------------------------------
# Template-Based Arithmetic/Comparison Methods
Series
The provided code snippet includes necessary dependencies for implementing the `_datetime_to_stata_elapsed_vec` function. Write a Python function `def _datetime_to_stata_elapsed_vec(dates: Series, fmt: str) -> Series` to solve the following problem:
Convert from datetime to SIF. https://www.stata.com/help.cgi?datetime Parameters ---------- dates : Series Series or array containing datetime.datetime or datetime64[ns] to convert to the Stata Internal Format given by fmt fmt : str The format to convert to. Can be, tc, td, tw, tm, tq, th, ty
Here is the function:
def _datetime_to_stata_elapsed_vec(dates: Series, fmt: str) -> Series:
"""
Convert from datetime to SIF. https://www.stata.com/help.cgi?datetime
Parameters
----------
dates : Series
Series or array containing datetime.datetime or datetime64[ns] to
convert to the Stata Internal Format given by fmt
fmt : str
The format to convert to. Can be, tc, td, tw, tm, tq, th, ty
"""
index = dates.index
NS_PER_DAY = 24 * 3600 * 1000 * 1000 * 1000
US_PER_DAY = NS_PER_DAY / 1000
def parse_dates_safe(
dates, delta: bool = False, year: bool = False, days: bool = False
):
d = {}
if is_datetime64_dtype(dates.dtype):
if delta:
time_delta = dates - Timestamp(stata_epoch).as_unit("ns")
d["delta"] = time_delta._values.view(np.int64) // 1000 # microseconds
if days or year:
date_index = DatetimeIndex(dates)
d["year"] = date_index._data.year
d["month"] = date_index._data.month
if days:
days_in_ns = dates.view(np.int64) - to_datetime(
d["year"], format="%Y"
).view(np.int64)
d["days"] = days_in_ns // NS_PER_DAY
elif infer_dtype(dates, skipna=False) == "datetime":
if delta:
delta = dates._values - stata_epoch
def f(x: datetime.timedelta) -> float:
return US_PER_DAY * x.days + 1000000 * x.seconds + x.microseconds
v = np.vectorize(f)
d["delta"] = v(delta)
if year:
year_month = dates.apply(lambda x: 100 * x.year + x.month)
d["year"] = year_month._values // 100
d["month"] = year_month._values - d["year"] * 100
if days:
def g(x: datetime.datetime) -> int:
return (x - datetime.datetime(x.year, 1, 1)).days
v = np.vectorize(g)
d["days"] = v(dates)
else:
raise ValueError(
"Columns containing dates must contain either "
"datetime64, datetime.datetime or null values."
)
return DataFrame(d, index=index)
bad_loc = isna(dates)
index = dates.index
if bad_loc.any():
dates = Series(dates)
if is_datetime64_dtype(dates):
dates[bad_loc] = to_datetime(stata_epoch)
else:
dates[bad_loc] = stata_epoch
if fmt in ["%tc", "tc"]:
d = parse_dates_safe(dates, delta=True)
conv_dates = d.delta / 1000
elif fmt in ["%tC", "tC"]:
warnings.warn(
"Stata Internal Format tC not supported.",
stacklevel=find_stack_level(),
)
conv_dates = dates
elif fmt in ["%td", "td"]:
d = parse_dates_safe(dates, delta=True)
conv_dates = d.delta // US_PER_DAY
elif fmt in ["%tw", "tw"]:
d = parse_dates_safe(dates, year=True, days=True)
conv_dates = 52 * (d.year - stata_epoch.year) + d.days // 7
elif fmt in ["%tm", "tm"]:
d = parse_dates_safe(dates, year=True)
conv_dates = 12 * (d.year - stata_epoch.year) + d.month - 1
elif fmt in ["%tq", "tq"]:
d = parse_dates_safe(dates, year=True)
conv_dates = 4 * (d.year - stata_epoch.year) + (d.month - 1) // 3
elif fmt in ["%th", "th"]:
d = parse_dates_safe(dates, year=True)
conv_dates = 2 * (d.year - stata_epoch.year) + (d.month > 6).astype(int)
elif fmt in ["%ty", "ty"]:
d = parse_dates_safe(dates, year=True)
conv_dates = d.year
else:
raise ValueError(f"Format {fmt} is not a known Stata date format")
conv_dates = Series(conv_dates, dtype=np.float64)
missing_value = struct.unpack("<d", b"\x00\x00\x00\x00\x00\x00\xe0\x7f")[0]
conv_dates[bad_loc] = missing_value
return Series(conv_dates, index=index) | Convert from datetime to SIF. https://www.stata.com/help.cgi?datetime Parameters ---------- dates : Series Series or array containing datetime.datetime or datetime64[ns] to convert to the Stata Internal Format given by fmt fmt : str The format to convert to. Can be, tc, td, tw, tm, tq, th, ty |
173,534 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
precision_loss_doc: Final = """
Column converted from {0} to {1}, and some data are outside of the lossless
conversion range. This may result in a loss of precision in the saved data.
"""
class StataMissingValue:
"""
An observation's missing value.
Parameters
----------
value : {int, float}
The Stata missing value code
Notes
-----
More information: <https://www.stata.com/help.cgi?missing>
Integer missing values make the code '.', '.a', ..., '.z' to the ranges
101 ... 127 (for int8), 32741 ... 32767 (for int16) and 2147483621 ...
2147483647 (for int32). Missing values for floating point data types are
more complex but the pattern is simple to discern from the following table.
np.float32 missing values (float in Stata)
0000007f .
0008007f .a
0010007f .b
...
00c0007f .x
00c8007f .y
00d0007f .z
np.float64 missing values (double in Stata)
000000000000e07f .
000000000001e07f .a
000000000002e07f .b
...
000000000018e07f .x
000000000019e07f .y
00000000001ae07f .z
"""
# Construct a dictionary of missing values
MISSING_VALUES: dict[float, str] = {}
bases: Final = (101, 32741, 2147483621)
for b in bases:
# Conversion to long to avoid hash issues on 32 bit platforms #8968
MISSING_VALUES[b] = "."
for i in range(1, 27):
MISSING_VALUES[i + b] = "." + chr(96 + i)
float32_base: bytes = b"\x00\x00\x00\x7f"
increment: int = struct.unpack("<i", b"\x00\x08\x00\x00")[0]
for i in range(27):
key = struct.unpack("<f", float32_base)[0]
MISSING_VALUES[key] = "."
if i > 0:
MISSING_VALUES[key] += chr(96 + i)
int_value = struct.unpack("<i", struct.pack("<f", key))[0] + increment
float32_base = struct.pack("<i", int_value)
float64_base: bytes = b"\x00\x00\x00\x00\x00\x00\xe0\x7f"
increment = struct.unpack("q", b"\x00\x00\x00\x00\x00\x01\x00\x00")[0]
for i in range(27):
key = struct.unpack("<d", float64_base)[0]
MISSING_VALUES[key] = "."
if i > 0:
MISSING_VALUES[key] += chr(96 + i)
int_value = struct.unpack("q", struct.pack("<d", key))[0] + increment
float64_base = struct.pack("q", int_value)
BASE_MISSING_VALUES: Final = {
"int8": 101,
"int16": 32741,
"int32": 2147483621,
"float32": struct.unpack("<f", float32_base)[0],
"float64": struct.unpack("<d", float64_base)[0],
}
def __init__(self, value: float) -> None:
self._value = value
# Conversion to int to avoid hash issues on 32 bit platforms #8968
value = int(value) if value < 2147483648 else float(value)
self._str = self.MISSING_VALUES[value]
def string(self) -> str:
"""
The Stata representation of the missing value: '.', '.a'..'.z'
Returns
-------
str
The representation of the missing value.
"""
return self._str
def value(self) -> float:
"""
The binary representation of the missing value.
Returns
-------
{int, float}
The binary representation of the missing value.
"""
return self._value
def __str__(self) -> str:
return self.string
def __repr__(self) -> str:
return f"{type(self)}({self})"
def __eq__(self, other: Any) -> bool:
return (
isinstance(other, type(self))
and self.string == other.string
and self.value == other.value
)
def get_base_missing_value(cls, dtype: np.dtype) -> float:
if dtype.type is np.int8:
value = cls.BASE_MISSING_VALUES["int8"]
elif dtype.type is np.int16:
value = cls.BASE_MISSING_VALUES["int16"]
elif dtype.type is np.int32:
value = cls.BASE_MISSING_VALUES["int32"]
elif dtype.type is np.float32:
value = cls.BASE_MISSING_VALUES["float32"]
elif dtype.type is np.float64:
value = cls.BASE_MISSING_VALUES["float64"]
else:
raise ValueError("Unsupported dtype")
return value
class PossiblePrecisionLoss(Warning):
"""
Warning raised by to_stata on a column with a value outside or equal to int64.
When the column value is outside or equal to the int64 value the column is
converted to a float64 dtype.
Examples
--------
>>> df = pd.DataFrame({"s": pd.Series([1, 2**53], dtype=np.int64)})
>>> df.to_stata('test') # doctest: +SKIP
... # PossiblePrecisionLoss: Column converted from int64 to float64...
"""
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
class BooleanDtype(BaseMaskedDtype):
"""
Extension dtype for boolean data.
.. warning::
BooleanDtype is considered experimental. The implementation and
parts of the API may change without warning.
Attributes
----------
None
Methods
-------
None
Examples
--------
>>> pd.BooleanDtype()
BooleanDtype
"""
name = "boolean"
# https://github.com/python/mypy/issues/4125
# error: Signature of "type" incompatible with supertype "BaseMaskedDtype"
def type(self) -> type: # type: ignore[override]
return np.bool_
def kind(self) -> str:
return "b"
def numpy_dtype(self) -> np.dtype:
return np.dtype("bool")
def construct_array_type(cls) -> type_t[BooleanArray]:
"""
Return the array type associated with this dtype.
Returns
-------
type
"""
return BooleanArray
def __repr__(self) -> str:
return "BooleanDtype"
def _is_boolean(self) -> bool:
return True
def _is_numeric(self) -> bool:
return True
def __from_arrow__(
self, array: pyarrow.Array | pyarrow.ChunkedArray
) -> BooleanArray:
"""
Construct BooleanArray from pyarrow Array/ChunkedArray.
"""
import pyarrow
if array.type != pyarrow.bool_():
raise TypeError(f"Expected array of boolean type, got {array.type} instead")
if isinstance(array, pyarrow.Array):
chunks = [array]
else:
# pyarrow.ChunkedArray
chunks = array.chunks
results = []
for arr in chunks:
buflist = arr.buffers()
data = pyarrow.BooleanArray.from_buffers(
arr.type, len(arr), [None, buflist[1]], offset=arr.offset
).to_numpy(zero_copy_only=False)
if arr.null_count != 0:
mask = pyarrow.BooleanArray.from_buffers(
arr.type, len(arr), [None, buflist[0]], offset=arr.offset
).to_numpy(zero_copy_only=False)
mask = ~mask
else:
mask = np.zeros(len(arr), dtype=bool)
bool_arr = BooleanArray(data, mask)
results.append(bool_arr)
if not results:
return BooleanArray(
np.array([], dtype=np.bool_), np.array([], dtype=np.bool_)
)
else:
return BooleanArray._concat_same_type(results)
class IntegerDtype(NumericDtype):
"""
An ExtensionDtype to hold a single size & kind of integer dtype.
These specific implementations are subclasses of the non-public
IntegerDtype. For example, we have Int8Dtype to represent signed int 8s.
The attributes name & type are set when these subclasses are created.
"""
_default_np_dtype = np.dtype(np.int64)
_checker = is_integer_dtype
def construct_array_type(cls) -> type[IntegerArray]:
"""
Return the array type associated with this dtype.
Returns
-------
type
"""
return IntegerArray
def _str_to_dtype_mapping(cls):
return INT_STR_TO_DTYPE
def _safe_cast(cls, values: np.ndarray, dtype: np.dtype, copy: bool) -> np.ndarray:
"""
Safely cast the values to the given dtype.
"safe" in this context means the casting is lossless. e.g. if 'values'
has a floating dtype, each value must be an integer.
"""
try:
return values.astype(dtype, casting="safe", copy=copy)
except TypeError as err:
casted = values.astype(dtype, copy=copy)
if (casted == values).all():
return casted
raise TypeError(
f"cannot safely cast non-equivalent {values.dtype} to {np.dtype(dtype)}"
) from err
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
The provided code snippet includes necessary dependencies for implementing the `_cast_to_stata_types` function. Write a Python function `def _cast_to_stata_types(data: DataFrame) -> DataFrame` to solve the following problem:
Checks the dtypes of the columns of a pandas DataFrame for compatibility with the data types and ranges supported by Stata, and converts if necessary. Parameters ---------- data : DataFrame The DataFrame to check and convert Notes ----- Numeric columns in Stata must be one of int8, int16, int32, float32 or float64, with some additional value restrictions. int8 and int16 columns are checked for violations of the value restrictions and upcast if needed. int64 data is not usable in Stata, and so it is downcast to int32 whenever the value are in the int32 range, and sidecast to float64 when larger than this range. If the int64 values are outside of the range of those perfectly representable as float64 values, a warning is raised. bool columns are cast to int8. uint columns are converted to int of the same size if there is no loss in precision, otherwise are upcast to a larger type. uint64 is currently not supported since it is concerted to object in a DataFrame.
Here is the function:
def _cast_to_stata_types(data: DataFrame) -> DataFrame:
"""
Checks the dtypes of the columns of a pandas DataFrame for
compatibility with the data types and ranges supported by Stata, and
converts if necessary.
Parameters
----------
data : DataFrame
The DataFrame to check and convert
Notes
-----
Numeric columns in Stata must be one of int8, int16, int32, float32 or
float64, with some additional value restrictions. int8 and int16 columns
are checked for violations of the value restrictions and upcast if needed.
int64 data is not usable in Stata, and so it is downcast to int32 whenever
the value are in the int32 range, and sidecast to float64 when larger than
this range. If the int64 values are outside of the range of those
perfectly representable as float64 values, a warning is raised.
bool columns are cast to int8. uint columns are converted to int of the
same size if there is no loss in precision, otherwise are upcast to a
larger type. uint64 is currently not supported since it is concerted to
object in a DataFrame.
"""
ws = ""
# original, if small, if large
conversion_data: tuple[
tuple[type, type, type],
tuple[type, type, type],
tuple[type, type, type],
tuple[type, type, type],
tuple[type, type, type],
] = (
(np.bool_, np.int8, np.int8),
(np.uint8, np.int8, np.int16),
(np.uint16, np.int16, np.int32),
(np.uint32, np.int32, np.int64),
(np.uint64, np.int64, np.float64),
)
float32_max = struct.unpack("<f", b"\xff\xff\xff\x7e")[0]
float64_max = struct.unpack("<d", b"\xff\xff\xff\xff\xff\xff\xdf\x7f")[0]
for col in data:
# Cast from unsupported types to supported types
is_nullable_int = isinstance(data[col].dtype, (IntegerDtype, BooleanDtype))
orig = data[col]
# We need to find orig_missing before altering data below
orig_missing = orig.isna()
if is_nullable_int:
missing_loc = data[col].isna()
if missing_loc.any():
# Replace with always safe value
fv = 0 if isinstance(data[col].dtype, IntegerDtype) else False
data.loc[missing_loc, col] = fv
# Replace with NumPy-compatible column
data[col] = data[col].astype(data[col].dtype.numpy_dtype)
dtype = data[col].dtype
for c_data in conversion_data:
if dtype == c_data[0]:
if data[col].max() <= np.iinfo(c_data[1]).max:
dtype = c_data[1]
else:
dtype = c_data[2]
if c_data[2] == np.int64: # Warn if necessary
if data[col].max() >= 2**53:
ws = precision_loss_doc.format("uint64", "float64")
data[col] = data[col].astype(dtype)
# Check values and upcast if necessary
if dtype == np.int8:
if data[col].max() > 100 or data[col].min() < -127:
data[col] = data[col].astype(np.int16)
elif dtype == np.int16:
if data[col].max() > 32740 or data[col].min() < -32767:
data[col] = data[col].astype(np.int32)
elif dtype == np.int64:
if data[col].max() <= 2147483620 and data[col].min() >= -2147483647:
data[col] = data[col].astype(np.int32)
else:
data[col] = data[col].astype(np.float64)
if data[col].max() >= 2**53 or data[col].min() <= -(2**53):
ws = precision_loss_doc.format("int64", "float64")
elif dtype in (np.float32, np.float64):
if np.isinf(data[col]).any():
raise ValueError(
f"Column {col} contains infinity or -infinity"
"which is outside the range supported by Stata."
)
value = data[col].max()
if dtype == np.float32 and value > float32_max:
data[col] = data[col].astype(np.float64)
elif dtype == np.float64:
if value > float64_max:
raise ValueError(
f"Column {col} has a maximum value ({value}) outside the range "
f"supported by Stata ({float64_max})"
)
if is_nullable_int:
if orig_missing.any():
# Replace missing by Stata sentinel value
sentinel = StataMissingValue.BASE_MISSING_VALUES[data[col].dtype.name]
data.loc[orig_missing, col] = sentinel
if ws:
warnings.warn(
ws,
PossiblePrecisionLoss,
stacklevel=find_stack_level(),
)
return data | Checks the dtypes of the columns of a pandas DataFrame for compatibility with the data types and ranges supported by Stata, and converts if necessary. Parameters ---------- data : DataFrame The DataFrame to check and convert Notes ----- Numeric columns in Stata must be one of int8, int16, int32, float32 or float64, with some additional value restrictions. int8 and int16 columns are checked for violations of the value restrictions and upcast if needed. int64 data is not usable in Stata, and so it is downcast to int32 whenever the value are in the int32 range, and sidecast to float64 when larger than this range. If the int64 values are outside of the range of those perfectly representable as float64 values, a warning is raised. bool columns are cast to int8. uint columns are converted to int of the same size if there is no loss in precision, otherwise are upcast to a larger type. uint64 is currently not supported since it is concerted to object in a DataFrame. |
173,535 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
class StataReader(StataParser, abc.Iterator):
__doc__ = _stata_reader_doc
_path_or_buf: IO[bytes] # Will be assigned by `_open_file`.
def __init__(
self,
path_or_buf: FilePath | ReadBuffer[bytes],
convert_dates: bool = True,
convert_categoricals: bool = True,
index_col: str | None = None,
convert_missing: bool = False,
preserve_dtypes: bool = True,
columns: Sequence[str] | None = None,
order_categoricals: bool = True,
chunksize: int | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> None:
super().__init__()
self._col_sizes: list[int] = []
# Arguments to the reader (can be temporarily overridden in
# calls to read).
self._convert_dates = convert_dates
self._convert_categoricals = convert_categoricals
self._index_col = index_col
self._convert_missing = convert_missing
self._preserve_dtypes = preserve_dtypes
self._columns = columns
self._order_categoricals = order_categoricals
self._original_path_or_buf = path_or_buf
self._compression = compression
self._storage_options = storage_options
self._encoding = ""
self._chunksize = chunksize
self._using_iterator = False
self._entered = False
if self._chunksize is None:
self._chunksize = 1
elif not isinstance(chunksize, int) or chunksize <= 0:
raise ValueError("chunksize must be a positive integer when set.")
# State variables for the file
self._close_file: Callable[[], None] | None = None
self._has_string_data = False
self._missing_values = False
self._can_read_value_labels = False
self._column_selector_set = False
self._value_labels_read = False
self._data_read = False
self._dtype: np.dtype | None = None
self._lines_read = 0
self._native_byteorder = _set_endianness(sys.byteorder)
def _ensure_open(self) -> None:
"""
Ensure the file has been opened and its header data read.
"""
if not hasattr(self, "_path_or_buf"):
self._open_file()
def _open_file(self) -> None:
"""
Open the file (with compression options, etc.), and read header information.
"""
if not self._entered:
warnings.warn(
"StataReader is being used without using a context manager. "
"Using StataReader as a context manager is the only supported method.",
ResourceWarning,
stacklevel=find_stack_level(),
)
handles = get_handle(
self._original_path_or_buf,
"rb",
storage_options=self._storage_options,
is_text=False,
compression=self._compression,
)
if hasattr(handles.handle, "seekable") and handles.handle.seekable():
# If the handle is directly seekable, use it without an extra copy.
self._path_or_buf = handles.handle
self._close_file = handles.close
else:
# Copy to memory, and ensure no encoding.
with handles:
self._path_or_buf = BytesIO(handles.handle.read())
self._close_file = self._path_or_buf.close
self._read_header()
self._setup_dtype()
def __enter__(self) -> StataReader:
"""enter context manager"""
self._entered = True
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: TracebackType | None,
) -> None:
if self._close_file:
self._close_file()
def close(self) -> None:
"""Close the handle if its open.
.. deprecated: 2.0.0
The close method is not part of the public API.
The only supported way to use StataReader is to use it as a context manager.
"""
warnings.warn(
"The StataReader.close() method is not part of the public API and "
"will be removed in a future version without notice. "
"Using StataReader as a context manager is the only supported method.",
FutureWarning,
stacklevel=find_stack_level(),
)
if self._close_file:
self._close_file()
def _set_encoding(self) -> None:
"""
Set string encoding which depends on file version
"""
if self._format_version < 118:
self._encoding = "latin-1"
else:
self._encoding = "utf-8"
def _read_int8(self) -> int:
return struct.unpack("b", self._path_or_buf.read(1))[0]
def _read_uint8(self) -> int:
return struct.unpack("B", self._path_or_buf.read(1))[0]
def _read_uint16(self) -> int:
return struct.unpack(f"{self._byteorder}H", self._path_or_buf.read(2))[0]
def _read_uint32(self) -> int:
return struct.unpack(f"{self._byteorder}I", self._path_or_buf.read(4))[0]
def _read_uint64(self) -> int:
return struct.unpack(f"{self._byteorder}Q", self._path_or_buf.read(8))[0]
def _read_int16(self) -> int:
return struct.unpack(f"{self._byteorder}h", self._path_or_buf.read(2))[0]
def _read_int32(self) -> int:
return struct.unpack(f"{self._byteorder}i", self._path_or_buf.read(4))[0]
def _read_int64(self) -> int:
return struct.unpack(f"{self._byteorder}q", self._path_or_buf.read(8))[0]
def _read_char8(self) -> bytes:
return struct.unpack("c", self._path_or_buf.read(1))[0]
def _read_int16_count(self, count: int) -> tuple[int, ...]:
return struct.unpack(
f"{self._byteorder}{'h' * count}",
self._path_or_buf.read(2 * count),
)
def _read_header(self) -> None:
first_char = self._read_char8()
if first_char == b"<":
self._read_new_header()
else:
self._read_old_header(first_char)
self._has_string_data = len([x for x in self._typlist if type(x) is int]) > 0
# calculate size of a data record
self._col_sizes = [self._calcsize(typ) for typ in self._typlist]
def _read_new_header(self) -> None:
# The first part of the header is common to 117 - 119.
self._path_or_buf.read(27) # stata_dta><header><release>
self._format_version = int(self._path_or_buf.read(3))
if self._format_version not in [117, 118, 119]:
raise ValueError(_version_error.format(version=self._format_version))
self._set_encoding()
self._path_or_buf.read(21) # </release><byteorder>
self._byteorder = ">" if self._path_or_buf.read(3) == b"MSF" else "<"
self._path_or_buf.read(15) # </byteorder><K>
self._nvar = (
self._read_uint16() if self._format_version <= 118 else self._read_uint32()
)
self._path_or_buf.read(7) # </K><N>
self._nobs = self._get_nobs()
self._path_or_buf.read(11) # </N><label>
self._data_label = self._get_data_label()
self._path_or_buf.read(19) # </label><timestamp>
self._time_stamp = self._get_time_stamp()
self._path_or_buf.read(26) # </timestamp></header><map>
self._path_or_buf.read(8) # 0x0000000000000000
self._path_or_buf.read(8) # position of <map>
self._seek_vartypes = self._read_int64() + 16
self._seek_varnames = self._read_int64() + 10
self._seek_sortlist = self._read_int64() + 10
self._seek_formats = self._read_int64() + 9
self._seek_value_label_names = self._read_int64() + 19
# Requires version-specific treatment
self._seek_variable_labels = self._get_seek_variable_labels()
self._path_or_buf.read(8) # <characteristics>
self._data_location = self._read_int64() + 6
self._seek_strls = self._read_int64() + 7
self._seek_value_labels = self._read_int64() + 14
self._typlist, self._dtyplist = self._get_dtypes(self._seek_vartypes)
self._path_or_buf.seek(self._seek_varnames)
self._varlist = self._get_varlist()
self._path_or_buf.seek(self._seek_sortlist)
self._srtlist = self._read_int16_count(self._nvar + 1)[:-1]
self._path_or_buf.seek(self._seek_formats)
self._fmtlist = self._get_fmtlist()
self._path_or_buf.seek(self._seek_value_label_names)
self._lbllist = self._get_lbllist()
self._path_or_buf.seek(self._seek_variable_labels)
self._variable_labels = self._get_variable_labels()
# Get data type information, works for versions 117-119.
def _get_dtypes(
self, seek_vartypes: int
) -> tuple[list[int | str], list[str | np.dtype]]:
self._path_or_buf.seek(seek_vartypes)
raw_typlist = [self._read_uint16() for _ in range(self._nvar)]
def f(typ: int) -> int | str:
if typ <= 2045:
return typ
try:
return self.TYPE_MAP_XML[typ]
except KeyError as err:
raise ValueError(f"cannot convert stata types [{typ}]") from err
typlist = [f(x) for x in raw_typlist]
def g(typ: int) -> str | np.dtype:
if typ <= 2045:
return str(typ)
try:
return self.DTYPE_MAP_XML[typ]
except KeyError as err:
raise ValueError(f"cannot convert stata dtype [{typ}]") from err
dtyplist = [g(x) for x in raw_typlist]
return typlist, dtyplist
def _get_varlist(self) -> list[str]:
# 33 in order formats, 129 in formats 118 and 119
b = 33 if self._format_version < 118 else 129
return [self._decode(self._path_or_buf.read(b)) for _ in range(self._nvar)]
# Returns the format list
def _get_fmtlist(self) -> list[str]:
if self._format_version >= 118:
b = 57
elif self._format_version > 113:
b = 49
elif self._format_version > 104:
b = 12
else:
b = 7
return [self._decode(self._path_or_buf.read(b)) for _ in range(self._nvar)]
# Returns the label list
def _get_lbllist(self) -> list[str]:
if self._format_version >= 118:
b = 129
elif self._format_version > 108:
b = 33
else:
b = 9
return [self._decode(self._path_or_buf.read(b)) for _ in range(self._nvar)]
def _get_variable_labels(self) -> list[str]:
if self._format_version >= 118:
vlblist = [
self._decode(self._path_or_buf.read(321)) for _ in range(self._nvar)
]
elif self._format_version > 105:
vlblist = [
self._decode(self._path_or_buf.read(81)) for _ in range(self._nvar)
]
else:
vlblist = [
self._decode(self._path_or_buf.read(32)) for _ in range(self._nvar)
]
return vlblist
def _get_nobs(self) -> int:
if self._format_version >= 118:
return self._read_uint64()
else:
return self._read_uint32()
def _get_data_label(self) -> str:
if self._format_version >= 118:
strlen = self._read_uint16()
return self._decode(self._path_or_buf.read(strlen))
elif self._format_version == 117:
strlen = self._read_int8()
return self._decode(self._path_or_buf.read(strlen))
elif self._format_version > 105:
return self._decode(self._path_or_buf.read(81))
else:
return self._decode(self._path_or_buf.read(32))
def _get_time_stamp(self) -> str:
if self._format_version >= 118:
strlen = self._read_int8()
return self._path_or_buf.read(strlen).decode("utf-8")
elif self._format_version == 117:
strlen = self._read_int8()
return self._decode(self._path_or_buf.read(strlen))
elif self._format_version > 104:
return self._decode(self._path_or_buf.read(18))
else:
raise ValueError()
def _get_seek_variable_labels(self) -> int:
if self._format_version == 117:
self._path_or_buf.read(8) # <variable_labels>, throw away
# Stata 117 data files do not follow the described format. This is
# a work around that uses the previous label, 33 bytes for each
# variable, 20 for the closing tag and 17 for the opening tag
return self._seek_value_label_names + (33 * self._nvar) + 20 + 17
elif self._format_version >= 118:
return self._read_int64() + 17
else:
raise ValueError()
def _read_old_header(self, first_char: bytes) -> None:
self._format_version = int(first_char[0])
if self._format_version not in [104, 105, 108, 111, 113, 114, 115]:
raise ValueError(_version_error.format(version=self._format_version))
self._set_encoding()
self._byteorder = ">" if self._read_int8() == 0x1 else "<"
self._filetype = self._read_int8()
self._path_or_buf.read(1) # unused
self._nvar = self._read_uint16()
self._nobs = self._get_nobs()
self._data_label = self._get_data_label()
self._time_stamp = self._get_time_stamp()
# descriptors
if self._format_version > 108:
typlist = [int(c) for c in self._path_or_buf.read(self._nvar)]
else:
buf = self._path_or_buf.read(self._nvar)
typlistb = np.frombuffer(buf, dtype=np.uint8)
typlist = []
for tp in typlistb:
if tp in self.OLD_TYPE_MAPPING:
typlist.append(self.OLD_TYPE_MAPPING[tp])
else:
typlist.append(tp - 127) # bytes
try:
self._typlist = [self.TYPE_MAP[typ] for typ in typlist]
except ValueError as err:
invalid_types = ",".join([str(x) for x in typlist])
raise ValueError(f"cannot convert stata types [{invalid_types}]") from err
try:
self._dtyplist = [self.DTYPE_MAP[typ] for typ in typlist]
except ValueError as err:
invalid_dtypes = ",".join([str(x) for x in typlist])
raise ValueError(f"cannot convert stata dtypes [{invalid_dtypes}]") from err
if self._format_version > 108:
self._varlist = [
self._decode(self._path_or_buf.read(33)) for _ in range(self._nvar)
]
else:
self._varlist = [
self._decode(self._path_or_buf.read(9)) for _ in range(self._nvar)
]
self._srtlist = self._read_int16_count(self._nvar + 1)[:-1]
self._fmtlist = self._get_fmtlist()
self._lbllist = self._get_lbllist()
self._variable_labels = self._get_variable_labels()
# ignore expansion fields (Format 105 and later)
# When reading, read five bytes; the last four bytes now tell you
# the size of the next read, which you discard. You then continue
# like this until you read 5 bytes of zeros.
if self._format_version > 104:
while True:
data_type = self._read_int8()
if self._format_version > 108:
data_len = self._read_int32()
else:
data_len = self._read_int16()
if data_type == 0:
break
self._path_or_buf.read(data_len)
# necessary data to continue parsing
self._data_location = self._path_or_buf.tell()
def _setup_dtype(self) -> np.dtype:
"""Map between numpy and state dtypes"""
if self._dtype is not None:
return self._dtype
dtypes = [] # Convert struct data types to numpy data type
for i, typ in enumerate(self._typlist):
if typ in self.NUMPY_TYPE_MAP:
typ = cast(str, typ) # only strs in NUMPY_TYPE_MAP
dtypes.append((f"s{i}", f"{self._byteorder}{self.NUMPY_TYPE_MAP[typ]}"))
else:
dtypes.append((f"s{i}", f"S{typ}"))
self._dtype = np.dtype(dtypes)
return self._dtype
def _calcsize(self, fmt: int | str) -> int:
if isinstance(fmt, int):
return fmt
return struct.calcsize(self._byteorder + fmt)
def _decode(self, s: bytes) -> str:
# have bytes not strings, so must decode
s = s.partition(b"\0")[0]
try:
return s.decode(self._encoding)
except UnicodeDecodeError:
# GH 25960, fallback to handle incorrect format produced when 117
# files are converted to 118 files in Stata
encoding = self._encoding
msg = f"""
One or more strings in the dta file could not be decoded using {encoding}, and
so the fallback encoding of latin-1 is being used. This can happen when a file
has been incorrectly encoded by Stata or some other software. You should verify
the string values returned are correct."""
warnings.warn(
msg,
UnicodeWarning,
stacklevel=find_stack_level(),
)
return s.decode("latin-1")
def _read_value_labels(self) -> None:
self._ensure_open()
if self._value_labels_read:
# Don't read twice
return
if self._format_version <= 108:
# Value labels are not supported in version 108 and earlier.
self._value_labels_read = True
self._value_label_dict: dict[str, dict[float, str]] = {}
return
if self._format_version >= 117:
self._path_or_buf.seek(self._seek_value_labels)
else:
assert self._dtype is not None
offset = self._nobs * self._dtype.itemsize
self._path_or_buf.seek(self._data_location + offset)
self._value_labels_read = True
self._value_label_dict = {}
while True:
if self._format_version >= 117:
if self._path_or_buf.read(5) == b"</val": # <lbl>
break # end of value label table
slength = self._path_or_buf.read(4)
if not slength:
break # end of value label table (format < 117)
if self._format_version <= 117:
labname = self._decode(self._path_or_buf.read(33))
else:
labname = self._decode(self._path_or_buf.read(129))
self._path_or_buf.read(3) # padding
n = self._read_uint32()
txtlen = self._read_uint32()
off = np.frombuffer(
self._path_or_buf.read(4 * n), dtype=f"{self._byteorder}i4", count=n
)
val = np.frombuffer(
self._path_or_buf.read(4 * n), dtype=f"{self._byteorder}i4", count=n
)
ii = np.argsort(off)
off = off[ii]
val = val[ii]
txt = self._path_or_buf.read(txtlen)
self._value_label_dict[labname] = {}
for i in range(n):
end = off[i + 1] if i < n - 1 else txtlen
self._value_label_dict[labname][val[i]] = self._decode(
txt[off[i] : end]
)
if self._format_version >= 117:
self._path_or_buf.read(6) # </lbl>
self._value_labels_read = True
def _read_strls(self) -> None:
self._path_or_buf.seek(self._seek_strls)
# Wrap v_o in a string to allow uint64 values as keys on 32bit OS
self.GSO = {"0": ""}
while True:
if self._path_or_buf.read(3) != b"GSO":
break
if self._format_version == 117:
v_o = self._read_uint64()
else:
buf = self._path_or_buf.read(12)
# Only tested on little endian file on little endian machine.
v_size = 2 if self._format_version == 118 else 3
if self._byteorder == "<":
buf = buf[0:v_size] + buf[4 : (12 - v_size)]
else:
# This path may not be correct, impossible to test
buf = buf[0:v_size] + buf[(4 + v_size) :]
v_o = struct.unpack("Q", buf)[0]
typ = self._read_uint8()
length = self._read_uint32()
va = self._path_or_buf.read(length)
if typ == 130:
decoded_va = va[0:-1].decode(self._encoding)
else:
# Stata says typ 129 can be binary, so use str
decoded_va = str(va)
# Wrap v_o in a string to allow uint64 values as keys on 32bit OS
self.GSO[str(v_o)] = decoded_va
def __next__(self) -> DataFrame:
self._using_iterator = True
return self.read(nrows=self._chunksize)
def get_chunk(self, size: int | None = None) -> DataFrame:
"""
Reads lines from Stata file and returns as dataframe
Parameters
----------
size : int, defaults to None
Number of lines to read. If None, reads whole file.
Returns
-------
DataFrame
"""
if size is None:
size = self._chunksize
return self.read(nrows=size)
def read(
self,
nrows: int | None = None,
convert_dates: bool | None = None,
convert_categoricals: bool | None = None,
index_col: str | None = None,
convert_missing: bool | None = None,
preserve_dtypes: bool | None = None,
columns: Sequence[str] | None = None,
order_categoricals: bool | None = None,
) -> DataFrame:
self._ensure_open()
# Handle empty file or chunk. If reading incrementally raise
# StopIteration. If reading the whole thing return an empty
# data frame.
if (self._nobs == 0) and (nrows is None):
self._can_read_value_labels = True
self._data_read = True
return DataFrame(columns=self._varlist)
# Handle options
if convert_dates is None:
convert_dates = self._convert_dates
if convert_categoricals is None:
convert_categoricals = self._convert_categoricals
if convert_missing is None:
convert_missing = self._convert_missing
if preserve_dtypes is None:
preserve_dtypes = self._preserve_dtypes
if columns is None:
columns = self._columns
if order_categoricals is None:
order_categoricals = self._order_categoricals
if index_col is None:
index_col = self._index_col
if nrows is None:
nrows = self._nobs
if (self._format_version >= 117) and (not self._value_labels_read):
self._can_read_value_labels = True
self._read_strls()
# Read data
assert self._dtype is not None
dtype = self._dtype
max_read_len = (self._nobs - self._lines_read) * dtype.itemsize
read_len = nrows * dtype.itemsize
read_len = min(read_len, max_read_len)
if read_len <= 0:
# Iterator has finished, should never be here unless
# we are reading the file incrementally
if convert_categoricals:
self._read_value_labels()
raise StopIteration
offset = self._lines_read * dtype.itemsize
self._path_or_buf.seek(self._data_location + offset)
read_lines = min(nrows, self._nobs - self._lines_read)
raw_data = np.frombuffer(
self._path_or_buf.read(read_len), dtype=dtype, count=read_lines
)
self._lines_read += read_lines
if self._lines_read == self._nobs:
self._can_read_value_labels = True
self._data_read = True
# if necessary, swap the byte order to native here
if self._byteorder != self._native_byteorder:
raw_data = raw_data.byteswap().newbyteorder()
if convert_categoricals:
self._read_value_labels()
if len(raw_data) == 0:
data = DataFrame(columns=self._varlist)
else:
data = DataFrame.from_records(raw_data)
data.columns = Index(self._varlist)
# If index is not specified, use actual row number rather than
# restarting at 0 for each chunk.
if index_col is None:
rng = range(self._lines_read - read_lines, self._lines_read)
data.index = Index(rng) # set attr instead of set_index to avoid copy
if columns is not None:
data = self._do_select_columns(data, columns)
# Decode strings
for col, typ in zip(data, self._typlist):
if type(typ) is int:
data[col] = data[col].apply(self._decode, convert_dtype=True)
data = self._insert_strls(data)
cols_ = np.where([dtyp is not None for dtyp in self._dtyplist])[0]
# Convert columns (if needed) to match input type
ix = data.index
requires_type_conversion = False
data_formatted = []
for i in cols_:
if self._dtyplist[i] is not None:
col = data.columns[i]
dtype = data[col].dtype
if dtype != np.dtype(object) and dtype != self._dtyplist[i]:
requires_type_conversion = True
data_formatted.append(
(col, Series(data[col], ix, self._dtyplist[i]))
)
else:
data_formatted.append((col, data[col]))
if requires_type_conversion:
data = DataFrame.from_dict(dict(data_formatted))
del data_formatted
data = self._do_convert_missing(data, convert_missing)
if convert_dates:
def any_startswith(x: str) -> bool:
return any(x.startswith(fmt) for fmt in _date_formats)
cols = np.where([any_startswith(x) for x in self._fmtlist])[0]
for i in cols:
col = data.columns[i]
data[col] = _stata_elapsed_date_to_datetime_vec(
data[col], self._fmtlist[i]
)
if convert_categoricals and self._format_version > 108:
data = self._do_convert_categoricals(
data, self._value_label_dict, self._lbllist, order_categoricals
)
if not preserve_dtypes:
retyped_data = []
convert = False
for col in data:
dtype = data[col].dtype
if dtype in (np.dtype(np.float16), np.dtype(np.float32)):
dtype = np.dtype(np.float64)
convert = True
elif dtype in (
np.dtype(np.int8),
np.dtype(np.int16),
np.dtype(np.int32),
):
dtype = np.dtype(np.int64)
convert = True
retyped_data.append((col, data[col].astype(dtype)))
if convert:
data = DataFrame.from_dict(dict(retyped_data))
if index_col is not None:
data = data.set_index(data.pop(index_col))
return data
def _do_convert_missing(self, data: DataFrame, convert_missing: bool) -> DataFrame:
# Check for missing values, and replace if found
replacements = {}
for i, colname in enumerate(data):
fmt = self._typlist[i]
if fmt not in self.VALID_RANGE:
continue
fmt = cast(str, fmt) # only strs in VALID_RANGE
nmin, nmax = self.VALID_RANGE[fmt]
series = data[colname]
# appreciably faster to do this with ndarray instead of Series
svals = series._values
missing = (svals < nmin) | (svals > nmax)
if not missing.any():
continue
if convert_missing: # Replacement follows Stata notation
missing_loc = np.nonzero(np.asarray(missing))[0]
umissing, umissing_loc = np.unique(series[missing], return_inverse=True)
replacement = Series(series, dtype=object)
for j, um in enumerate(umissing):
missing_value = StataMissingValue(um)
loc = missing_loc[umissing_loc == j]
replacement.iloc[loc] = missing_value
else: # All replacements are identical
dtype = series.dtype
if dtype not in (np.float32, np.float64):
dtype = np.float64
replacement = Series(series, dtype=dtype)
if not replacement._values.flags["WRITEABLE"]:
# only relevant for ArrayManager; construction
# path for BlockManager ensures writeability
replacement = replacement.copy()
# Note: operating on ._values is much faster than directly
# TODO: can we fix that?
replacement._values[missing] = np.nan
replacements[colname] = replacement
if replacements:
for col, value in replacements.items():
data[col] = value
return data
def _insert_strls(self, data: DataFrame) -> DataFrame:
if not hasattr(self, "GSO") or len(self.GSO) == 0:
return data
for i, typ in enumerate(self._typlist):
if typ != "Q":
continue
# Wrap v_o in a string to allow uint64 values as keys on 32bit OS
data.iloc[:, i] = [self.GSO[str(k)] for k in data.iloc[:, i]]
return data
def _do_select_columns(self, data: DataFrame, columns: Sequence[str]) -> DataFrame:
if not self._column_selector_set:
column_set = set(columns)
if len(column_set) != len(columns):
raise ValueError("columns contains duplicate entries")
unmatched = column_set.difference(data.columns)
if unmatched:
joined = ", ".join(list(unmatched))
raise ValueError(
"The following columns were not "
f"found in the Stata data set: {joined}"
)
# Copy information for retained columns for later processing
dtyplist = []
typlist = []
fmtlist = []
lbllist = []
for col in columns:
i = data.columns.get_loc(col)
dtyplist.append(self._dtyplist[i])
typlist.append(self._typlist[i])
fmtlist.append(self._fmtlist[i])
lbllist.append(self._lbllist[i])
self._dtyplist = dtyplist
self._typlist = typlist
self._fmtlist = fmtlist
self._lbllist = lbllist
self._column_selector_set = True
return data[columns]
def _do_convert_categoricals(
self,
data: DataFrame,
value_label_dict: dict[str, dict[float, str]],
lbllist: Sequence[str],
order_categoricals: bool,
) -> DataFrame:
"""
Converts categorical columns to Categorical type.
"""
value_labels = list(value_label_dict.keys())
cat_converted_data = []
for col, label in zip(data, lbllist):
if label in value_labels:
# Explicit call with ordered=True
vl = value_label_dict[label]
keys = np.array(list(vl.keys()))
column = data[col]
key_matches = column.isin(keys)
if self._using_iterator and key_matches.all():
initial_categories: np.ndarray | None = keys
# If all categories are in the keys and we are iterating,
# use the same keys for all chunks. If some are missing
# value labels, then we will fall back to the categories
# varying across chunks.
else:
if self._using_iterator:
# warn is using an iterator
warnings.warn(
categorical_conversion_warning,
CategoricalConversionWarning,
stacklevel=find_stack_level(),
)
initial_categories = None
cat_data = Categorical(
column, categories=initial_categories, ordered=order_categoricals
)
if initial_categories is None:
# If None here, then we need to match the cats in the Categorical
categories = []
for category in cat_data.categories:
if category in vl:
categories.append(vl[category])
else:
categories.append(category)
else:
# If all cats are matched, we can use the values
categories = list(vl.values())
try:
# Try to catch duplicate categories
# TODO: if we get a non-copying rename_categories, use that
cat_data = cat_data.rename_categories(categories)
except ValueError as err:
vc = Series(categories, copy=False).value_counts()
repeated_cats = list(vc.index[vc > 1])
repeats = "-" * 80 + "\n" + "\n".join(repeated_cats)
# GH 25772
msg = f"""
Value labels for column {col} are not unique. These cannot be converted to
pandas categoricals.
Either read the file with `convert_categoricals` set to False or use the
low level interface in `StataReader` to separately read the values and the
value_labels.
The repeated labels are:
{repeats}
"""
raise ValueError(msg) from err
# TODO: is the next line needed above in the data(...) method?
cat_series = Series(cat_data, index=data.index, copy=False)
cat_converted_data.append((col, cat_series))
else:
cat_converted_data.append((col, data[col]))
data = DataFrame(dict(cat_converted_data), copy=False)
return data
def data_label(self) -> str:
"""
Return data label of Stata file.
"""
self._ensure_open()
return self._data_label
def time_stamp(self) -> str:
"""
Return time stamp of Stata file.
"""
self._ensure_open()
return self._time_stamp
def variable_labels(self) -> dict[str, str]:
"""
Return a dict associating each variable name with corresponding label.
Returns
-------
dict
"""
self._ensure_open()
return dict(zip(self._varlist, self._variable_labels))
def value_labels(self) -> dict[str, dict[float, str]]:
"""
Return a nested dict associating each variable name to its value and label.
Returns
-------
dict
"""
if not self._value_labels_read:
self._read_value_labels()
return self._value_label_dict
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
CompressionOptions = Optional[
Union[Literal["infer", "gzip", "bz2", "zip", "xz", "zstd", "tar"], CompressionDict]
]
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
def read_stata(
filepath_or_buffer: FilePath | ReadBuffer[bytes],
*,
convert_dates: bool = True,
convert_categoricals: bool = True,
index_col: str | None = None,
convert_missing: bool = False,
preserve_dtypes: bool = True,
columns: Sequence[str] | None = None,
order_categoricals: bool = True,
chunksize: int | None = None,
iterator: bool = False,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> DataFrame | StataReader:
reader = StataReader(
filepath_or_buffer,
convert_dates=convert_dates,
convert_categoricals=convert_categoricals,
index_col=index_col,
convert_missing=convert_missing,
preserve_dtypes=preserve_dtypes,
columns=columns,
order_categoricals=order_categoricals,
chunksize=chunksize,
storage_options=storage_options,
compression=compression,
)
if iterator or chunksize:
return reader
with reader:
return reader.read() | null |
173,536 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
def _set_endianness(endianness: str) -> str:
if endianness.lower() in ["<", "little"]:
return "<"
elif endianness.lower() in [">", "big"]:
return ">"
else: # pragma : no cover
raise ValueError(f"Endianness {endianness} not understood") | null |
173,537 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
AnyStr = TypeVar("AnyStr", str, bytes)
The provided code snippet includes necessary dependencies for implementing the `_pad_bytes` function. Write a Python function `def _pad_bytes(name: AnyStr, length: int) -> AnyStr` to solve the following problem:
Take a char string and pads it with null bytes until it's length chars.
Here is the function:
def _pad_bytes(name: AnyStr, length: int) -> AnyStr:
"""
Take a char string and pads it with null bytes until it's length chars.
"""
if isinstance(name, bytes):
return name + b"\x00" * (length - len(name))
return name + "\x00" * (length - len(name)) | Take a char string and pads it with null bytes until it's length chars. |
173,538 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
The provided code snippet includes necessary dependencies for implementing the `_convert_datetime_to_stata_type` function. Write a Python function `def _convert_datetime_to_stata_type(fmt: str) -> np.dtype` to solve the following problem:
Convert from one of the stata date formats to a type in TYPE_MAP.
Here is the function:
def _convert_datetime_to_stata_type(fmt: str) -> np.dtype:
"""
Convert from one of the stata date formats to a type in TYPE_MAP.
"""
if fmt in [
"tc",
"%tc",
"td",
"%td",
"tw",
"%tw",
"tm",
"%tm",
"tq",
"%tq",
"th",
"%th",
"ty",
"%ty",
]:
return np.dtype(np.float64) # Stata expects doubles for SIFs
else:
raise NotImplementedError(f"Format {fmt} not implemented") | Convert from one of the stata date formats to a type in TYPE_MAP. |
173,539 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
def _maybe_convert_to_int_keys(convert_dates: dict, varlist: list[Hashable]) -> dict:
new_dict = {}
for key in convert_dates:
if not convert_dates[key].startswith("%"): # make sure proper fmts
convert_dates[key] = "%" + convert_dates[key]
if key in varlist:
new_dict.update({varlist.index(key): convert_dates[key]})
else:
if not isinstance(key, int):
raise ValueError("convert_dates key must be a column or an integer")
new_dict.update({key: convert_dates[key]})
return new_dict | null |
173,540 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
ensure_object = algos.ensure_object
class Series(base.IndexOpsMixin, NDFrame): # type: ignore[misc]
"""
One-dimensional ndarray with axis labels (including time series).
Labels need not be unique but must be a hashable type. The object
supports both integer- and label-based indexing and provides a host of
methods for performing operations involving the index. Statistical
methods from ndarray have been overridden to automatically exclude
missing data (currently represented as NaN).
Operations between Series (+, -, /, \\*, \\*\\*) align values based on their
associated index values-- they need not be the same length. The result
index will be the sorted union of the two indexes.
Parameters
----------
data : array-like, Iterable, dict, or scalar value
Contains data stored in Series. If data is a dict, argument order is
maintained.
index : array-like or Index (1d)
Values must be hashable and have the same length as `data`.
Non-unique index values are allowed. Will default to
RangeIndex (0, 1, 2, ..., n) if not provided. If data is dict-like
and index is None, then the keys in the data are used as the index. If the
index is not None, the resulting Series is reindexed with the index values.
dtype : str, numpy.dtype, or ExtensionDtype, optional
Data type for the output Series. If not specified, this will be
inferred from `data`.
See the :ref:`user guide <basics.dtypes>` for more usages.
name : Hashable, default None
The name to give to the Series.
copy : bool, default False
Copy input data. Only affects Series or 1d ndarray input. See examples.
Notes
-----
Please reference the :ref:`User Guide <basics.series>` for more information.
Examples
--------
Constructing Series from a dictionary with an Index specified
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['a', 'b', 'c'])
>>> ser
a 1
b 2
c 3
dtype: int64
The keys of the dictionary match with the Index values, hence the Index
values have no effect.
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['x', 'y', 'z'])
>>> ser
x NaN
y NaN
z NaN
dtype: float64
Note that the Index is first build with the keys from the dictionary.
After this the Series is reindexed with the given Index values, hence we
get all NaN as a result.
Constructing Series from a list with `copy=False`.
>>> r = [1, 2]
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
[1, 2]
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `copy` of
the original data even though `copy=False`, so
the data is unchanged.
Constructing Series from a 1d ndarray with `copy=False`.
>>> r = np.array([1, 2])
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
array([999, 2])
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `view` on
the original data, so
the data is changed as well.
"""
_typ = "series"
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
_name: Hashable
_metadata: list[str] = ["name"]
_internal_names_set = {"index"} | NDFrame._internal_names_set
_accessors = {"dt", "cat", "str", "sparse"}
_hidden_attrs = (
base.IndexOpsMixin._hidden_attrs | NDFrame._hidden_attrs | frozenset([])
)
# Override cache_readonly bc Series is mutable
# error: Incompatible types in assignment (expression has type "property",
# base class "IndexOpsMixin" defined the type as "Callable[[IndexOpsMixin], bool]")
hasnans = property( # type: ignore[assignment]
# error: "Callable[[IndexOpsMixin], bool]" has no attribute "fget"
base.IndexOpsMixin.hasnans.fget, # type: ignore[attr-defined]
doc=base.IndexOpsMixin.hasnans.__doc__,
)
_mgr: SingleManager
div: Callable[[Series, Any], Series]
rdiv: Callable[[Series, Any], Series]
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index=None,
dtype: Dtype | None = None,
name=None,
copy: bool | None = None,
fastpath: bool = False,
) -> None:
if (
isinstance(data, (SingleBlockManager, SingleArrayManager))
and index is None
and dtype is None
and (copy is False or copy is None)
):
if using_copy_on_write():
data = data.copy(deep=False)
# GH#33357 called with just the SingleBlockManager
NDFrame.__init__(self, data)
if fastpath:
# e.g. from _box_col_values, skip validation of name
object.__setattr__(self, "_name", name)
else:
self.name = name
return
if isinstance(data, (ExtensionArray, np.ndarray)):
if copy is not False and using_copy_on_write():
if dtype is None or astype_is_view(data.dtype, pandas_dtype(dtype)):
data = data.copy()
if copy is None:
copy = False
# we are called internally, so short-circuit
if fastpath:
# data is a ndarray, index is defined
if not isinstance(data, (SingleBlockManager, SingleArrayManager)):
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
elif using_copy_on_write() and not copy:
data = data.copy(deep=False)
if copy:
data = data.copy()
# skips validation of the name
object.__setattr__(self, "_name", name)
NDFrame.__init__(self, data)
return
if isinstance(data, SingleBlockManager) and using_copy_on_write() and not copy:
data = data.copy(deep=False)
name = ibase.maybe_extract_name(name, data, type(self))
if index is not None:
index = ensure_index(index)
if dtype is not None:
dtype = self._validate_dtype(dtype)
if data is None:
index = index if index is not None else default_index(0)
if len(index) or dtype is not None:
data = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
data = []
if isinstance(data, MultiIndex):
raise NotImplementedError(
"initializing a Series from a MultiIndex is not supported"
)
refs = None
if isinstance(data, Index):
if dtype is not None:
data = data.astype(dtype, copy=False)
if using_copy_on_write():
refs = data._references
data = data._values
else:
# GH#24096 we need to ensure the index remains immutable
data = data._values.copy()
copy = False
elif isinstance(data, np.ndarray):
if len(data.dtype):
# GH#13296 we are dealing with a compound dtype, which
# should be treated as 2D
raise ValueError(
"Cannot construct a Series from an ndarray with "
"compound dtype. Use DataFrame instead."
)
elif isinstance(data, Series):
if index is None:
index = data.index
data = data._mgr.copy(deep=False)
else:
data = data.reindex(index, copy=copy)
copy = False
data = data._mgr
elif is_dict_like(data):
data, index = self._init_dict(data, index, dtype)
dtype = None
copy = False
elif isinstance(data, (SingleBlockManager, SingleArrayManager)):
if index is None:
index = data.index
elif not data.index.equals(index) or copy:
# GH#19275 SingleBlockManager input should only be called
# internally
raise AssertionError(
"Cannot pass both SingleBlockManager "
"`data` argument and a different "
"`index` argument. `copy` must be False."
)
elif isinstance(data, ExtensionArray):
pass
else:
data = com.maybe_iterable_to_list(data)
if is_list_like(data) and not len(data) and dtype is None:
# GH 29405: Pre-2.0, this defaulted to float.
dtype = np.dtype(object)
if index is None:
if not is_list_like(data):
data = [data]
index = default_index(len(data))
elif is_list_like(data):
com.require_length_match(data, index)
# create/copy the manager
if isinstance(data, (SingleBlockManager, SingleArrayManager)):
if dtype is not None:
data = data.astype(dtype=dtype, errors="ignore", copy=copy)
elif copy:
data = data.copy()
else:
data = sanitize_array(data, index, dtype, copy)
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index, refs=refs)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
NDFrame.__init__(self, data)
self.name = name
self._set_axis(0, index)
def _init_dict(
self, data, index: Index | None = None, dtype: DtypeObj | None = None
):
"""
Derive the "_mgr" and "index" attributes of a new Series from a
dictionary input.
Parameters
----------
data : dict or dict-like
Data used to populate the new Series.
index : Index or None, default None
Index for the new Series: if None, use dict keys.
dtype : np.dtype, ExtensionDtype, or None, default None
The dtype for the new Series: if None, infer from data.
Returns
-------
_data : BlockManager for the new Series
index : index for the new Series
"""
keys: Index | tuple
# Looking for NaN in dict doesn't work ({np.nan : 1}[float('nan')]
# raises KeyError), so we iterate the entire dict, and align
if data:
# GH:34717, issue was using zip to extract key and values from data.
# using generators in effects the performance.
# Below is the new way of extracting the keys and values
keys = tuple(data.keys())
values = list(data.values()) # Generating list of values- faster way
elif index is not None:
# fastpath for Series(data=None). Just use broadcasting a scalar
# instead of reindexing.
if len(index) or dtype is not None:
values = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
values = []
keys = index
else:
keys, values = (), []
# Input is now list-like, so rely on "standard" construction:
s = self._constructor(
values,
index=keys,
dtype=dtype,
)
# Now we just make sure the order is respected, if any
if data and index is not None:
s = s.reindex(index, copy=False)
return s._mgr, s.index
# ----------------------------------------------------------------------
def _constructor(self) -> Callable[..., Series]:
return Series
def _constructor_expanddim(self) -> Callable[..., DataFrame]:
"""
Used when a manipulation result has one higher dimension as the
original, such as Series.to_frame()
"""
from pandas.core.frame import DataFrame
return DataFrame
# types
def _can_hold_na(self) -> bool:
return self._mgr._can_hold_na
# ndarray compatibility
def dtype(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtype
dtype('int64')
"""
return self._mgr.dtype
def dtypes(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtypes
dtype('int64')
"""
# DataFrame compatibility
return self.dtype
def name(self) -> Hashable:
"""
Return the name of the Series.
The name of a Series becomes its index or column name if it is used
to form a DataFrame. It is also used whenever displaying the Series
using the interpreter.
Returns
-------
label (hashable object)
The name of the Series, also the column name if part of a DataFrame.
See Also
--------
Series.rename : Sets the Series name when given a scalar input.
Index.name : Corresponding Index property.
Examples
--------
The Series name can be set initially when calling the constructor.
>>> s = pd.Series([1, 2, 3], dtype=np.int64, name='Numbers')
>>> s
0 1
1 2
2 3
Name: Numbers, dtype: int64
>>> s.name = "Integers"
>>> s
0 1
1 2
2 3
Name: Integers, dtype: int64
The name of a Series within a DataFrame is its column name.
>>> df = pd.DataFrame([[1, 2], [3, 4], [5, 6]],
... columns=["Odd Numbers", "Even Numbers"])
>>> df
Odd Numbers Even Numbers
0 1 2
1 3 4
2 5 6
>>> df["Even Numbers"].name
'Even Numbers'
"""
return self._name
def name(self, value: Hashable) -> None:
validate_all_hashable(value, error_name=f"{type(self).__name__}.name")
object.__setattr__(self, "_name", value)
def values(self):
"""
Return Series as ndarray or ndarray-like depending on the dtype.
.. warning::
We recommend using :attr:`Series.array` or
:meth:`Series.to_numpy`, depending on whether you need
a reference to the underlying data or a NumPy array.
Returns
-------
numpy.ndarray or ndarray-like
See Also
--------
Series.array : Reference to the underlying data.
Series.to_numpy : A NumPy array representing the underlying data.
Examples
--------
>>> pd.Series([1, 2, 3]).values
array([1, 2, 3])
>>> pd.Series(list('aabc')).values
array(['a', 'a', 'b', 'c'], dtype=object)
>>> pd.Series(list('aabc')).astype('category').values
['a', 'a', 'b', 'c']
Categories (3, object): ['a', 'b', 'c']
Timezone aware datetime data is converted to UTC:
>>> pd.Series(pd.date_range('20130101', periods=3,
... tz='US/Eastern')).values
array(['2013-01-01T05:00:00.000000000',
'2013-01-02T05:00:00.000000000',
'2013-01-03T05:00:00.000000000'], dtype='datetime64[ns]')
"""
return self._mgr.external_values()
def _values(self):
"""
Return the internal repr of this data (defined by Block.interval_values).
This are the values as stored in the Block (ndarray or ExtensionArray
depending on the Block class), with datetime64[ns] and timedelta64[ns]
wrapped in ExtensionArrays to match Index._values behavior.
Differs from the public ``.values`` for certain data types, because of
historical backwards compatibility of the public attribute (e.g. period
returns object ndarray and datetimetz a datetime64[ns] ndarray for
``.values`` while it returns an ExtensionArray for ``._values`` in those
cases).
Differs from ``.array`` in that this still returns the numpy array if
the Block is backed by a numpy array (except for datetime64 and
timedelta64 dtypes), while ``.array`` ensures to always return an
ExtensionArray.
Overview:
dtype | values | _values | array |
----------- | ------------- | ------------- | ------------- |
Numeric | ndarray | ndarray | PandasArray |
Category | Categorical | Categorical | Categorical |
dt64[ns] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
dt64[ns tz] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
td64[ns] | ndarray[m8ns] | TimedeltaArray| ndarray[m8ns] |
Period | ndarray[obj] | PeriodArray | PeriodArray |
Nullable | EA | EA | EA |
"""
return self._mgr.internal_values()
def _references(self) -> BlockValuesRefs | None:
if isinstance(self._mgr, SingleArrayManager):
return None
return self._mgr._block.refs
# error: Decorated property not supported
def array(self) -> ExtensionArray:
return self._mgr.array_values()
# ops
def ravel(self, order: str = "C") -> ArrayLike:
"""
Return the flattened underlying data as an ndarray or ExtensionArray.
Returns
-------
numpy.ndarray or ExtensionArray
Flattened data of the Series.
See Also
--------
numpy.ndarray.ravel : Return a flattened array.
"""
arr = self._values.ravel(order=order)
if isinstance(arr, np.ndarray) and using_copy_on_write():
arr.flags.writeable = False
return arr
def __len__(self) -> int:
"""
Return the length of the Series.
"""
return len(self._mgr)
def view(self, dtype: Dtype | None = None) -> Series:
"""
Create a new view of the Series.
This function will return a new Series with a view of the same
underlying values in memory, optionally reinterpreted with a new data
type. The new data type must preserve the same size in bytes as to not
cause index misalignment.
Parameters
----------
dtype : data type
Data type object or one of their string representations.
Returns
-------
Series
A new Series object as a view of the same data in memory.
See Also
--------
numpy.ndarray.view : Equivalent numpy function to create a new view of
the same data in memory.
Notes
-----
Series are instantiated with ``dtype=float64`` by default. While
``numpy.ndarray.view()`` will return a view with the same data type as
the original array, ``Series.view()`` (without specified dtype)
will try using ``float64`` and may fail if the original data type size
in bytes is not the same.
Examples
--------
>>> s = pd.Series([-2, -1, 0, 1, 2], dtype='int8')
>>> s
0 -2
1 -1
2 0
3 1
4 2
dtype: int8
The 8 bit signed integer representation of `-1` is `0b11111111`, but
the same bytes represent 255 if read as an 8 bit unsigned integer:
>>> us = s.view('uint8')
>>> us
0 254
1 255
2 0
3 1
4 2
dtype: uint8
The views share the same underlying values:
>>> us[0] = 128
>>> s
0 -128
1 -1
2 0
3 1
4 2
dtype: int8
"""
# self.array instead of self._values so we piggyback on PandasArray
# implementation
res_values = self.array.view(dtype)
res_ser = self._constructor(res_values, index=self.index, copy=False)
if isinstance(res_ser._mgr, SingleBlockManager) and using_copy_on_write():
blk = res_ser._mgr._block
blk.refs = cast("BlockValuesRefs", self._references)
blk.refs.add_reference(blk) # type: ignore[arg-type]
return res_ser.__finalize__(self, method="view")
# ----------------------------------------------------------------------
# NDArray Compat
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
"""
Return the values as a NumPy array.
Users should not call this directly. Rather, it is invoked by
:func:`numpy.array` and :func:`numpy.asarray`.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to use for the resulting NumPy array. By default,
the dtype is inferred from the data.
Returns
-------
numpy.ndarray
The values in the series converted to a :class:`numpy.ndarray`
with the specified `dtype`.
See Also
--------
array : Create a new array from data.
Series.array : Zero-copy view to the array backing the Series.
Series.to_numpy : Series method for similar behavior.
Examples
--------
>>> ser = pd.Series([1, 2, 3])
>>> np.asarray(ser)
array([1, 2, 3])
For timezone-aware data, the timezones may be retained with
``dtype='object'``
>>> tzser = pd.Series(pd.date_range('2000', periods=2, tz="CET"))
>>> np.asarray(tzser, dtype="object")
array([Timestamp('2000-01-01 00:00:00+0100', tz='CET'),
Timestamp('2000-01-02 00:00:00+0100', tz='CET')],
dtype=object)
Or the values may be localized to UTC and the tzinfo discarded with
``dtype='datetime64[ns]'``
>>> np.asarray(tzser, dtype="datetime64[ns]") # doctest: +ELLIPSIS
array(['1999-12-31T23:00:00.000000000', ...],
dtype='datetime64[ns]')
"""
values = self._values
arr = np.asarray(values, dtype=dtype)
if using_copy_on_write() and astype_is_view(values.dtype, arr.dtype):
arr = arr.view()
arr.flags.writeable = False
return arr
# ----------------------------------------------------------------------
# Unary Methods
# coercion
__float__ = _coerce_method(float)
__int__ = _coerce_method(int)
# ----------------------------------------------------------------------
# indexers
def axes(self) -> list[Index]:
"""
Return a list of the row axis labels.
"""
return [self.index]
# ----------------------------------------------------------------------
# Indexing Methods
def take(self, indices, axis: Axis = 0, **kwargs) -> Series:
nv.validate_take((), kwargs)
indices = ensure_platform_int(indices)
if (
indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_index = self.index.take(indices)
new_values = self._values.take(indices)
result = self._constructor(new_values, index=new_index, fastpath=True)
return result.__finalize__(self, method="take")
def _take_with_is_copy(self, indices, axis: Axis = 0) -> Series:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning). For Series this does the same
as the public take (it never sets `_is_copy`).
See the docstring of `take` for full explanation of the parameters.
"""
return self.take(indices=indices, axis=axis)
def _ixs(self, i: int, axis: AxisInt = 0) -> Any:
"""
Return the i-th value or values in the Series by location.
Parameters
----------
i : int
Returns
-------
scalar (int) or Series (slice, sequence)
"""
return self._values[i]
def _slice(self, slobj: slice | np.ndarray, axis: Axis = 0) -> Series:
# axis kwarg is retained for compat with NDFrame method
# _slice is *always* positional
return self._get_values(slobj)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
if key is Ellipsis:
return self
key_is_scalar = is_scalar(key)
if isinstance(key, (list, tuple)):
key = unpack_1tuple(key)
if is_integer(key) and self.index._should_fallback_to_positional:
return self._values[key]
elif key_is_scalar:
return self._get_value(key)
if is_hashable(key):
# Otherwise index.get_value will raise InvalidIndexError
try:
# For labels that don't resolve as scalars like tuples and frozensets
result = self._get_value(key)
return result
except (KeyError, TypeError, InvalidIndexError):
# InvalidIndexError for e.g. generator
# see test_series_getitem_corner_generator
if isinstance(key, tuple) and isinstance(self.index, MultiIndex):
# We still have the corner case where a tuple is a key
# in the first level of our MultiIndex
return self._get_values_tuple(key)
if is_iterator(key):
key = list(key)
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
return self._get_values(key)
return self._get_with(key)
def _get_with(self, key):
# other: fancy integer or otherwise
if isinstance(key, slice):
# _convert_slice_indexer to determine if this slice is positional
# or label based, and if the latter, convert to positional
slobj = self.index._convert_slice_indexer(key, kind="getitem")
return self._slice(slobj)
elif isinstance(key, ABCDataFrame):
raise TypeError(
"Indexing a Series with DataFrame is not "
"supported, use the appropriate DataFrame column"
)
elif isinstance(key, tuple):
return self._get_values_tuple(key)
elif not is_list_like(key):
# e.g. scalars that aren't recognized by lib.is_scalar, GH#32684
return self.loc[key]
if not isinstance(key, (list, np.ndarray, ExtensionArray, Series, Index)):
key = list(key)
if isinstance(key, Index):
key_type = key.inferred_type
else:
key_type = lib.infer_dtype(key, skipna=False)
# Note: The key_type == "boolean" case should be caught by the
# com.is_bool_indexer check in __getitem__
if key_type == "integer":
# We need to decide whether to treat this as a positional indexer
# (i.e. self.iloc) or label-based (i.e. self.loc)
if not self.index._should_fallback_to_positional:
return self.loc[key]
else:
return self.iloc[key]
# handle the dup indexing case GH#4246
return self.loc[key]
def _get_values_tuple(self, key: tuple):
# mpl hackaround
if com.any_none(*key):
# mpl compat if we look up e.g. ser[:, np.newaxis];
# see tests.series.timeseries.test_mpl_compat_hack
# the asarray is needed to avoid returning a 2D DatetimeArray
result = np.asarray(self._values[key])
disallow_ndim_indexing(result)
return result
if not isinstance(self.index, MultiIndex):
raise KeyError("key of type tuple not found and not a MultiIndex")
# If key is contained, would have returned by now
indexer, new_index = self.index.get_loc_level(key)
new_ser = self._constructor(self._values[indexer], index=new_index, copy=False)
if using_copy_on_write() and isinstance(indexer, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
def _get_values(self, indexer: slice | npt.NDArray[np.bool_]) -> Series:
new_mgr = self._mgr.getitem_mgr(indexer)
return self._constructor(new_mgr).__finalize__(self)
def _get_value(self, label, takeable: bool = False):
"""
Quickly retrieve single value at passed index label.
Parameters
----------
label : object
takeable : interpret the index as indexers, default False
Returns
-------
scalar value
"""
if takeable:
return self._values[label]
# Similar to Index.get_value, but we do not fall back to positional
loc = self.index.get_loc(label)
if is_integer(loc):
return self._values[loc]
if isinstance(self.index, MultiIndex):
mi = self.index
new_values = self._values[loc]
if len(new_values) == 1 and mi.nlevels == 1:
# If more than one level left, we can not return a scalar
return new_values[0]
new_index = mi[loc]
new_index = maybe_droplevels(new_index, label)
new_ser = self._constructor(
new_values, index=new_index, name=self.name, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
else:
return self.iloc[loc]
def __setitem__(self, key, value) -> None:
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
cacher_needs_updating = self._check_is_chained_assignment_possible()
if key is Ellipsis:
key = slice(None)
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
return self._set_values(indexer, value)
try:
self._set_with_engine(key, value)
except KeyError:
# We have a scalar (or for MultiIndex or object-dtype, scalar-like)
# key that is not present in self.index.
if is_integer(key):
if not self.index._should_fallback_to_positional:
# GH#33469
self.loc[key] = value
else:
# positional setter
# can't use _mgr.setitem_inplace yet bc could have *both*
# KeyError and then ValueError, xref GH#45070
self._set_values(key, value)
else:
# GH#12862 adding a new key to the Series
self.loc[key] = value
except (TypeError, ValueError, LossySetitemError):
# The key was OK, but we cannot set the value losslessly
indexer = self.index.get_loc(key)
self._set_values(indexer, value)
except InvalidIndexError as err:
if isinstance(key, tuple) and not isinstance(self.index, MultiIndex):
# cases with MultiIndex don't get here bc they raise KeyError
# e.g. test_basic_getitem_setitem_corner
raise KeyError(
"key of type tuple not found and not a MultiIndex"
) from err
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
if (
is_list_like(value)
and len(value) != len(self)
and not isinstance(value, Series)
and not is_object_dtype(self.dtype)
):
# Series will be reindexed to have matching length inside
# _where call below
# GH#44265
indexer = key.nonzero()[0]
self._set_values(indexer, value)
return
# otherwise with listlike other we interpret series[mask] = other
# as series[mask] = other[mask]
try:
self._where(~key, value, inplace=True)
except InvalidIndexError:
# test_where_dups
self.iloc[key] = value
return
else:
self._set_with(key, value)
if cacher_needs_updating:
self._maybe_update_cacher(inplace=True)
def _set_with_engine(self, key, value) -> None:
loc = self.index.get_loc(key)
# this is equivalent to self._values[key] = value
self._mgr.setitem_inplace(loc, value)
def _set_with(self, key, value) -> None:
# We got here via exception-handling off of InvalidIndexError, so
# key should always be listlike at this point.
assert not isinstance(key, tuple)
if is_iterator(key):
# Without this, the call to infer_dtype will consume the generator
key = list(key)
if not self.index._should_fallback_to_positional:
# Regardless of the key type, we're treating it as labels
self._set_labels(key, value)
else:
# Note: key_type == "boolean" should not occur because that
# should be caught by the is_bool_indexer check in __setitem__
key_type = lib.infer_dtype(key, skipna=False)
if key_type == "integer":
self._set_values(key, value)
else:
self._set_labels(key, value)
def _set_labels(self, key, value) -> None:
key = com.asarray_tuplesafe(key)
indexer: np.ndarray = self.index.get_indexer(key)
mask = indexer == -1
if mask.any():
raise KeyError(f"{key[mask]} not in index")
self._set_values(indexer, value)
def _set_values(self, key, value) -> None:
if isinstance(key, (Index, Series)):
key = key._values
self._mgr = self._mgr.setitem(indexer=key, value=value)
self._maybe_update_cacher()
def _set_value(self, label, value, takeable: bool = False) -> None:
"""
Quickly set single value at passed label.
If label is not contained, a new object is created with the label
placed at the end of the result index.
Parameters
----------
label : object
Partial indexing with MultiIndex not allowed.
value : object
Scalar value.
takeable : interpret the index as indexers, default False
"""
if not takeable:
try:
loc = self.index.get_loc(label)
except KeyError:
# set using a non-recursive method
self.loc[label] = value
return
else:
loc = label
self._set_values(loc, value)
# ----------------------------------------------------------------------
# Lookup Caching
def _is_cached(self) -> bool:
"""Return boolean indicating if self is cached or not."""
return getattr(self, "_cacher", None) is not None
def _get_cacher(self):
"""return my cacher or None"""
cacher = getattr(self, "_cacher", None)
if cacher is not None:
cacher = cacher[1]()
return cacher
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
if hasattr(self, "_cacher"):
del self._cacher
def _set_as_cached(self, item, cacher) -> None:
"""
Set the _cacher attribute on the calling object with a weakref to
cacher.
"""
if using_copy_on_write():
return
self._cacher = (item, weakref.ref(cacher))
def _clear_item_cache(self) -> None:
# no-op for Series
pass
def _check_is_chained_assignment_possible(self) -> bool:
"""
See NDFrame._check_is_chained_assignment_possible.__doc__
"""
if self._is_view and self._is_cached:
ref = self._get_cacher()
if ref is not None and ref._is_mixed_type:
self._check_setitem_copy(t="referent", force=True)
return True
return super()._check_is_chained_assignment_possible()
def _maybe_update_cacher(
self, clear: bool = False, verify_is_copy: bool = True, inplace: bool = False
) -> None:
"""
See NDFrame._maybe_update_cacher.__doc__
"""
# for CoW, we never want to update the parent DataFrame cache
# if the Series changed, but don't keep track of any cacher
if using_copy_on_write():
return
cacher = getattr(self, "_cacher", None)
if cacher is not None:
assert self.ndim == 1
ref: DataFrame = cacher[1]()
# we are trying to reference a dead referent, hence
# a copy
if ref is None:
del self._cacher
elif len(self) == len(ref) and self.name in ref.columns:
# GH#42530 self.name must be in ref.columns
# to ensure column still in dataframe
# otherwise, either self or ref has swapped in new arrays
ref._maybe_cache_changed(cacher[0], self, inplace=inplace)
else:
# GH#33675 we have swapped in a new array, so parent
# reference to self is now invalid
ref._item_cache.pop(cacher[0], None)
super()._maybe_update_cacher(
clear=clear, verify_is_copy=verify_is_copy, inplace=inplace
)
# ----------------------------------------------------------------------
# Unsorted
def _is_mixed_type(self) -> bool:
return False
def repeat(self, repeats: int | Sequence[int], axis: None = None) -> Series:
"""
Repeat elements of a Series.
Returns a new Series where each element of the current Series
is repeated consecutively a given number of times.
Parameters
----------
repeats : int or array of ints
The number of repetitions for each element. This should be a
non-negative integer. Repeating 0 times will return an empty
Series.
axis : None
Unused. Parameter needed for compatibility with DataFrame.
Returns
-------
Series
Newly created Series with repeated elements.
See Also
--------
Index.repeat : Equivalent function for Index.
numpy.repeat : Similar method for :class:`numpy.ndarray`.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c'])
>>> s
0 a
1 b
2 c
dtype: object
>>> s.repeat(2)
0 a
0 a
1 b
1 b
2 c
2 c
dtype: object
>>> s.repeat([1, 2, 3])
0 a
1 b
1 b
2 c
2 c
2 c
dtype: object
"""
nv.validate_repeat((), {"axis": axis})
new_index = self.index.repeat(repeats)
new_values = self._values.repeat(repeats)
return self._constructor(new_values, index=new_index, copy=False).__finalize__(
self, method="repeat"
)
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[False] = ...,
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> DataFrame:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[True],
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> Series:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: bool = ...,
name: Level = ...,
inplace: Literal[True],
allow_duplicates: bool = ...,
) -> None:
...
def reset_index(
self,
level: IndexLabel = None,
*,
drop: bool = False,
name: Level = lib.no_default,
inplace: bool = False,
allow_duplicates: bool = False,
) -> DataFrame | Series | None:
"""
Generate a new DataFrame or Series with the index reset.
This is useful when the index needs to be treated as a column, or
when the index is meaningless and needs to be reset to the default
before another operation.
Parameters
----------
level : int, str, tuple, or list, default optional
For a Series with a MultiIndex, only remove the specified levels
from the index. Removes all levels by default.
drop : bool, default False
Just reset the index, without inserting it as a column in
the new DataFrame.
name : object, optional
The name to use for the column containing the original Series
values. Uses ``self.name`` by default. This argument is ignored
when `drop` is True.
inplace : bool, default False
Modify the Series in place (do not create a new object).
allow_duplicates : bool, default False
Allow duplicate column labels to be created.
.. versionadded:: 1.5.0
Returns
-------
Series or DataFrame or None
When `drop` is False (the default), a DataFrame is returned.
The newly created columns will come first in the DataFrame,
followed by the original Series values.
When `drop` is True, a `Series` is returned.
In either case, if ``inplace=True``, no value is returned.
See Also
--------
DataFrame.reset_index: Analogous function for DataFrame.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4], name='foo',
... index=pd.Index(['a', 'b', 'c', 'd'], name='idx'))
Generate a DataFrame with default index.
>>> s.reset_index()
idx foo
0 a 1
1 b 2
2 c 3
3 d 4
To specify the name of the new column use `name`.
>>> s.reset_index(name='values')
idx values
0 a 1
1 b 2
2 c 3
3 d 4
To generate a new Series with the default set `drop` to True.
>>> s.reset_index(drop=True)
0 1
1 2
2 3
3 4
Name: foo, dtype: int64
The `level` parameter is interesting for Series with a multi-level
index.
>>> arrays = [np.array(['bar', 'bar', 'baz', 'baz']),
... np.array(['one', 'two', 'one', 'two'])]
>>> s2 = pd.Series(
... range(4), name='foo',
... index=pd.MultiIndex.from_arrays(arrays,
... names=['a', 'b']))
To remove a specific level from the Index, use `level`.
>>> s2.reset_index(level='a')
a foo
b
one bar 0
two bar 1
one baz 2
two baz 3
If `level` is not set, all levels are removed from the Index.
>>> s2.reset_index()
a b foo
0 bar one 0
1 bar two 1
2 baz one 2
3 baz two 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if drop:
new_index = default_index(len(self))
if level is not None:
level_list: Sequence[Hashable]
if not isinstance(level, (tuple, list)):
level_list = [level]
else:
level_list = level
level_list = [self.index._get_level_number(lev) for lev in level_list]
if len(level_list) < self.index.nlevels:
new_index = self.index.droplevel(level_list)
if inplace:
self.index = new_index
elif using_copy_on_write():
new_ser = self.copy(deep=False)
new_ser.index = new_index
return new_ser.__finalize__(self, method="reset_index")
else:
return self._constructor(
self._values.copy(), index=new_index, copy=False
).__finalize__(self, method="reset_index")
elif inplace:
raise TypeError(
"Cannot reset_index inplace on a Series to create a DataFrame"
)
else:
if name is lib.no_default:
# For backwards compatibility, keep columns as [0] instead of
# [None] when self.name is None
if self.name is None:
name = 0
else:
name = self.name
df = self.to_frame(name)
return df.reset_index(
level=level, drop=drop, allow_duplicates=allow_duplicates
)
return None
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
"""
Return a string representation for a particular Series.
"""
# pylint: disable=invalid-repr-returned
repr_params = fmt.get_series_repr_params()
return self.to_string(**repr_params)
def to_string(
self,
buf: None = ...,
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> None:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
na_rep: str = "NaN",
float_format: str | None = None,
header: bool = True,
index: bool = True,
length: bool = False,
dtype: bool = False,
name: bool = False,
max_rows: int | None = None,
min_rows: int | None = None,
) -> str | None:
"""
Render a string representation of the Series.
Parameters
----------
buf : StringIO-like, optional
Buffer to write to.
na_rep : str, optional
String representation of NaN to use, default 'NaN'.
float_format : one-parameter function, optional
Formatter function to apply to columns' elements if they are
floats, default None.
header : bool, default True
Add the Series header (index name).
index : bool, optional
Add index (row) labels, default True.
length : bool, default False
Add the Series length.
dtype : bool, default False
Add the Series dtype.
name : bool, default False
Add the Series name if not None.
max_rows : int, optional
Maximum number of rows to show before truncating. If None, show
all.
min_rows : int, optional
The number of rows to display in a truncated repr (when number
of rows is above `max_rows`).
Returns
-------
str or None
String representation of Series if ``buf=None``, otherwise None.
"""
formatter = fmt.SeriesFormatter(
self,
name=name,
length=length,
header=header,
index=index,
dtype=dtype,
na_rep=na_rep,
float_format=float_format,
min_rows=min_rows,
max_rows=max_rows,
)
result = formatter.to_string()
# catch contract violations
if not isinstance(result, str):
raise AssertionError(
"result must be of type str, type "
f"of result is {repr(type(result).__name__)}"
)
if buf is None:
return result
else:
if hasattr(buf, "write"):
buf.write(result)
else:
with open(buf, "w") as f:
f.write(result)
return None
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples=dedent(
"""Examples
--------
>>> s = pd.Series(["elk", "pig", "dog", "quetzal"], name="animal")
>>> print(s.to_markdown())
| | animal |
|---:|:---------|
| 0 | elk |
| 1 | pig |
| 2 | dog |
| 3 | quetzal |
Output markdown with a tabulate option.
>>> print(s.to_markdown(tablefmt="grid"))
+----+----------+
| | animal |
+====+==========+
| 0 | elk |
+----+----------+
| 1 | pig |
+----+----------+
| 2 | dog |
+----+----------+
| 3 | quetzal |
+----+----------+"""
),
)
def to_markdown(
self,
buf: IO[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
"""
Print {klass} in Markdown-friendly format.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
mode : str, optional
Mode in which file is opened, "wt" by default.
index : bool, optional, default True
Add index (row) labels.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
**kwargs
These parameters will be passed to `tabulate \
<https://pypi.org/project/tabulate>`_.
Returns
-------
str
{klass} in Markdown-friendly format.
Notes
-----
Requires the `tabulate <https://pypi.org/project/tabulate>`_ package.
{examples}
"""
return self.to_frame().to_markdown(
buf, mode, index, storage_options=storage_options, **kwargs
)
# ----------------------------------------------------------------------
def items(self) -> Iterable[tuple[Hashable, Any]]:
"""
Lazily iterate over (index, value) tuples.
This method returns an iterable tuple (index, value). This is
convenient if you want to create a lazy iterator.
Returns
-------
iterable
Iterable of tuples containing the (index, value) pairs from a
Series.
See Also
--------
DataFrame.items : Iterate over (column name, Series) pairs.
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series) pairs.
Examples
--------
>>> s = pd.Series(['A', 'B', 'C'])
>>> for index, value in s.items():
... print(f"Index : {index}, Value : {value}")
Index : 0, Value : A
Index : 1, Value : B
Index : 2, Value : C
"""
return zip(iter(self.index), iter(self))
# ----------------------------------------------------------------------
# Misc public methods
def keys(self) -> Index:
"""
Return alias for index.
Returns
-------
Index
Index of the Series.
"""
return self.index
def to_dict(self, into: type[dict] = dict) -> dict:
"""
Convert Series to {label -> value} dict or dict-like object.
Parameters
----------
into : class, default dict
The collections.abc.Mapping subclass to use as the return
object. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
Returns
-------
collections.abc.Mapping
Key-value representation of Series.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.to_dict()
{0: 1, 1: 2, 2: 3, 3: 4}
>>> from collections import OrderedDict, defaultdict
>>> s.to_dict(OrderedDict)
OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
>>> dd = defaultdict(list)
>>> s.to_dict(dd)
defaultdict(<class 'list'>, {0: 1, 1: 2, 2: 3, 3: 4})
"""
# GH16122
into_c = com.standardize_mapping(into)
if is_object_dtype(self) or is_extension_array_dtype(self):
return into_c((k, maybe_box_native(v)) for k, v in self.items())
else:
# Not an object dtype => all types will be the same so let the default
# indexer return native python type
return into_c(self.items())
def to_frame(self, name: Hashable = lib.no_default) -> DataFrame:
"""
Convert Series to DataFrame.
Parameters
----------
name : object, optional
The passed name should substitute for the series name (if it has
one).
Returns
-------
DataFrame
DataFrame representation of Series.
Examples
--------
>>> s = pd.Series(["a", "b", "c"],
... name="vals")
>>> s.to_frame()
vals
0 a
1 b
2 c
"""
columns: Index
if name is lib.no_default:
name = self.name
if name is None:
# default to [0], same as we would get with DataFrame(self)
columns = default_index(1)
else:
columns = Index([name])
else:
columns = Index([name])
mgr = self._mgr.to_2d_mgr(columns)
df = self._constructor_expanddim(mgr)
return df.__finalize__(self, method="to_frame")
def _set_name(self, name, inplace: bool = False) -> Series:
"""
Set the Series name.
Parameters
----------
name : str
inplace : bool
Whether to modify `self` directly or return a copy.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
ser = self if inplace else self.copy()
ser.name = name
return ser
"""
Examples
--------
>>> ser = pd.Series([390., 350., 30., 20.],
... index=['Falcon', 'Falcon', 'Parrot', 'Parrot'], name="Max Speed")
>>> ser
Falcon 390.0
Falcon 350.0
Parrot 30.0
Parrot 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", "b"]).mean()
a 210.0
b 185.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(ser > 100).mean()
Max Speed
False 25.0
True 370.0
Name: Max Speed, dtype: float64
**Grouping by Indexes**
We can groupby different levels of a hierarchical index
using the `level` parameter:
>>> arrays = [['Falcon', 'Falcon', 'Parrot', 'Parrot'],
... ['Captive', 'Wild', 'Captive', 'Wild']]
>>> index = pd.MultiIndex.from_arrays(arrays, names=('Animal', 'Type'))
>>> ser = pd.Series([390., 350., 30., 20.], index=index, name="Max Speed")
>>> ser
Animal Type
Falcon Captive 390.0
Wild 350.0
Parrot Captive 30.0
Wild 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Animal
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level="Type").mean()
Type
Captive 210.0
Wild 185.0
Name: Max Speed, dtype: float64
We can also choose to include `NA` in group keys or not by defining
`dropna` parameter, the default setting is `True`.
>>> ser = pd.Series([1, 2, 3, 3], index=["a", 'a', 'b', np.nan])
>>> ser.groupby(level=0).sum()
a 3
b 3
dtype: int64
>>> ser.groupby(level=0, dropna=False).sum()
a 3
b 3
NaN 3
dtype: int64
>>> arrays = ['Falcon', 'Falcon', 'Parrot', 'Parrot']
>>> ser = pd.Series([390., 350., 30., 20.], index=arrays, name="Max Speed")
>>> ser.groupby(["a", "b", "a", np.nan]).mean()
a 210.0
b 350.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", np.nan], dropna=False).mean()
a 210.0
b 350.0
NaN 20.0
Name: Max Speed, dtype: float64
"""
)
def groupby(
self,
by=None,
axis: Axis = 0,
level: IndexLabel = None,
as_index: bool = True,
sort: bool = True,
group_keys: bool = True,
observed: bool = False,
dropna: bool = True,
) -> SeriesGroupBy:
from pandas.core.groupby.generic import SeriesGroupBy
if level is None and by is None:
raise TypeError("You have to supply one of 'by' and 'level'")
if not as_index:
raise TypeError("as_index=False only valid with DataFrame")
axis = self._get_axis_number(axis)
return SeriesGroupBy(
obj=self,
keys=by,
axis=axis,
level=level,
as_index=as_index,
sort=sort,
group_keys=group_keys,
observed=observed,
dropna=dropna,
)
# ----------------------------------------------------------------------
# Statistics, overridden ndarray methods
# TODO: integrate bottleneck
def count(self):
"""
Return number of non-NA/null observations in the Series.
Returns
-------
int or Series (if level specified)
Number of non-null values in the Series.
See Also
--------
DataFrame.count : Count non-NA cells for each column or row.
Examples
--------
>>> s = pd.Series([0.0, 1.0, np.nan])
>>> s.count()
2
"""
return notna(self._values).sum().astype("int64")
def mode(self, dropna: bool = True) -> Series:
"""
Return the mode(s) of the Series.
The mode is the value that appears most often. There can be multiple modes.
Always returns Series even if only one value is returned.
Parameters
----------
dropna : bool, default True
Don't consider counts of NaN/NaT.
Returns
-------
Series
Modes of the Series in sorted order.
"""
# TODO: Add option for bins like value_counts()
values = self._values
if isinstance(values, np.ndarray):
res_values = algorithms.mode(values, dropna=dropna)
else:
res_values = values._mode(dropna=dropna)
# Ensure index is type stable (should always use int index)
return self._constructor(
res_values, index=range(len(res_values)), name=self.name, copy=False
)
def unique(self) -> ArrayLike: # pylint: disable=useless-parent-delegation
"""
Return unique values of Series object.
Uniques are returned in order of appearance. Hash table-based unique,
therefore does NOT sort.
Returns
-------
ndarray or ExtensionArray
The unique values returned as a NumPy array. See Notes.
See Also
--------
Series.drop_duplicates : Return Series with duplicate values removed.
unique : Top-level unique method for any 1-d array-like object.
Index.unique : Return Index with unique values from an Index object.
Notes
-----
Returns the unique values as a NumPy array. In case of an
extension-array backed Series, a new
:class:`~api.extensions.ExtensionArray` of that type with just
the unique values is returned. This includes
* Categorical
* Period
* Datetime with Timezone
* Datetime without Timezone
* Timedelta
* Interval
* Sparse
* IntegerNA
See Examples section.
Examples
--------
>>> pd.Series([2, 1, 3, 3], name='A').unique()
array([2, 1, 3])
>>> pd.Series([pd.Timestamp('2016-01-01') for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00']
Length: 1, dtype: datetime64[ns]
>>> pd.Series([pd.Timestamp('2016-01-01', tz='US/Eastern')
... for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00-05:00']
Length: 1, dtype: datetime64[ns, US/Eastern]
An Categorical will return categories in the order of
appearance and with the same dtype.
>>> pd.Series(pd.Categorical(list('baabc'))).unique()
['b', 'a', 'c']
Categories (3, object): ['a', 'b', 'c']
>>> pd.Series(pd.Categorical(list('baabc'), categories=list('abc'),
... ordered=True)).unique()
['b', 'a', 'c']
Categories (3, object): ['a' < 'b' < 'c']
"""
return super().unique()
def drop_duplicates(
self,
*,
keep: DropKeep = ...,
inplace: Literal[False] = ...,
ignore_index: bool = ...,
) -> Series:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: Literal[True], ignore_index: bool = ...
) -> None:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: bool = ..., ignore_index: bool = ...
) -> Series | None:
...
def drop_duplicates(
self,
*,
keep: DropKeep = "first",
inplace: bool = False,
ignore_index: bool = False,
) -> Series | None:
"""
Return Series with duplicate values removed.
Parameters
----------
keep : {'first', 'last', ``False``}, default 'first'
Method to handle dropping duplicates:
- 'first' : Drop duplicates except for the first occurrence.
- 'last' : Drop duplicates except for the last occurrence.
- ``False`` : Drop all duplicates.
inplace : bool, default ``False``
If ``True``, performs operation inplace and returns None.
ignore_index : bool, default ``False``
If ``True``, the resulting axis will be labeled 0, 1, …, n - 1.
.. versionadded:: 2.0.0
Returns
-------
Series or None
Series with duplicates dropped or None if ``inplace=True``.
See Also
--------
Index.drop_duplicates : Equivalent method on Index.
DataFrame.drop_duplicates : Equivalent method on DataFrame.
Series.duplicated : Related method on Series, indicating duplicate
Series values.
Series.unique : Return unique values as an array.
Examples
--------
Generate a Series with duplicated entries.
>>> s = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama', 'hippo'],
... name='animal')
>>> s
0 lama
1 cow
2 lama
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
With the 'keep' parameter, the selection behaviour of duplicated values
can be changed. The value 'first' keeps the first occurrence for each
set of duplicated entries. The default value of keep is 'first'.
>>> s.drop_duplicates()
0 lama
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
The value 'last' for parameter 'keep' keeps the last occurrence for
each set of duplicated entries.
>>> s.drop_duplicates(keep='last')
1 cow
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
The value ``False`` for parameter 'keep' discards all sets of
duplicated entries.
>>> s.drop_duplicates(keep=False)
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
"""
inplace = validate_bool_kwarg(inplace, "inplace")
result = super().drop_duplicates(keep=keep)
if ignore_index:
result.index = default_index(len(result))
if inplace:
self._update_inplace(result)
return None
else:
return result
def duplicated(self, keep: DropKeep = "first") -> Series:
"""
Indicate duplicate Series values.
Duplicated values are indicated as ``True`` values in the resulting
Series. Either all duplicates, all except the first or all except the
last occurrence of duplicates can be indicated.
Parameters
----------
keep : {'first', 'last', False}, default 'first'
Method to handle dropping duplicates:
- 'first' : Mark duplicates as ``True`` except for the first
occurrence.
- 'last' : Mark duplicates as ``True`` except for the last
occurrence.
- ``False`` : Mark all duplicates as ``True``.
Returns
-------
Series[bool]
Series indicating whether each value has occurred in the
preceding values.
See Also
--------
Index.duplicated : Equivalent method on pandas.Index.
DataFrame.duplicated : Equivalent method on pandas.DataFrame.
Series.drop_duplicates : Remove duplicate values from Series.
Examples
--------
By default, for each set of duplicated values, the first occurrence is
set on False and all others on True:
>>> animals = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama'])
>>> animals.duplicated()
0 False
1 False
2 True
3 False
4 True
dtype: bool
which is equivalent to
>>> animals.duplicated(keep='first')
0 False
1 False
2 True
3 False
4 True
dtype: bool
By using 'last', the last occurrence of each set of duplicated values
is set on False and all others on True:
>>> animals.duplicated(keep='last')
0 True
1 False
2 True
3 False
4 False
dtype: bool
By setting keep on ``False``, all duplicates are True:
>>> animals.duplicated(keep=False)
0 True
1 False
2 True
3 False
4 True
dtype: bool
"""
res = self._duplicated(keep=keep)
result = self._constructor(res, index=self.index, copy=False)
return result.__finalize__(self, method="duplicated")
def idxmin(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the minimum value.
If multiple values equal the minimum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the minimum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmin : Return indices of the minimum values
along the given axis.
DataFrame.idxmin : Return index of first occurrence of minimum
over requested axis.
Series.idxmax : Return index *label* of the first occurrence
of maximum of values.
Notes
-----
This method is the Series version of ``ndarray.argmin``. This method
returns the label of the minimum, while ``ndarray.argmin`` returns
the position. To get the position, use ``series.values.argmin()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 1],
... index=['A', 'B', 'C', 'D'])
>>> s
A 1.0
B NaN
C 4.0
D 1.0
dtype: float64
>>> s.idxmin()
'A'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmin(skipna=False)
nan
"""
# error: Argument 1 to "argmin" of "IndexOpsMixin" has incompatible type "Union
# [int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmin(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def idxmax(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the maximum value.
If multiple values equal the maximum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the maximum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmax : Return indices of the maximum values
along the given axis.
DataFrame.idxmax : Return index of first occurrence of maximum
over requested axis.
Series.idxmin : Return index *label* of the first occurrence
of minimum of values.
Notes
-----
This method is the Series version of ``ndarray.argmax``. This method
returns the label of the maximum, while ``ndarray.argmax`` returns
the position. To get the position, use ``series.values.argmax()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 3, 4],
... index=['A', 'B', 'C', 'D', 'E'])
>>> s
A 1.0
B NaN
C 4.0
D 3.0
E 4.0
dtype: float64
>>> s.idxmax()
'C'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmax(skipna=False)
nan
"""
# error: Argument 1 to "argmax" of "IndexOpsMixin" has incompatible type
# "Union[int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmax(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def round(self, decimals: int = 0, *args, **kwargs) -> Series:
"""
Round each value in a Series to the given number of decimals.
Parameters
----------
decimals : int, default 0
Number of decimal places to round to. If decimals is negative,
it specifies the number of positions to the left of the decimal point.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Series
Rounded values of the Series.
See Also
--------
numpy.around : Round values of an np.array.
DataFrame.round : Round values of a DataFrame.
Examples
--------
>>> s = pd.Series([0.1, 1.3, 2.7])
>>> s.round()
0 0.0
1 1.0
2 3.0
dtype: float64
"""
nv.validate_round(args, kwargs)
result = self._values.round(decimals)
result = self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="round"
)
return result
def quantile(
self, q: float = ..., interpolation: QuantileInterpolation = ...
) -> float:
...
def quantile(
self,
q: Sequence[float] | AnyArrayLike,
interpolation: QuantileInterpolation = ...,
) -> Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = ...,
interpolation: QuantileInterpolation = ...,
) -> float | Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = 0.5,
interpolation: QuantileInterpolation = "linear",
) -> float | Series:
"""
Return value at the given quantile.
Parameters
----------
q : float or array-like, default 0.5 (50% quantile)
The quantile(s) to compute, which can lie in range: 0 <= q <= 1.
interpolation : {'linear', 'lower', 'higher', 'midpoint', 'nearest'}
This optional parameter specifies the interpolation method to use,
when the desired quantile lies between two data points `i` and `j`:
* linear: `i + (j - i) * fraction`, where `fraction` is the
fractional part of the index surrounded by `i` and `j`.
* lower: `i`.
* higher: `j`.
* nearest: `i` or `j` whichever is nearest.
* midpoint: (`i` + `j`) / 2.
Returns
-------
float or Series
If ``q`` is an array, a Series will be returned where the
index is ``q`` and the values are the quantiles, otherwise
a float will be returned.
See Also
--------
core.window.Rolling.quantile : Calculate the rolling quantile.
numpy.percentile : Returns the q-th percentile(s) of the array elements.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.quantile(.5)
2.5
>>> s.quantile([.25, .5, .75])
0.25 1.75
0.50 2.50
0.75 3.25
dtype: float64
"""
validate_percentile(q)
# We dispatch to DataFrame so that core.internals only has to worry
# about 2D cases.
df = self.to_frame()
result = df.quantile(q=q, interpolation=interpolation, numeric_only=False)
if result.ndim == 2:
result = result.iloc[:, 0]
if is_list_like(q):
result.name = self.name
idx = Index(q, dtype=np.float64)
return self._constructor(result, index=idx, name=self.name)
else:
# scalar
return result.iloc[0]
def corr(
self,
other: Series,
method: CorrelationMethod = "pearson",
min_periods: int | None = None,
) -> float:
"""
Compute correlation with `other` Series, excluding missing values.
The two `Series` objects are not required to be the same length and will be
aligned internally before the correlation function is applied.
Parameters
----------
other : Series
Series with which to compute the correlation.
method : {'pearson', 'kendall', 'spearman'} or callable
Method used to compute correlation:
- pearson : Standard correlation coefficient
- kendall : Kendall Tau correlation coefficient
- spearman : Spearman rank correlation
- callable: Callable with input two 1d ndarrays and returning a float.
.. warning::
Note that the returned matrix from corr will have 1 along the
diagonals and will be symmetric regardless of the callable's
behavior.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
Returns
-------
float
Correlation with other.
See Also
--------
DataFrame.corr : Compute pairwise correlation between columns.
DataFrame.corrwith : Compute pairwise correlation with another
DataFrame or Series.
Notes
-----
Pearson, Kendall and Spearman correlation are currently computed using pairwise complete observations.
* `Pearson correlation coefficient <https://en.wikipedia.org/wiki/Pearson_correlation_coefficient>`_
* `Kendall rank correlation coefficient <https://en.wikipedia.org/wiki/Kendall_rank_correlation_coefficient>`_
* `Spearman's rank correlation coefficient <https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient>`_
Examples
--------
>>> def histogram_intersection(a, b):
... v = np.minimum(a, b).sum().round(decimals=1)
... return v
>>> s1 = pd.Series([.2, .0, .6, .2])
>>> s2 = pd.Series([.3, .6, .0, .1])
>>> s1.corr(s2, method=histogram_intersection)
0.3
""" # noqa:E501
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
if method in ["pearson", "spearman", "kendall"] or callable(method):
return nanops.nancorr(
this.values, other.values, method=method, min_periods=min_periods
)
raise ValueError(
"method must be either 'pearson', "
"'spearman', 'kendall', or a callable, "
f"'{method}' was supplied"
)
def cov(
self,
other: Series,
min_periods: int | None = None,
ddof: int | None = 1,
) -> float:
"""
Compute covariance with Series, excluding missing values.
The two `Series` objects are not required to be the same length and
will be aligned internally before the covariance is calculated.
Parameters
----------
other : Series
Series with which to compute the covariance.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
ddof : int, default 1
Delta degrees of freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.
.. versionadded:: 1.1.0
Returns
-------
float
Covariance between Series and other normalized by N-1
(unbiased estimator).
See Also
--------
DataFrame.cov : Compute pairwise covariance of columns.
Examples
--------
>>> s1 = pd.Series([0.90010907, 0.13484424, 0.62036035])
>>> s2 = pd.Series([0.12528585, 0.26962463, 0.51111198])
>>> s1.cov(s2)
-0.01685762652715874
"""
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
return nanops.nancov(
this.values, other.values, min_periods=min_periods, ddof=ddof
)
klass="Series",
extra_params="",
other_klass="DataFrame",
examples=dedent(
"""
Difference with previous row
>>> s = pd.Series([1, 1, 2, 3, 5, 8])
>>> s.diff()
0 NaN
1 0.0
2 1.0
3 1.0
4 2.0
5 3.0
dtype: float64
Difference with 3rd previous row
>>> s.diff(periods=3)
0 NaN
1 NaN
2 NaN
3 2.0
4 4.0
5 6.0
dtype: float64
Difference with following row
>>> s.diff(periods=-1)
0 0.0
1 -1.0
2 -1.0
3 -2.0
4 -3.0
5 NaN
dtype: float64
Overflow in input dtype
>>> s = pd.Series([1, 0], dtype=np.uint8)
>>> s.diff()
0 NaN
1 255.0
dtype: float64"""
),
)
def diff(self, periods: int = 1) -> Series:
"""
First discrete difference of element.
Calculates the difference of a {klass} element compared with another
element in the {klass} (default is element in previous row).
Parameters
----------
periods : int, default 1
Periods to shift for calculating difference, accepts negative
values.
{extra_params}
Returns
-------
{klass}
First differences of the Series.
See Also
--------
{klass}.pct_change: Percent change over given number of periods.
{klass}.shift: Shift index by desired number of periods with an
optional time freq.
{other_klass}.diff: First discrete difference of object.
Notes
-----
For boolean dtypes, this uses :meth:`operator.xor` rather than
:meth:`operator.sub`.
The result is calculated according to current dtype in {klass},
however dtype of the result is always float64.
Examples
--------
{examples}
"""
result = algorithms.diff(self._values, periods)
return self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="diff"
)
def autocorr(self, lag: int = 1) -> float:
"""
Compute the lag-N autocorrelation.
This method computes the Pearson correlation between
the Series and its shifted self.
Parameters
----------
lag : int, default 1
Number of lags to apply before performing autocorrelation.
Returns
-------
float
The Pearson correlation between self and self.shift(lag).
See Also
--------
Series.corr : Compute the correlation between two Series.
Series.shift : Shift index by desired number of periods.
DataFrame.corr : Compute pairwise correlation of columns.
DataFrame.corrwith : Compute pairwise correlation between rows or
columns of two DataFrame objects.
Notes
-----
If the Pearson correlation is not well defined return 'NaN'.
Examples
--------
>>> s = pd.Series([0.25, 0.5, 0.2, -0.05])
>>> s.autocorr() # doctest: +ELLIPSIS
0.10355...
>>> s.autocorr(lag=2) # doctest: +ELLIPSIS
-0.99999...
If the Pearson correlation is not well defined, then 'NaN' is returned.
>>> s = pd.Series([1, 0, 0, 0])
>>> s.autocorr()
nan
"""
return self.corr(self.shift(lag))
def dot(self, other: AnyArrayLike) -> Series | np.ndarray:
"""
Compute the dot product between the Series and the columns of other.
This method computes the dot product between the Series and another
one, or the Series and each columns of a DataFrame, or the Series and
each columns of an array.
It can also be called using `self @ other` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the dot product with its columns.
Returns
-------
scalar, Series or numpy.ndarray
Return the dot product of the Series and other if other is a
Series, the Series of the dot product of Series and each rows of
other if other is a DataFrame or a numpy.ndarray between the Series
and each columns of the numpy array.
See Also
--------
DataFrame.dot: Compute the matrix product with the DataFrame.
Series.mul: Multiplication of series and other, element-wise.
Notes
-----
The Series and other has to share the same index if other is a Series
or a DataFrame.
Examples
--------
>>> s = pd.Series([0, 1, 2, 3])
>>> other = pd.Series([-1, 2, -3, 4])
>>> s.dot(other)
8
>>> s @ other
8
>>> df = pd.DataFrame([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(df)
0 24
1 14
dtype: int64
>>> arr = np.array([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(arr)
array([24, 14])
"""
if isinstance(other, (Series, ABCDataFrame)):
common = self.index.union(other.index)
if len(common) > len(self.index) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(index=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right.values
else:
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[0] != rvals.shape[0]:
raise Exception(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, ABCDataFrame):
return self._constructor(
np.dot(lvals, rvals), index=other.columns, copy=False
).__finalize__(self, method="dot")
elif isinstance(other, Series):
return np.dot(lvals, rvals)
elif isinstance(rvals, np.ndarray):
return np.dot(lvals, rvals)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(np.transpose(other))
# Signature of "searchsorted" incompatible with supertype "IndexOpsMixin"
def searchsorted( # type: ignore[override]
self,
value: NumpyValueArrayLike | ExtensionArray,
side: Literal["left", "right"] = "left",
sorter: NumpySorter = None,
) -> npt.NDArray[np.intp] | np.intp:
return base.IndexOpsMixin.searchsorted(self, value, side=side, sorter=sorter)
# -------------------------------------------------------------------
# Combination
def _append(
self, to_append, ignore_index: bool = False, verify_integrity: bool = False
):
from pandas.core.reshape.concat import concat
if isinstance(to_append, (list, tuple)):
to_concat = [self]
to_concat.extend(to_append)
else:
to_concat = [self, to_append]
if any(isinstance(x, (ABCDataFrame,)) for x in to_concat[1:]):
msg = "to_append should be a Series or list/tuple of Series, got DataFrame"
raise TypeError(msg)
return concat(
to_concat, ignore_index=ignore_index, verify_integrity=verify_integrity
)
def _binop(self, other: Series, func, level=None, fill_value=None):
"""
Perform generic binary operation with optional fill value.
Parameters
----------
other : Series
func : binary operator
fill_value : float or object
Value to substitute for NA/null values. If both Series are NA in a
location, the result will be NA regardless of the passed fill value.
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
Returns
-------
Series
"""
if not isinstance(other, Series):
raise AssertionError("Other operand must be Series")
this = self
if not self.index.equals(other.index):
this, other = self.align(other, level=level, join="outer", copy=False)
this_vals, other_vals = ops.fill_binop(this._values, other._values, fill_value)
with np.errstate(all="ignore"):
result = func(this_vals, other_vals)
name = ops.get_op_result_name(self, other)
return this._construct_result(result, name)
def _construct_result(
self, result: ArrayLike | tuple[ArrayLike, ArrayLike], name: Hashable
) -> Series | tuple[Series, Series]:
"""
Construct an appropriately-labelled Series from the result of an op.
Parameters
----------
result : ndarray or ExtensionArray
name : Label
Returns
-------
Series
In the case of __divmod__ or __rdivmod__, a 2-tuple of Series.
"""
if isinstance(result, tuple):
# produced by divmod or rdivmod
res1 = self._construct_result(result[0], name=name)
res2 = self._construct_result(result[1], name=name)
# GH#33427 assertions to keep mypy happy
assert isinstance(res1, Series)
assert isinstance(res2, Series)
return (res1, res2)
# TODO: result should always be ArrayLike, but this fails for some
# JSONArray tests
dtype = getattr(result, "dtype", None)
out = self._constructor(result, index=self.index, dtype=dtype)
out = out.__finalize__(self)
# Set the result's name after __finalize__ is called because __finalize__
# would set it back to self.name
out.name = name
return out
_shared_docs["compare"],
"""
Returns
-------
Series or DataFrame
If axis is 0 or 'index' the result will be a Series.
The resulting index will be a MultiIndex with 'self' and 'other'
stacked alternately at the inner level.
If axis is 1 or 'columns' the result will be a DataFrame.
It will have two columns namely 'self' and 'other'.
See Also
--------
DataFrame.compare : Compare with another DataFrame and show differences.
Notes
-----
Matching NaNs will not appear as a difference.
Examples
--------
>>> s1 = pd.Series(["a", "b", "c", "d", "e"])
>>> s2 = pd.Series(["a", "a", "c", "b", "e"])
Align the differences on columns
>>> s1.compare(s2)
self other
1 b a
3 d b
Stack the differences on indices
>>> s1.compare(s2, align_axis=0)
1 self b
other a
3 self d
other b
dtype: object
Keep all original rows
>>> s1.compare(s2, keep_shape=True)
self other
0 NaN NaN
1 b a
2 NaN NaN
3 d b
4 NaN NaN
Keep all original rows and also all original values
>>> s1.compare(s2, keep_shape=True, keep_equal=True)
self other
0 a a
1 b a
2 c c
3 d b
4 e e
""",
klass=_shared_doc_kwargs["klass"],
)
def compare(
self,
other: Series,
align_axis: Axis = 1,
keep_shape: bool = False,
keep_equal: bool = False,
result_names: Suffixes = ("self", "other"),
) -> DataFrame | Series:
return super().compare(
other=other,
align_axis=align_axis,
keep_shape=keep_shape,
keep_equal=keep_equal,
result_names=result_names,
)
def combine(
self,
other: Series | Hashable,
func: Callable[[Hashable, Hashable], Hashable],
fill_value: Hashable = None,
) -> Series:
"""
Combine the Series with a Series or scalar according to `func`.
Combine the Series and `other` using `func` to perform elementwise
selection for combined Series.
`fill_value` is assumed when value is missing at some index
from one of the two objects being combined.
Parameters
----------
other : Series or scalar
The value(s) to be combined with the `Series`.
func : function
Function that takes two scalars as inputs and returns an element.
fill_value : scalar, optional
The value to assume when an index is missing from
one Series or the other. The default specifies to use the
appropriate NaN value for the underlying dtype of the Series.
Returns
-------
Series
The result of combining the Series with the other object.
See Also
--------
Series.combine_first : Combine Series values, choosing the calling
Series' values first.
Examples
--------
Consider 2 Datasets ``s1`` and ``s2`` containing
highest clocked speeds of different birds.
>>> s1 = pd.Series({'falcon': 330.0, 'eagle': 160.0})
>>> s1
falcon 330.0
eagle 160.0
dtype: float64
>>> s2 = pd.Series({'falcon': 345.0, 'eagle': 200.0, 'duck': 30.0})
>>> s2
falcon 345.0
eagle 200.0
duck 30.0
dtype: float64
Now, to combine the two datasets and view the highest speeds
of the birds across the two datasets
>>> s1.combine(s2, max)
duck NaN
eagle 200.0
falcon 345.0
dtype: float64
In the previous example, the resulting value for duck is missing,
because the maximum of a NaN and a float is a NaN.
So, in the example, we set ``fill_value=0``,
so the maximum value returned will be the value from some dataset.
>>> s1.combine(s2, max, fill_value=0)
duck 30.0
eagle 200.0
falcon 345.0
dtype: float64
"""
if fill_value is None:
fill_value = na_value_for_dtype(self.dtype, compat=False)
if isinstance(other, Series):
# If other is a Series, result is based on union of Series,
# so do this element by element
new_index = self.index.union(other.index)
new_name = ops.get_op_result_name(self, other)
new_values = np.empty(len(new_index), dtype=object)
for i, idx in enumerate(new_index):
lv = self.get(idx, fill_value)
rv = other.get(idx, fill_value)
with np.errstate(all="ignore"):
new_values[i] = func(lv, rv)
else:
# Assume that other is a scalar, so apply the function for
# each element in the Series
new_index = self.index
new_values = np.empty(len(new_index), dtype=object)
with np.errstate(all="ignore"):
new_values[:] = [func(lv, other) for lv in self._values]
new_name = self.name
# try_float=False is to match agg_series
npvalues = lib.maybe_convert_objects(new_values, try_float=False)
res_values = maybe_cast_pointwise_result(npvalues, self.dtype, same_dtype=False)
return self._constructor(res_values, index=new_index, name=new_name, copy=False)
def combine_first(self, other) -> Series:
"""
Update null elements with value in the same location in 'other'.
Combine two Series objects by filling null values in one Series with
non-null values from the other Series. Result index will be the union
of the two indexes.
Parameters
----------
other : Series
The value(s) to be used for filling null values.
Returns
-------
Series
The result of combining the provided Series with the other object.
See Also
--------
Series.combine : Perform element-wise operation on two Series
using a given function.
Examples
--------
>>> s1 = pd.Series([1, np.nan])
>>> s2 = pd.Series([3, 4, 5])
>>> s1.combine_first(s2)
0 1.0
1 4.0
2 5.0
dtype: float64
Null values still persist if the location of that null value
does not exist in `other`
>>> s1 = pd.Series({'falcon': np.nan, 'eagle': 160.0})
>>> s2 = pd.Series({'eagle': 200.0, 'duck': 30.0})
>>> s1.combine_first(s2)
duck 30.0
eagle 160.0
falcon NaN
dtype: float64
"""
new_index = self.index.union(other.index)
this = self.reindex(new_index, copy=False)
other = other.reindex(new_index, copy=False)
if this.dtype.kind == "M" and other.dtype.kind != "M":
other = to_datetime(other)
return this.where(notna(this), other)
def update(self, other: Series | Sequence | Mapping) -> None:
"""
Modify Series in place using values from passed Series.
Uses non-NA values from passed Series to make updates. Aligns
on index.
Parameters
----------
other : Series, or object coercible into Series
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6]))
>>> s
0 4
1 5
2 6
dtype: int64
>>> s = pd.Series(['a', 'b', 'c'])
>>> s.update(pd.Series(['d', 'e'], index=[0, 2]))
>>> s
0 d
1 b
2 e
dtype: object
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6, 7, 8]))
>>> s
0 4
1 5
2 6
dtype: int64
If ``other`` contains NaNs the corresponding values are not updated
in the original Series.
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, np.nan, 6]))
>>> s
0 4
1 2
2 6
dtype: int64
``other`` can also be a non-Series object type
that is coercible into a Series
>>> s = pd.Series([1, 2, 3])
>>> s.update([4, np.nan, 6])
>>> s
0 4
1 2
2 6
dtype: int64
>>> s = pd.Series([1, 2, 3])
>>> s.update({1: 9})
>>> s
0 1
1 9
2 3
dtype: int64
"""
if not isinstance(other, Series):
other = Series(other)
other = other.reindex_like(self)
mask = notna(other)
self._mgr = self._mgr.putmask(mask=mask, new=other)
self._maybe_update_cacher()
# ----------------------------------------------------------------------
# Reindexing, sorting
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> Series:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self,
*,
axis: Axis = 0,
ascending: bool | int | Sequence[bool] | Sequence[int] = True,
inplace: bool = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool = False,
key: ValueKeyFunc = None,
) -> Series | None:
"""
Sort by the values.
Sort a Series in ascending or descending order by some
criterion.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
ascending : bool or list of bools, default True
If True, sort values in ascending order, otherwise descending.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
na_position : {'first' or 'last'}, default 'last'
Argument 'first' puts NaNs at the beginning, 'last' puts NaNs at
the end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the series values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return an array-like.
.. versionadded:: 1.1.0
Returns
-------
Series or None
Series ordered by values or None if ``inplace=True``.
See Also
--------
Series.sort_index : Sort by the Series indices.
DataFrame.sort_values : Sort DataFrame by the values along either axis.
DataFrame.sort_index : Sort DataFrame by indices.
Examples
--------
>>> s = pd.Series([np.nan, 1, 3, 10, 5])
>>> s
0 NaN
1 1.0
2 3.0
3 10.0
4 5.0
dtype: float64
Sort values ascending order (default behaviour)
>>> s.sort_values(ascending=True)
1 1.0
2 3.0
4 5.0
3 10.0
0 NaN
dtype: float64
Sort values descending order
>>> s.sort_values(ascending=False)
3 10.0
4 5.0
2 3.0
1 1.0
0 NaN
dtype: float64
Sort values putting NAs first
>>> s.sort_values(na_position='first')
0 NaN
1 1.0
2 3.0
4 5.0
3 10.0
dtype: float64
Sort a series of strings
>>> s = pd.Series(['z', 'b', 'd', 'a', 'c'])
>>> s
0 z
1 b
2 d
3 a
4 c
dtype: object
>>> s.sort_values()
3 a
1 b
4 c
2 d
0 z
dtype: object
Sort using a key function. Your `key` function will be
given the ``Series`` of values and should return an array-like.
>>> s = pd.Series(['a', 'B', 'c', 'D', 'e'])
>>> s.sort_values()
1 B
3 D
0 a
2 c
4 e
dtype: object
>>> s.sort_values(key=lambda x: x.str.lower())
0 a
1 B
2 c
3 D
4 e
dtype: object
NumPy ufuncs work well here. For example, we can
sort by the ``sin`` of the value
>>> s = pd.Series([-4, -2, 0, 2, 4])
>>> s.sort_values(key=np.sin)
1 -2
4 4
2 0
0 -4
3 2
dtype: int64
More complicated user-defined functions can be used,
as long as they expect a Series and return an array-like
>>> s.sort_values(key=lambda x: (np.tan(x.cumsum())))
0 -4
3 2
4 4
1 -2
2 0
dtype: int64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
# Validate the axis parameter
self._get_axis_number(axis)
# GH 5856/5853
if inplace and self._is_cached:
raise ValueError(
"This Series is a view of some other array, to "
"sort in-place you must create a copy"
)
if is_list_like(ascending):
ascending = cast(Sequence[Union[bool, int]], ascending)
if len(ascending) != 1:
raise ValueError(
f"Length of ascending ({len(ascending)}) must be 1 for Series"
)
ascending = ascending[0]
ascending = validate_ascending(ascending)
if na_position not in ["first", "last"]:
raise ValueError(f"invalid na_position: {na_position}")
# GH 35922. Make sorting stable by leveraging nargsort
values_to_sort = ensure_key_mapped(self, key)._values if key else self._values
sorted_index = nargsort(values_to_sort, kind, bool(ascending), na_position)
if is_range_indexer(sorted_index, len(sorted_index)):
if inplace:
return self._update_inplace(self)
return self.copy(deep=None)
result = self._constructor(
self._values[sorted_index], index=self.index[sorted_index], copy=False
)
if ignore_index:
result.index = default_index(len(sorted_index))
if not inplace:
return result.__finalize__(self, method="sort_values")
self._update_inplace(result)
return None
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: bool = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series | None:
...
def sort_index(
self,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool | Sequence[bool] = True,
inplace: bool = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool = True,
ignore_index: bool = False,
key: IndexKeyFunc = None,
) -> Series | None:
"""
Sort Series by index labels.
Returns a new Series sorted by label if `inplace` argument is
``False``, otherwise updates the original series and returns None.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
level : int, optional
If not None, sort on values in specified index level(s).
ascending : bool or list-like of bools, default True
Sort ascending vs. descending. When the index is a MultiIndex the
sort direction can be controlled for each level individually.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
If 'first' puts NaNs at the beginning, 'last' puts NaNs at the end.
Not implemented for MultiIndex.
sort_remaining : bool, default True
If True and sorting by level and index is multilevel, sort by other
levels too (in order) after sorting by specified level.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the index values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect an
``Index`` and return an ``Index`` of the same shape.
.. versionadded:: 1.1.0
Returns
-------
Series or None
The original Series sorted by the labels or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index: Sort DataFrame by the index.
DataFrame.sort_values: Sort DataFrame by the value.
Series.sort_values : Sort Series by the value.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, 4])
>>> s.sort_index()
1 c
2 b
3 a
4 d
dtype: object
Sort Descending
>>> s.sort_index(ascending=False)
4 d
3 a
2 b
1 c
dtype: object
By default NaNs are put at the end, but use `na_position` to place
them at the beginning
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, np.nan])
>>> s.sort_index(na_position='first')
NaN d
1.0 c
2.0 b
3.0 a
dtype: object
Specify index level to sort
>>> arrays = [np.array(['qux', 'qux', 'foo', 'foo',
... 'baz', 'baz', 'bar', 'bar']),
... np.array(['two', 'one', 'two', 'one',
... 'two', 'one', 'two', 'one'])]
>>> s = pd.Series([1, 2, 3, 4, 5, 6, 7, 8], index=arrays)
>>> s.sort_index(level=1)
bar one 8
baz one 6
foo one 4
qux one 2
bar two 7
baz two 5
foo two 3
qux two 1
dtype: int64
Does not sort by remaining levels when sorting by levels
>>> s.sort_index(level=1, sort_remaining=False)
qux one 2
foo one 4
baz one 6
bar one 8
qux two 1
foo two 3
baz two 5
bar two 7
dtype: int64
Apply a key function before sorting
>>> s = pd.Series([1, 2, 3, 4], index=['A', 'b', 'C', 'd'])
>>> s.sort_index(key=lambda x : x.str.lower())
A 1
b 2
C 3
d 4
dtype: int64
"""
return super().sort_index(
axis=axis,
level=level,
ascending=ascending,
inplace=inplace,
kind=kind,
na_position=na_position,
sort_remaining=sort_remaining,
ignore_index=ignore_index,
key=key,
)
def argsort(
self,
axis: Axis = 0,
kind: SortKind = "quicksort",
order: None = None,
) -> Series:
"""
Return the integer indices that would sort the Series values.
Override ndarray.argsort. Argsorts the value, omitting NA/null values,
and places the result in the same locations as the non-NA values.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
kind : {'mergesort', 'quicksort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
order : None
Has no effect but is accepted for compatibility with numpy.
Returns
-------
Series[np.intp]
Positions of values within the sort order with -1 indicating
nan values.
See Also
--------
numpy.ndarray.argsort : Returns the indices that would sort this array.
"""
values = self._values
mask = isna(values)
if mask.any():
result = np.full(len(self), -1, dtype=np.intp)
notmask = ~mask
result[notmask] = np.argsort(values[notmask], kind=kind)
else:
result = np.argsort(values, kind=kind)
res = self._constructor(
result, index=self.index, name=self.name, dtype=np.intp, copy=False
)
return res.__finalize__(self, method="argsort")
def nlargest(
self, n: int = 5, keep: Literal["first", "last", "all"] = "first"
) -> Series:
"""
Return the largest `n` elements.
Parameters
----------
n : int, default 5
Return this many descending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` largest values in the Series, sorted in decreasing order.
See Also
--------
Series.nsmallest: Get the `n` smallest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values(ascending=False).head(n)`` for small `n`
relative to the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Malta": 434000, "Maldives": 434000,
... "Brunei": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Malta 434000
Maldives 434000
Brunei 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` largest elements where ``n=5`` by default.
>>> s.nlargest()
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3``. Default `keep` value is 'first'
so Malta will be kept.
>>> s.nlargest(3)
France 65000000
Italy 59000000
Malta 434000
dtype: int64
The `n` largest elements where ``n=3`` and keeping the last duplicates.
Brunei will be kept since it is the last with value 434000 based on
the index order.
>>> s.nlargest(3, keep='last')
France 65000000
Italy 59000000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has five elements due to the three duplicates.
>>> s.nlargest(3, keep='all')
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nlargest()
def nsmallest(self, n: int = 5, keep: str = "first") -> Series:
"""
Return the smallest `n` elements.
Parameters
----------
n : int, default 5
Return this many ascending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` smallest values in the Series, sorted in increasing order.
See Also
--------
Series.nlargest: Get the `n` largest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values().head(n)`` for small `n` relative to
the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Brunei": 434000, "Malta": 434000,
... "Maldives": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Brunei 434000
Malta 434000
Maldives 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` smallest elements where ``n=5`` by default.
>>> s.nsmallest()
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
Iceland 337000
dtype: int64
The `n` smallest elements where ``n=3``. Default `keep` value is
'first' so Nauru and Tuvalu will be kept.
>>> s.nsmallest(3)
Montserrat 5200
Nauru 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` and keeping the last
duplicates. Anguilla and Tuvalu will be kept since they are the last
with value 11300 based on the index order.
>>> s.nsmallest(3, keep='last')
Montserrat 5200
Anguilla 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has four elements due to the three duplicates.
>>> s.nsmallest(3, keep='all')
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nsmallest()
klass=_shared_doc_kwargs["klass"],
extra_params=dedent(
"""copy : bool, default True
Whether to copy underlying data."""
),
examples=dedent(
"""\
Examples
--------
>>> s = pd.Series(
... ["A", "B", "A", "C"],
... index=[
... ["Final exam", "Final exam", "Coursework", "Coursework"],
... ["History", "Geography", "History", "Geography"],
... ["January", "February", "March", "April"],
... ],
... )
>>> s
Final exam History January A
Geography February B
Coursework History March A
Geography April C
dtype: object
In the following example, we will swap the levels of the indices.
Here, we will swap the levels column-wise, but levels can be swapped row-wise
in a similar manner. Note that column-wise is the default behaviour.
By not supplying any arguments for i and j, we swap the last and second to
last indices.
>>> s.swaplevel()
Final exam January History A
February Geography B
Coursework March History A
April Geography C
dtype: object
By supplying one argument, we can choose which index to swap the last
index with. We can for example swap the first index with the last one as
follows.
>>> s.swaplevel(0)
January History Final exam A
February Geography Final exam B
March History Coursework A
April Geography Coursework C
dtype: object
We can also define explicitly which indices we want to swap by supplying values
for both i and j. Here, we for example swap the first and second indices.
>>> s.swaplevel(0, 1)
History Final exam January A
Geography Final exam February B
History Coursework March A
Geography Coursework April C
dtype: object"""
),
)
def swaplevel(
self, i: Level = -2, j: Level = -1, copy: bool | None = None
) -> Series:
"""
Swap levels i and j in a :class:`MultiIndex`.
Default is to swap the two innermost levels of the index.
Parameters
----------
i, j : int or str
Levels of the indices to be swapped. Can pass level name as string.
{extra_params}
Returns
-------
{klass}
{klass} with levels swapped in MultiIndex.
{examples}
"""
assert isinstance(self.index, MultiIndex)
result = self.copy(deep=copy and not using_copy_on_write())
result.index = self.index.swaplevel(i, j)
return result
def reorder_levels(self, order: Sequence[Level]) -> Series:
"""
Rearrange index levels using input order.
May not drop or duplicate levels.
Parameters
----------
order : list of int representing new level order
Reference level by number or key.
Returns
-------
type of caller (new object)
"""
if not isinstance(self.index, MultiIndex): # pragma: no cover
raise Exception("Can only reorder levels on a hierarchical axis.")
result = self.copy(deep=None)
assert isinstance(result.index, MultiIndex)
result.index = result.index.reorder_levels(order)
return result
def explode(self, ignore_index: bool = False) -> Series:
"""
Transform each element of a list-like to a row.
Parameters
----------
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.1.0
Returns
-------
Series
Exploded lists to rows; index will be duplicated for these rows.
See Also
--------
Series.str.split : Split string values on specified separator.
Series.unstack : Unstack, a.k.a. pivot, Series with MultiIndex
to produce DataFrame.
DataFrame.melt : Unpivot a DataFrame from wide format to long format.
DataFrame.explode : Explode a DataFrame from list-like
columns to long format.
Notes
-----
This routine will explode list-likes including lists, tuples, sets,
Series, and np.ndarray. The result dtype of the subset rows will
be object. Scalars will be returned unchanged, and empty list-likes will
result in a np.nan for that row. In addition, the ordering of elements in
the output will be non-deterministic when exploding sets.
Reference :ref:`the user guide <reshaping.explode>` for more examples.
Examples
--------
>>> s = pd.Series([[1, 2, 3], 'foo', [], [3, 4]])
>>> s
0 [1, 2, 3]
1 foo
2 []
3 [3, 4]
dtype: object
>>> s.explode()
0 1
0 2
0 3
1 foo
2 NaN
3 3
3 4
dtype: object
"""
if not len(self) or not is_object_dtype(self):
result = self.copy()
return result.reset_index(drop=True) if ignore_index else result
values, counts = reshape.explode(np.asarray(self._values))
if ignore_index:
index = default_index(len(values))
else:
index = self.index.repeat(counts)
return self._constructor(values, index=index, name=self.name, copy=False)
def unstack(self, level: IndexLabel = -1, fill_value: Hashable = None) -> DataFrame:
"""
Unstack, also known as pivot, Series with MultiIndex to produce DataFrame.
Parameters
----------
level : int, str, or list of these, default last level
Level(s) to unstack, can pass level name.
fill_value : scalar value, default None
Value to use when replacing NaN values.
Returns
-------
DataFrame
Unstacked Series.
Notes
-----
Reference :ref:`the user guide <reshaping.stacking>` for more examples.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4],
... index=pd.MultiIndex.from_product([['one', 'two'],
... ['a', 'b']]))
>>> s
one a 1
b 2
two a 3
b 4
dtype: int64
>>> s.unstack(level=-1)
a b
one 1 2
two 3 4
>>> s.unstack(level=0)
one two
a 1 3
b 2 4
"""
from pandas.core.reshape.reshape import unstack
return unstack(self, level, fill_value)
# ----------------------------------------------------------------------
# function application
def map(
self,
arg: Callable | Mapping | Series,
na_action: Literal["ignore"] | None = None,
) -> Series:
"""
Map values of Series according to an input mapping or function.
Used for substituting each value in a Series with another value,
that may be derived from a function, a ``dict`` or
a :class:`Series`.
Parameters
----------
arg : function, collections.abc.Mapping subclass or Series
Mapping correspondence.
na_action : {None, 'ignore'}, default None
If 'ignore', propagate NaN values, without passing them to the
mapping correspondence.
Returns
-------
Series
Same index as caller.
See Also
--------
Series.apply : For applying more complex functions on a Series.
DataFrame.apply : Apply a function row-/column-wise.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Notes
-----
When ``arg`` is a dictionary, values in Series that are not in the
dictionary (as keys) are converted to ``NaN``. However, if the
dictionary is a ``dict`` subclass that defines ``__missing__`` (i.e.
provides a method for default values), then this default is used
rather than ``NaN``.
Examples
--------
>>> s = pd.Series(['cat', 'dog', np.nan, 'rabbit'])
>>> s
0 cat
1 dog
2 NaN
3 rabbit
dtype: object
``map`` accepts a ``dict`` or a ``Series``. Values that are not found
in the ``dict`` are converted to ``NaN``, unless the dict has a default
value (e.g. ``defaultdict``):
>>> s.map({'cat': 'kitten', 'dog': 'puppy'})
0 kitten
1 puppy
2 NaN
3 NaN
dtype: object
It also accepts a function:
>>> s.map('I am a {}'.format)
0 I am a cat
1 I am a dog
2 I am a nan
3 I am a rabbit
dtype: object
To avoid applying the function to missing values (and keep them as
``NaN``) ``na_action='ignore'`` can be used:
>>> s.map('I am a {}'.format, na_action='ignore')
0 I am a cat
1 I am a dog
2 NaN
3 I am a rabbit
dtype: object
"""
new_values = self._map_values(arg, na_action=na_action)
return self._constructor(new_values, index=self.index, copy=False).__finalize__(
self, method="map"
)
def _gotitem(self, key, ndim, subset=None) -> Series:
"""
Sub-classes to define. Return a sliced object.
Parameters
----------
key : string / list of selections
ndim : {1, 2}
Requested ndim of result.
subset : object, default None
Subset to act on.
"""
return self
_agg_see_also_doc = dedent(
"""
See Also
--------
Series.apply : Invoke function on a Series.
Series.transform : Transform function producing a Series with like indexes.
"""
)
_agg_examples_doc = dedent(
"""
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.agg('min')
1
>>> s.agg(['min', 'max'])
min 1
max 4
dtype: int64
"""
)
_shared_docs["aggregate"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
see_also=_agg_see_also_doc,
examples=_agg_examples_doc,
)
def aggregate(self, func=None, axis: Axis = 0, *args, **kwargs):
# Validate the axis parameter
self._get_axis_number(axis)
# if func is None, will switch to user-provided "named aggregation" kwargs
if func is None:
func = dict(kwargs.items())
op = SeriesApply(self, func, convert_dtype=False, args=args, kwargs=kwargs)
result = op.agg()
return result
agg = aggregate
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: None = ...,
**kwargs,
) -> bool:
...
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: Level,
**kwargs,
) -> Series | bool:
...
# error: Missing return statement
def any( # type: ignore[empty-body]
self,
axis: Axis = 0,
bool_only: bool | None = None,
skipna: bool = True,
level: Level | None = None,
**kwargs,
) -> Series | bool:
...
_shared_docs["transform"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
)
def transform(
self, func: AggFuncType, axis: Axis = 0, *args, **kwargs
) -> DataFrame | Series:
# Validate axis argument
self._get_axis_number(axis)
result = SeriesApply(
self, func=func, convert_dtype=True, args=args, kwargs=kwargs
).transform()
return result
def apply(
self,
func: AggFuncType,
convert_dtype: bool = True,
args: tuple[Any, ...] = (),
**kwargs,
) -> DataFrame | Series:
"""
Invoke function on values of Series.
Can be ufunc (a NumPy function that applies to the entire Series)
or a Python function that only works on single values.
Parameters
----------
func : function
Python function or NumPy ufunc to apply.
convert_dtype : bool, default True
Try to find better dtype for elementwise function results. If
False, leave as dtype=object. Note that the dtype is always
preserved for some extension array dtypes, such as Categorical.
args : tuple
Positional arguments passed to func after the series value.
**kwargs
Additional keyword arguments passed to func.
Returns
-------
Series or DataFrame
If func returns a Series object the result will be a DataFrame.
See Also
--------
Series.map: For element-wise operations.
Series.agg: Only perform aggregating type operations.
Series.transform: Only perform transforming type operations.
Notes
-----
Functions that mutate the passed object can produce unexpected
behavior or errors and are not supported. See :ref:`gotchas.udf-mutation`
for more details.
Examples
--------
Create a series with typical summer temperatures for each city.
>>> s = pd.Series([20, 21, 12],
... index=['London', 'New York', 'Helsinki'])
>>> s
London 20
New York 21
Helsinki 12
dtype: int64
Square the values by defining a function and passing it as an
argument to ``apply()``.
>>> def square(x):
... return x ** 2
>>> s.apply(square)
London 400
New York 441
Helsinki 144
dtype: int64
Square the values by passing an anonymous function as an
argument to ``apply()``.
>>> s.apply(lambda x: x ** 2)
London 400
New York 441
Helsinki 144
dtype: int64
Define a custom function that needs additional positional
arguments and pass these additional arguments using the
``args`` keyword.
>>> def subtract_custom_value(x, custom_value):
... return x - custom_value
>>> s.apply(subtract_custom_value, args=(5,))
London 15
New York 16
Helsinki 7
dtype: int64
Define a custom function that takes keyword arguments
and pass these arguments to ``apply``.
>>> def add_custom_values(x, **kwargs):
... for month in kwargs:
... x += kwargs[month]
... return x
>>> s.apply(add_custom_values, june=30, july=20, august=25)
London 95
New York 96
Helsinki 87
dtype: int64
Use a function from the Numpy library.
>>> s.apply(np.log)
London 2.995732
New York 3.044522
Helsinki 2.484907
dtype: float64
"""
return SeriesApply(self, func, convert_dtype, args, kwargs).apply()
def _reduce(
self,
op,
name: str,
*,
axis: Axis = 0,
skipna: bool = True,
numeric_only: bool = False,
filter_type=None,
**kwds,
):
"""
Perform a reduction operation.
If we have an ndarray as a value, then simply perform the operation,
otherwise delegate to the object.
"""
delegate = self._values
if axis is not None:
self._get_axis_number(axis)
if isinstance(delegate, ExtensionArray):
# dispatch to ExtensionArray interface
return delegate._reduce(name, skipna=skipna, **kwds)
else:
# dispatch to numpy arrays
if numeric_only and not is_numeric_dtype(self.dtype):
kwd_name = "numeric_only"
if name in ["any", "all"]:
kwd_name = "bool_only"
# GH#47500 - change to TypeError to match other methods
raise TypeError(
f"Series.{name} does not allow {kwd_name}={numeric_only} "
"with non-numeric dtypes."
)
with np.errstate(all="ignore"):
return op(delegate, skipna=skipna, **kwds)
def _reindex_indexer(
self,
new_index: Index | None,
indexer: npt.NDArray[np.intp] | None,
copy: bool | None,
) -> Series:
# Note: new_index is None iff indexer is None
# if not None, indexer is np.intp
if indexer is None and (
new_index is None or new_index.names == self.index.names
):
if using_copy_on_write():
return self.copy(deep=copy)
if copy or copy is None:
return self.copy(deep=copy)
return self
new_values = algorithms.take_nd(
self._values, indexer, allow_fill=True, fill_value=None
)
return self._constructor(new_values, index=new_index, copy=False)
def _needs_reindex_multi(self, axes, method, level) -> bool:
"""
Check if we do need a multi reindex; this is for compat with
higher dims.
"""
return False
# error: Cannot determine type of 'align'
NDFrame.align, # type: ignore[has-type]
klass=_shared_doc_kwargs["klass"],
axes_single_arg=_shared_doc_kwargs["axes_single_arg"],
)
def align(
self,
other: Series,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> Series:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[True],
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> None:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[False] = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: bool = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series | None:
...
def rename(
self,
index: Renamer | Hashable | None = None,
*,
axis: Axis | None = None,
copy: bool = True,
inplace: bool = False,
level: Level | None = None,
errors: IgnoreRaise = "ignore",
) -> Series | None:
"""
Alter Series index labels or name.
Function / dict values must be unique (1-to-1). Labels not contained in
a dict / Series will be left as-is. Extra labels listed don't throw an
error.
Alternatively, change ``Series.name`` with a scalar value.
See the :ref:`user guide <basics.rename>` for more.
Parameters
----------
index : scalar, hashable sequence, dict-like or function optional
Functions or dict-like are transformations to apply to
the index.
Scalar or hashable sequence-like will alter the ``Series.name``
attribute.
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
copy : bool, default True
Also copy underlying data.
inplace : bool, default False
Whether to return a new Series. If True the value of copy is ignored.
level : int or level name, default None
In case of MultiIndex, only rename labels in the specified level.
errors : {'ignore', 'raise'}, default 'ignore'
If 'raise', raise `KeyError` when a `dict-like mapper` or
`index` contains labels that are not present in the index being transformed.
If 'ignore', existing keys will be renamed and extra keys will be ignored.
Returns
-------
Series or None
Series with index labels or name altered or None if ``inplace=True``.
See Also
--------
DataFrame.rename : Corresponding DataFrame method.
Series.rename_axis : Set the name of the axis.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.rename("my_name") # scalar, changes Series.name
0 1
1 2
2 3
Name: my_name, dtype: int64
>>> s.rename(lambda x: x ** 2) # function, changes labels
0 1
1 2
4 3
dtype: int64
>>> s.rename({1: 3, 2: 5}) # mapping, changes labels
0 1
3 2
5 3
dtype: int64
"""
if axis is not None:
# Make sure we raise if an invalid 'axis' is passed.
axis = self._get_axis_number(axis)
if callable(index) or is_dict_like(index):
# error: Argument 1 to "_rename" of "NDFrame" has incompatible
# type "Union[Union[Mapping[Any, Hashable], Callable[[Any],
# Hashable]], Hashable, None]"; expected "Union[Mapping[Any,
# Hashable], Callable[[Any], Hashable], None]"
return super()._rename(
index, # type: ignore[arg-type]
copy=copy,
inplace=inplace,
level=level,
errors=errors,
)
else:
return self._set_name(index, inplace=inplace)
"""
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.set_axis(['a', 'b', 'c'], axis=0)
a 1
b 2
c 3
dtype: int64
"""
)
**_shared_doc_kwargs,
extended_summary_sub="",
axis_description_sub="",
see_also_sub="",
)
)
)
# error: Cannot determine type of 'shift'
# ----------------------------------------------------------------------
# Convert to types that support pd.NA
# error: Cannot determine type of 'isna'
# error: Return type "Series" of "isna" incompatible with return type "ndarray
# [Any, dtype[bool_]]" in supertype "IndexOpsMixin"
# error: Cannot determine type of 'isna'
# error: Cannot determine type of 'notna'
# error: Cannot determine type of 'notna'
# ----------------------------------------------------------------------
# Time series-oriented methods
# error: Cannot determine type of 'asfreq'
# error: Cannot determine type of 'resample'
# ----------------------------------------------------------------------
# Add index
# ----------------------------------------------------------------------
# Accessor Methods
# ----------------------------------------------------------------------
# ----------------------------------------------------------------------
# Add plotting methods to Series
# ----------------------------------------------------------------------
# Template-Based Arithmetic/Comparison Methods
Series
The provided code snippet includes necessary dependencies for implementing the `_dtype_to_stata_type` function. Write a Python function `def _dtype_to_stata_type(dtype: np.dtype, column: Series) -> int` to solve the following problem:
Convert dtype types to stata types. Returns the byte of the given ordinal. See TYPE_MAP and comments for an explanation. This is also explained in the dta spec. 1 - 244 are strings of this length Pandas Stata 251 - for int8 byte 252 - for int16 int 253 - for int32 long 254 - for float32 float 255 - for double double If there are dates to convert, then dtype will already have the correct type inserted.
Here is the function:
def _dtype_to_stata_type(dtype: np.dtype, column: Series) -> int:
"""
Convert dtype types to stata types. Returns the byte of the given ordinal.
See TYPE_MAP and comments for an explanation. This is also explained in
the dta spec.
1 - 244 are strings of this length
Pandas Stata
251 - for int8 byte
252 - for int16 int
253 - for int32 long
254 - for float32 float
255 - for double double
If there are dates to convert, then dtype will already have the correct
type inserted.
"""
# TODO: expand to handle datetime to integer conversion
if dtype.type is np.object_: # try to coerce it to the biggest string
# not memory efficient, what else could we
# do?
itemsize = max_len_string_array(ensure_object(column._values))
return max(itemsize, 1)
elif dtype.type is np.float64:
return 255
elif dtype.type is np.float32:
return 254
elif dtype.type is np.int32:
return 253
elif dtype.type is np.int16:
return 252
elif dtype.type is np.int8:
return 251
else: # pragma : no cover
raise NotImplementedError(f"Data type {dtype} not supported.") | Convert dtype types to stata types. Returns the byte of the given ordinal. See TYPE_MAP and comments for an explanation. This is also explained in the dta spec. 1 - 244 are strings of this length Pandas Stata 251 - for int8 byte 252 - for int16 int 253 - for int32 long 254 - for float32 float 255 - for double double If there are dates to convert, then dtype will already have the correct type inserted. |
173,541 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
excessive_string_length_error: Final = """
Fixed width strings in Stata .dta files are limited to 244 (or fewer)
characters. Column '{0}' does not satisfy this restriction. Use the
'version=117' parameter to write the newer (Stata 13 and later) format.
"""
ensure_object = algos.ensure_object
class Series(base.IndexOpsMixin, NDFrame): # type: ignore[misc]
"""
One-dimensional ndarray with axis labels (including time series).
Labels need not be unique but must be a hashable type. The object
supports both integer- and label-based indexing and provides a host of
methods for performing operations involving the index. Statistical
methods from ndarray have been overridden to automatically exclude
missing data (currently represented as NaN).
Operations between Series (+, -, /, \\*, \\*\\*) align values based on their
associated index values-- they need not be the same length. The result
index will be the sorted union of the two indexes.
Parameters
----------
data : array-like, Iterable, dict, or scalar value
Contains data stored in Series. If data is a dict, argument order is
maintained.
index : array-like or Index (1d)
Values must be hashable and have the same length as `data`.
Non-unique index values are allowed. Will default to
RangeIndex (0, 1, 2, ..., n) if not provided. If data is dict-like
and index is None, then the keys in the data are used as the index. If the
index is not None, the resulting Series is reindexed with the index values.
dtype : str, numpy.dtype, or ExtensionDtype, optional
Data type for the output Series. If not specified, this will be
inferred from `data`.
See the :ref:`user guide <basics.dtypes>` for more usages.
name : Hashable, default None
The name to give to the Series.
copy : bool, default False
Copy input data. Only affects Series or 1d ndarray input. See examples.
Notes
-----
Please reference the :ref:`User Guide <basics.series>` for more information.
Examples
--------
Constructing Series from a dictionary with an Index specified
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['a', 'b', 'c'])
>>> ser
a 1
b 2
c 3
dtype: int64
The keys of the dictionary match with the Index values, hence the Index
values have no effect.
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['x', 'y', 'z'])
>>> ser
x NaN
y NaN
z NaN
dtype: float64
Note that the Index is first build with the keys from the dictionary.
After this the Series is reindexed with the given Index values, hence we
get all NaN as a result.
Constructing Series from a list with `copy=False`.
>>> r = [1, 2]
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
[1, 2]
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `copy` of
the original data even though `copy=False`, so
the data is unchanged.
Constructing Series from a 1d ndarray with `copy=False`.
>>> r = np.array([1, 2])
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
array([999, 2])
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `view` on
the original data, so
the data is changed as well.
"""
_typ = "series"
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
_name: Hashable
_metadata: list[str] = ["name"]
_internal_names_set = {"index"} | NDFrame._internal_names_set
_accessors = {"dt", "cat", "str", "sparse"}
_hidden_attrs = (
base.IndexOpsMixin._hidden_attrs | NDFrame._hidden_attrs | frozenset([])
)
# Override cache_readonly bc Series is mutable
# error: Incompatible types in assignment (expression has type "property",
# base class "IndexOpsMixin" defined the type as "Callable[[IndexOpsMixin], bool]")
hasnans = property( # type: ignore[assignment]
# error: "Callable[[IndexOpsMixin], bool]" has no attribute "fget"
base.IndexOpsMixin.hasnans.fget, # type: ignore[attr-defined]
doc=base.IndexOpsMixin.hasnans.__doc__,
)
_mgr: SingleManager
div: Callable[[Series, Any], Series]
rdiv: Callable[[Series, Any], Series]
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index=None,
dtype: Dtype | None = None,
name=None,
copy: bool | None = None,
fastpath: bool = False,
) -> None:
if (
isinstance(data, (SingleBlockManager, SingleArrayManager))
and index is None
and dtype is None
and (copy is False or copy is None)
):
if using_copy_on_write():
data = data.copy(deep=False)
# GH#33357 called with just the SingleBlockManager
NDFrame.__init__(self, data)
if fastpath:
# e.g. from _box_col_values, skip validation of name
object.__setattr__(self, "_name", name)
else:
self.name = name
return
if isinstance(data, (ExtensionArray, np.ndarray)):
if copy is not False and using_copy_on_write():
if dtype is None or astype_is_view(data.dtype, pandas_dtype(dtype)):
data = data.copy()
if copy is None:
copy = False
# we are called internally, so short-circuit
if fastpath:
# data is a ndarray, index is defined
if not isinstance(data, (SingleBlockManager, SingleArrayManager)):
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
elif using_copy_on_write() and not copy:
data = data.copy(deep=False)
if copy:
data = data.copy()
# skips validation of the name
object.__setattr__(self, "_name", name)
NDFrame.__init__(self, data)
return
if isinstance(data, SingleBlockManager) and using_copy_on_write() and not copy:
data = data.copy(deep=False)
name = ibase.maybe_extract_name(name, data, type(self))
if index is not None:
index = ensure_index(index)
if dtype is not None:
dtype = self._validate_dtype(dtype)
if data is None:
index = index if index is not None else default_index(0)
if len(index) or dtype is not None:
data = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
data = []
if isinstance(data, MultiIndex):
raise NotImplementedError(
"initializing a Series from a MultiIndex is not supported"
)
refs = None
if isinstance(data, Index):
if dtype is not None:
data = data.astype(dtype, copy=False)
if using_copy_on_write():
refs = data._references
data = data._values
else:
# GH#24096 we need to ensure the index remains immutable
data = data._values.copy()
copy = False
elif isinstance(data, np.ndarray):
if len(data.dtype):
# GH#13296 we are dealing with a compound dtype, which
# should be treated as 2D
raise ValueError(
"Cannot construct a Series from an ndarray with "
"compound dtype. Use DataFrame instead."
)
elif isinstance(data, Series):
if index is None:
index = data.index
data = data._mgr.copy(deep=False)
else:
data = data.reindex(index, copy=copy)
copy = False
data = data._mgr
elif is_dict_like(data):
data, index = self._init_dict(data, index, dtype)
dtype = None
copy = False
elif isinstance(data, (SingleBlockManager, SingleArrayManager)):
if index is None:
index = data.index
elif not data.index.equals(index) or copy:
# GH#19275 SingleBlockManager input should only be called
# internally
raise AssertionError(
"Cannot pass both SingleBlockManager "
"`data` argument and a different "
"`index` argument. `copy` must be False."
)
elif isinstance(data, ExtensionArray):
pass
else:
data = com.maybe_iterable_to_list(data)
if is_list_like(data) and not len(data) and dtype is None:
# GH 29405: Pre-2.0, this defaulted to float.
dtype = np.dtype(object)
if index is None:
if not is_list_like(data):
data = [data]
index = default_index(len(data))
elif is_list_like(data):
com.require_length_match(data, index)
# create/copy the manager
if isinstance(data, (SingleBlockManager, SingleArrayManager)):
if dtype is not None:
data = data.astype(dtype=dtype, errors="ignore", copy=copy)
elif copy:
data = data.copy()
else:
data = sanitize_array(data, index, dtype, copy)
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index, refs=refs)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
NDFrame.__init__(self, data)
self.name = name
self._set_axis(0, index)
def _init_dict(
self, data, index: Index | None = None, dtype: DtypeObj | None = None
):
"""
Derive the "_mgr" and "index" attributes of a new Series from a
dictionary input.
Parameters
----------
data : dict or dict-like
Data used to populate the new Series.
index : Index or None, default None
Index for the new Series: if None, use dict keys.
dtype : np.dtype, ExtensionDtype, or None, default None
The dtype for the new Series: if None, infer from data.
Returns
-------
_data : BlockManager for the new Series
index : index for the new Series
"""
keys: Index | tuple
# Looking for NaN in dict doesn't work ({np.nan : 1}[float('nan')]
# raises KeyError), so we iterate the entire dict, and align
if data:
# GH:34717, issue was using zip to extract key and values from data.
# using generators in effects the performance.
# Below is the new way of extracting the keys and values
keys = tuple(data.keys())
values = list(data.values()) # Generating list of values- faster way
elif index is not None:
# fastpath for Series(data=None). Just use broadcasting a scalar
# instead of reindexing.
if len(index) or dtype is not None:
values = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
values = []
keys = index
else:
keys, values = (), []
# Input is now list-like, so rely on "standard" construction:
s = self._constructor(
values,
index=keys,
dtype=dtype,
)
# Now we just make sure the order is respected, if any
if data and index is not None:
s = s.reindex(index, copy=False)
return s._mgr, s.index
# ----------------------------------------------------------------------
def _constructor(self) -> Callable[..., Series]:
return Series
def _constructor_expanddim(self) -> Callable[..., DataFrame]:
"""
Used when a manipulation result has one higher dimension as the
original, such as Series.to_frame()
"""
from pandas.core.frame import DataFrame
return DataFrame
# types
def _can_hold_na(self) -> bool:
return self._mgr._can_hold_na
# ndarray compatibility
def dtype(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtype
dtype('int64')
"""
return self._mgr.dtype
def dtypes(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtypes
dtype('int64')
"""
# DataFrame compatibility
return self.dtype
def name(self) -> Hashable:
"""
Return the name of the Series.
The name of a Series becomes its index or column name if it is used
to form a DataFrame. It is also used whenever displaying the Series
using the interpreter.
Returns
-------
label (hashable object)
The name of the Series, also the column name if part of a DataFrame.
See Also
--------
Series.rename : Sets the Series name when given a scalar input.
Index.name : Corresponding Index property.
Examples
--------
The Series name can be set initially when calling the constructor.
>>> s = pd.Series([1, 2, 3], dtype=np.int64, name='Numbers')
>>> s
0 1
1 2
2 3
Name: Numbers, dtype: int64
>>> s.name = "Integers"
>>> s
0 1
1 2
2 3
Name: Integers, dtype: int64
The name of a Series within a DataFrame is its column name.
>>> df = pd.DataFrame([[1, 2], [3, 4], [5, 6]],
... columns=["Odd Numbers", "Even Numbers"])
>>> df
Odd Numbers Even Numbers
0 1 2
1 3 4
2 5 6
>>> df["Even Numbers"].name
'Even Numbers'
"""
return self._name
def name(self, value: Hashable) -> None:
validate_all_hashable(value, error_name=f"{type(self).__name__}.name")
object.__setattr__(self, "_name", value)
def values(self):
"""
Return Series as ndarray or ndarray-like depending on the dtype.
.. warning::
We recommend using :attr:`Series.array` or
:meth:`Series.to_numpy`, depending on whether you need
a reference to the underlying data or a NumPy array.
Returns
-------
numpy.ndarray or ndarray-like
See Also
--------
Series.array : Reference to the underlying data.
Series.to_numpy : A NumPy array representing the underlying data.
Examples
--------
>>> pd.Series([1, 2, 3]).values
array([1, 2, 3])
>>> pd.Series(list('aabc')).values
array(['a', 'a', 'b', 'c'], dtype=object)
>>> pd.Series(list('aabc')).astype('category').values
['a', 'a', 'b', 'c']
Categories (3, object): ['a', 'b', 'c']
Timezone aware datetime data is converted to UTC:
>>> pd.Series(pd.date_range('20130101', periods=3,
... tz='US/Eastern')).values
array(['2013-01-01T05:00:00.000000000',
'2013-01-02T05:00:00.000000000',
'2013-01-03T05:00:00.000000000'], dtype='datetime64[ns]')
"""
return self._mgr.external_values()
def _values(self):
"""
Return the internal repr of this data (defined by Block.interval_values).
This are the values as stored in the Block (ndarray or ExtensionArray
depending on the Block class), with datetime64[ns] and timedelta64[ns]
wrapped in ExtensionArrays to match Index._values behavior.
Differs from the public ``.values`` for certain data types, because of
historical backwards compatibility of the public attribute (e.g. period
returns object ndarray and datetimetz a datetime64[ns] ndarray for
``.values`` while it returns an ExtensionArray for ``._values`` in those
cases).
Differs from ``.array`` in that this still returns the numpy array if
the Block is backed by a numpy array (except for datetime64 and
timedelta64 dtypes), while ``.array`` ensures to always return an
ExtensionArray.
Overview:
dtype | values | _values | array |
----------- | ------------- | ------------- | ------------- |
Numeric | ndarray | ndarray | PandasArray |
Category | Categorical | Categorical | Categorical |
dt64[ns] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
dt64[ns tz] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
td64[ns] | ndarray[m8ns] | TimedeltaArray| ndarray[m8ns] |
Period | ndarray[obj] | PeriodArray | PeriodArray |
Nullable | EA | EA | EA |
"""
return self._mgr.internal_values()
def _references(self) -> BlockValuesRefs | None:
if isinstance(self._mgr, SingleArrayManager):
return None
return self._mgr._block.refs
# error: Decorated property not supported
def array(self) -> ExtensionArray:
return self._mgr.array_values()
# ops
def ravel(self, order: str = "C") -> ArrayLike:
"""
Return the flattened underlying data as an ndarray or ExtensionArray.
Returns
-------
numpy.ndarray or ExtensionArray
Flattened data of the Series.
See Also
--------
numpy.ndarray.ravel : Return a flattened array.
"""
arr = self._values.ravel(order=order)
if isinstance(arr, np.ndarray) and using_copy_on_write():
arr.flags.writeable = False
return arr
def __len__(self) -> int:
"""
Return the length of the Series.
"""
return len(self._mgr)
def view(self, dtype: Dtype | None = None) -> Series:
"""
Create a new view of the Series.
This function will return a new Series with a view of the same
underlying values in memory, optionally reinterpreted with a new data
type. The new data type must preserve the same size in bytes as to not
cause index misalignment.
Parameters
----------
dtype : data type
Data type object or one of their string representations.
Returns
-------
Series
A new Series object as a view of the same data in memory.
See Also
--------
numpy.ndarray.view : Equivalent numpy function to create a new view of
the same data in memory.
Notes
-----
Series are instantiated with ``dtype=float64`` by default. While
``numpy.ndarray.view()`` will return a view with the same data type as
the original array, ``Series.view()`` (without specified dtype)
will try using ``float64`` and may fail if the original data type size
in bytes is not the same.
Examples
--------
>>> s = pd.Series([-2, -1, 0, 1, 2], dtype='int8')
>>> s
0 -2
1 -1
2 0
3 1
4 2
dtype: int8
The 8 bit signed integer representation of `-1` is `0b11111111`, but
the same bytes represent 255 if read as an 8 bit unsigned integer:
>>> us = s.view('uint8')
>>> us
0 254
1 255
2 0
3 1
4 2
dtype: uint8
The views share the same underlying values:
>>> us[0] = 128
>>> s
0 -128
1 -1
2 0
3 1
4 2
dtype: int8
"""
# self.array instead of self._values so we piggyback on PandasArray
# implementation
res_values = self.array.view(dtype)
res_ser = self._constructor(res_values, index=self.index, copy=False)
if isinstance(res_ser._mgr, SingleBlockManager) and using_copy_on_write():
blk = res_ser._mgr._block
blk.refs = cast("BlockValuesRefs", self._references)
blk.refs.add_reference(blk) # type: ignore[arg-type]
return res_ser.__finalize__(self, method="view")
# ----------------------------------------------------------------------
# NDArray Compat
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
"""
Return the values as a NumPy array.
Users should not call this directly. Rather, it is invoked by
:func:`numpy.array` and :func:`numpy.asarray`.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to use for the resulting NumPy array. By default,
the dtype is inferred from the data.
Returns
-------
numpy.ndarray
The values in the series converted to a :class:`numpy.ndarray`
with the specified `dtype`.
See Also
--------
array : Create a new array from data.
Series.array : Zero-copy view to the array backing the Series.
Series.to_numpy : Series method for similar behavior.
Examples
--------
>>> ser = pd.Series([1, 2, 3])
>>> np.asarray(ser)
array([1, 2, 3])
For timezone-aware data, the timezones may be retained with
``dtype='object'``
>>> tzser = pd.Series(pd.date_range('2000', periods=2, tz="CET"))
>>> np.asarray(tzser, dtype="object")
array([Timestamp('2000-01-01 00:00:00+0100', tz='CET'),
Timestamp('2000-01-02 00:00:00+0100', tz='CET')],
dtype=object)
Or the values may be localized to UTC and the tzinfo discarded with
``dtype='datetime64[ns]'``
>>> np.asarray(tzser, dtype="datetime64[ns]") # doctest: +ELLIPSIS
array(['1999-12-31T23:00:00.000000000', ...],
dtype='datetime64[ns]')
"""
values = self._values
arr = np.asarray(values, dtype=dtype)
if using_copy_on_write() and astype_is_view(values.dtype, arr.dtype):
arr = arr.view()
arr.flags.writeable = False
return arr
# ----------------------------------------------------------------------
# Unary Methods
# coercion
__float__ = _coerce_method(float)
__int__ = _coerce_method(int)
# ----------------------------------------------------------------------
# indexers
def axes(self) -> list[Index]:
"""
Return a list of the row axis labels.
"""
return [self.index]
# ----------------------------------------------------------------------
# Indexing Methods
def take(self, indices, axis: Axis = 0, **kwargs) -> Series:
nv.validate_take((), kwargs)
indices = ensure_platform_int(indices)
if (
indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_index = self.index.take(indices)
new_values = self._values.take(indices)
result = self._constructor(new_values, index=new_index, fastpath=True)
return result.__finalize__(self, method="take")
def _take_with_is_copy(self, indices, axis: Axis = 0) -> Series:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning). For Series this does the same
as the public take (it never sets `_is_copy`).
See the docstring of `take` for full explanation of the parameters.
"""
return self.take(indices=indices, axis=axis)
def _ixs(self, i: int, axis: AxisInt = 0) -> Any:
"""
Return the i-th value or values in the Series by location.
Parameters
----------
i : int
Returns
-------
scalar (int) or Series (slice, sequence)
"""
return self._values[i]
def _slice(self, slobj: slice | np.ndarray, axis: Axis = 0) -> Series:
# axis kwarg is retained for compat with NDFrame method
# _slice is *always* positional
return self._get_values(slobj)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
if key is Ellipsis:
return self
key_is_scalar = is_scalar(key)
if isinstance(key, (list, tuple)):
key = unpack_1tuple(key)
if is_integer(key) and self.index._should_fallback_to_positional:
return self._values[key]
elif key_is_scalar:
return self._get_value(key)
if is_hashable(key):
# Otherwise index.get_value will raise InvalidIndexError
try:
# For labels that don't resolve as scalars like tuples and frozensets
result = self._get_value(key)
return result
except (KeyError, TypeError, InvalidIndexError):
# InvalidIndexError for e.g. generator
# see test_series_getitem_corner_generator
if isinstance(key, tuple) and isinstance(self.index, MultiIndex):
# We still have the corner case where a tuple is a key
# in the first level of our MultiIndex
return self._get_values_tuple(key)
if is_iterator(key):
key = list(key)
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
return self._get_values(key)
return self._get_with(key)
def _get_with(self, key):
# other: fancy integer or otherwise
if isinstance(key, slice):
# _convert_slice_indexer to determine if this slice is positional
# or label based, and if the latter, convert to positional
slobj = self.index._convert_slice_indexer(key, kind="getitem")
return self._slice(slobj)
elif isinstance(key, ABCDataFrame):
raise TypeError(
"Indexing a Series with DataFrame is not "
"supported, use the appropriate DataFrame column"
)
elif isinstance(key, tuple):
return self._get_values_tuple(key)
elif not is_list_like(key):
# e.g. scalars that aren't recognized by lib.is_scalar, GH#32684
return self.loc[key]
if not isinstance(key, (list, np.ndarray, ExtensionArray, Series, Index)):
key = list(key)
if isinstance(key, Index):
key_type = key.inferred_type
else:
key_type = lib.infer_dtype(key, skipna=False)
# Note: The key_type == "boolean" case should be caught by the
# com.is_bool_indexer check in __getitem__
if key_type == "integer":
# We need to decide whether to treat this as a positional indexer
# (i.e. self.iloc) or label-based (i.e. self.loc)
if not self.index._should_fallback_to_positional:
return self.loc[key]
else:
return self.iloc[key]
# handle the dup indexing case GH#4246
return self.loc[key]
def _get_values_tuple(self, key: tuple):
# mpl hackaround
if com.any_none(*key):
# mpl compat if we look up e.g. ser[:, np.newaxis];
# see tests.series.timeseries.test_mpl_compat_hack
# the asarray is needed to avoid returning a 2D DatetimeArray
result = np.asarray(self._values[key])
disallow_ndim_indexing(result)
return result
if not isinstance(self.index, MultiIndex):
raise KeyError("key of type tuple not found and not a MultiIndex")
# If key is contained, would have returned by now
indexer, new_index = self.index.get_loc_level(key)
new_ser = self._constructor(self._values[indexer], index=new_index, copy=False)
if using_copy_on_write() and isinstance(indexer, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
def _get_values(self, indexer: slice | npt.NDArray[np.bool_]) -> Series:
new_mgr = self._mgr.getitem_mgr(indexer)
return self._constructor(new_mgr).__finalize__(self)
def _get_value(self, label, takeable: bool = False):
"""
Quickly retrieve single value at passed index label.
Parameters
----------
label : object
takeable : interpret the index as indexers, default False
Returns
-------
scalar value
"""
if takeable:
return self._values[label]
# Similar to Index.get_value, but we do not fall back to positional
loc = self.index.get_loc(label)
if is_integer(loc):
return self._values[loc]
if isinstance(self.index, MultiIndex):
mi = self.index
new_values = self._values[loc]
if len(new_values) == 1 and mi.nlevels == 1:
# If more than one level left, we can not return a scalar
return new_values[0]
new_index = mi[loc]
new_index = maybe_droplevels(new_index, label)
new_ser = self._constructor(
new_values, index=new_index, name=self.name, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
else:
return self.iloc[loc]
def __setitem__(self, key, value) -> None:
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
cacher_needs_updating = self._check_is_chained_assignment_possible()
if key is Ellipsis:
key = slice(None)
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
return self._set_values(indexer, value)
try:
self._set_with_engine(key, value)
except KeyError:
# We have a scalar (or for MultiIndex or object-dtype, scalar-like)
# key that is not present in self.index.
if is_integer(key):
if not self.index._should_fallback_to_positional:
# GH#33469
self.loc[key] = value
else:
# positional setter
# can't use _mgr.setitem_inplace yet bc could have *both*
# KeyError and then ValueError, xref GH#45070
self._set_values(key, value)
else:
# GH#12862 adding a new key to the Series
self.loc[key] = value
except (TypeError, ValueError, LossySetitemError):
# The key was OK, but we cannot set the value losslessly
indexer = self.index.get_loc(key)
self._set_values(indexer, value)
except InvalidIndexError as err:
if isinstance(key, tuple) and not isinstance(self.index, MultiIndex):
# cases with MultiIndex don't get here bc they raise KeyError
# e.g. test_basic_getitem_setitem_corner
raise KeyError(
"key of type tuple not found and not a MultiIndex"
) from err
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
if (
is_list_like(value)
and len(value) != len(self)
and not isinstance(value, Series)
and not is_object_dtype(self.dtype)
):
# Series will be reindexed to have matching length inside
# _where call below
# GH#44265
indexer = key.nonzero()[0]
self._set_values(indexer, value)
return
# otherwise with listlike other we interpret series[mask] = other
# as series[mask] = other[mask]
try:
self._where(~key, value, inplace=True)
except InvalidIndexError:
# test_where_dups
self.iloc[key] = value
return
else:
self._set_with(key, value)
if cacher_needs_updating:
self._maybe_update_cacher(inplace=True)
def _set_with_engine(self, key, value) -> None:
loc = self.index.get_loc(key)
# this is equivalent to self._values[key] = value
self._mgr.setitem_inplace(loc, value)
def _set_with(self, key, value) -> None:
# We got here via exception-handling off of InvalidIndexError, so
# key should always be listlike at this point.
assert not isinstance(key, tuple)
if is_iterator(key):
# Without this, the call to infer_dtype will consume the generator
key = list(key)
if not self.index._should_fallback_to_positional:
# Regardless of the key type, we're treating it as labels
self._set_labels(key, value)
else:
# Note: key_type == "boolean" should not occur because that
# should be caught by the is_bool_indexer check in __setitem__
key_type = lib.infer_dtype(key, skipna=False)
if key_type == "integer":
self._set_values(key, value)
else:
self._set_labels(key, value)
def _set_labels(self, key, value) -> None:
key = com.asarray_tuplesafe(key)
indexer: np.ndarray = self.index.get_indexer(key)
mask = indexer == -1
if mask.any():
raise KeyError(f"{key[mask]} not in index")
self._set_values(indexer, value)
def _set_values(self, key, value) -> None:
if isinstance(key, (Index, Series)):
key = key._values
self._mgr = self._mgr.setitem(indexer=key, value=value)
self._maybe_update_cacher()
def _set_value(self, label, value, takeable: bool = False) -> None:
"""
Quickly set single value at passed label.
If label is not contained, a new object is created with the label
placed at the end of the result index.
Parameters
----------
label : object
Partial indexing with MultiIndex not allowed.
value : object
Scalar value.
takeable : interpret the index as indexers, default False
"""
if not takeable:
try:
loc = self.index.get_loc(label)
except KeyError:
# set using a non-recursive method
self.loc[label] = value
return
else:
loc = label
self._set_values(loc, value)
# ----------------------------------------------------------------------
# Lookup Caching
def _is_cached(self) -> bool:
"""Return boolean indicating if self is cached or not."""
return getattr(self, "_cacher", None) is not None
def _get_cacher(self):
"""return my cacher or None"""
cacher = getattr(self, "_cacher", None)
if cacher is not None:
cacher = cacher[1]()
return cacher
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
if hasattr(self, "_cacher"):
del self._cacher
def _set_as_cached(self, item, cacher) -> None:
"""
Set the _cacher attribute on the calling object with a weakref to
cacher.
"""
if using_copy_on_write():
return
self._cacher = (item, weakref.ref(cacher))
def _clear_item_cache(self) -> None:
# no-op for Series
pass
def _check_is_chained_assignment_possible(self) -> bool:
"""
See NDFrame._check_is_chained_assignment_possible.__doc__
"""
if self._is_view and self._is_cached:
ref = self._get_cacher()
if ref is not None and ref._is_mixed_type:
self._check_setitem_copy(t="referent", force=True)
return True
return super()._check_is_chained_assignment_possible()
def _maybe_update_cacher(
self, clear: bool = False, verify_is_copy: bool = True, inplace: bool = False
) -> None:
"""
See NDFrame._maybe_update_cacher.__doc__
"""
# for CoW, we never want to update the parent DataFrame cache
# if the Series changed, but don't keep track of any cacher
if using_copy_on_write():
return
cacher = getattr(self, "_cacher", None)
if cacher is not None:
assert self.ndim == 1
ref: DataFrame = cacher[1]()
# we are trying to reference a dead referent, hence
# a copy
if ref is None:
del self._cacher
elif len(self) == len(ref) and self.name in ref.columns:
# GH#42530 self.name must be in ref.columns
# to ensure column still in dataframe
# otherwise, either self or ref has swapped in new arrays
ref._maybe_cache_changed(cacher[0], self, inplace=inplace)
else:
# GH#33675 we have swapped in a new array, so parent
# reference to self is now invalid
ref._item_cache.pop(cacher[0], None)
super()._maybe_update_cacher(
clear=clear, verify_is_copy=verify_is_copy, inplace=inplace
)
# ----------------------------------------------------------------------
# Unsorted
def _is_mixed_type(self) -> bool:
return False
def repeat(self, repeats: int | Sequence[int], axis: None = None) -> Series:
"""
Repeat elements of a Series.
Returns a new Series where each element of the current Series
is repeated consecutively a given number of times.
Parameters
----------
repeats : int or array of ints
The number of repetitions for each element. This should be a
non-negative integer. Repeating 0 times will return an empty
Series.
axis : None
Unused. Parameter needed for compatibility with DataFrame.
Returns
-------
Series
Newly created Series with repeated elements.
See Also
--------
Index.repeat : Equivalent function for Index.
numpy.repeat : Similar method for :class:`numpy.ndarray`.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c'])
>>> s
0 a
1 b
2 c
dtype: object
>>> s.repeat(2)
0 a
0 a
1 b
1 b
2 c
2 c
dtype: object
>>> s.repeat([1, 2, 3])
0 a
1 b
1 b
2 c
2 c
2 c
dtype: object
"""
nv.validate_repeat((), {"axis": axis})
new_index = self.index.repeat(repeats)
new_values = self._values.repeat(repeats)
return self._constructor(new_values, index=new_index, copy=False).__finalize__(
self, method="repeat"
)
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[False] = ...,
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> DataFrame:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[True],
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> Series:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: bool = ...,
name: Level = ...,
inplace: Literal[True],
allow_duplicates: bool = ...,
) -> None:
...
def reset_index(
self,
level: IndexLabel = None,
*,
drop: bool = False,
name: Level = lib.no_default,
inplace: bool = False,
allow_duplicates: bool = False,
) -> DataFrame | Series | None:
"""
Generate a new DataFrame or Series with the index reset.
This is useful when the index needs to be treated as a column, or
when the index is meaningless and needs to be reset to the default
before another operation.
Parameters
----------
level : int, str, tuple, or list, default optional
For a Series with a MultiIndex, only remove the specified levels
from the index. Removes all levels by default.
drop : bool, default False
Just reset the index, without inserting it as a column in
the new DataFrame.
name : object, optional
The name to use for the column containing the original Series
values. Uses ``self.name`` by default. This argument is ignored
when `drop` is True.
inplace : bool, default False
Modify the Series in place (do not create a new object).
allow_duplicates : bool, default False
Allow duplicate column labels to be created.
.. versionadded:: 1.5.0
Returns
-------
Series or DataFrame or None
When `drop` is False (the default), a DataFrame is returned.
The newly created columns will come first in the DataFrame,
followed by the original Series values.
When `drop` is True, a `Series` is returned.
In either case, if ``inplace=True``, no value is returned.
See Also
--------
DataFrame.reset_index: Analogous function for DataFrame.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4], name='foo',
... index=pd.Index(['a', 'b', 'c', 'd'], name='idx'))
Generate a DataFrame with default index.
>>> s.reset_index()
idx foo
0 a 1
1 b 2
2 c 3
3 d 4
To specify the name of the new column use `name`.
>>> s.reset_index(name='values')
idx values
0 a 1
1 b 2
2 c 3
3 d 4
To generate a new Series with the default set `drop` to True.
>>> s.reset_index(drop=True)
0 1
1 2
2 3
3 4
Name: foo, dtype: int64
The `level` parameter is interesting for Series with a multi-level
index.
>>> arrays = [np.array(['bar', 'bar', 'baz', 'baz']),
... np.array(['one', 'two', 'one', 'two'])]
>>> s2 = pd.Series(
... range(4), name='foo',
... index=pd.MultiIndex.from_arrays(arrays,
... names=['a', 'b']))
To remove a specific level from the Index, use `level`.
>>> s2.reset_index(level='a')
a foo
b
one bar 0
two bar 1
one baz 2
two baz 3
If `level` is not set, all levels are removed from the Index.
>>> s2.reset_index()
a b foo
0 bar one 0
1 bar two 1
2 baz one 2
3 baz two 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if drop:
new_index = default_index(len(self))
if level is not None:
level_list: Sequence[Hashable]
if not isinstance(level, (tuple, list)):
level_list = [level]
else:
level_list = level
level_list = [self.index._get_level_number(lev) for lev in level_list]
if len(level_list) < self.index.nlevels:
new_index = self.index.droplevel(level_list)
if inplace:
self.index = new_index
elif using_copy_on_write():
new_ser = self.copy(deep=False)
new_ser.index = new_index
return new_ser.__finalize__(self, method="reset_index")
else:
return self._constructor(
self._values.copy(), index=new_index, copy=False
).__finalize__(self, method="reset_index")
elif inplace:
raise TypeError(
"Cannot reset_index inplace on a Series to create a DataFrame"
)
else:
if name is lib.no_default:
# For backwards compatibility, keep columns as [0] instead of
# [None] when self.name is None
if self.name is None:
name = 0
else:
name = self.name
df = self.to_frame(name)
return df.reset_index(
level=level, drop=drop, allow_duplicates=allow_duplicates
)
return None
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
"""
Return a string representation for a particular Series.
"""
# pylint: disable=invalid-repr-returned
repr_params = fmt.get_series_repr_params()
return self.to_string(**repr_params)
def to_string(
self,
buf: None = ...,
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> None:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
na_rep: str = "NaN",
float_format: str | None = None,
header: bool = True,
index: bool = True,
length: bool = False,
dtype: bool = False,
name: bool = False,
max_rows: int | None = None,
min_rows: int | None = None,
) -> str | None:
"""
Render a string representation of the Series.
Parameters
----------
buf : StringIO-like, optional
Buffer to write to.
na_rep : str, optional
String representation of NaN to use, default 'NaN'.
float_format : one-parameter function, optional
Formatter function to apply to columns' elements if they are
floats, default None.
header : bool, default True
Add the Series header (index name).
index : bool, optional
Add index (row) labels, default True.
length : bool, default False
Add the Series length.
dtype : bool, default False
Add the Series dtype.
name : bool, default False
Add the Series name if not None.
max_rows : int, optional
Maximum number of rows to show before truncating. If None, show
all.
min_rows : int, optional
The number of rows to display in a truncated repr (when number
of rows is above `max_rows`).
Returns
-------
str or None
String representation of Series if ``buf=None``, otherwise None.
"""
formatter = fmt.SeriesFormatter(
self,
name=name,
length=length,
header=header,
index=index,
dtype=dtype,
na_rep=na_rep,
float_format=float_format,
min_rows=min_rows,
max_rows=max_rows,
)
result = formatter.to_string()
# catch contract violations
if not isinstance(result, str):
raise AssertionError(
"result must be of type str, type "
f"of result is {repr(type(result).__name__)}"
)
if buf is None:
return result
else:
if hasattr(buf, "write"):
buf.write(result)
else:
with open(buf, "w") as f:
f.write(result)
return None
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples=dedent(
"""Examples
--------
>>> s = pd.Series(["elk", "pig", "dog", "quetzal"], name="animal")
>>> print(s.to_markdown())
| | animal |
|---:|:---------|
| 0 | elk |
| 1 | pig |
| 2 | dog |
| 3 | quetzal |
Output markdown with a tabulate option.
>>> print(s.to_markdown(tablefmt="grid"))
+----+----------+
| | animal |
+====+==========+
| 0 | elk |
+----+----------+
| 1 | pig |
+----+----------+
| 2 | dog |
+----+----------+
| 3 | quetzal |
+----+----------+"""
),
)
def to_markdown(
self,
buf: IO[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
"""
Print {klass} in Markdown-friendly format.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
mode : str, optional
Mode in which file is opened, "wt" by default.
index : bool, optional, default True
Add index (row) labels.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
**kwargs
These parameters will be passed to `tabulate \
<https://pypi.org/project/tabulate>`_.
Returns
-------
str
{klass} in Markdown-friendly format.
Notes
-----
Requires the `tabulate <https://pypi.org/project/tabulate>`_ package.
{examples}
"""
return self.to_frame().to_markdown(
buf, mode, index, storage_options=storage_options, **kwargs
)
# ----------------------------------------------------------------------
def items(self) -> Iterable[tuple[Hashable, Any]]:
"""
Lazily iterate over (index, value) tuples.
This method returns an iterable tuple (index, value). This is
convenient if you want to create a lazy iterator.
Returns
-------
iterable
Iterable of tuples containing the (index, value) pairs from a
Series.
See Also
--------
DataFrame.items : Iterate over (column name, Series) pairs.
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series) pairs.
Examples
--------
>>> s = pd.Series(['A', 'B', 'C'])
>>> for index, value in s.items():
... print(f"Index : {index}, Value : {value}")
Index : 0, Value : A
Index : 1, Value : B
Index : 2, Value : C
"""
return zip(iter(self.index), iter(self))
# ----------------------------------------------------------------------
# Misc public methods
def keys(self) -> Index:
"""
Return alias for index.
Returns
-------
Index
Index of the Series.
"""
return self.index
def to_dict(self, into: type[dict] = dict) -> dict:
"""
Convert Series to {label -> value} dict or dict-like object.
Parameters
----------
into : class, default dict
The collections.abc.Mapping subclass to use as the return
object. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
Returns
-------
collections.abc.Mapping
Key-value representation of Series.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.to_dict()
{0: 1, 1: 2, 2: 3, 3: 4}
>>> from collections import OrderedDict, defaultdict
>>> s.to_dict(OrderedDict)
OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
>>> dd = defaultdict(list)
>>> s.to_dict(dd)
defaultdict(<class 'list'>, {0: 1, 1: 2, 2: 3, 3: 4})
"""
# GH16122
into_c = com.standardize_mapping(into)
if is_object_dtype(self) or is_extension_array_dtype(self):
return into_c((k, maybe_box_native(v)) for k, v in self.items())
else:
# Not an object dtype => all types will be the same so let the default
# indexer return native python type
return into_c(self.items())
def to_frame(self, name: Hashable = lib.no_default) -> DataFrame:
"""
Convert Series to DataFrame.
Parameters
----------
name : object, optional
The passed name should substitute for the series name (if it has
one).
Returns
-------
DataFrame
DataFrame representation of Series.
Examples
--------
>>> s = pd.Series(["a", "b", "c"],
... name="vals")
>>> s.to_frame()
vals
0 a
1 b
2 c
"""
columns: Index
if name is lib.no_default:
name = self.name
if name is None:
# default to [0], same as we would get with DataFrame(self)
columns = default_index(1)
else:
columns = Index([name])
else:
columns = Index([name])
mgr = self._mgr.to_2d_mgr(columns)
df = self._constructor_expanddim(mgr)
return df.__finalize__(self, method="to_frame")
def _set_name(self, name, inplace: bool = False) -> Series:
"""
Set the Series name.
Parameters
----------
name : str
inplace : bool
Whether to modify `self` directly or return a copy.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
ser = self if inplace else self.copy()
ser.name = name
return ser
"""
Examples
--------
>>> ser = pd.Series([390., 350., 30., 20.],
... index=['Falcon', 'Falcon', 'Parrot', 'Parrot'], name="Max Speed")
>>> ser
Falcon 390.0
Falcon 350.0
Parrot 30.0
Parrot 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", "b"]).mean()
a 210.0
b 185.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(ser > 100).mean()
Max Speed
False 25.0
True 370.0
Name: Max Speed, dtype: float64
**Grouping by Indexes**
We can groupby different levels of a hierarchical index
using the `level` parameter:
>>> arrays = [['Falcon', 'Falcon', 'Parrot', 'Parrot'],
... ['Captive', 'Wild', 'Captive', 'Wild']]
>>> index = pd.MultiIndex.from_arrays(arrays, names=('Animal', 'Type'))
>>> ser = pd.Series([390., 350., 30., 20.], index=index, name="Max Speed")
>>> ser
Animal Type
Falcon Captive 390.0
Wild 350.0
Parrot Captive 30.0
Wild 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Animal
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level="Type").mean()
Type
Captive 210.0
Wild 185.0
Name: Max Speed, dtype: float64
We can also choose to include `NA` in group keys or not by defining
`dropna` parameter, the default setting is `True`.
>>> ser = pd.Series([1, 2, 3, 3], index=["a", 'a', 'b', np.nan])
>>> ser.groupby(level=0).sum()
a 3
b 3
dtype: int64
>>> ser.groupby(level=0, dropna=False).sum()
a 3
b 3
NaN 3
dtype: int64
>>> arrays = ['Falcon', 'Falcon', 'Parrot', 'Parrot']
>>> ser = pd.Series([390., 350., 30., 20.], index=arrays, name="Max Speed")
>>> ser.groupby(["a", "b", "a", np.nan]).mean()
a 210.0
b 350.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", np.nan], dropna=False).mean()
a 210.0
b 350.0
NaN 20.0
Name: Max Speed, dtype: float64
"""
)
def groupby(
self,
by=None,
axis: Axis = 0,
level: IndexLabel = None,
as_index: bool = True,
sort: bool = True,
group_keys: bool = True,
observed: bool = False,
dropna: bool = True,
) -> SeriesGroupBy:
from pandas.core.groupby.generic import SeriesGroupBy
if level is None and by is None:
raise TypeError("You have to supply one of 'by' and 'level'")
if not as_index:
raise TypeError("as_index=False only valid with DataFrame")
axis = self._get_axis_number(axis)
return SeriesGroupBy(
obj=self,
keys=by,
axis=axis,
level=level,
as_index=as_index,
sort=sort,
group_keys=group_keys,
observed=observed,
dropna=dropna,
)
# ----------------------------------------------------------------------
# Statistics, overridden ndarray methods
# TODO: integrate bottleneck
def count(self):
"""
Return number of non-NA/null observations in the Series.
Returns
-------
int or Series (if level specified)
Number of non-null values in the Series.
See Also
--------
DataFrame.count : Count non-NA cells for each column or row.
Examples
--------
>>> s = pd.Series([0.0, 1.0, np.nan])
>>> s.count()
2
"""
return notna(self._values).sum().astype("int64")
def mode(self, dropna: bool = True) -> Series:
"""
Return the mode(s) of the Series.
The mode is the value that appears most often. There can be multiple modes.
Always returns Series even if only one value is returned.
Parameters
----------
dropna : bool, default True
Don't consider counts of NaN/NaT.
Returns
-------
Series
Modes of the Series in sorted order.
"""
# TODO: Add option for bins like value_counts()
values = self._values
if isinstance(values, np.ndarray):
res_values = algorithms.mode(values, dropna=dropna)
else:
res_values = values._mode(dropna=dropna)
# Ensure index is type stable (should always use int index)
return self._constructor(
res_values, index=range(len(res_values)), name=self.name, copy=False
)
def unique(self) -> ArrayLike: # pylint: disable=useless-parent-delegation
"""
Return unique values of Series object.
Uniques are returned in order of appearance. Hash table-based unique,
therefore does NOT sort.
Returns
-------
ndarray or ExtensionArray
The unique values returned as a NumPy array. See Notes.
See Also
--------
Series.drop_duplicates : Return Series with duplicate values removed.
unique : Top-level unique method for any 1-d array-like object.
Index.unique : Return Index with unique values from an Index object.
Notes
-----
Returns the unique values as a NumPy array. In case of an
extension-array backed Series, a new
:class:`~api.extensions.ExtensionArray` of that type with just
the unique values is returned. This includes
* Categorical
* Period
* Datetime with Timezone
* Datetime without Timezone
* Timedelta
* Interval
* Sparse
* IntegerNA
See Examples section.
Examples
--------
>>> pd.Series([2, 1, 3, 3], name='A').unique()
array([2, 1, 3])
>>> pd.Series([pd.Timestamp('2016-01-01') for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00']
Length: 1, dtype: datetime64[ns]
>>> pd.Series([pd.Timestamp('2016-01-01', tz='US/Eastern')
... for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00-05:00']
Length: 1, dtype: datetime64[ns, US/Eastern]
An Categorical will return categories in the order of
appearance and with the same dtype.
>>> pd.Series(pd.Categorical(list('baabc'))).unique()
['b', 'a', 'c']
Categories (3, object): ['a', 'b', 'c']
>>> pd.Series(pd.Categorical(list('baabc'), categories=list('abc'),
... ordered=True)).unique()
['b', 'a', 'c']
Categories (3, object): ['a' < 'b' < 'c']
"""
return super().unique()
def drop_duplicates(
self,
*,
keep: DropKeep = ...,
inplace: Literal[False] = ...,
ignore_index: bool = ...,
) -> Series:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: Literal[True], ignore_index: bool = ...
) -> None:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: bool = ..., ignore_index: bool = ...
) -> Series | None:
...
def drop_duplicates(
self,
*,
keep: DropKeep = "first",
inplace: bool = False,
ignore_index: bool = False,
) -> Series | None:
"""
Return Series with duplicate values removed.
Parameters
----------
keep : {'first', 'last', ``False``}, default 'first'
Method to handle dropping duplicates:
- 'first' : Drop duplicates except for the first occurrence.
- 'last' : Drop duplicates except for the last occurrence.
- ``False`` : Drop all duplicates.
inplace : bool, default ``False``
If ``True``, performs operation inplace and returns None.
ignore_index : bool, default ``False``
If ``True``, the resulting axis will be labeled 0, 1, …, n - 1.
.. versionadded:: 2.0.0
Returns
-------
Series or None
Series with duplicates dropped or None if ``inplace=True``.
See Also
--------
Index.drop_duplicates : Equivalent method on Index.
DataFrame.drop_duplicates : Equivalent method on DataFrame.
Series.duplicated : Related method on Series, indicating duplicate
Series values.
Series.unique : Return unique values as an array.
Examples
--------
Generate a Series with duplicated entries.
>>> s = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama', 'hippo'],
... name='animal')
>>> s
0 lama
1 cow
2 lama
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
With the 'keep' parameter, the selection behaviour of duplicated values
can be changed. The value 'first' keeps the first occurrence for each
set of duplicated entries. The default value of keep is 'first'.
>>> s.drop_duplicates()
0 lama
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
The value 'last' for parameter 'keep' keeps the last occurrence for
each set of duplicated entries.
>>> s.drop_duplicates(keep='last')
1 cow
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
The value ``False`` for parameter 'keep' discards all sets of
duplicated entries.
>>> s.drop_duplicates(keep=False)
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
"""
inplace = validate_bool_kwarg(inplace, "inplace")
result = super().drop_duplicates(keep=keep)
if ignore_index:
result.index = default_index(len(result))
if inplace:
self._update_inplace(result)
return None
else:
return result
def duplicated(self, keep: DropKeep = "first") -> Series:
"""
Indicate duplicate Series values.
Duplicated values are indicated as ``True`` values in the resulting
Series. Either all duplicates, all except the first or all except the
last occurrence of duplicates can be indicated.
Parameters
----------
keep : {'first', 'last', False}, default 'first'
Method to handle dropping duplicates:
- 'first' : Mark duplicates as ``True`` except for the first
occurrence.
- 'last' : Mark duplicates as ``True`` except for the last
occurrence.
- ``False`` : Mark all duplicates as ``True``.
Returns
-------
Series[bool]
Series indicating whether each value has occurred in the
preceding values.
See Also
--------
Index.duplicated : Equivalent method on pandas.Index.
DataFrame.duplicated : Equivalent method on pandas.DataFrame.
Series.drop_duplicates : Remove duplicate values from Series.
Examples
--------
By default, for each set of duplicated values, the first occurrence is
set on False and all others on True:
>>> animals = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama'])
>>> animals.duplicated()
0 False
1 False
2 True
3 False
4 True
dtype: bool
which is equivalent to
>>> animals.duplicated(keep='first')
0 False
1 False
2 True
3 False
4 True
dtype: bool
By using 'last', the last occurrence of each set of duplicated values
is set on False and all others on True:
>>> animals.duplicated(keep='last')
0 True
1 False
2 True
3 False
4 False
dtype: bool
By setting keep on ``False``, all duplicates are True:
>>> animals.duplicated(keep=False)
0 True
1 False
2 True
3 False
4 True
dtype: bool
"""
res = self._duplicated(keep=keep)
result = self._constructor(res, index=self.index, copy=False)
return result.__finalize__(self, method="duplicated")
def idxmin(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the minimum value.
If multiple values equal the minimum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the minimum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmin : Return indices of the minimum values
along the given axis.
DataFrame.idxmin : Return index of first occurrence of minimum
over requested axis.
Series.idxmax : Return index *label* of the first occurrence
of maximum of values.
Notes
-----
This method is the Series version of ``ndarray.argmin``. This method
returns the label of the minimum, while ``ndarray.argmin`` returns
the position. To get the position, use ``series.values.argmin()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 1],
... index=['A', 'B', 'C', 'D'])
>>> s
A 1.0
B NaN
C 4.0
D 1.0
dtype: float64
>>> s.idxmin()
'A'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmin(skipna=False)
nan
"""
# error: Argument 1 to "argmin" of "IndexOpsMixin" has incompatible type "Union
# [int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmin(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def idxmax(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the maximum value.
If multiple values equal the maximum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the maximum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmax : Return indices of the maximum values
along the given axis.
DataFrame.idxmax : Return index of first occurrence of maximum
over requested axis.
Series.idxmin : Return index *label* of the first occurrence
of minimum of values.
Notes
-----
This method is the Series version of ``ndarray.argmax``. This method
returns the label of the maximum, while ``ndarray.argmax`` returns
the position. To get the position, use ``series.values.argmax()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 3, 4],
... index=['A', 'B', 'C', 'D', 'E'])
>>> s
A 1.0
B NaN
C 4.0
D 3.0
E 4.0
dtype: float64
>>> s.idxmax()
'C'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmax(skipna=False)
nan
"""
# error: Argument 1 to "argmax" of "IndexOpsMixin" has incompatible type
# "Union[int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmax(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def round(self, decimals: int = 0, *args, **kwargs) -> Series:
"""
Round each value in a Series to the given number of decimals.
Parameters
----------
decimals : int, default 0
Number of decimal places to round to. If decimals is negative,
it specifies the number of positions to the left of the decimal point.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Series
Rounded values of the Series.
See Also
--------
numpy.around : Round values of an np.array.
DataFrame.round : Round values of a DataFrame.
Examples
--------
>>> s = pd.Series([0.1, 1.3, 2.7])
>>> s.round()
0 0.0
1 1.0
2 3.0
dtype: float64
"""
nv.validate_round(args, kwargs)
result = self._values.round(decimals)
result = self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="round"
)
return result
def quantile(
self, q: float = ..., interpolation: QuantileInterpolation = ...
) -> float:
...
def quantile(
self,
q: Sequence[float] | AnyArrayLike,
interpolation: QuantileInterpolation = ...,
) -> Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = ...,
interpolation: QuantileInterpolation = ...,
) -> float | Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = 0.5,
interpolation: QuantileInterpolation = "linear",
) -> float | Series:
"""
Return value at the given quantile.
Parameters
----------
q : float or array-like, default 0.5 (50% quantile)
The quantile(s) to compute, which can lie in range: 0 <= q <= 1.
interpolation : {'linear', 'lower', 'higher', 'midpoint', 'nearest'}
This optional parameter specifies the interpolation method to use,
when the desired quantile lies between two data points `i` and `j`:
* linear: `i + (j - i) * fraction`, where `fraction` is the
fractional part of the index surrounded by `i` and `j`.
* lower: `i`.
* higher: `j`.
* nearest: `i` or `j` whichever is nearest.
* midpoint: (`i` + `j`) / 2.
Returns
-------
float or Series
If ``q`` is an array, a Series will be returned where the
index is ``q`` and the values are the quantiles, otherwise
a float will be returned.
See Also
--------
core.window.Rolling.quantile : Calculate the rolling quantile.
numpy.percentile : Returns the q-th percentile(s) of the array elements.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.quantile(.5)
2.5
>>> s.quantile([.25, .5, .75])
0.25 1.75
0.50 2.50
0.75 3.25
dtype: float64
"""
validate_percentile(q)
# We dispatch to DataFrame so that core.internals only has to worry
# about 2D cases.
df = self.to_frame()
result = df.quantile(q=q, interpolation=interpolation, numeric_only=False)
if result.ndim == 2:
result = result.iloc[:, 0]
if is_list_like(q):
result.name = self.name
idx = Index(q, dtype=np.float64)
return self._constructor(result, index=idx, name=self.name)
else:
# scalar
return result.iloc[0]
def corr(
self,
other: Series,
method: CorrelationMethod = "pearson",
min_periods: int | None = None,
) -> float:
"""
Compute correlation with `other` Series, excluding missing values.
The two `Series` objects are not required to be the same length and will be
aligned internally before the correlation function is applied.
Parameters
----------
other : Series
Series with which to compute the correlation.
method : {'pearson', 'kendall', 'spearman'} or callable
Method used to compute correlation:
- pearson : Standard correlation coefficient
- kendall : Kendall Tau correlation coefficient
- spearman : Spearman rank correlation
- callable: Callable with input two 1d ndarrays and returning a float.
.. warning::
Note that the returned matrix from corr will have 1 along the
diagonals and will be symmetric regardless of the callable's
behavior.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
Returns
-------
float
Correlation with other.
See Also
--------
DataFrame.corr : Compute pairwise correlation between columns.
DataFrame.corrwith : Compute pairwise correlation with another
DataFrame or Series.
Notes
-----
Pearson, Kendall and Spearman correlation are currently computed using pairwise complete observations.
* `Pearson correlation coefficient <https://en.wikipedia.org/wiki/Pearson_correlation_coefficient>`_
* `Kendall rank correlation coefficient <https://en.wikipedia.org/wiki/Kendall_rank_correlation_coefficient>`_
* `Spearman's rank correlation coefficient <https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient>`_
Examples
--------
>>> def histogram_intersection(a, b):
... v = np.minimum(a, b).sum().round(decimals=1)
... return v
>>> s1 = pd.Series([.2, .0, .6, .2])
>>> s2 = pd.Series([.3, .6, .0, .1])
>>> s1.corr(s2, method=histogram_intersection)
0.3
""" # noqa:E501
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
if method in ["pearson", "spearman", "kendall"] or callable(method):
return nanops.nancorr(
this.values, other.values, method=method, min_periods=min_periods
)
raise ValueError(
"method must be either 'pearson', "
"'spearman', 'kendall', or a callable, "
f"'{method}' was supplied"
)
def cov(
self,
other: Series,
min_periods: int | None = None,
ddof: int | None = 1,
) -> float:
"""
Compute covariance with Series, excluding missing values.
The two `Series` objects are not required to be the same length and
will be aligned internally before the covariance is calculated.
Parameters
----------
other : Series
Series with which to compute the covariance.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
ddof : int, default 1
Delta degrees of freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.
.. versionadded:: 1.1.0
Returns
-------
float
Covariance between Series and other normalized by N-1
(unbiased estimator).
See Also
--------
DataFrame.cov : Compute pairwise covariance of columns.
Examples
--------
>>> s1 = pd.Series([0.90010907, 0.13484424, 0.62036035])
>>> s2 = pd.Series([0.12528585, 0.26962463, 0.51111198])
>>> s1.cov(s2)
-0.01685762652715874
"""
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
return nanops.nancov(
this.values, other.values, min_periods=min_periods, ddof=ddof
)
klass="Series",
extra_params="",
other_klass="DataFrame",
examples=dedent(
"""
Difference with previous row
>>> s = pd.Series([1, 1, 2, 3, 5, 8])
>>> s.diff()
0 NaN
1 0.0
2 1.0
3 1.0
4 2.0
5 3.0
dtype: float64
Difference with 3rd previous row
>>> s.diff(periods=3)
0 NaN
1 NaN
2 NaN
3 2.0
4 4.0
5 6.0
dtype: float64
Difference with following row
>>> s.diff(periods=-1)
0 0.0
1 -1.0
2 -1.0
3 -2.0
4 -3.0
5 NaN
dtype: float64
Overflow in input dtype
>>> s = pd.Series([1, 0], dtype=np.uint8)
>>> s.diff()
0 NaN
1 255.0
dtype: float64"""
),
)
def diff(self, periods: int = 1) -> Series:
"""
First discrete difference of element.
Calculates the difference of a {klass} element compared with another
element in the {klass} (default is element in previous row).
Parameters
----------
periods : int, default 1
Periods to shift for calculating difference, accepts negative
values.
{extra_params}
Returns
-------
{klass}
First differences of the Series.
See Also
--------
{klass}.pct_change: Percent change over given number of periods.
{klass}.shift: Shift index by desired number of periods with an
optional time freq.
{other_klass}.diff: First discrete difference of object.
Notes
-----
For boolean dtypes, this uses :meth:`operator.xor` rather than
:meth:`operator.sub`.
The result is calculated according to current dtype in {klass},
however dtype of the result is always float64.
Examples
--------
{examples}
"""
result = algorithms.diff(self._values, periods)
return self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="diff"
)
def autocorr(self, lag: int = 1) -> float:
"""
Compute the lag-N autocorrelation.
This method computes the Pearson correlation between
the Series and its shifted self.
Parameters
----------
lag : int, default 1
Number of lags to apply before performing autocorrelation.
Returns
-------
float
The Pearson correlation between self and self.shift(lag).
See Also
--------
Series.corr : Compute the correlation between two Series.
Series.shift : Shift index by desired number of periods.
DataFrame.corr : Compute pairwise correlation of columns.
DataFrame.corrwith : Compute pairwise correlation between rows or
columns of two DataFrame objects.
Notes
-----
If the Pearson correlation is not well defined return 'NaN'.
Examples
--------
>>> s = pd.Series([0.25, 0.5, 0.2, -0.05])
>>> s.autocorr() # doctest: +ELLIPSIS
0.10355...
>>> s.autocorr(lag=2) # doctest: +ELLIPSIS
-0.99999...
If the Pearson correlation is not well defined, then 'NaN' is returned.
>>> s = pd.Series([1, 0, 0, 0])
>>> s.autocorr()
nan
"""
return self.corr(self.shift(lag))
def dot(self, other: AnyArrayLike) -> Series | np.ndarray:
"""
Compute the dot product between the Series and the columns of other.
This method computes the dot product between the Series and another
one, or the Series and each columns of a DataFrame, or the Series and
each columns of an array.
It can also be called using `self @ other` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the dot product with its columns.
Returns
-------
scalar, Series or numpy.ndarray
Return the dot product of the Series and other if other is a
Series, the Series of the dot product of Series and each rows of
other if other is a DataFrame or a numpy.ndarray between the Series
and each columns of the numpy array.
See Also
--------
DataFrame.dot: Compute the matrix product with the DataFrame.
Series.mul: Multiplication of series and other, element-wise.
Notes
-----
The Series and other has to share the same index if other is a Series
or a DataFrame.
Examples
--------
>>> s = pd.Series([0, 1, 2, 3])
>>> other = pd.Series([-1, 2, -3, 4])
>>> s.dot(other)
8
>>> s @ other
8
>>> df = pd.DataFrame([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(df)
0 24
1 14
dtype: int64
>>> arr = np.array([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(arr)
array([24, 14])
"""
if isinstance(other, (Series, ABCDataFrame)):
common = self.index.union(other.index)
if len(common) > len(self.index) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(index=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right.values
else:
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[0] != rvals.shape[0]:
raise Exception(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, ABCDataFrame):
return self._constructor(
np.dot(lvals, rvals), index=other.columns, copy=False
).__finalize__(self, method="dot")
elif isinstance(other, Series):
return np.dot(lvals, rvals)
elif isinstance(rvals, np.ndarray):
return np.dot(lvals, rvals)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(np.transpose(other))
# Signature of "searchsorted" incompatible with supertype "IndexOpsMixin"
def searchsorted( # type: ignore[override]
self,
value: NumpyValueArrayLike | ExtensionArray,
side: Literal["left", "right"] = "left",
sorter: NumpySorter = None,
) -> npt.NDArray[np.intp] | np.intp:
return base.IndexOpsMixin.searchsorted(self, value, side=side, sorter=sorter)
# -------------------------------------------------------------------
# Combination
def _append(
self, to_append, ignore_index: bool = False, verify_integrity: bool = False
):
from pandas.core.reshape.concat import concat
if isinstance(to_append, (list, tuple)):
to_concat = [self]
to_concat.extend(to_append)
else:
to_concat = [self, to_append]
if any(isinstance(x, (ABCDataFrame,)) for x in to_concat[1:]):
msg = "to_append should be a Series or list/tuple of Series, got DataFrame"
raise TypeError(msg)
return concat(
to_concat, ignore_index=ignore_index, verify_integrity=verify_integrity
)
def _binop(self, other: Series, func, level=None, fill_value=None):
"""
Perform generic binary operation with optional fill value.
Parameters
----------
other : Series
func : binary operator
fill_value : float or object
Value to substitute for NA/null values. If both Series are NA in a
location, the result will be NA regardless of the passed fill value.
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
Returns
-------
Series
"""
if not isinstance(other, Series):
raise AssertionError("Other operand must be Series")
this = self
if not self.index.equals(other.index):
this, other = self.align(other, level=level, join="outer", copy=False)
this_vals, other_vals = ops.fill_binop(this._values, other._values, fill_value)
with np.errstate(all="ignore"):
result = func(this_vals, other_vals)
name = ops.get_op_result_name(self, other)
return this._construct_result(result, name)
def _construct_result(
self, result: ArrayLike | tuple[ArrayLike, ArrayLike], name: Hashable
) -> Series | tuple[Series, Series]:
"""
Construct an appropriately-labelled Series from the result of an op.
Parameters
----------
result : ndarray or ExtensionArray
name : Label
Returns
-------
Series
In the case of __divmod__ or __rdivmod__, a 2-tuple of Series.
"""
if isinstance(result, tuple):
# produced by divmod or rdivmod
res1 = self._construct_result(result[0], name=name)
res2 = self._construct_result(result[1], name=name)
# GH#33427 assertions to keep mypy happy
assert isinstance(res1, Series)
assert isinstance(res2, Series)
return (res1, res2)
# TODO: result should always be ArrayLike, but this fails for some
# JSONArray tests
dtype = getattr(result, "dtype", None)
out = self._constructor(result, index=self.index, dtype=dtype)
out = out.__finalize__(self)
# Set the result's name after __finalize__ is called because __finalize__
# would set it back to self.name
out.name = name
return out
_shared_docs["compare"],
"""
Returns
-------
Series or DataFrame
If axis is 0 or 'index' the result will be a Series.
The resulting index will be a MultiIndex with 'self' and 'other'
stacked alternately at the inner level.
If axis is 1 or 'columns' the result will be a DataFrame.
It will have two columns namely 'self' and 'other'.
See Also
--------
DataFrame.compare : Compare with another DataFrame and show differences.
Notes
-----
Matching NaNs will not appear as a difference.
Examples
--------
>>> s1 = pd.Series(["a", "b", "c", "d", "e"])
>>> s2 = pd.Series(["a", "a", "c", "b", "e"])
Align the differences on columns
>>> s1.compare(s2)
self other
1 b a
3 d b
Stack the differences on indices
>>> s1.compare(s2, align_axis=0)
1 self b
other a
3 self d
other b
dtype: object
Keep all original rows
>>> s1.compare(s2, keep_shape=True)
self other
0 NaN NaN
1 b a
2 NaN NaN
3 d b
4 NaN NaN
Keep all original rows and also all original values
>>> s1.compare(s2, keep_shape=True, keep_equal=True)
self other
0 a a
1 b a
2 c c
3 d b
4 e e
""",
klass=_shared_doc_kwargs["klass"],
)
def compare(
self,
other: Series,
align_axis: Axis = 1,
keep_shape: bool = False,
keep_equal: bool = False,
result_names: Suffixes = ("self", "other"),
) -> DataFrame | Series:
return super().compare(
other=other,
align_axis=align_axis,
keep_shape=keep_shape,
keep_equal=keep_equal,
result_names=result_names,
)
def combine(
self,
other: Series | Hashable,
func: Callable[[Hashable, Hashable], Hashable],
fill_value: Hashable = None,
) -> Series:
"""
Combine the Series with a Series or scalar according to `func`.
Combine the Series and `other` using `func` to perform elementwise
selection for combined Series.
`fill_value` is assumed when value is missing at some index
from one of the two objects being combined.
Parameters
----------
other : Series or scalar
The value(s) to be combined with the `Series`.
func : function
Function that takes two scalars as inputs and returns an element.
fill_value : scalar, optional
The value to assume when an index is missing from
one Series or the other. The default specifies to use the
appropriate NaN value for the underlying dtype of the Series.
Returns
-------
Series
The result of combining the Series with the other object.
See Also
--------
Series.combine_first : Combine Series values, choosing the calling
Series' values first.
Examples
--------
Consider 2 Datasets ``s1`` and ``s2`` containing
highest clocked speeds of different birds.
>>> s1 = pd.Series({'falcon': 330.0, 'eagle': 160.0})
>>> s1
falcon 330.0
eagle 160.0
dtype: float64
>>> s2 = pd.Series({'falcon': 345.0, 'eagle': 200.0, 'duck': 30.0})
>>> s2
falcon 345.0
eagle 200.0
duck 30.0
dtype: float64
Now, to combine the two datasets and view the highest speeds
of the birds across the two datasets
>>> s1.combine(s2, max)
duck NaN
eagle 200.0
falcon 345.0
dtype: float64
In the previous example, the resulting value for duck is missing,
because the maximum of a NaN and a float is a NaN.
So, in the example, we set ``fill_value=0``,
so the maximum value returned will be the value from some dataset.
>>> s1.combine(s2, max, fill_value=0)
duck 30.0
eagle 200.0
falcon 345.0
dtype: float64
"""
if fill_value is None:
fill_value = na_value_for_dtype(self.dtype, compat=False)
if isinstance(other, Series):
# If other is a Series, result is based on union of Series,
# so do this element by element
new_index = self.index.union(other.index)
new_name = ops.get_op_result_name(self, other)
new_values = np.empty(len(new_index), dtype=object)
for i, idx in enumerate(new_index):
lv = self.get(idx, fill_value)
rv = other.get(idx, fill_value)
with np.errstate(all="ignore"):
new_values[i] = func(lv, rv)
else:
# Assume that other is a scalar, so apply the function for
# each element in the Series
new_index = self.index
new_values = np.empty(len(new_index), dtype=object)
with np.errstate(all="ignore"):
new_values[:] = [func(lv, other) for lv in self._values]
new_name = self.name
# try_float=False is to match agg_series
npvalues = lib.maybe_convert_objects(new_values, try_float=False)
res_values = maybe_cast_pointwise_result(npvalues, self.dtype, same_dtype=False)
return self._constructor(res_values, index=new_index, name=new_name, copy=False)
def combine_first(self, other) -> Series:
"""
Update null elements with value in the same location in 'other'.
Combine two Series objects by filling null values in one Series with
non-null values from the other Series. Result index will be the union
of the two indexes.
Parameters
----------
other : Series
The value(s) to be used for filling null values.
Returns
-------
Series
The result of combining the provided Series with the other object.
See Also
--------
Series.combine : Perform element-wise operation on two Series
using a given function.
Examples
--------
>>> s1 = pd.Series([1, np.nan])
>>> s2 = pd.Series([3, 4, 5])
>>> s1.combine_first(s2)
0 1.0
1 4.0
2 5.0
dtype: float64
Null values still persist if the location of that null value
does not exist in `other`
>>> s1 = pd.Series({'falcon': np.nan, 'eagle': 160.0})
>>> s2 = pd.Series({'eagle': 200.0, 'duck': 30.0})
>>> s1.combine_first(s2)
duck 30.0
eagle 160.0
falcon NaN
dtype: float64
"""
new_index = self.index.union(other.index)
this = self.reindex(new_index, copy=False)
other = other.reindex(new_index, copy=False)
if this.dtype.kind == "M" and other.dtype.kind != "M":
other = to_datetime(other)
return this.where(notna(this), other)
def update(self, other: Series | Sequence | Mapping) -> None:
"""
Modify Series in place using values from passed Series.
Uses non-NA values from passed Series to make updates. Aligns
on index.
Parameters
----------
other : Series, or object coercible into Series
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6]))
>>> s
0 4
1 5
2 6
dtype: int64
>>> s = pd.Series(['a', 'b', 'c'])
>>> s.update(pd.Series(['d', 'e'], index=[0, 2]))
>>> s
0 d
1 b
2 e
dtype: object
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6, 7, 8]))
>>> s
0 4
1 5
2 6
dtype: int64
If ``other`` contains NaNs the corresponding values are not updated
in the original Series.
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, np.nan, 6]))
>>> s
0 4
1 2
2 6
dtype: int64
``other`` can also be a non-Series object type
that is coercible into a Series
>>> s = pd.Series([1, 2, 3])
>>> s.update([4, np.nan, 6])
>>> s
0 4
1 2
2 6
dtype: int64
>>> s = pd.Series([1, 2, 3])
>>> s.update({1: 9})
>>> s
0 1
1 9
2 3
dtype: int64
"""
if not isinstance(other, Series):
other = Series(other)
other = other.reindex_like(self)
mask = notna(other)
self._mgr = self._mgr.putmask(mask=mask, new=other)
self._maybe_update_cacher()
# ----------------------------------------------------------------------
# Reindexing, sorting
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> Series:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self,
*,
axis: Axis = 0,
ascending: bool | int | Sequence[bool] | Sequence[int] = True,
inplace: bool = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool = False,
key: ValueKeyFunc = None,
) -> Series | None:
"""
Sort by the values.
Sort a Series in ascending or descending order by some
criterion.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
ascending : bool or list of bools, default True
If True, sort values in ascending order, otherwise descending.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
na_position : {'first' or 'last'}, default 'last'
Argument 'first' puts NaNs at the beginning, 'last' puts NaNs at
the end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the series values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return an array-like.
.. versionadded:: 1.1.0
Returns
-------
Series or None
Series ordered by values or None if ``inplace=True``.
See Also
--------
Series.sort_index : Sort by the Series indices.
DataFrame.sort_values : Sort DataFrame by the values along either axis.
DataFrame.sort_index : Sort DataFrame by indices.
Examples
--------
>>> s = pd.Series([np.nan, 1, 3, 10, 5])
>>> s
0 NaN
1 1.0
2 3.0
3 10.0
4 5.0
dtype: float64
Sort values ascending order (default behaviour)
>>> s.sort_values(ascending=True)
1 1.0
2 3.0
4 5.0
3 10.0
0 NaN
dtype: float64
Sort values descending order
>>> s.sort_values(ascending=False)
3 10.0
4 5.0
2 3.0
1 1.0
0 NaN
dtype: float64
Sort values putting NAs first
>>> s.sort_values(na_position='first')
0 NaN
1 1.0
2 3.0
4 5.0
3 10.0
dtype: float64
Sort a series of strings
>>> s = pd.Series(['z', 'b', 'd', 'a', 'c'])
>>> s
0 z
1 b
2 d
3 a
4 c
dtype: object
>>> s.sort_values()
3 a
1 b
4 c
2 d
0 z
dtype: object
Sort using a key function. Your `key` function will be
given the ``Series`` of values and should return an array-like.
>>> s = pd.Series(['a', 'B', 'c', 'D', 'e'])
>>> s.sort_values()
1 B
3 D
0 a
2 c
4 e
dtype: object
>>> s.sort_values(key=lambda x: x.str.lower())
0 a
1 B
2 c
3 D
4 e
dtype: object
NumPy ufuncs work well here. For example, we can
sort by the ``sin`` of the value
>>> s = pd.Series([-4, -2, 0, 2, 4])
>>> s.sort_values(key=np.sin)
1 -2
4 4
2 0
0 -4
3 2
dtype: int64
More complicated user-defined functions can be used,
as long as they expect a Series and return an array-like
>>> s.sort_values(key=lambda x: (np.tan(x.cumsum())))
0 -4
3 2
4 4
1 -2
2 0
dtype: int64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
# Validate the axis parameter
self._get_axis_number(axis)
# GH 5856/5853
if inplace and self._is_cached:
raise ValueError(
"This Series is a view of some other array, to "
"sort in-place you must create a copy"
)
if is_list_like(ascending):
ascending = cast(Sequence[Union[bool, int]], ascending)
if len(ascending) != 1:
raise ValueError(
f"Length of ascending ({len(ascending)}) must be 1 for Series"
)
ascending = ascending[0]
ascending = validate_ascending(ascending)
if na_position not in ["first", "last"]:
raise ValueError(f"invalid na_position: {na_position}")
# GH 35922. Make sorting stable by leveraging nargsort
values_to_sort = ensure_key_mapped(self, key)._values if key else self._values
sorted_index = nargsort(values_to_sort, kind, bool(ascending), na_position)
if is_range_indexer(sorted_index, len(sorted_index)):
if inplace:
return self._update_inplace(self)
return self.copy(deep=None)
result = self._constructor(
self._values[sorted_index], index=self.index[sorted_index], copy=False
)
if ignore_index:
result.index = default_index(len(sorted_index))
if not inplace:
return result.__finalize__(self, method="sort_values")
self._update_inplace(result)
return None
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: bool = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series | None:
...
def sort_index(
self,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool | Sequence[bool] = True,
inplace: bool = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool = True,
ignore_index: bool = False,
key: IndexKeyFunc = None,
) -> Series | None:
"""
Sort Series by index labels.
Returns a new Series sorted by label if `inplace` argument is
``False``, otherwise updates the original series and returns None.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
level : int, optional
If not None, sort on values in specified index level(s).
ascending : bool or list-like of bools, default True
Sort ascending vs. descending. When the index is a MultiIndex the
sort direction can be controlled for each level individually.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
If 'first' puts NaNs at the beginning, 'last' puts NaNs at the end.
Not implemented for MultiIndex.
sort_remaining : bool, default True
If True and sorting by level and index is multilevel, sort by other
levels too (in order) after sorting by specified level.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the index values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect an
``Index`` and return an ``Index`` of the same shape.
.. versionadded:: 1.1.0
Returns
-------
Series or None
The original Series sorted by the labels or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index: Sort DataFrame by the index.
DataFrame.sort_values: Sort DataFrame by the value.
Series.sort_values : Sort Series by the value.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, 4])
>>> s.sort_index()
1 c
2 b
3 a
4 d
dtype: object
Sort Descending
>>> s.sort_index(ascending=False)
4 d
3 a
2 b
1 c
dtype: object
By default NaNs are put at the end, but use `na_position` to place
them at the beginning
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, np.nan])
>>> s.sort_index(na_position='first')
NaN d
1.0 c
2.0 b
3.0 a
dtype: object
Specify index level to sort
>>> arrays = [np.array(['qux', 'qux', 'foo', 'foo',
... 'baz', 'baz', 'bar', 'bar']),
... np.array(['two', 'one', 'two', 'one',
... 'two', 'one', 'two', 'one'])]
>>> s = pd.Series([1, 2, 3, 4, 5, 6, 7, 8], index=arrays)
>>> s.sort_index(level=1)
bar one 8
baz one 6
foo one 4
qux one 2
bar two 7
baz two 5
foo two 3
qux two 1
dtype: int64
Does not sort by remaining levels when sorting by levels
>>> s.sort_index(level=1, sort_remaining=False)
qux one 2
foo one 4
baz one 6
bar one 8
qux two 1
foo two 3
baz two 5
bar two 7
dtype: int64
Apply a key function before sorting
>>> s = pd.Series([1, 2, 3, 4], index=['A', 'b', 'C', 'd'])
>>> s.sort_index(key=lambda x : x.str.lower())
A 1
b 2
C 3
d 4
dtype: int64
"""
return super().sort_index(
axis=axis,
level=level,
ascending=ascending,
inplace=inplace,
kind=kind,
na_position=na_position,
sort_remaining=sort_remaining,
ignore_index=ignore_index,
key=key,
)
def argsort(
self,
axis: Axis = 0,
kind: SortKind = "quicksort",
order: None = None,
) -> Series:
"""
Return the integer indices that would sort the Series values.
Override ndarray.argsort. Argsorts the value, omitting NA/null values,
and places the result in the same locations as the non-NA values.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
kind : {'mergesort', 'quicksort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
order : None
Has no effect but is accepted for compatibility with numpy.
Returns
-------
Series[np.intp]
Positions of values within the sort order with -1 indicating
nan values.
See Also
--------
numpy.ndarray.argsort : Returns the indices that would sort this array.
"""
values = self._values
mask = isna(values)
if mask.any():
result = np.full(len(self), -1, dtype=np.intp)
notmask = ~mask
result[notmask] = np.argsort(values[notmask], kind=kind)
else:
result = np.argsort(values, kind=kind)
res = self._constructor(
result, index=self.index, name=self.name, dtype=np.intp, copy=False
)
return res.__finalize__(self, method="argsort")
def nlargest(
self, n: int = 5, keep: Literal["first", "last", "all"] = "first"
) -> Series:
"""
Return the largest `n` elements.
Parameters
----------
n : int, default 5
Return this many descending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` largest values in the Series, sorted in decreasing order.
See Also
--------
Series.nsmallest: Get the `n` smallest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values(ascending=False).head(n)`` for small `n`
relative to the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Malta": 434000, "Maldives": 434000,
... "Brunei": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Malta 434000
Maldives 434000
Brunei 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` largest elements where ``n=5`` by default.
>>> s.nlargest()
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3``. Default `keep` value is 'first'
so Malta will be kept.
>>> s.nlargest(3)
France 65000000
Italy 59000000
Malta 434000
dtype: int64
The `n` largest elements where ``n=3`` and keeping the last duplicates.
Brunei will be kept since it is the last with value 434000 based on
the index order.
>>> s.nlargest(3, keep='last')
France 65000000
Italy 59000000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has five elements due to the three duplicates.
>>> s.nlargest(3, keep='all')
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nlargest()
def nsmallest(self, n: int = 5, keep: str = "first") -> Series:
"""
Return the smallest `n` elements.
Parameters
----------
n : int, default 5
Return this many ascending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` smallest values in the Series, sorted in increasing order.
See Also
--------
Series.nlargest: Get the `n` largest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values().head(n)`` for small `n` relative to
the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Brunei": 434000, "Malta": 434000,
... "Maldives": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Brunei 434000
Malta 434000
Maldives 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` smallest elements where ``n=5`` by default.
>>> s.nsmallest()
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
Iceland 337000
dtype: int64
The `n` smallest elements where ``n=3``. Default `keep` value is
'first' so Nauru and Tuvalu will be kept.
>>> s.nsmallest(3)
Montserrat 5200
Nauru 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` and keeping the last
duplicates. Anguilla and Tuvalu will be kept since they are the last
with value 11300 based on the index order.
>>> s.nsmallest(3, keep='last')
Montserrat 5200
Anguilla 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has four elements due to the three duplicates.
>>> s.nsmallest(3, keep='all')
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nsmallest()
klass=_shared_doc_kwargs["klass"],
extra_params=dedent(
"""copy : bool, default True
Whether to copy underlying data."""
),
examples=dedent(
"""\
Examples
--------
>>> s = pd.Series(
... ["A", "B", "A", "C"],
... index=[
... ["Final exam", "Final exam", "Coursework", "Coursework"],
... ["History", "Geography", "History", "Geography"],
... ["January", "February", "March", "April"],
... ],
... )
>>> s
Final exam History January A
Geography February B
Coursework History March A
Geography April C
dtype: object
In the following example, we will swap the levels of the indices.
Here, we will swap the levels column-wise, but levels can be swapped row-wise
in a similar manner. Note that column-wise is the default behaviour.
By not supplying any arguments for i and j, we swap the last and second to
last indices.
>>> s.swaplevel()
Final exam January History A
February Geography B
Coursework March History A
April Geography C
dtype: object
By supplying one argument, we can choose which index to swap the last
index with. We can for example swap the first index with the last one as
follows.
>>> s.swaplevel(0)
January History Final exam A
February Geography Final exam B
March History Coursework A
April Geography Coursework C
dtype: object
We can also define explicitly which indices we want to swap by supplying values
for both i and j. Here, we for example swap the first and second indices.
>>> s.swaplevel(0, 1)
History Final exam January A
Geography Final exam February B
History Coursework March A
Geography Coursework April C
dtype: object"""
),
)
def swaplevel(
self, i: Level = -2, j: Level = -1, copy: bool | None = None
) -> Series:
"""
Swap levels i and j in a :class:`MultiIndex`.
Default is to swap the two innermost levels of the index.
Parameters
----------
i, j : int or str
Levels of the indices to be swapped. Can pass level name as string.
{extra_params}
Returns
-------
{klass}
{klass} with levels swapped in MultiIndex.
{examples}
"""
assert isinstance(self.index, MultiIndex)
result = self.copy(deep=copy and not using_copy_on_write())
result.index = self.index.swaplevel(i, j)
return result
def reorder_levels(self, order: Sequence[Level]) -> Series:
"""
Rearrange index levels using input order.
May not drop or duplicate levels.
Parameters
----------
order : list of int representing new level order
Reference level by number or key.
Returns
-------
type of caller (new object)
"""
if not isinstance(self.index, MultiIndex): # pragma: no cover
raise Exception("Can only reorder levels on a hierarchical axis.")
result = self.copy(deep=None)
assert isinstance(result.index, MultiIndex)
result.index = result.index.reorder_levels(order)
return result
def explode(self, ignore_index: bool = False) -> Series:
"""
Transform each element of a list-like to a row.
Parameters
----------
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.1.0
Returns
-------
Series
Exploded lists to rows; index will be duplicated for these rows.
See Also
--------
Series.str.split : Split string values on specified separator.
Series.unstack : Unstack, a.k.a. pivot, Series with MultiIndex
to produce DataFrame.
DataFrame.melt : Unpivot a DataFrame from wide format to long format.
DataFrame.explode : Explode a DataFrame from list-like
columns to long format.
Notes
-----
This routine will explode list-likes including lists, tuples, sets,
Series, and np.ndarray. The result dtype of the subset rows will
be object. Scalars will be returned unchanged, and empty list-likes will
result in a np.nan for that row. In addition, the ordering of elements in
the output will be non-deterministic when exploding sets.
Reference :ref:`the user guide <reshaping.explode>` for more examples.
Examples
--------
>>> s = pd.Series([[1, 2, 3], 'foo', [], [3, 4]])
>>> s
0 [1, 2, 3]
1 foo
2 []
3 [3, 4]
dtype: object
>>> s.explode()
0 1
0 2
0 3
1 foo
2 NaN
3 3
3 4
dtype: object
"""
if not len(self) or not is_object_dtype(self):
result = self.copy()
return result.reset_index(drop=True) if ignore_index else result
values, counts = reshape.explode(np.asarray(self._values))
if ignore_index:
index = default_index(len(values))
else:
index = self.index.repeat(counts)
return self._constructor(values, index=index, name=self.name, copy=False)
def unstack(self, level: IndexLabel = -1, fill_value: Hashable = None) -> DataFrame:
"""
Unstack, also known as pivot, Series with MultiIndex to produce DataFrame.
Parameters
----------
level : int, str, or list of these, default last level
Level(s) to unstack, can pass level name.
fill_value : scalar value, default None
Value to use when replacing NaN values.
Returns
-------
DataFrame
Unstacked Series.
Notes
-----
Reference :ref:`the user guide <reshaping.stacking>` for more examples.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4],
... index=pd.MultiIndex.from_product([['one', 'two'],
... ['a', 'b']]))
>>> s
one a 1
b 2
two a 3
b 4
dtype: int64
>>> s.unstack(level=-1)
a b
one 1 2
two 3 4
>>> s.unstack(level=0)
one two
a 1 3
b 2 4
"""
from pandas.core.reshape.reshape import unstack
return unstack(self, level, fill_value)
# ----------------------------------------------------------------------
# function application
def map(
self,
arg: Callable | Mapping | Series,
na_action: Literal["ignore"] | None = None,
) -> Series:
"""
Map values of Series according to an input mapping or function.
Used for substituting each value in a Series with another value,
that may be derived from a function, a ``dict`` or
a :class:`Series`.
Parameters
----------
arg : function, collections.abc.Mapping subclass or Series
Mapping correspondence.
na_action : {None, 'ignore'}, default None
If 'ignore', propagate NaN values, without passing them to the
mapping correspondence.
Returns
-------
Series
Same index as caller.
See Also
--------
Series.apply : For applying more complex functions on a Series.
DataFrame.apply : Apply a function row-/column-wise.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Notes
-----
When ``arg`` is a dictionary, values in Series that are not in the
dictionary (as keys) are converted to ``NaN``. However, if the
dictionary is a ``dict`` subclass that defines ``__missing__`` (i.e.
provides a method for default values), then this default is used
rather than ``NaN``.
Examples
--------
>>> s = pd.Series(['cat', 'dog', np.nan, 'rabbit'])
>>> s
0 cat
1 dog
2 NaN
3 rabbit
dtype: object
``map`` accepts a ``dict`` or a ``Series``. Values that are not found
in the ``dict`` are converted to ``NaN``, unless the dict has a default
value (e.g. ``defaultdict``):
>>> s.map({'cat': 'kitten', 'dog': 'puppy'})
0 kitten
1 puppy
2 NaN
3 NaN
dtype: object
It also accepts a function:
>>> s.map('I am a {}'.format)
0 I am a cat
1 I am a dog
2 I am a nan
3 I am a rabbit
dtype: object
To avoid applying the function to missing values (and keep them as
``NaN``) ``na_action='ignore'`` can be used:
>>> s.map('I am a {}'.format, na_action='ignore')
0 I am a cat
1 I am a dog
2 NaN
3 I am a rabbit
dtype: object
"""
new_values = self._map_values(arg, na_action=na_action)
return self._constructor(new_values, index=self.index, copy=False).__finalize__(
self, method="map"
)
def _gotitem(self, key, ndim, subset=None) -> Series:
"""
Sub-classes to define. Return a sliced object.
Parameters
----------
key : string / list of selections
ndim : {1, 2}
Requested ndim of result.
subset : object, default None
Subset to act on.
"""
return self
_agg_see_also_doc = dedent(
"""
See Also
--------
Series.apply : Invoke function on a Series.
Series.transform : Transform function producing a Series with like indexes.
"""
)
_agg_examples_doc = dedent(
"""
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.agg('min')
1
>>> s.agg(['min', 'max'])
min 1
max 4
dtype: int64
"""
)
_shared_docs["aggregate"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
see_also=_agg_see_also_doc,
examples=_agg_examples_doc,
)
def aggregate(self, func=None, axis: Axis = 0, *args, **kwargs):
# Validate the axis parameter
self._get_axis_number(axis)
# if func is None, will switch to user-provided "named aggregation" kwargs
if func is None:
func = dict(kwargs.items())
op = SeriesApply(self, func, convert_dtype=False, args=args, kwargs=kwargs)
result = op.agg()
return result
agg = aggregate
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: None = ...,
**kwargs,
) -> bool:
...
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: Level,
**kwargs,
) -> Series | bool:
...
# error: Missing return statement
def any( # type: ignore[empty-body]
self,
axis: Axis = 0,
bool_only: bool | None = None,
skipna: bool = True,
level: Level | None = None,
**kwargs,
) -> Series | bool:
...
_shared_docs["transform"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
)
def transform(
self, func: AggFuncType, axis: Axis = 0, *args, **kwargs
) -> DataFrame | Series:
# Validate axis argument
self._get_axis_number(axis)
result = SeriesApply(
self, func=func, convert_dtype=True, args=args, kwargs=kwargs
).transform()
return result
def apply(
self,
func: AggFuncType,
convert_dtype: bool = True,
args: tuple[Any, ...] = (),
**kwargs,
) -> DataFrame | Series:
"""
Invoke function on values of Series.
Can be ufunc (a NumPy function that applies to the entire Series)
or a Python function that only works on single values.
Parameters
----------
func : function
Python function or NumPy ufunc to apply.
convert_dtype : bool, default True
Try to find better dtype for elementwise function results. If
False, leave as dtype=object. Note that the dtype is always
preserved for some extension array dtypes, such as Categorical.
args : tuple
Positional arguments passed to func after the series value.
**kwargs
Additional keyword arguments passed to func.
Returns
-------
Series or DataFrame
If func returns a Series object the result will be a DataFrame.
See Also
--------
Series.map: For element-wise operations.
Series.agg: Only perform aggregating type operations.
Series.transform: Only perform transforming type operations.
Notes
-----
Functions that mutate the passed object can produce unexpected
behavior or errors and are not supported. See :ref:`gotchas.udf-mutation`
for more details.
Examples
--------
Create a series with typical summer temperatures for each city.
>>> s = pd.Series([20, 21, 12],
... index=['London', 'New York', 'Helsinki'])
>>> s
London 20
New York 21
Helsinki 12
dtype: int64
Square the values by defining a function and passing it as an
argument to ``apply()``.
>>> def square(x):
... return x ** 2
>>> s.apply(square)
London 400
New York 441
Helsinki 144
dtype: int64
Square the values by passing an anonymous function as an
argument to ``apply()``.
>>> s.apply(lambda x: x ** 2)
London 400
New York 441
Helsinki 144
dtype: int64
Define a custom function that needs additional positional
arguments and pass these additional arguments using the
``args`` keyword.
>>> def subtract_custom_value(x, custom_value):
... return x - custom_value
>>> s.apply(subtract_custom_value, args=(5,))
London 15
New York 16
Helsinki 7
dtype: int64
Define a custom function that takes keyword arguments
and pass these arguments to ``apply``.
>>> def add_custom_values(x, **kwargs):
... for month in kwargs:
... x += kwargs[month]
... return x
>>> s.apply(add_custom_values, june=30, july=20, august=25)
London 95
New York 96
Helsinki 87
dtype: int64
Use a function from the Numpy library.
>>> s.apply(np.log)
London 2.995732
New York 3.044522
Helsinki 2.484907
dtype: float64
"""
return SeriesApply(self, func, convert_dtype, args, kwargs).apply()
def _reduce(
self,
op,
name: str,
*,
axis: Axis = 0,
skipna: bool = True,
numeric_only: bool = False,
filter_type=None,
**kwds,
):
"""
Perform a reduction operation.
If we have an ndarray as a value, then simply perform the operation,
otherwise delegate to the object.
"""
delegate = self._values
if axis is not None:
self._get_axis_number(axis)
if isinstance(delegate, ExtensionArray):
# dispatch to ExtensionArray interface
return delegate._reduce(name, skipna=skipna, **kwds)
else:
# dispatch to numpy arrays
if numeric_only and not is_numeric_dtype(self.dtype):
kwd_name = "numeric_only"
if name in ["any", "all"]:
kwd_name = "bool_only"
# GH#47500 - change to TypeError to match other methods
raise TypeError(
f"Series.{name} does not allow {kwd_name}={numeric_only} "
"with non-numeric dtypes."
)
with np.errstate(all="ignore"):
return op(delegate, skipna=skipna, **kwds)
def _reindex_indexer(
self,
new_index: Index | None,
indexer: npt.NDArray[np.intp] | None,
copy: bool | None,
) -> Series:
# Note: new_index is None iff indexer is None
# if not None, indexer is np.intp
if indexer is None and (
new_index is None or new_index.names == self.index.names
):
if using_copy_on_write():
return self.copy(deep=copy)
if copy or copy is None:
return self.copy(deep=copy)
return self
new_values = algorithms.take_nd(
self._values, indexer, allow_fill=True, fill_value=None
)
return self._constructor(new_values, index=new_index, copy=False)
def _needs_reindex_multi(self, axes, method, level) -> bool:
"""
Check if we do need a multi reindex; this is for compat with
higher dims.
"""
return False
# error: Cannot determine type of 'align'
NDFrame.align, # type: ignore[has-type]
klass=_shared_doc_kwargs["klass"],
axes_single_arg=_shared_doc_kwargs["axes_single_arg"],
)
def align(
self,
other: Series,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> Series:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[True],
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> None:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[False] = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: bool = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series | None:
...
def rename(
self,
index: Renamer | Hashable | None = None,
*,
axis: Axis | None = None,
copy: bool = True,
inplace: bool = False,
level: Level | None = None,
errors: IgnoreRaise = "ignore",
) -> Series | None:
"""
Alter Series index labels or name.
Function / dict values must be unique (1-to-1). Labels not contained in
a dict / Series will be left as-is. Extra labels listed don't throw an
error.
Alternatively, change ``Series.name`` with a scalar value.
See the :ref:`user guide <basics.rename>` for more.
Parameters
----------
index : scalar, hashable sequence, dict-like or function optional
Functions or dict-like are transformations to apply to
the index.
Scalar or hashable sequence-like will alter the ``Series.name``
attribute.
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
copy : bool, default True
Also copy underlying data.
inplace : bool, default False
Whether to return a new Series. If True the value of copy is ignored.
level : int or level name, default None
In case of MultiIndex, only rename labels in the specified level.
errors : {'ignore', 'raise'}, default 'ignore'
If 'raise', raise `KeyError` when a `dict-like mapper` or
`index` contains labels that are not present in the index being transformed.
If 'ignore', existing keys will be renamed and extra keys will be ignored.
Returns
-------
Series or None
Series with index labels or name altered or None if ``inplace=True``.
See Also
--------
DataFrame.rename : Corresponding DataFrame method.
Series.rename_axis : Set the name of the axis.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.rename("my_name") # scalar, changes Series.name
0 1
1 2
2 3
Name: my_name, dtype: int64
>>> s.rename(lambda x: x ** 2) # function, changes labels
0 1
1 2
4 3
dtype: int64
>>> s.rename({1: 3, 2: 5}) # mapping, changes labels
0 1
3 2
5 3
dtype: int64
"""
if axis is not None:
# Make sure we raise if an invalid 'axis' is passed.
axis = self._get_axis_number(axis)
if callable(index) or is_dict_like(index):
# error: Argument 1 to "_rename" of "NDFrame" has incompatible
# type "Union[Union[Mapping[Any, Hashable], Callable[[Any],
# Hashable]], Hashable, None]"; expected "Union[Mapping[Any,
# Hashable], Callable[[Any], Hashable], None]"
return super()._rename(
index, # type: ignore[arg-type]
copy=copy,
inplace=inplace,
level=level,
errors=errors,
)
else:
return self._set_name(index, inplace=inplace)
"""
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.set_axis(['a', 'b', 'c'], axis=0)
a 1
b 2
c 3
dtype: int64
"""
)
**_shared_doc_kwargs,
extended_summary_sub="",
axis_description_sub="",
see_also_sub="",
)
)
)
# error: Cannot determine type of 'shift'
# ----------------------------------------------------------------------
# Convert to types that support pd.NA
# error: Cannot determine type of 'isna'
# error: Return type "Series" of "isna" incompatible with return type "ndarray
# [Any, dtype[bool_]]" in supertype "IndexOpsMixin"
# error: Cannot determine type of 'isna'
# error: Cannot determine type of 'notna'
# error: Cannot determine type of 'notna'
# ----------------------------------------------------------------------
# Time series-oriented methods
# error: Cannot determine type of 'asfreq'
# error: Cannot determine type of 'resample'
# ----------------------------------------------------------------------
# Add index
# ----------------------------------------------------------------------
# Accessor Methods
# ----------------------------------------------------------------------
# ----------------------------------------------------------------------
# Add plotting methods to Series
# ----------------------------------------------------------------------
# Template-Based Arithmetic/Comparison Methods
Series
The provided code snippet includes necessary dependencies for implementing the `_dtype_to_default_stata_fmt` function. Write a Python function `def _dtype_to_default_stata_fmt( dtype, column: Series, dta_version: int = 114, force_strl: bool = False ) -> str` to solve the following problem:
Map numpy dtype to stata's default format for this type. Not terribly important since users can change this in Stata. Semantics are object -> "%DDs" where DD is the length of the string. If not a string, raise ValueError float64 -> "%10.0g" float32 -> "%9.0g" int64 -> "%9.0g" int32 -> "%12.0g" int16 -> "%8.0g" int8 -> "%8.0g" strl -> "%9s"
Here is the function:
def _dtype_to_default_stata_fmt(
dtype, column: Series, dta_version: int = 114, force_strl: bool = False
) -> str:
"""
Map numpy dtype to stata's default format for this type. Not terribly
important since users can change this in Stata. Semantics are
object -> "%DDs" where DD is the length of the string. If not a string,
raise ValueError
float64 -> "%10.0g"
float32 -> "%9.0g"
int64 -> "%9.0g"
int32 -> "%12.0g"
int16 -> "%8.0g"
int8 -> "%8.0g"
strl -> "%9s"
"""
# TODO: Refactor to combine type with format
# TODO: expand this to handle a default datetime format?
if dta_version < 117:
max_str_len = 244
else:
max_str_len = 2045
if force_strl:
return "%9s"
if dtype.type is np.object_:
itemsize = max_len_string_array(ensure_object(column._values))
if itemsize > max_str_len:
if dta_version >= 117:
return "%9s"
else:
raise ValueError(excessive_string_length_error.format(column.name))
return "%" + str(max(itemsize, 1)) + "s"
elif dtype == np.float64:
return "%10.0g"
elif dtype == np.float32:
return "%9.0g"
elif dtype == np.int32:
return "%12.0g"
elif dtype in (np.int8, np.int16):
return "%8.0g"
else: # pragma : no cover
raise NotImplementedError(f"Data type {dtype} not supported.") | Map numpy dtype to stata's default format for this type. Not terribly important since users can change this in Stata. Semantics are object -> "%DDs" where DD is the length of the string. If not a string, raise ValueError float64 -> "%10.0g" float32 -> "%9.0g" int64 -> "%9.0g" int32 -> "%12.0g" int16 -> "%8.0g" int8 -> "%8.0g" strl -> "%9s" |
173,542 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
ensure_object = algos.ensure_object
class Series(base.IndexOpsMixin, NDFrame): # type: ignore[misc]
"""
One-dimensional ndarray with axis labels (including time series).
Labels need not be unique but must be a hashable type. The object
supports both integer- and label-based indexing and provides a host of
methods for performing operations involving the index. Statistical
methods from ndarray have been overridden to automatically exclude
missing data (currently represented as NaN).
Operations between Series (+, -, /, \\*, \\*\\*) align values based on their
associated index values-- they need not be the same length. The result
index will be the sorted union of the two indexes.
Parameters
----------
data : array-like, Iterable, dict, or scalar value
Contains data stored in Series. If data is a dict, argument order is
maintained.
index : array-like or Index (1d)
Values must be hashable and have the same length as `data`.
Non-unique index values are allowed. Will default to
RangeIndex (0, 1, 2, ..., n) if not provided. If data is dict-like
and index is None, then the keys in the data are used as the index. If the
index is not None, the resulting Series is reindexed with the index values.
dtype : str, numpy.dtype, or ExtensionDtype, optional
Data type for the output Series. If not specified, this will be
inferred from `data`.
See the :ref:`user guide <basics.dtypes>` for more usages.
name : Hashable, default None
The name to give to the Series.
copy : bool, default False
Copy input data. Only affects Series or 1d ndarray input. See examples.
Notes
-----
Please reference the :ref:`User Guide <basics.series>` for more information.
Examples
--------
Constructing Series from a dictionary with an Index specified
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['a', 'b', 'c'])
>>> ser
a 1
b 2
c 3
dtype: int64
The keys of the dictionary match with the Index values, hence the Index
values have no effect.
>>> d = {'a': 1, 'b': 2, 'c': 3}
>>> ser = pd.Series(data=d, index=['x', 'y', 'z'])
>>> ser
x NaN
y NaN
z NaN
dtype: float64
Note that the Index is first build with the keys from the dictionary.
After this the Series is reindexed with the given Index values, hence we
get all NaN as a result.
Constructing Series from a list with `copy=False`.
>>> r = [1, 2]
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
[1, 2]
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `copy` of
the original data even though `copy=False`, so
the data is unchanged.
Constructing Series from a 1d ndarray with `copy=False`.
>>> r = np.array([1, 2])
>>> ser = pd.Series(r, copy=False)
>>> ser.iloc[0] = 999
>>> r
array([999, 2])
>>> ser
0 999
1 2
dtype: int64
Due to input data type the Series has a `view` on
the original data, so
the data is changed as well.
"""
_typ = "series"
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
_name: Hashable
_metadata: list[str] = ["name"]
_internal_names_set = {"index"} | NDFrame._internal_names_set
_accessors = {"dt", "cat", "str", "sparse"}
_hidden_attrs = (
base.IndexOpsMixin._hidden_attrs | NDFrame._hidden_attrs | frozenset([])
)
# Override cache_readonly bc Series is mutable
# error: Incompatible types in assignment (expression has type "property",
# base class "IndexOpsMixin" defined the type as "Callable[[IndexOpsMixin], bool]")
hasnans = property( # type: ignore[assignment]
# error: "Callable[[IndexOpsMixin], bool]" has no attribute "fget"
base.IndexOpsMixin.hasnans.fget, # type: ignore[attr-defined]
doc=base.IndexOpsMixin.hasnans.__doc__,
)
_mgr: SingleManager
div: Callable[[Series, Any], Series]
rdiv: Callable[[Series, Any], Series]
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index=None,
dtype: Dtype | None = None,
name=None,
copy: bool | None = None,
fastpath: bool = False,
) -> None:
if (
isinstance(data, (SingleBlockManager, SingleArrayManager))
and index is None
and dtype is None
and (copy is False or copy is None)
):
if using_copy_on_write():
data = data.copy(deep=False)
# GH#33357 called with just the SingleBlockManager
NDFrame.__init__(self, data)
if fastpath:
# e.g. from _box_col_values, skip validation of name
object.__setattr__(self, "_name", name)
else:
self.name = name
return
if isinstance(data, (ExtensionArray, np.ndarray)):
if copy is not False and using_copy_on_write():
if dtype is None or astype_is_view(data.dtype, pandas_dtype(dtype)):
data = data.copy()
if copy is None:
copy = False
# we are called internally, so short-circuit
if fastpath:
# data is a ndarray, index is defined
if not isinstance(data, (SingleBlockManager, SingleArrayManager)):
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
elif using_copy_on_write() and not copy:
data = data.copy(deep=False)
if copy:
data = data.copy()
# skips validation of the name
object.__setattr__(self, "_name", name)
NDFrame.__init__(self, data)
return
if isinstance(data, SingleBlockManager) and using_copy_on_write() and not copy:
data = data.copy(deep=False)
name = ibase.maybe_extract_name(name, data, type(self))
if index is not None:
index = ensure_index(index)
if dtype is not None:
dtype = self._validate_dtype(dtype)
if data is None:
index = index if index is not None else default_index(0)
if len(index) or dtype is not None:
data = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
data = []
if isinstance(data, MultiIndex):
raise NotImplementedError(
"initializing a Series from a MultiIndex is not supported"
)
refs = None
if isinstance(data, Index):
if dtype is not None:
data = data.astype(dtype, copy=False)
if using_copy_on_write():
refs = data._references
data = data._values
else:
# GH#24096 we need to ensure the index remains immutable
data = data._values.copy()
copy = False
elif isinstance(data, np.ndarray):
if len(data.dtype):
# GH#13296 we are dealing with a compound dtype, which
# should be treated as 2D
raise ValueError(
"Cannot construct a Series from an ndarray with "
"compound dtype. Use DataFrame instead."
)
elif isinstance(data, Series):
if index is None:
index = data.index
data = data._mgr.copy(deep=False)
else:
data = data.reindex(index, copy=copy)
copy = False
data = data._mgr
elif is_dict_like(data):
data, index = self._init_dict(data, index, dtype)
dtype = None
copy = False
elif isinstance(data, (SingleBlockManager, SingleArrayManager)):
if index is None:
index = data.index
elif not data.index.equals(index) or copy:
# GH#19275 SingleBlockManager input should only be called
# internally
raise AssertionError(
"Cannot pass both SingleBlockManager "
"`data` argument and a different "
"`index` argument. `copy` must be False."
)
elif isinstance(data, ExtensionArray):
pass
else:
data = com.maybe_iterable_to_list(data)
if is_list_like(data) and not len(data) and dtype is None:
# GH 29405: Pre-2.0, this defaulted to float.
dtype = np.dtype(object)
if index is None:
if not is_list_like(data):
data = [data]
index = default_index(len(data))
elif is_list_like(data):
com.require_length_match(data, index)
# create/copy the manager
if isinstance(data, (SingleBlockManager, SingleArrayManager)):
if dtype is not None:
data = data.astype(dtype=dtype, errors="ignore", copy=copy)
elif copy:
data = data.copy()
else:
data = sanitize_array(data, index, dtype, copy)
manager = get_option("mode.data_manager")
if manager == "block":
data = SingleBlockManager.from_array(data, index, refs=refs)
elif manager == "array":
data = SingleArrayManager.from_array(data, index)
NDFrame.__init__(self, data)
self.name = name
self._set_axis(0, index)
def _init_dict(
self, data, index: Index | None = None, dtype: DtypeObj | None = None
):
"""
Derive the "_mgr" and "index" attributes of a new Series from a
dictionary input.
Parameters
----------
data : dict or dict-like
Data used to populate the new Series.
index : Index or None, default None
Index for the new Series: if None, use dict keys.
dtype : np.dtype, ExtensionDtype, or None, default None
The dtype for the new Series: if None, infer from data.
Returns
-------
_data : BlockManager for the new Series
index : index for the new Series
"""
keys: Index | tuple
# Looking for NaN in dict doesn't work ({np.nan : 1}[float('nan')]
# raises KeyError), so we iterate the entire dict, and align
if data:
# GH:34717, issue was using zip to extract key and values from data.
# using generators in effects the performance.
# Below is the new way of extracting the keys and values
keys = tuple(data.keys())
values = list(data.values()) # Generating list of values- faster way
elif index is not None:
# fastpath for Series(data=None). Just use broadcasting a scalar
# instead of reindexing.
if len(index) or dtype is not None:
values = na_value_for_dtype(pandas_dtype(dtype), compat=False)
else:
values = []
keys = index
else:
keys, values = (), []
# Input is now list-like, so rely on "standard" construction:
s = self._constructor(
values,
index=keys,
dtype=dtype,
)
# Now we just make sure the order is respected, if any
if data and index is not None:
s = s.reindex(index, copy=False)
return s._mgr, s.index
# ----------------------------------------------------------------------
def _constructor(self) -> Callable[..., Series]:
return Series
def _constructor_expanddim(self) -> Callable[..., DataFrame]:
"""
Used when a manipulation result has one higher dimension as the
original, such as Series.to_frame()
"""
from pandas.core.frame import DataFrame
return DataFrame
# types
def _can_hold_na(self) -> bool:
return self._mgr._can_hold_na
# ndarray compatibility
def dtype(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtype
dtype('int64')
"""
return self._mgr.dtype
def dtypes(self) -> DtypeObj:
"""
Return the dtype object of the underlying data.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.dtypes
dtype('int64')
"""
# DataFrame compatibility
return self.dtype
def name(self) -> Hashable:
"""
Return the name of the Series.
The name of a Series becomes its index or column name if it is used
to form a DataFrame. It is also used whenever displaying the Series
using the interpreter.
Returns
-------
label (hashable object)
The name of the Series, also the column name if part of a DataFrame.
See Also
--------
Series.rename : Sets the Series name when given a scalar input.
Index.name : Corresponding Index property.
Examples
--------
The Series name can be set initially when calling the constructor.
>>> s = pd.Series([1, 2, 3], dtype=np.int64, name='Numbers')
>>> s
0 1
1 2
2 3
Name: Numbers, dtype: int64
>>> s.name = "Integers"
>>> s
0 1
1 2
2 3
Name: Integers, dtype: int64
The name of a Series within a DataFrame is its column name.
>>> df = pd.DataFrame([[1, 2], [3, 4], [5, 6]],
... columns=["Odd Numbers", "Even Numbers"])
>>> df
Odd Numbers Even Numbers
0 1 2
1 3 4
2 5 6
>>> df["Even Numbers"].name
'Even Numbers'
"""
return self._name
def name(self, value: Hashable) -> None:
validate_all_hashable(value, error_name=f"{type(self).__name__}.name")
object.__setattr__(self, "_name", value)
def values(self):
"""
Return Series as ndarray or ndarray-like depending on the dtype.
.. warning::
We recommend using :attr:`Series.array` or
:meth:`Series.to_numpy`, depending on whether you need
a reference to the underlying data or a NumPy array.
Returns
-------
numpy.ndarray or ndarray-like
See Also
--------
Series.array : Reference to the underlying data.
Series.to_numpy : A NumPy array representing the underlying data.
Examples
--------
>>> pd.Series([1, 2, 3]).values
array([1, 2, 3])
>>> pd.Series(list('aabc')).values
array(['a', 'a', 'b', 'c'], dtype=object)
>>> pd.Series(list('aabc')).astype('category').values
['a', 'a', 'b', 'c']
Categories (3, object): ['a', 'b', 'c']
Timezone aware datetime data is converted to UTC:
>>> pd.Series(pd.date_range('20130101', periods=3,
... tz='US/Eastern')).values
array(['2013-01-01T05:00:00.000000000',
'2013-01-02T05:00:00.000000000',
'2013-01-03T05:00:00.000000000'], dtype='datetime64[ns]')
"""
return self._mgr.external_values()
def _values(self):
"""
Return the internal repr of this data (defined by Block.interval_values).
This are the values as stored in the Block (ndarray or ExtensionArray
depending on the Block class), with datetime64[ns] and timedelta64[ns]
wrapped in ExtensionArrays to match Index._values behavior.
Differs from the public ``.values`` for certain data types, because of
historical backwards compatibility of the public attribute (e.g. period
returns object ndarray and datetimetz a datetime64[ns] ndarray for
``.values`` while it returns an ExtensionArray for ``._values`` in those
cases).
Differs from ``.array`` in that this still returns the numpy array if
the Block is backed by a numpy array (except for datetime64 and
timedelta64 dtypes), while ``.array`` ensures to always return an
ExtensionArray.
Overview:
dtype | values | _values | array |
----------- | ------------- | ------------- | ------------- |
Numeric | ndarray | ndarray | PandasArray |
Category | Categorical | Categorical | Categorical |
dt64[ns] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
dt64[ns tz] | ndarray[M8ns] | DatetimeArray | DatetimeArray |
td64[ns] | ndarray[m8ns] | TimedeltaArray| ndarray[m8ns] |
Period | ndarray[obj] | PeriodArray | PeriodArray |
Nullable | EA | EA | EA |
"""
return self._mgr.internal_values()
def _references(self) -> BlockValuesRefs | None:
if isinstance(self._mgr, SingleArrayManager):
return None
return self._mgr._block.refs
# error: Decorated property not supported
def array(self) -> ExtensionArray:
return self._mgr.array_values()
# ops
def ravel(self, order: str = "C") -> ArrayLike:
"""
Return the flattened underlying data as an ndarray or ExtensionArray.
Returns
-------
numpy.ndarray or ExtensionArray
Flattened data of the Series.
See Also
--------
numpy.ndarray.ravel : Return a flattened array.
"""
arr = self._values.ravel(order=order)
if isinstance(arr, np.ndarray) and using_copy_on_write():
arr.flags.writeable = False
return arr
def __len__(self) -> int:
"""
Return the length of the Series.
"""
return len(self._mgr)
def view(self, dtype: Dtype | None = None) -> Series:
"""
Create a new view of the Series.
This function will return a new Series with a view of the same
underlying values in memory, optionally reinterpreted with a new data
type. The new data type must preserve the same size in bytes as to not
cause index misalignment.
Parameters
----------
dtype : data type
Data type object or one of their string representations.
Returns
-------
Series
A new Series object as a view of the same data in memory.
See Also
--------
numpy.ndarray.view : Equivalent numpy function to create a new view of
the same data in memory.
Notes
-----
Series are instantiated with ``dtype=float64`` by default. While
``numpy.ndarray.view()`` will return a view with the same data type as
the original array, ``Series.view()`` (without specified dtype)
will try using ``float64`` and may fail if the original data type size
in bytes is not the same.
Examples
--------
>>> s = pd.Series([-2, -1, 0, 1, 2], dtype='int8')
>>> s
0 -2
1 -1
2 0
3 1
4 2
dtype: int8
The 8 bit signed integer representation of `-1` is `0b11111111`, but
the same bytes represent 255 if read as an 8 bit unsigned integer:
>>> us = s.view('uint8')
>>> us
0 254
1 255
2 0
3 1
4 2
dtype: uint8
The views share the same underlying values:
>>> us[0] = 128
>>> s
0 -128
1 -1
2 0
3 1
4 2
dtype: int8
"""
# self.array instead of self._values so we piggyback on PandasArray
# implementation
res_values = self.array.view(dtype)
res_ser = self._constructor(res_values, index=self.index, copy=False)
if isinstance(res_ser._mgr, SingleBlockManager) and using_copy_on_write():
blk = res_ser._mgr._block
blk.refs = cast("BlockValuesRefs", self._references)
blk.refs.add_reference(blk) # type: ignore[arg-type]
return res_ser.__finalize__(self, method="view")
# ----------------------------------------------------------------------
# NDArray Compat
_HANDLED_TYPES = (Index, ExtensionArray, np.ndarray)
def __array__(self, dtype: npt.DTypeLike | None = None) -> np.ndarray:
"""
Return the values as a NumPy array.
Users should not call this directly. Rather, it is invoked by
:func:`numpy.array` and :func:`numpy.asarray`.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to use for the resulting NumPy array. By default,
the dtype is inferred from the data.
Returns
-------
numpy.ndarray
The values in the series converted to a :class:`numpy.ndarray`
with the specified `dtype`.
See Also
--------
array : Create a new array from data.
Series.array : Zero-copy view to the array backing the Series.
Series.to_numpy : Series method for similar behavior.
Examples
--------
>>> ser = pd.Series([1, 2, 3])
>>> np.asarray(ser)
array([1, 2, 3])
For timezone-aware data, the timezones may be retained with
``dtype='object'``
>>> tzser = pd.Series(pd.date_range('2000', periods=2, tz="CET"))
>>> np.asarray(tzser, dtype="object")
array([Timestamp('2000-01-01 00:00:00+0100', tz='CET'),
Timestamp('2000-01-02 00:00:00+0100', tz='CET')],
dtype=object)
Or the values may be localized to UTC and the tzinfo discarded with
``dtype='datetime64[ns]'``
>>> np.asarray(tzser, dtype="datetime64[ns]") # doctest: +ELLIPSIS
array(['1999-12-31T23:00:00.000000000', ...],
dtype='datetime64[ns]')
"""
values = self._values
arr = np.asarray(values, dtype=dtype)
if using_copy_on_write() and astype_is_view(values.dtype, arr.dtype):
arr = arr.view()
arr.flags.writeable = False
return arr
# ----------------------------------------------------------------------
# Unary Methods
# coercion
__float__ = _coerce_method(float)
__int__ = _coerce_method(int)
# ----------------------------------------------------------------------
# indexers
def axes(self) -> list[Index]:
"""
Return a list of the row axis labels.
"""
return [self.index]
# ----------------------------------------------------------------------
# Indexing Methods
def take(self, indices, axis: Axis = 0, **kwargs) -> Series:
nv.validate_take((), kwargs)
indices = ensure_platform_int(indices)
if (
indices.ndim == 1
and using_copy_on_write()
and is_range_indexer(indices, len(self))
):
return self.copy(deep=None)
new_index = self.index.take(indices)
new_values = self._values.take(indices)
result = self._constructor(new_values, index=new_index, fastpath=True)
return result.__finalize__(self, method="take")
def _take_with_is_copy(self, indices, axis: Axis = 0) -> Series:
"""
Internal version of the `take` method that sets the `_is_copy`
attribute to keep track of the parent dataframe (using in indexing
for the SettingWithCopyWarning). For Series this does the same
as the public take (it never sets `_is_copy`).
See the docstring of `take` for full explanation of the parameters.
"""
return self.take(indices=indices, axis=axis)
def _ixs(self, i: int, axis: AxisInt = 0) -> Any:
"""
Return the i-th value or values in the Series by location.
Parameters
----------
i : int
Returns
-------
scalar (int) or Series (slice, sequence)
"""
return self._values[i]
def _slice(self, slobj: slice | np.ndarray, axis: Axis = 0) -> Series:
# axis kwarg is retained for compat with NDFrame method
# _slice is *always* positional
return self._get_values(slobj)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
if key is Ellipsis:
return self
key_is_scalar = is_scalar(key)
if isinstance(key, (list, tuple)):
key = unpack_1tuple(key)
if is_integer(key) and self.index._should_fallback_to_positional:
return self._values[key]
elif key_is_scalar:
return self._get_value(key)
if is_hashable(key):
# Otherwise index.get_value will raise InvalidIndexError
try:
# For labels that don't resolve as scalars like tuples and frozensets
result = self._get_value(key)
return result
except (KeyError, TypeError, InvalidIndexError):
# InvalidIndexError for e.g. generator
# see test_series_getitem_corner_generator
if isinstance(key, tuple) and isinstance(self.index, MultiIndex):
# We still have the corner case where a tuple is a key
# in the first level of our MultiIndex
return self._get_values_tuple(key)
if is_iterator(key):
key = list(key)
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
return self._get_values(key)
return self._get_with(key)
def _get_with(self, key):
# other: fancy integer or otherwise
if isinstance(key, slice):
# _convert_slice_indexer to determine if this slice is positional
# or label based, and if the latter, convert to positional
slobj = self.index._convert_slice_indexer(key, kind="getitem")
return self._slice(slobj)
elif isinstance(key, ABCDataFrame):
raise TypeError(
"Indexing a Series with DataFrame is not "
"supported, use the appropriate DataFrame column"
)
elif isinstance(key, tuple):
return self._get_values_tuple(key)
elif not is_list_like(key):
# e.g. scalars that aren't recognized by lib.is_scalar, GH#32684
return self.loc[key]
if not isinstance(key, (list, np.ndarray, ExtensionArray, Series, Index)):
key = list(key)
if isinstance(key, Index):
key_type = key.inferred_type
else:
key_type = lib.infer_dtype(key, skipna=False)
# Note: The key_type == "boolean" case should be caught by the
# com.is_bool_indexer check in __getitem__
if key_type == "integer":
# We need to decide whether to treat this as a positional indexer
# (i.e. self.iloc) or label-based (i.e. self.loc)
if not self.index._should_fallback_to_positional:
return self.loc[key]
else:
return self.iloc[key]
# handle the dup indexing case GH#4246
return self.loc[key]
def _get_values_tuple(self, key: tuple):
# mpl hackaround
if com.any_none(*key):
# mpl compat if we look up e.g. ser[:, np.newaxis];
# see tests.series.timeseries.test_mpl_compat_hack
# the asarray is needed to avoid returning a 2D DatetimeArray
result = np.asarray(self._values[key])
disallow_ndim_indexing(result)
return result
if not isinstance(self.index, MultiIndex):
raise KeyError("key of type tuple not found and not a MultiIndex")
# If key is contained, would have returned by now
indexer, new_index = self.index.get_loc_level(key)
new_ser = self._constructor(self._values[indexer], index=new_index, copy=False)
if using_copy_on_write() and isinstance(indexer, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
def _get_values(self, indexer: slice | npt.NDArray[np.bool_]) -> Series:
new_mgr = self._mgr.getitem_mgr(indexer)
return self._constructor(new_mgr).__finalize__(self)
def _get_value(self, label, takeable: bool = False):
"""
Quickly retrieve single value at passed index label.
Parameters
----------
label : object
takeable : interpret the index as indexers, default False
Returns
-------
scalar value
"""
if takeable:
return self._values[label]
# Similar to Index.get_value, but we do not fall back to positional
loc = self.index.get_loc(label)
if is_integer(loc):
return self._values[loc]
if isinstance(self.index, MultiIndex):
mi = self.index
new_values = self._values[loc]
if len(new_values) == 1 and mi.nlevels == 1:
# If more than one level left, we can not return a scalar
return new_values[0]
new_index = mi[loc]
new_index = maybe_droplevels(new_index, label)
new_ser = self._constructor(
new_values, index=new_index, name=self.name, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
new_ser._mgr.add_references(self._mgr) # type: ignore[arg-type]
return new_ser.__finalize__(self)
else:
return self.iloc[loc]
def __setitem__(self, key, value) -> None:
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
check_dict_or_set_indexers(key)
key = com.apply_if_callable(key, self)
cacher_needs_updating = self._check_is_chained_assignment_possible()
if key is Ellipsis:
key = slice(None)
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
return self._set_values(indexer, value)
try:
self._set_with_engine(key, value)
except KeyError:
# We have a scalar (or for MultiIndex or object-dtype, scalar-like)
# key that is not present in self.index.
if is_integer(key):
if not self.index._should_fallback_to_positional:
# GH#33469
self.loc[key] = value
else:
# positional setter
# can't use _mgr.setitem_inplace yet bc could have *both*
# KeyError and then ValueError, xref GH#45070
self._set_values(key, value)
else:
# GH#12862 adding a new key to the Series
self.loc[key] = value
except (TypeError, ValueError, LossySetitemError):
# The key was OK, but we cannot set the value losslessly
indexer = self.index.get_loc(key)
self._set_values(indexer, value)
except InvalidIndexError as err:
if isinstance(key, tuple) and not isinstance(self.index, MultiIndex):
# cases with MultiIndex don't get here bc they raise KeyError
# e.g. test_basic_getitem_setitem_corner
raise KeyError(
"key of type tuple not found and not a MultiIndex"
) from err
if com.is_bool_indexer(key):
key = check_bool_indexer(self.index, key)
key = np.asarray(key, dtype=bool)
if (
is_list_like(value)
and len(value) != len(self)
and not isinstance(value, Series)
and not is_object_dtype(self.dtype)
):
# Series will be reindexed to have matching length inside
# _where call below
# GH#44265
indexer = key.nonzero()[0]
self._set_values(indexer, value)
return
# otherwise with listlike other we interpret series[mask] = other
# as series[mask] = other[mask]
try:
self._where(~key, value, inplace=True)
except InvalidIndexError:
# test_where_dups
self.iloc[key] = value
return
else:
self._set_with(key, value)
if cacher_needs_updating:
self._maybe_update_cacher(inplace=True)
def _set_with_engine(self, key, value) -> None:
loc = self.index.get_loc(key)
# this is equivalent to self._values[key] = value
self._mgr.setitem_inplace(loc, value)
def _set_with(self, key, value) -> None:
# We got here via exception-handling off of InvalidIndexError, so
# key should always be listlike at this point.
assert not isinstance(key, tuple)
if is_iterator(key):
# Without this, the call to infer_dtype will consume the generator
key = list(key)
if not self.index._should_fallback_to_positional:
# Regardless of the key type, we're treating it as labels
self._set_labels(key, value)
else:
# Note: key_type == "boolean" should not occur because that
# should be caught by the is_bool_indexer check in __setitem__
key_type = lib.infer_dtype(key, skipna=False)
if key_type == "integer":
self._set_values(key, value)
else:
self._set_labels(key, value)
def _set_labels(self, key, value) -> None:
key = com.asarray_tuplesafe(key)
indexer: np.ndarray = self.index.get_indexer(key)
mask = indexer == -1
if mask.any():
raise KeyError(f"{key[mask]} not in index")
self._set_values(indexer, value)
def _set_values(self, key, value) -> None:
if isinstance(key, (Index, Series)):
key = key._values
self._mgr = self._mgr.setitem(indexer=key, value=value)
self._maybe_update_cacher()
def _set_value(self, label, value, takeable: bool = False) -> None:
"""
Quickly set single value at passed label.
If label is not contained, a new object is created with the label
placed at the end of the result index.
Parameters
----------
label : object
Partial indexing with MultiIndex not allowed.
value : object
Scalar value.
takeable : interpret the index as indexers, default False
"""
if not takeable:
try:
loc = self.index.get_loc(label)
except KeyError:
# set using a non-recursive method
self.loc[label] = value
return
else:
loc = label
self._set_values(loc, value)
# ----------------------------------------------------------------------
# Lookup Caching
def _is_cached(self) -> bool:
"""Return boolean indicating if self is cached or not."""
return getattr(self, "_cacher", None) is not None
def _get_cacher(self):
"""return my cacher or None"""
cacher = getattr(self, "_cacher", None)
if cacher is not None:
cacher = cacher[1]()
return cacher
def _reset_cacher(self) -> None:
"""
Reset the cacher.
"""
if hasattr(self, "_cacher"):
del self._cacher
def _set_as_cached(self, item, cacher) -> None:
"""
Set the _cacher attribute on the calling object with a weakref to
cacher.
"""
if using_copy_on_write():
return
self._cacher = (item, weakref.ref(cacher))
def _clear_item_cache(self) -> None:
# no-op for Series
pass
def _check_is_chained_assignment_possible(self) -> bool:
"""
See NDFrame._check_is_chained_assignment_possible.__doc__
"""
if self._is_view and self._is_cached:
ref = self._get_cacher()
if ref is not None and ref._is_mixed_type:
self._check_setitem_copy(t="referent", force=True)
return True
return super()._check_is_chained_assignment_possible()
def _maybe_update_cacher(
self, clear: bool = False, verify_is_copy: bool = True, inplace: bool = False
) -> None:
"""
See NDFrame._maybe_update_cacher.__doc__
"""
# for CoW, we never want to update the parent DataFrame cache
# if the Series changed, but don't keep track of any cacher
if using_copy_on_write():
return
cacher = getattr(self, "_cacher", None)
if cacher is not None:
assert self.ndim == 1
ref: DataFrame = cacher[1]()
# we are trying to reference a dead referent, hence
# a copy
if ref is None:
del self._cacher
elif len(self) == len(ref) and self.name in ref.columns:
# GH#42530 self.name must be in ref.columns
# to ensure column still in dataframe
# otherwise, either self or ref has swapped in new arrays
ref._maybe_cache_changed(cacher[0], self, inplace=inplace)
else:
# GH#33675 we have swapped in a new array, so parent
# reference to self is now invalid
ref._item_cache.pop(cacher[0], None)
super()._maybe_update_cacher(
clear=clear, verify_is_copy=verify_is_copy, inplace=inplace
)
# ----------------------------------------------------------------------
# Unsorted
def _is_mixed_type(self) -> bool:
return False
def repeat(self, repeats: int | Sequence[int], axis: None = None) -> Series:
"""
Repeat elements of a Series.
Returns a new Series where each element of the current Series
is repeated consecutively a given number of times.
Parameters
----------
repeats : int or array of ints
The number of repetitions for each element. This should be a
non-negative integer. Repeating 0 times will return an empty
Series.
axis : None
Unused. Parameter needed for compatibility with DataFrame.
Returns
-------
Series
Newly created Series with repeated elements.
See Also
--------
Index.repeat : Equivalent function for Index.
numpy.repeat : Similar method for :class:`numpy.ndarray`.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c'])
>>> s
0 a
1 b
2 c
dtype: object
>>> s.repeat(2)
0 a
0 a
1 b
1 b
2 c
2 c
dtype: object
>>> s.repeat([1, 2, 3])
0 a
1 b
1 b
2 c
2 c
2 c
dtype: object
"""
nv.validate_repeat((), {"axis": axis})
new_index = self.index.repeat(repeats)
new_values = self._values.repeat(repeats)
return self._constructor(new_values, index=new_index, copy=False).__finalize__(
self, method="repeat"
)
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[False] = ...,
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> DataFrame:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: Literal[True],
name: Level = ...,
inplace: Literal[False] = ...,
allow_duplicates: bool = ...,
) -> Series:
...
def reset_index(
self,
level: IndexLabel = ...,
*,
drop: bool = ...,
name: Level = ...,
inplace: Literal[True],
allow_duplicates: bool = ...,
) -> None:
...
def reset_index(
self,
level: IndexLabel = None,
*,
drop: bool = False,
name: Level = lib.no_default,
inplace: bool = False,
allow_duplicates: bool = False,
) -> DataFrame | Series | None:
"""
Generate a new DataFrame or Series with the index reset.
This is useful when the index needs to be treated as a column, or
when the index is meaningless and needs to be reset to the default
before another operation.
Parameters
----------
level : int, str, tuple, or list, default optional
For a Series with a MultiIndex, only remove the specified levels
from the index. Removes all levels by default.
drop : bool, default False
Just reset the index, without inserting it as a column in
the new DataFrame.
name : object, optional
The name to use for the column containing the original Series
values. Uses ``self.name`` by default. This argument is ignored
when `drop` is True.
inplace : bool, default False
Modify the Series in place (do not create a new object).
allow_duplicates : bool, default False
Allow duplicate column labels to be created.
.. versionadded:: 1.5.0
Returns
-------
Series or DataFrame or None
When `drop` is False (the default), a DataFrame is returned.
The newly created columns will come first in the DataFrame,
followed by the original Series values.
When `drop` is True, a `Series` is returned.
In either case, if ``inplace=True``, no value is returned.
See Also
--------
DataFrame.reset_index: Analogous function for DataFrame.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4], name='foo',
... index=pd.Index(['a', 'b', 'c', 'd'], name='idx'))
Generate a DataFrame with default index.
>>> s.reset_index()
idx foo
0 a 1
1 b 2
2 c 3
3 d 4
To specify the name of the new column use `name`.
>>> s.reset_index(name='values')
idx values
0 a 1
1 b 2
2 c 3
3 d 4
To generate a new Series with the default set `drop` to True.
>>> s.reset_index(drop=True)
0 1
1 2
2 3
3 4
Name: foo, dtype: int64
The `level` parameter is interesting for Series with a multi-level
index.
>>> arrays = [np.array(['bar', 'bar', 'baz', 'baz']),
... np.array(['one', 'two', 'one', 'two'])]
>>> s2 = pd.Series(
... range(4), name='foo',
... index=pd.MultiIndex.from_arrays(arrays,
... names=['a', 'b']))
To remove a specific level from the Index, use `level`.
>>> s2.reset_index(level='a')
a foo
b
one bar 0
two bar 1
one baz 2
two baz 3
If `level` is not set, all levels are removed from the Index.
>>> s2.reset_index()
a b foo
0 bar one 0
1 bar two 1
2 baz one 2
3 baz two 3
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if drop:
new_index = default_index(len(self))
if level is not None:
level_list: Sequence[Hashable]
if not isinstance(level, (tuple, list)):
level_list = [level]
else:
level_list = level
level_list = [self.index._get_level_number(lev) for lev in level_list]
if len(level_list) < self.index.nlevels:
new_index = self.index.droplevel(level_list)
if inplace:
self.index = new_index
elif using_copy_on_write():
new_ser = self.copy(deep=False)
new_ser.index = new_index
return new_ser.__finalize__(self, method="reset_index")
else:
return self._constructor(
self._values.copy(), index=new_index, copy=False
).__finalize__(self, method="reset_index")
elif inplace:
raise TypeError(
"Cannot reset_index inplace on a Series to create a DataFrame"
)
else:
if name is lib.no_default:
# For backwards compatibility, keep columns as [0] instead of
# [None] when self.name is None
if self.name is None:
name = 0
else:
name = self.name
df = self.to_frame(name)
return df.reset_index(
level=level, drop=drop, allow_duplicates=allow_duplicates
)
return None
# ----------------------------------------------------------------------
# Rendering Methods
def __repr__(self) -> str:
"""
Return a string representation for a particular Series.
"""
# pylint: disable=invalid-repr-returned
repr_params = fmt.get_series_repr_params()
return self.to_string(**repr_params)
def to_string(
self,
buf: None = ...,
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
na_rep: str = ...,
float_format: str | None = ...,
header: bool = ...,
index: bool = ...,
length=...,
dtype=...,
name=...,
max_rows: int | None = ...,
min_rows: int | None = ...,
) -> None:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
na_rep: str = "NaN",
float_format: str | None = None,
header: bool = True,
index: bool = True,
length: bool = False,
dtype: bool = False,
name: bool = False,
max_rows: int | None = None,
min_rows: int | None = None,
) -> str | None:
"""
Render a string representation of the Series.
Parameters
----------
buf : StringIO-like, optional
Buffer to write to.
na_rep : str, optional
String representation of NaN to use, default 'NaN'.
float_format : one-parameter function, optional
Formatter function to apply to columns' elements if they are
floats, default None.
header : bool, default True
Add the Series header (index name).
index : bool, optional
Add index (row) labels, default True.
length : bool, default False
Add the Series length.
dtype : bool, default False
Add the Series dtype.
name : bool, default False
Add the Series name if not None.
max_rows : int, optional
Maximum number of rows to show before truncating. If None, show
all.
min_rows : int, optional
The number of rows to display in a truncated repr (when number
of rows is above `max_rows`).
Returns
-------
str or None
String representation of Series if ``buf=None``, otherwise None.
"""
formatter = fmt.SeriesFormatter(
self,
name=name,
length=length,
header=header,
index=index,
dtype=dtype,
na_rep=na_rep,
float_format=float_format,
min_rows=min_rows,
max_rows=max_rows,
)
result = formatter.to_string()
# catch contract violations
if not isinstance(result, str):
raise AssertionError(
"result must be of type str, type "
f"of result is {repr(type(result).__name__)}"
)
if buf is None:
return result
else:
if hasattr(buf, "write"):
buf.write(result)
else:
with open(buf, "w") as f:
f.write(result)
return None
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples=dedent(
"""Examples
--------
>>> s = pd.Series(["elk", "pig", "dog", "quetzal"], name="animal")
>>> print(s.to_markdown())
| | animal |
|---:|:---------|
| 0 | elk |
| 1 | pig |
| 2 | dog |
| 3 | quetzal |
Output markdown with a tabulate option.
>>> print(s.to_markdown(tablefmt="grid"))
+----+----------+
| | animal |
+====+==========+
| 0 | elk |
+----+----------+
| 1 | pig |
+----+----------+
| 2 | dog |
+----+----------+
| 3 | quetzal |
+----+----------+"""
),
)
def to_markdown(
self,
buf: IO[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
"""
Print {klass} in Markdown-friendly format.
Parameters
----------
buf : str, Path or StringIO-like, optional, default None
Buffer to write to. If None, the output is returned as a string.
mode : str, optional
Mode in which file is opened, "wt" by default.
index : bool, optional, default True
Add index (row) labels.
.. versionadded:: 1.1.0
{storage_options}
.. versionadded:: 1.2.0
**kwargs
These parameters will be passed to `tabulate \
<https://pypi.org/project/tabulate>`_.
Returns
-------
str
{klass} in Markdown-friendly format.
Notes
-----
Requires the `tabulate <https://pypi.org/project/tabulate>`_ package.
{examples}
"""
return self.to_frame().to_markdown(
buf, mode, index, storage_options=storage_options, **kwargs
)
# ----------------------------------------------------------------------
def items(self) -> Iterable[tuple[Hashable, Any]]:
"""
Lazily iterate over (index, value) tuples.
This method returns an iterable tuple (index, value). This is
convenient if you want to create a lazy iterator.
Returns
-------
iterable
Iterable of tuples containing the (index, value) pairs from a
Series.
See Also
--------
DataFrame.items : Iterate over (column name, Series) pairs.
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series) pairs.
Examples
--------
>>> s = pd.Series(['A', 'B', 'C'])
>>> for index, value in s.items():
... print(f"Index : {index}, Value : {value}")
Index : 0, Value : A
Index : 1, Value : B
Index : 2, Value : C
"""
return zip(iter(self.index), iter(self))
# ----------------------------------------------------------------------
# Misc public methods
def keys(self) -> Index:
"""
Return alias for index.
Returns
-------
Index
Index of the Series.
"""
return self.index
def to_dict(self, into: type[dict] = dict) -> dict:
"""
Convert Series to {label -> value} dict or dict-like object.
Parameters
----------
into : class, default dict
The collections.abc.Mapping subclass to use as the return
object. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
Returns
-------
collections.abc.Mapping
Key-value representation of Series.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.to_dict()
{0: 1, 1: 2, 2: 3, 3: 4}
>>> from collections import OrderedDict, defaultdict
>>> s.to_dict(OrderedDict)
OrderedDict([(0, 1), (1, 2), (2, 3), (3, 4)])
>>> dd = defaultdict(list)
>>> s.to_dict(dd)
defaultdict(<class 'list'>, {0: 1, 1: 2, 2: 3, 3: 4})
"""
# GH16122
into_c = com.standardize_mapping(into)
if is_object_dtype(self) or is_extension_array_dtype(self):
return into_c((k, maybe_box_native(v)) for k, v in self.items())
else:
# Not an object dtype => all types will be the same so let the default
# indexer return native python type
return into_c(self.items())
def to_frame(self, name: Hashable = lib.no_default) -> DataFrame:
"""
Convert Series to DataFrame.
Parameters
----------
name : object, optional
The passed name should substitute for the series name (if it has
one).
Returns
-------
DataFrame
DataFrame representation of Series.
Examples
--------
>>> s = pd.Series(["a", "b", "c"],
... name="vals")
>>> s.to_frame()
vals
0 a
1 b
2 c
"""
columns: Index
if name is lib.no_default:
name = self.name
if name is None:
# default to [0], same as we would get with DataFrame(self)
columns = default_index(1)
else:
columns = Index([name])
else:
columns = Index([name])
mgr = self._mgr.to_2d_mgr(columns)
df = self._constructor_expanddim(mgr)
return df.__finalize__(self, method="to_frame")
def _set_name(self, name, inplace: bool = False) -> Series:
"""
Set the Series name.
Parameters
----------
name : str
inplace : bool
Whether to modify `self` directly or return a copy.
"""
inplace = validate_bool_kwarg(inplace, "inplace")
ser = self if inplace else self.copy()
ser.name = name
return ser
"""
Examples
--------
>>> ser = pd.Series([390., 350., 30., 20.],
... index=['Falcon', 'Falcon', 'Parrot', 'Parrot'], name="Max Speed")
>>> ser
Falcon 390.0
Falcon 350.0
Parrot 30.0
Parrot 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", "b"]).mean()
a 210.0
b 185.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(ser > 100).mean()
Max Speed
False 25.0
True 370.0
Name: Max Speed, dtype: float64
**Grouping by Indexes**
We can groupby different levels of a hierarchical index
using the `level` parameter:
>>> arrays = [['Falcon', 'Falcon', 'Parrot', 'Parrot'],
... ['Captive', 'Wild', 'Captive', 'Wild']]
>>> index = pd.MultiIndex.from_arrays(arrays, names=('Animal', 'Type'))
>>> ser = pd.Series([390., 350., 30., 20.], index=index, name="Max Speed")
>>> ser
Animal Type
Falcon Captive 390.0
Wild 350.0
Parrot Captive 30.0
Wild 20.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level=0).mean()
Animal
Falcon 370.0
Parrot 25.0
Name: Max Speed, dtype: float64
>>> ser.groupby(level="Type").mean()
Type
Captive 210.0
Wild 185.0
Name: Max Speed, dtype: float64
We can also choose to include `NA` in group keys or not by defining
`dropna` parameter, the default setting is `True`.
>>> ser = pd.Series([1, 2, 3, 3], index=["a", 'a', 'b', np.nan])
>>> ser.groupby(level=0).sum()
a 3
b 3
dtype: int64
>>> ser.groupby(level=0, dropna=False).sum()
a 3
b 3
NaN 3
dtype: int64
>>> arrays = ['Falcon', 'Falcon', 'Parrot', 'Parrot']
>>> ser = pd.Series([390., 350., 30., 20.], index=arrays, name="Max Speed")
>>> ser.groupby(["a", "b", "a", np.nan]).mean()
a 210.0
b 350.0
Name: Max Speed, dtype: float64
>>> ser.groupby(["a", "b", "a", np.nan], dropna=False).mean()
a 210.0
b 350.0
NaN 20.0
Name: Max Speed, dtype: float64
"""
)
def groupby(
self,
by=None,
axis: Axis = 0,
level: IndexLabel = None,
as_index: bool = True,
sort: bool = True,
group_keys: bool = True,
observed: bool = False,
dropna: bool = True,
) -> SeriesGroupBy:
from pandas.core.groupby.generic import SeriesGroupBy
if level is None and by is None:
raise TypeError("You have to supply one of 'by' and 'level'")
if not as_index:
raise TypeError("as_index=False only valid with DataFrame")
axis = self._get_axis_number(axis)
return SeriesGroupBy(
obj=self,
keys=by,
axis=axis,
level=level,
as_index=as_index,
sort=sort,
group_keys=group_keys,
observed=observed,
dropna=dropna,
)
# ----------------------------------------------------------------------
# Statistics, overridden ndarray methods
# TODO: integrate bottleneck
def count(self):
"""
Return number of non-NA/null observations in the Series.
Returns
-------
int or Series (if level specified)
Number of non-null values in the Series.
See Also
--------
DataFrame.count : Count non-NA cells for each column or row.
Examples
--------
>>> s = pd.Series([0.0, 1.0, np.nan])
>>> s.count()
2
"""
return notna(self._values).sum().astype("int64")
def mode(self, dropna: bool = True) -> Series:
"""
Return the mode(s) of the Series.
The mode is the value that appears most often. There can be multiple modes.
Always returns Series even if only one value is returned.
Parameters
----------
dropna : bool, default True
Don't consider counts of NaN/NaT.
Returns
-------
Series
Modes of the Series in sorted order.
"""
# TODO: Add option for bins like value_counts()
values = self._values
if isinstance(values, np.ndarray):
res_values = algorithms.mode(values, dropna=dropna)
else:
res_values = values._mode(dropna=dropna)
# Ensure index is type stable (should always use int index)
return self._constructor(
res_values, index=range(len(res_values)), name=self.name, copy=False
)
def unique(self) -> ArrayLike: # pylint: disable=useless-parent-delegation
"""
Return unique values of Series object.
Uniques are returned in order of appearance. Hash table-based unique,
therefore does NOT sort.
Returns
-------
ndarray or ExtensionArray
The unique values returned as a NumPy array. See Notes.
See Also
--------
Series.drop_duplicates : Return Series with duplicate values removed.
unique : Top-level unique method for any 1-d array-like object.
Index.unique : Return Index with unique values from an Index object.
Notes
-----
Returns the unique values as a NumPy array. In case of an
extension-array backed Series, a new
:class:`~api.extensions.ExtensionArray` of that type with just
the unique values is returned. This includes
* Categorical
* Period
* Datetime with Timezone
* Datetime without Timezone
* Timedelta
* Interval
* Sparse
* IntegerNA
See Examples section.
Examples
--------
>>> pd.Series([2, 1, 3, 3], name='A').unique()
array([2, 1, 3])
>>> pd.Series([pd.Timestamp('2016-01-01') for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00']
Length: 1, dtype: datetime64[ns]
>>> pd.Series([pd.Timestamp('2016-01-01', tz='US/Eastern')
... for _ in range(3)]).unique()
<DatetimeArray>
['2016-01-01 00:00:00-05:00']
Length: 1, dtype: datetime64[ns, US/Eastern]
An Categorical will return categories in the order of
appearance and with the same dtype.
>>> pd.Series(pd.Categorical(list('baabc'))).unique()
['b', 'a', 'c']
Categories (3, object): ['a', 'b', 'c']
>>> pd.Series(pd.Categorical(list('baabc'), categories=list('abc'),
... ordered=True)).unique()
['b', 'a', 'c']
Categories (3, object): ['a' < 'b' < 'c']
"""
return super().unique()
def drop_duplicates(
self,
*,
keep: DropKeep = ...,
inplace: Literal[False] = ...,
ignore_index: bool = ...,
) -> Series:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: Literal[True], ignore_index: bool = ...
) -> None:
...
def drop_duplicates(
self, *, keep: DropKeep = ..., inplace: bool = ..., ignore_index: bool = ...
) -> Series | None:
...
def drop_duplicates(
self,
*,
keep: DropKeep = "first",
inplace: bool = False,
ignore_index: bool = False,
) -> Series | None:
"""
Return Series with duplicate values removed.
Parameters
----------
keep : {'first', 'last', ``False``}, default 'first'
Method to handle dropping duplicates:
- 'first' : Drop duplicates except for the first occurrence.
- 'last' : Drop duplicates except for the last occurrence.
- ``False`` : Drop all duplicates.
inplace : bool, default ``False``
If ``True``, performs operation inplace and returns None.
ignore_index : bool, default ``False``
If ``True``, the resulting axis will be labeled 0, 1, …, n - 1.
.. versionadded:: 2.0.0
Returns
-------
Series or None
Series with duplicates dropped or None if ``inplace=True``.
See Also
--------
Index.drop_duplicates : Equivalent method on Index.
DataFrame.drop_duplicates : Equivalent method on DataFrame.
Series.duplicated : Related method on Series, indicating duplicate
Series values.
Series.unique : Return unique values as an array.
Examples
--------
Generate a Series with duplicated entries.
>>> s = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama', 'hippo'],
... name='animal')
>>> s
0 lama
1 cow
2 lama
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
With the 'keep' parameter, the selection behaviour of duplicated values
can be changed. The value 'first' keeps the first occurrence for each
set of duplicated entries. The default value of keep is 'first'.
>>> s.drop_duplicates()
0 lama
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
The value 'last' for parameter 'keep' keeps the last occurrence for
each set of duplicated entries.
>>> s.drop_duplicates(keep='last')
1 cow
3 beetle
4 lama
5 hippo
Name: animal, dtype: object
The value ``False`` for parameter 'keep' discards all sets of
duplicated entries.
>>> s.drop_duplicates(keep=False)
1 cow
3 beetle
5 hippo
Name: animal, dtype: object
"""
inplace = validate_bool_kwarg(inplace, "inplace")
result = super().drop_duplicates(keep=keep)
if ignore_index:
result.index = default_index(len(result))
if inplace:
self._update_inplace(result)
return None
else:
return result
def duplicated(self, keep: DropKeep = "first") -> Series:
"""
Indicate duplicate Series values.
Duplicated values are indicated as ``True`` values in the resulting
Series. Either all duplicates, all except the first or all except the
last occurrence of duplicates can be indicated.
Parameters
----------
keep : {'first', 'last', False}, default 'first'
Method to handle dropping duplicates:
- 'first' : Mark duplicates as ``True`` except for the first
occurrence.
- 'last' : Mark duplicates as ``True`` except for the last
occurrence.
- ``False`` : Mark all duplicates as ``True``.
Returns
-------
Series[bool]
Series indicating whether each value has occurred in the
preceding values.
See Also
--------
Index.duplicated : Equivalent method on pandas.Index.
DataFrame.duplicated : Equivalent method on pandas.DataFrame.
Series.drop_duplicates : Remove duplicate values from Series.
Examples
--------
By default, for each set of duplicated values, the first occurrence is
set on False and all others on True:
>>> animals = pd.Series(['lama', 'cow', 'lama', 'beetle', 'lama'])
>>> animals.duplicated()
0 False
1 False
2 True
3 False
4 True
dtype: bool
which is equivalent to
>>> animals.duplicated(keep='first')
0 False
1 False
2 True
3 False
4 True
dtype: bool
By using 'last', the last occurrence of each set of duplicated values
is set on False and all others on True:
>>> animals.duplicated(keep='last')
0 True
1 False
2 True
3 False
4 False
dtype: bool
By setting keep on ``False``, all duplicates are True:
>>> animals.duplicated(keep=False)
0 True
1 False
2 True
3 False
4 True
dtype: bool
"""
res = self._duplicated(keep=keep)
result = self._constructor(res, index=self.index, copy=False)
return result.__finalize__(self, method="duplicated")
def idxmin(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the minimum value.
If multiple values equal the minimum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the minimum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmin : Return indices of the minimum values
along the given axis.
DataFrame.idxmin : Return index of first occurrence of minimum
over requested axis.
Series.idxmax : Return index *label* of the first occurrence
of maximum of values.
Notes
-----
This method is the Series version of ``ndarray.argmin``. This method
returns the label of the minimum, while ``ndarray.argmin`` returns
the position. To get the position, use ``series.values.argmin()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 1],
... index=['A', 'B', 'C', 'D'])
>>> s
A 1.0
B NaN
C 4.0
D 1.0
dtype: float64
>>> s.idxmin()
'A'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmin(skipna=False)
nan
"""
# error: Argument 1 to "argmin" of "IndexOpsMixin" has incompatible type "Union
# [int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmin(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def idxmax(self, axis: Axis = 0, skipna: bool = True, *args, **kwargs) -> Hashable:
"""
Return the row label of the maximum value.
If multiple values equal the maximum, the first row label with that
value is returned.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
skipna : bool, default True
Exclude NA/null values. If the entire Series is NA, the result
will be NA.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Index
Label of the maximum value.
Raises
------
ValueError
If the Series is empty.
See Also
--------
numpy.argmax : Return indices of the maximum values
along the given axis.
DataFrame.idxmax : Return index of first occurrence of maximum
over requested axis.
Series.idxmin : Return index *label* of the first occurrence
of minimum of values.
Notes
-----
This method is the Series version of ``ndarray.argmax``. This method
returns the label of the maximum, while ``ndarray.argmax`` returns
the position. To get the position, use ``series.values.argmax()``.
Examples
--------
>>> s = pd.Series(data=[1, None, 4, 3, 4],
... index=['A', 'B', 'C', 'D', 'E'])
>>> s
A 1.0
B NaN
C 4.0
D 3.0
E 4.0
dtype: float64
>>> s.idxmax()
'C'
If `skipna` is False and there is an NA value in the data,
the function returns ``nan``.
>>> s.idxmax(skipna=False)
nan
"""
# error: Argument 1 to "argmax" of "IndexOpsMixin" has incompatible type
# "Union[int, Literal['index', 'columns']]"; expected "Optional[int]"
i = self.argmax(axis, skipna, *args, **kwargs) # type: ignore[arg-type]
if i == -1:
return np.nan
return self.index[i]
def round(self, decimals: int = 0, *args, **kwargs) -> Series:
"""
Round each value in a Series to the given number of decimals.
Parameters
----------
decimals : int, default 0
Number of decimal places to round to. If decimals is negative,
it specifies the number of positions to the left of the decimal point.
*args, **kwargs
Additional arguments and keywords have no effect but might be
accepted for compatibility with NumPy.
Returns
-------
Series
Rounded values of the Series.
See Also
--------
numpy.around : Round values of an np.array.
DataFrame.round : Round values of a DataFrame.
Examples
--------
>>> s = pd.Series([0.1, 1.3, 2.7])
>>> s.round()
0 0.0
1 1.0
2 3.0
dtype: float64
"""
nv.validate_round(args, kwargs)
result = self._values.round(decimals)
result = self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="round"
)
return result
def quantile(
self, q: float = ..., interpolation: QuantileInterpolation = ...
) -> float:
...
def quantile(
self,
q: Sequence[float] | AnyArrayLike,
interpolation: QuantileInterpolation = ...,
) -> Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = ...,
interpolation: QuantileInterpolation = ...,
) -> float | Series:
...
def quantile(
self,
q: float | Sequence[float] | AnyArrayLike = 0.5,
interpolation: QuantileInterpolation = "linear",
) -> float | Series:
"""
Return value at the given quantile.
Parameters
----------
q : float or array-like, default 0.5 (50% quantile)
The quantile(s) to compute, which can lie in range: 0 <= q <= 1.
interpolation : {'linear', 'lower', 'higher', 'midpoint', 'nearest'}
This optional parameter specifies the interpolation method to use,
when the desired quantile lies between two data points `i` and `j`:
* linear: `i + (j - i) * fraction`, where `fraction` is the
fractional part of the index surrounded by `i` and `j`.
* lower: `i`.
* higher: `j`.
* nearest: `i` or `j` whichever is nearest.
* midpoint: (`i` + `j`) / 2.
Returns
-------
float or Series
If ``q`` is an array, a Series will be returned where the
index is ``q`` and the values are the quantiles, otherwise
a float will be returned.
See Also
--------
core.window.Rolling.quantile : Calculate the rolling quantile.
numpy.percentile : Returns the q-th percentile(s) of the array elements.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s.quantile(.5)
2.5
>>> s.quantile([.25, .5, .75])
0.25 1.75
0.50 2.50
0.75 3.25
dtype: float64
"""
validate_percentile(q)
# We dispatch to DataFrame so that core.internals only has to worry
# about 2D cases.
df = self.to_frame()
result = df.quantile(q=q, interpolation=interpolation, numeric_only=False)
if result.ndim == 2:
result = result.iloc[:, 0]
if is_list_like(q):
result.name = self.name
idx = Index(q, dtype=np.float64)
return self._constructor(result, index=idx, name=self.name)
else:
# scalar
return result.iloc[0]
def corr(
self,
other: Series,
method: CorrelationMethod = "pearson",
min_periods: int | None = None,
) -> float:
"""
Compute correlation with `other` Series, excluding missing values.
The two `Series` objects are not required to be the same length and will be
aligned internally before the correlation function is applied.
Parameters
----------
other : Series
Series with which to compute the correlation.
method : {'pearson', 'kendall', 'spearman'} or callable
Method used to compute correlation:
- pearson : Standard correlation coefficient
- kendall : Kendall Tau correlation coefficient
- spearman : Spearman rank correlation
- callable: Callable with input two 1d ndarrays and returning a float.
.. warning::
Note that the returned matrix from corr will have 1 along the
diagonals and will be symmetric regardless of the callable's
behavior.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
Returns
-------
float
Correlation with other.
See Also
--------
DataFrame.corr : Compute pairwise correlation between columns.
DataFrame.corrwith : Compute pairwise correlation with another
DataFrame or Series.
Notes
-----
Pearson, Kendall and Spearman correlation are currently computed using pairwise complete observations.
* `Pearson correlation coefficient <https://en.wikipedia.org/wiki/Pearson_correlation_coefficient>`_
* `Kendall rank correlation coefficient <https://en.wikipedia.org/wiki/Kendall_rank_correlation_coefficient>`_
* `Spearman's rank correlation coefficient <https://en.wikipedia.org/wiki/Spearman%27s_rank_correlation_coefficient>`_
Examples
--------
>>> def histogram_intersection(a, b):
... v = np.minimum(a, b).sum().round(decimals=1)
... return v
>>> s1 = pd.Series([.2, .0, .6, .2])
>>> s2 = pd.Series([.3, .6, .0, .1])
>>> s1.corr(s2, method=histogram_intersection)
0.3
""" # noqa:E501
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
if method in ["pearson", "spearman", "kendall"] or callable(method):
return nanops.nancorr(
this.values, other.values, method=method, min_periods=min_periods
)
raise ValueError(
"method must be either 'pearson', "
"'spearman', 'kendall', or a callable, "
f"'{method}' was supplied"
)
def cov(
self,
other: Series,
min_periods: int | None = None,
ddof: int | None = 1,
) -> float:
"""
Compute covariance with Series, excluding missing values.
The two `Series` objects are not required to be the same length and
will be aligned internally before the covariance is calculated.
Parameters
----------
other : Series
Series with which to compute the covariance.
min_periods : int, optional
Minimum number of observations needed to have a valid result.
ddof : int, default 1
Delta degrees of freedom. The divisor used in calculations
is ``N - ddof``, where ``N`` represents the number of elements.
.. versionadded:: 1.1.0
Returns
-------
float
Covariance between Series and other normalized by N-1
(unbiased estimator).
See Also
--------
DataFrame.cov : Compute pairwise covariance of columns.
Examples
--------
>>> s1 = pd.Series([0.90010907, 0.13484424, 0.62036035])
>>> s2 = pd.Series([0.12528585, 0.26962463, 0.51111198])
>>> s1.cov(s2)
-0.01685762652715874
"""
this, other = self.align(other, join="inner", copy=False)
if len(this) == 0:
return np.nan
return nanops.nancov(
this.values, other.values, min_periods=min_periods, ddof=ddof
)
klass="Series",
extra_params="",
other_klass="DataFrame",
examples=dedent(
"""
Difference with previous row
>>> s = pd.Series([1, 1, 2, 3, 5, 8])
>>> s.diff()
0 NaN
1 0.0
2 1.0
3 1.0
4 2.0
5 3.0
dtype: float64
Difference with 3rd previous row
>>> s.diff(periods=3)
0 NaN
1 NaN
2 NaN
3 2.0
4 4.0
5 6.0
dtype: float64
Difference with following row
>>> s.diff(periods=-1)
0 0.0
1 -1.0
2 -1.0
3 -2.0
4 -3.0
5 NaN
dtype: float64
Overflow in input dtype
>>> s = pd.Series([1, 0], dtype=np.uint8)
>>> s.diff()
0 NaN
1 255.0
dtype: float64"""
),
)
def diff(self, periods: int = 1) -> Series:
"""
First discrete difference of element.
Calculates the difference of a {klass} element compared with another
element in the {klass} (default is element in previous row).
Parameters
----------
periods : int, default 1
Periods to shift for calculating difference, accepts negative
values.
{extra_params}
Returns
-------
{klass}
First differences of the Series.
See Also
--------
{klass}.pct_change: Percent change over given number of periods.
{klass}.shift: Shift index by desired number of periods with an
optional time freq.
{other_klass}.diff: First discrete difference of object.
Notes
-----
For boolean dtypes, this uses :meth:`operator.xor` rather than
:meth:`operator.sub`.
The result is calculated according to current dtype in {klass},
however dtype of the result is always float64.
Examples
--------
{examples}
"""
result = algorithms.diff(self._values, periods)
return self._constructor(result, index=self.index, copy=False).__finalize__(
self, method="diff"
)
def autocorr(self, lag: int = 1) -> float:
"""
Compute the lag-N autocorrelation.
This method computes the Pearson correlation between
the Series and its shifted self.
Parameters
----------
lag : int, default 1
Number of lags to apply before performing autocorrelation.
Returns
-------
float
The Pearson correlation between self and self.shift(lag).
See Also
--------
Series.corr : Compute the correlation between two Series.
Series.shift : Shift index by desired number of periods.
DataFrame.corr : Compute pairwise correlation of columns.
DataFrame.corrwith : Compute pairwise correlation between rows or
columns of two DataFrame objects.
Notes
-----
If the Pearson correlation is not well defined return 'NaN'.
Examples
--------
>>> s = pd.Series([0.25, 0.5, 0.2, -0.05])
>>> s.autocorr() # doctest: +ELLIPSIS
0.10355...
>>> s.autocorr(lag=2) # doctest: +ELLIPSIS
-0.99999...
If the Pearson correlation is not well defined, then 'NaN' is returned.
>>> s = pd.Series([1, 0, 0, 0])
>>> s.autocorr()
nan
"""
return self.corr(self.shift(lag))
def dot(self, other: AnyArrayLike) -> Series | np.ndarray:
"""
Compute the dot product between the Series and the columns of other.
This method computes the dot product between the Series and another
one, or the Series and each columns of a DataFrame, or the Series and
each columns of an array.
It can also be called using `self @ other` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the dot product with its columns.
Returns
-------
scalar, Series or numpy.ndarray
Return the dot product of the Series and other if other is a
Series, the Series of the dot product of Series and each rows of
other if other is a DataFrame or a numpy.ndarray between the Series
and each columns of the numpy array.
See Also
--------
DataFrame.dot: Compute the matrix product with the DataFrame.
Series.mul: Multiplication of series and other, element-wise.
Notes
-----
The Series and other has to share the same index if other is a Series
or a DataFrame.
Examples
--------
>>> s = pd.Series([0, 1, 2, 3])
>>> other = pd.Series([-1, 2, -3, 4])
>>> s.dot(other)
8
>>> s @ other
8
>>> df = pd.DataFrame([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(df)
0 24
1 14
dtype: int64
>>> arr = np.array([[0, 1], [-2, 3], [4, -5], [6, 7]])
>>> s.dot(arr)
array([24, 14])
"""
if isinstance(other, (Series, ABCDataFrame)):
common = self.index.union(other.index)
if len(common) > len(self.index) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(index=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right.values
else:
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[0] != rvals.shape[0]:
raise Exception(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, ABCDataFrame):
return self._constructor(
np.dot(lvals, rvals), index=other.columns, copy=False
).__finalize__(self, method="dot")
elif isinstance(other, Series):
return np.dot(lvals, rvals)
elif isinstance(rvals, np.ndarray):
return np.dot(lvals, rvals)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other):
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(np.transpose(other))
# Signature of "searchsorted" incompatible with supertype "IndexOpsMixin"
def searchsorted( # type: ignore[override]
self,
value: NumpyValueArrayLike | ExtensionArray,
side: Literal["left", "right"] = "left",
sorter: NumpySorter = None,
) -> npt.NDArray[np.intp] | np.intp:
return base.IndexOpsMixin.searchsorted(self, value, side=side, sorter=sorter)
# -------------------------------------------------------------------
# Combination
def _append(
self, to_append, ignore_index: bool = False, verify_integrity: bool = False
):
from pandas.core.reshape.concat import concat
if isinstance(to_append, (list, tuple)):
to_concat = [self]
to_concat.extend(to_append)
else:
to_concat = [self, to_append]
if any(isinstance(x, (ABCDataFrame,)) for x in to_concat[1:]):
msg = "to_append should be a Series or list/tuple of Series, got DataFrame"
raise TypeError(msg)
return concat(
to_concat, ignore_index=ignore_index, verify_integrity=verify_integrity
)
def _binop(self, other: Series, func, level=None, fill_value=None):
"""
Perform generic binary operation with optional fill value.
Parameters
----------
other : Series
func : binary operator
fill_value : float or object
Value to substitute for NA/null values. If both Series are NA in a
location, the result will be NA regardless of the passed fill value.
level : int or level name, default None
Broadcast across a level, matching Index values on the
passed MultiIndex level.
Returns
-------
Series
"""
if not isinstance(other, Series):
raise AssertionError("Other operand must be Series")
this = self
if not self.index.equals(other.index):
this, other = self.align(other, level=level, join="outer", copy=False)
this_vals, other_vals = ops.fill_binop(this._values, other._values, fill_value)
with np.errstate(all="ignore"):
result = func(this_vals, other_vals)
name = ops.get_op_result_name(self, other)
return this._construct_result(result, name)
def _construct_result(
self, result: ArrayLike | tuple[ArrayLike, ArrayLike], name: Hashable
) -> Series | tuple[Series, Series]:
"""
Construct an appropriately-labelled Series from the result of an op.
Parameters
----------
result : ndarray or ExtensionArray
name : Label
Returns
-------
Series
In the case of __divmod__ or __rdivmod__, a 2-tuple of Series.
"""
if isinstance(result, tuple):
# produced by divmod or rdivmod
res1 = self._construct_result(result[0], name=name)
res2 = self._construct_result(result[1], name=name)
# GH#33427 assertions to keep mypy happy
assert isinstance(res1, Series)
assert isinstance(res2, Series)
return (res1, res2)
# TODO: result should always be ArrayLike, but this fails for some
# JSONArray tests
dtype = getattr(result, "dtype", None)
out = self._constructor(result, index=self.index, dtype=dtype)
out = out.__finalize__(self)
# Set the result's name after __finalize__ is called because __finalize__
# would set it back to self.name
out.name = name
return out
_shared_docs["compare"],
"""
Returns
-------
Series or DataFrame
If axis is 0 or 'index' the result will be a Series.
The resulting index will be a MultiIndex with 'self' and 'other'
stacked alternately at the inner level.
If axis is 1 or 'columns' the result will be a DataFrame.
It will have two columns namely 'self' and 'other'.
See Also
--------
DataFrame.compare : Compare with another DataFrame and show differences.
Notes
-----
Matching NaNs will not appear as a difference.
Examples
--------
>>> s1 = pd.Series(["a", "b", "c", "d", "e"])
>>> s2 = pd.Series(["a", "a", "c", "b", "e"])
Align the differences on columns
>>> s1.compare(s2)
self other
1 b a
3 d b
Stack the differences on indices
>>> s1.compare(s2, align_axis=0)
1 self b
other a
3 self d
other b
dtype: object
Keep all original rows
>>> s1.compare(s2, keep_shape=True)
self other
0 NaN NaN
1 b a
2 NaN NaN
3 d b
4 NaN NaN
Keep all original rows and also all original values
>>> s1.compare(s2, keep_shape=True, keep_equal=True)
self other
0 a a
1 b a
2 c c
3 d b
4 e e
""",
klass=_shared_doc_kwargs["klass"],
)
def compare(
self,
other: Series,
align_axis: Axis = 1,
keep_shape: bool = False,
keep_equal: bool = False,
result_names: Suffixes = ("self", "other"),
) -> DataFrame | Series:
return super().compare(
other=other,
align_axis=align_axis,
keep_shape=keep_shape,
keep_equal=keep_equal,
result_names=result_names,
)
def combine(
self,
other: Series | Hashable,
func: Callable[[Hashable, Hashable], Hashable],
fill_value: Hashable = None,
) -> Series:
"""
Combine the Series with a Series or scalar according to `func`.
Combine the Series and `other` using `func` to perform elementwise
selection for combined Series.
`fill_value` is assumed when value is missing at some index
from one of the two objects being combined.
Parameters
----------
other : Series or scalar
The value(s) to be combined with the `Series`.
func : function
Function that takes two scalars as inputs and returns an element.
fill_value : scalar, optional
The value to assume when an index is missing from
one Series or the other. The default specifies to use the
appropriate NaN value for the underlying dtype of the Series.
Returns
-------
Series
The result of combining the Series with the other object.
See Also
--------
Series.combine_first : Combine Series values, choosing the calling
Series' values first.
Examples
--------
Consider 2 Datasets ``s1`` and ``s2`` containing
highest clocked speeds of different birds.
>>> s1 = pd.Series({'falcon': 330.0, 'eagle': 160.0})
>>> s1
falcon 330.0
eagle 160.0
dtype: float64
>>> s2 = pd.Series({'falcon': 345.0, 'eagle': 200.0, 'duck': 30.0})
>>> s2
falcon 345.0
eagle 200.0
duck 30.0
dtype: float64
Now, to combine the two datasets and view the highest speeds
of the birds across the two datasets
>>> s1.combine(s2, max)
duck NaN
eagle 200.0
falcon 345.0
dtype: float64
In the previous example, the resulting value for duck is missing,
because the maximum of a NaN and a float is a NaN.
So, in the example, we set ``fill_value=0``,
so the maximum value returned will be the value from some dataset.
>>> s1.combine(s2, max, fill_value=0)
duck 30.0
eagle 200.0
falcon 345.0
dtype: float64
"""
if fill_value is None:
fill_value = na_value_for_dtype(self.dtype, compat=False)
if isinstance(other, Series):
# If other is a Series, result is based on union of Series,
# so do this element by element
new_index = self.index.union(other.index)
new_name = ops.get_op_result_name(self, other)
new_values = np.empty(len(new_index), dtype=object)
for i, idx in enumerate(new_index):
lv = self.get(idx, fill_value)
rv = other.get(idx, fill_value)
with np.errstate(all="ignore"):
new_values[i] = func(lv, rv)
else:
# Assume that other is a scalar, so apply the function for
# each element in the Series
new_index = self.index
new_values = np.empty(len(new_index), dtype=object)
with np.errstate(all="ignore"):
new_values[:] = [func(lv, other) for lv in self._values]
new_name = self.name
# try_float=False is to match agg_series
npvalues = lib.maybe_convert_objects(new_values, try_float=False)
res_values = maybe_cast_pointwise_result(npvalues, self.dtype, same_dtype=False)
return self._constructor(res_values, index=new_index, name=new_name, copy=False)
def combine_first(self, other) -> Series:
"""
Update null elements with value in the same location in 'other'.
Combine two Series objects by filling null values in one Series with
non-null values from the other Series. Result index will be the union
of the two indexes.
Parameters
----------
other : Series
The value(s) to be used for filling null values.
Returns
-------
Series
The result of combining the provided Series with the other object.
See Also
--------
Series.combine : Perform element-wise operation on two Series
using a given function.
Examples
--------
>>> s1 = pd.Series([1, np.nan])
>>> s2 = pd.Series([3, 4, 5])
>>> s1.combine_first(s2)
0 1.0
1 4.0
2 5.0
dtype: float64
Null values still persist if the location of that null value
does not exist in `other`
>>> s1 = pd.Series({'falcon': np.nan, 'eagle': 160.0})
>>> s2 = pd.Series({'eagle': 200.0, 'duck': 30.0})
>>> s1.combine_first(s2)
duck 30.0
eagle 160.0
falcon NaN
dtype: float64
"""
new_index = self.index.union(other.index)
this = self.reindex(new_index, copy=False)
other = other.reindex(new_index, copy=False)
if this.dtype.kind == "M" and other.dtype.kind != "M":
other = to_datetime(other)
return this.where(notna(this), other)
def update(self, other: Series | Sequence | Mapping) -> None:
"""
Modify Series in place using values from passed Series.
Uses non-NA values from passed Series to make updates. Aligns
on index.
Parameters
----------
other : Series, or object coercible into Series
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6]))
>>> s
0 4
1 5
2 6
dtype: int64
>>> s = pd.Series(['a', 'b', 'c'])
>>> s.update(pd.Series(['d', 'e'], index=[0, 2]))
>>> s
0 d
1 b
2 e
dtype: object
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, 5, 6, 7, 8]))
>>> s
0 4
1 5
2 6
dtype: int64
If ``other`` contains NaNs the corresponding values are not updated
in the original Series.
>>> s = pd.Series([1, 2, 3])
>>> s.update(pd.Series([4, np.nan, 6]))
>>> s
0 4
1 2
2 6
dtype: int64
``other`` can also be a non-Series object type
that is coercible into a Series
>>> s = pd.Series([1, 2, 3])
>>> s.update([4, np.nan, 6])
>>> s
0 4
1 2
2 6
dtype: int64
>>> s = pd.Series([1, 2, 3])
>>> s.update({1: 9})
>>> s
0 1
1 9
2 3
dtype: int64
"""
if not isinstance(other, Series):
other = Series(other)
other = other.reindex_like(self)
mask = notna(other)
self._mgr = self._mgr.putmask(mask=mask, new=other)
self._maybe_update_cacher()
# ----------------------------------------------------------------------
# Reindexing, sorting
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[False] = ...,
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> Series:
...
def sort_values(
self,
*,
axis: Axis = ...,
ascending: bool | int | Sequence[bool] | Sequence[int] = ...,
inplace: Literal[True],
kind: str = ...,
na_position: str = ...,
ignore_index: bool = ...,
key: ValueKeyFunc = ...,
) -> None:
...
def sort_values(
self,
*,
axis: Axis = 0,
ascending: bool | int | Sequence[bool] | Sequence[int] = True,
inplace: bool = False,
kind: str = "quicksort",
na_position: str = "last",
ignore_index: bool = False,
key: ValueKeyFunc = None,
) -> Series | None:
"""
Sort by the values.
Sort a Series in ascending or descending order by some
criterion.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
ascending : bool or list of bools, default True
If True, sort values in ascending order, otherwise descending.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
na_position : {'first' or 'last'}, default 'last'
Argument 'first' puts NaNs at the beginning, 'last' puts NaNs at
the end.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the series values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect a
``Series`` and return an array-like.
.. versionadded:: 1.1.0
Returns
-------
Series or None
Series ordered by values or None if ``inplace=True``.
See Also
--------
Series.sort_index : Sort by the Series indices.
DataFrame.sort_values : Sort DataFrame by the values along either axis.
DataFrame.sort_index : Sort DataFrame by indices.
Examples
--------
>>> s = pd.Series([np.nan, 1, 3, 10, 5])
>>> s
0 NaN
1 1.0
2 3.0
3 10.0
4 5.0
dtype: float64
Sort values ascending order (default behaviour)
>>> s.sort_values(ascending=True)
1 1.0
2 3.0
4 5.0
3 10.0
0 NaN
dtype: float64
Sort values descending order
>>> s.sort_values(ascending=False)
3 10.0
4 5.0
2 3.0
1 1.0
0 NaN
dtype: float64
Sort values putting NAs first
>>> s.sort_values(na_position='first')
0 NaN
1 1.0
2 3.0
4 5.0
3 10.0
dtype: float64
Sort a series of strings
>>> s = pd.Series(['z', 'b', 'd', 'a', 'c'])
>>> s
0 z
1 b
2 d
3 a
4 c
dtype: object
>>> s.sort_values()
3 a
1 b
4 c
2 d
0 z
dtype: object
Sort using a key function. Your `key` function will be
given the ``Series`` of values and should return an array-like.
>>> s = pd.Series(['a', 'B', 'c', 'D', 'e'])
>>> s.sort_values()
1 B
3 D
0 a
2 c
4 e
dtype: object
>>> s.sort_values(key=lambda x: x.str.lower())
0 a
1 B
2 c
3 D
4 e
dtype: object
NumPy ufuncs work well here. For example, we can
sort by the ``sin`` of the value
>>> s = pd.Series([-4, -2, 0, 2, 4])
>>> s.sort_values(key=np.sin)
1 -2
4 4
2 0
0 -4
3 2
dtype: int64
More complicated user-defined functions can be used,
as long as they expect a Series and return an array-like
>>> s.sort_values(key=lambda x: (np.tan(x.cumsum())))
0 -4
3 2
4 4
1 -2
2 0
dtype: int64
"""
inplace = validate_bool_kwarg(inplace, "inplace")
# Validate the axis parameter
self._get_axis_number(axis)
# GH 5856/5853
if inplace and self._is_cached:
raise ValueError(
"This Series is a view of some other array, to "
"sort in-place you must create a copy"
)
if is_list_like(ascending):
ascending = cast(Sequence[Union[bool, int]], ascending)
if len(ascending) != 1:
raise ValueError(
f"Length of ascending ({len(ascending)}) must be 1 for Series"
)
ascending = ascending[0]
ascending = validate_ascending(ascending)
if na_position not in ["first", "last"]:
raise ValueError(f"invalid na_position: {na_position}")
# GH 35922. Make sorting stable by leveraging nargsort
values_to_sort = ensure_key_mapped(self, key)._values if key else self._values
sorted_index = nargsort(values_to_sort, kind, bool(ascending), na_position)
if is_range_indexer(sorted_index, len(sorted_index)):
if inplace:
return self._update_inplace(self)
return self.copy(deep=None)
result = self._constructor(
self._values[sorted_index], index=self.index[sorted_index], copy=False
)
if ignore_index:
result.index = default_index(len(sorted_index))
if not inplace:
return result.__finalize__(self, method="sort_values")
self._update_inplace(result)
return None
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[True],
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> None:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: Literal[False] = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series:
...
def sort_index(
self,
*,
axis: Axis = ...,
level: IndexLabel = ...,
ascending: bool | Sequence[bool] = ...,
inplace: bool = ...,
kind: SortKind = ...,
na_position: NaPosition = ...,
sort_remaining: bool = ...,
ignore_index: bool = ...,
key: IndexKeyFunc = ...,
) -> Series | None:
...
def sort_index(
self,
*,
axis: Axis = 0,
level: IndexLabel = None,
ascending: bool | Sequence[bool] = True,
inplace: bool = False,
kind: SortKind = "quicksort",
na_position: NaPosition = "last",
sort_remaining: bool = True,
ignore_index: bool = False,
key: IndexKeyFunc = None,
) -> Series | None:
"""
Sort Series by index labels.
Returns a new Series sorted by label if `inplace` argument is
``False``, otherwise updates the original series and returns None.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
level : int, optional
If not None, sort on values in specified index level(s).
ascending : bool or list-like of bools, default True
Sort ascending vs. descending. When the index is a MultiIndex the
sort direction can be controlled for each level individually.
inplace : bool, default False
If True, perform operation in-place.
kind : {'quicksort', 'mergesort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See also :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms. For
DataFrames, this option is only applied when sorting on a single
column or label.
na_position : {'first', 'last'}, default 'last'
If 'first' puts NaNs at the beginning, 'last' puts NaNs at the end.
Not implemented for MultiIndex.
sort_remaining : bool, default True
If True and sorting by level and index is multilevel, sort by other
levels too (in order) after sorting by specified level.
ignore_index : bool, default False
If True, the resulting axis will be labeled 0, 1, …, n - 1.
key : callable, optional
If not None, apply the key function to the index values
before sorting. This is similar to the `key` argument in the
builtin :meth:`sorted` function, with the notable difference that
this `key` function should be *vectorized*. It should expect an
``Index`` and return an ``Index`` of the same shape.
.. versionadded:: 1.1.0
Returns
-------
Series or None
The original Series sorted by the labels or None if ``inplace=True``.
See Also
--------
DataFrame.sort_index: Sort DataFrame by the index.
DataFrame.sort_values: Sort DataFrame by the value.
Series.sort_values : Sort Series by the value.
Examples
--------
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, 4])
>>> s.sort_index()
1 c
2 b
3 a
4 d
dtype: object
Sort Descending
>>> s.sort_index(ascending=False)
4 d
3 a
2 b
1 c
dtype: object
By default NaNs are put at the end, but use `na_position` to place
them at the beginning
>>> s = pd.Series(['a', 'b', 'c', 'd'], index=[3, 2, 1, np.nan])
>>> s.sort_index(na_position='first')
NaN d
1.0 c
2.0 b
3.0 a
dtype: object
Specify index level to sort
>>> arrays = [np.array(['qux', 'qux', 'foo', 'foo',
... 'baz', 'baz', 'bar', 'bar']),
... np.array(['two', 'one', 'two', 'one',
... 'two', 'one', 'two', 'one'])]
>>> s = pd.Series([1, 2, 3, 4, 5, 6, 7, 8], index=arrays)
>>> s.sort_index(level=1)
bar one 8
baz one 6
foo one 4
qux one 2
bar two 7
baz two 5
foo two 3
qux two 1
dtype: int64
Does not sort by remaining levels when sorting by levels
>>> s.sort_index(level=1, sort_remaining=False)
qux one 2
foo one 4
baz one 6
bar one 8
qux two 1
foo two 3
baz two 5
bar two 7
dtype: int64
Apply a key function before sorting
>>> s = pd.Series([1, 2, 3, 4], index=['A', 'b', 'C', 'd'])
>>> s.sort_index(key=lambda x : x.str.lower())
A 1
b 2
C 3
d 4
dtype: int64
"""
return super().sort_index(
axis=axis,
level=level,
ascending=ascending,
inplace=inplace,
kind=kind,
na_position=na_position,
sort_remaining=sort_remaining,
ignore_index=ignore_index,
key=key,
)
def argsort(
self,
axis: Axis = 0,
kind: SortKind = "quicksort",
order: None = None,
) -> Series:
"""
Return the integer indices that would sort the Series values.
Override ndarray.argsort. Argsorts the value, omitting NA/null values,
and places the result in the same locations as the non-NA values.
Parameters
----------
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
kind : {'mergesort', 'quicksort', 'heapsort', 'stable'}, default 'quicksort'
Choice of sorting algorithm. See :func:`numpy.sort` for more
information. 'mergesort' and 'stable' are the only stable algorithms.
order : None
Has no effect but is accepted for compatibility with numpy.
Returns
-------
Series[np.intp]
Positions of values within the sort order with -1 indicating
nan values.
See Also
--------
numpy.ndarray.argsort : Returns the indices that would sort this array.
"""
values = self._values
mask = isna(values)
if mask.any():
result = np.full(len(self), -1, dtype=np.intp)
notmask = ~mask
result[notmask] = np.argsort(values[notmask], kind=kind)
else:
result = np.argsort(values, kind=kind)
res = self._constructor(
result, index=self.index, name=self.name, dtype=np.intp, copy=False
)
return res.__finalize__(self, method="argsort")
def nlargest(
self, n: int = 5, keep: Literal["first", "last", "all"] = "first"
) -> Series:
"""
Return the largest `n` elements.
Parameters
----------
n : int, default 5
Return this many descending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` largest values in the Series, sorted in decreasing order.
See Also
--------
Series.nsmallest: Get the `n` smallest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values(ascending=False).head(n)`` for small `n`
relative to the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Malta": 434000, "Maldives": 434000,
... "Brunei": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Malta 434000
Maldives 434000
Brunei 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` largest elements where ``n=5`` by default.
>>> s.nlargest()
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3``. Default `keep` value is 'first'
so Malta will be kept.
>>> s.nlargest(3)
France 65000000
Italy 59000000
Malta 434000
dtype: int64
The `n` largest elements where ``n=3`` and keeping the last duplicates.
Brunei will be kept since it is the last with value 434000 based on
the index order.
>>> s.nlargest(3, keep='last')
France 65000000
Italy 59000000
Brunei 434000
dtype: int64
The `n` largest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has five elements due to the three duplicates.
>>> s.nlargest(3, keep='all')
France 65000000
Italy 59000000
Malta 434000
Maldives 434000
Brunei 434000
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nlargest()
def nsmallest(self, n: int = 5, keep: str = "first") -> Series:
"""
Return the smallest `n` elements.
Parameters
----------
n : int, default 5
Return this many ascending sorted values.
keep : {'first', 'last', 'all'}, default 'first'
When there are duplicate values that cannot all fit in a
Series of `n` elements:
- ``first`` : return the first `n` occurrences in order
of appearance.
- ``last`` : return the last `n` occurrences in reverse
order of appearance.
- ``all`` : keep all occurrences. This can result in a Series of
size larger than `n`.
Returns
-------
Series
The `n` smallest values in the Series, sorted in increasing order.
See Also
--------
Series.nlargest: Get the `n` largest elements.
Series.sort_values: Sort Series by values.
Series.head: Return the first `n` rows.
Notes
-----
Faster than ``.sort_values().head(n)`` for small `n` relative to
the size of the ``Series`` object.
Examples
--------
>>> countries_population = {"Italy": 59000000, "France": 65000000,
... "Brunei": 434000, "Malta": 434000,
... "Maldives": 434000, "Iceland": 337000,
... "Nauru": 11300, "Tuvalu": 11300,
... "Anguilla": 11300, "Montserrat": 5200}
>>> s = pd.Series(countries_population)
>>> s
Italy 59000000
France 65000000
Brunei 434000
Malta 434000
Maldives 434000
Iceland 337000
Nauru 11300
Tuvalu 11300
Anguilla 11300
Montserrat 5200
dtype: int64
The `n` smallest elements where ``n=5`` by default.
>>> s.nsmallest()
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
Iceland 337000
dtype: int64
The `n` smallest elements where ``n=3``. Default `keep` value is
'first' so Nauru and Tuvalu will be kept.
>>> s.nsmallest(3)
Montserrat 5200
Nauru 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` and keeping the last
duplicates. Anguilla and Tuvalu will be kept since they are the last
with value 11300 based on the index order.
>>> s.nsmallest(3, keep='last')
Montserrat 5200
Anguilla 11300
Tuvalu 11300
dtype: int64
The `n` smallest elements where ``n=3`` with all duplicates kept. Note
that the returned Series has four elements due to the three duplicates.
>>> s.nsmallest(3, keep='all')
Montserrat 5200
Nauru 11300
Tuvalu 11300
Anguilla 11300
dtype: int64
"""
return selectn.SelectNSeries(self, n=n, keep=keep).nsmallest()
klass=_shared_doc_kwargs["klass"],
extra_params=dedent(
"""copy : bool, default True
Whether to copy underlying data."""
),
examples=dedent(
"""\
Examples
--------
>>> s = pd.Series(
... ["A", "B", "A", "C"],
... index=[
... ["Final exam", "Final exam", "Coursework", "Coursework"],
... ["History", "Geography", "History", "Geography"],
... ["January", "February", "March", "April"],
... ],
... )
>>> s
Final exam History January A
Geography February B
Coursework History March A
Geography April C
dtype: object
In the following example, we will swap the levels of the indices.
Here, we will swap the levels column-wise, but levels can be swapped row-wise
in a similar manner. Note that column-wise is the default behaviour.
By not supplying any arguments for i and j, we swap the last and second to
last indices.
>>> s.swaplevel()
Final exam January History A
February Geography B
Coursework March History A
April Geography C
dtype: object
By supplying one argument, we can choose which index to swap the last
index with. We can for example swap the first index with the last one as
follows.
>>> s.swaplevel(0)
January History Final exam A
February Geography Final exam B
March History Coursework A
April Geography Coursework C
dtype: object
We can also define explicitly which indices we want to swap by supplying values
for both i and j. Here, we for example swap the first and second indices.
>>> s.swaplevel(0, 1)
History Final exam January A
Geography Final exam February B
History Coursework March A
Geography Coursework April C
dtype: object"""
),
)
def swaplevel(
self, i: Level = -2, j: Level = -1, copy: bool | None = None
) -> Series:
"""
Swap levels i and j in a :class:`MultiIndex`.
Default is to swap the two innermost levels of the index.
Parameters
----------
i, j : int or str
Levels of the indices to be swapped. Can pass level name as string.
{extra_params}
Returns
-------
{klass}
{klass} with levels swapped in MultiIndex.
{examples}
"""
assert isinstance(self.index, MultiIndex)
result = self.copy(deep=copy and not using_copy_on_write())
result.index = self.index.swaplevel(i, j)
return result
def reorder_levels(self, order: Sequence[Level]) -> Series:
"""
Rearrange index levels using input order.
May not drop or duplicate levels.
Parameters
----------
order : list of int representing new level order
Reference level by number or key.
Returns
-------
type of caller (new object)
"""
if not isinstance(self.index, MultiIndex): # pragma: no cover
raise Exception("Can only reorder levels on a hierarchical axis.")
result = self.copy(deep=None)
assert isinstance(result.index, MultiIndex)
result.index = result.index.reorder_levels(order)
return result
def explode(self, ignore_index: bool = False) -> Series:
"""
Transform each element of a list-like to a row.
Parameters
----------
ignore_index : bool, default False
If True, the resulting index will be labeled 0, 1, …, n - 1.
.. versionadded:: 1.1.0
Returns
-------
Series
Exploded lists to rows; index will be duplicated for these rows.
See Also
--------
Series.str.split : Split string values on specified separator.
Series.unstack : Unstack, a.k.a. pivot, Series with MultiIndex
to produce DataFrame.
DataFrame.melt : Unpivot a DataFrame from wide format to long format.
DataFrame.explode : Explode a DataFrame from list-like
columns to long format.
Notes
-----
This routine will explode list-likes including lists, tuples, sets,
Series, and np.ndarray. The result dtype of the subset rows will
be object. Scalars will be returned unchanged, and empty list-likes will
result in a np.nan for that row. In addition, the ordering of elements in
the output will be non-deterministic when exploding sets.
Reference :ref:`the user guide <reshaping.explode>` for more examples.
Examples
--------
>>> s = pd.Series([[1, 2, 3], 'foo', [], [3, 4]])
>>> s
0 [1, 2, 3]
1 foo
2 []
3 [3, 4]
dtype: object
>>> s.explode()
0 1
0 2
0 3
1 foo
2 NaN
3 3
3 4
dtype: object
"""
if not len(self) or not is_object_dtype(self):
result = self.copy()
return result.reset_index(drop=True) if ignore_index else result
values, counts = reshape.explode(np.asarray(self._values))
if ignore_index:
index = default_index(len(values))
else:
index = self.index.repeat(counts)
return self._constructor(values, index=index, name=self.name, copy=False)
def unstack(self, level: IndexLabel = -1, fill_value: Hashable = None) -> DataFrame:
"""
Unstack, also known as pivot, Series with MultiIndex to produce DataFrame.
Parameters
----------
level : int, str, or list of these, default last level
Level(s) to unstack, can pass level name.
fill_value : scalar value, default None
Value to use when replacing NaN values.
Returns
-------
DataFrame
Unstacked Series.
Notes
-----
Reference :ref:`the user guide <reshaping.stacking>` for more examples.
Examples
--------
>>> s = pd.Series([1, 2, 3, 4],
... index=pd.MultiIndex.from_product([['one', 'two'],
... ['a', 'b']]))
>>> s
one a 1
b 2
two a 3
b 4
dtype: int64
>>> s.unstack(level=-1)
a b
one 1 2
two 3 4
>>> s.unstack(level=0)
one two
a 1 3
b 2 4
"""
from pandas.core.reshape.reshape import unstack
return unstack(self, level, fill_value)
# ----------------------------------------------------------------------
# function application
def map(
self,
arg: Callable | Mapping | Series,
na_action: Literal["ignore"] | None = None,
) -> Series:
"""
Map values of Series according to an input mapping or function.
Used for substituting each value in a Series with another value,
that may be derived from a function, a ``dict`` or
a :class:`Series`.
Parameters
----------
arg : function, collections.abc.Mapping subclass or Series
Mapping correspondence.
na_action : {None, 'ignore'}, default None
If 'ignore', propagate NaN values, without passing them to the
mapping correspondence.
Returns
-------
Series
Same index as caller.
See Also
--------
Series.apply : For applying more complex functions on a Series.
DataFrame.apply : Apply a function row-/column-wise.
DataFrame.applymap : Apply a function elementwise on a whole DataFrame.
Notes
-----
When ``arg`` is a dictionary, values in Series that are not in the
dictionary (as keys) are converted to ``NaN``. However, if the
dictionary is a ``dict`` subclass that defines ``__missing__`` (i.e.
provides a method for default values), then this default is used
rather than ``NaN``.
Examples
--------
>>> s = pd.Series(['cat', 'dog', np.nan, 'rabbit'])
>>> s
0 cat
1 dog
2 NaN
3 rabbit
dtype: object
``map`` accepts a ``dict`` or a ``Series``. Values that are not found
in the ``dict`` are converted to ``NaN``, unless the dict has a default
value (e.g. ``defaultdict``):
>>> s.map({'cat': 'kitten', 'dog': 'puppy'})
0 kitten
1 puppy
2 NaN
3 NaN
dtype: object
It also accepts a function:
>>> s.map('I am a {}'.format)
0 I am a cat
1 I am a dog
2 I am a nan
3 I am a rabbit
dtype: object
To avoid applying the function to missing values (and keep them as
``NaN``) ``na_action='ignore'`` can be used:
>>> s.map('I am a {}'.format, na_action='ignore')
0 I am a cat
1 I am a dog
2 NaN
3 I am a rabbit
dtype: object
"""
new_values = self._map_values(arg, na_action=na_action)
return self._constructor(new_values, index=self.index, copy=False).__finalize__(
self, method="map"
)
def _gotitem(self, key, ndim, subset=None) -> Series:
"""
Sub-classes to define. Return a sliced object.
Parameters
----------
key : string / list of selections
ndim : {1, 2}
Requested ndim of result.
subset : object, default None
Subset to act on.
"""
return self
_agg_see_also_doc = dedent(
"""
See Also
--------
Series.apply : Invoke function on a Series.
Series.transform : Transform function producing a Series with like indexes.
"""
)
_agg_examples_doc = dedent(
"""
Examples
--------
>>> s = pd.Series([1, 2, 3, 4])
>>> s
0 1
1 2
2 3
3 4
dtype: int64
>>> s.agg('min')
1
>>> s.agg(['min', 'max'])
min 1
max 4
dtype: int64
"""
)
_shared_docs["aggregate"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
see_also=_agg_see_also_doc,
examples=_agg_examples_doc,
)
def aggregate(self, func=None, axis: Axis = 0, *args, **kwargs):
# Validate the axis parameter
self._get_axis_number(axis)
# if func is None, will switch to user-provided "named aggregation" kwargs
if func is None:
func = dict(kwargs.items())
op = SeriesApply(self, func, convert_dtype=False, args=args, kwargs=kwargs)
result = op.agg()
return result
agg = aggregate
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: None = ...,
**kwargs,
) -> bool:
...
def any(
self,
*,
axis: Axis = ...,
bool_only: bool | None = ...,
skipna: bool = ...,
level: Level,
**kwargs,
) -> Series | bool:
...
# error: Missing return statement
def any( # type: ignore[empty-body]
self,
axis: Axis = 0,
bool_only: bool | None = None,
skipna: bool = True,
level: Level | None = None,
**kwargs,
) -> Series | bool:
...
_shared_docs["transform"],
klass=_shared_doc_kwargs["klass"],
axis=_shared_doc_kwargs["axis"],
)
def transform(
self, func: AggFuncType, axis: Axis = 0, *args, **kwargs
) -> DataFrame | Series:
# Validate axis argument
self._get_axis_number(axis)
result = SeriesApply(
self, func=func, convert_dtype=True, args=args, kwargs=kwargs
).transform()
return result
def apply(
self,
func: AggFuncType,
convert_dtype: bool = True,
args: tuple[Any, ...] = (),
**kwargs,
) -> DataFrame | Series:
"""
Invoke function on values of Series.
Can be ufunc (a NumPy function that applies to the entire Series)
or a Python function that only works on single values.
Parameters
----------
func : function
Python function or NumPy ufunc to apply.
convert_dtype : bool, default True
Try to find better dtype for elementwise function results. If
False, leave as dtype=object. Note that the dtype is always
preserved for some extension array dtypes, such as Categorical.
args : tuple
Positional arguments passed to func after the series value.
**kwargs
Additional keyword arguments passed to func.
Returns
-------
Series or DataFrame
If func returns a Series object the result will be a DataFrame.
See Also
--------
Series.map: For element-wise operations.
Series.agg: Only perform aggregating type operations.
Series.transform: Only perform transforming type operations.
Notes
-----
Functions that mutate the passed object can produce unexpected
behavior or errors and are not supported. See :ref:`gotchas.udf-mutation`
for more details.
Examples
--------
Create a series with typical summer temperatures for each city.
>>> s = pd.Series([20, 21, 12],
... index=['London', 'New York', 'Helsinki'])
>>> s
London 20
New York 21
Helsinki 12
dtype: int64
Square the values by defining a function and passing it as an
argument to ``apply()``.
>>> def square(x):
... return x ** 2
>>> s.apply(square)
London 400
New York 441
Helsinki 144
dtype: int64
Square the values by passing an anonymous function as an
argument to ``apply()``.
>>> s.apply(lambda x: x ** 2)
London 400
New York 441
Helsinki 144
dtype: int64
Define a custom function that needs additional positional
arguments and pass these additional arguments using the
``args`` keyword.
>>> def subtract_custom_value(x, custom_value):
... return x - custom_value
>>> s.apply(subtract_custom_value, args=(5,))
London 15
New York 16
Helsinki 7
dtype: int64
Define a custom function that takes keyword arguments
and pass these arguments to ``apply``.
>>> def add_custom_values(x, **kwargs):
... for month in kwargs:
... x += kwargs[month]
... return x
>>> s.apply(add_custom_values, june=30, july=20, august=25)
London 95
New York 96
Helsinki 87
dtype: int64
Use a function from the Numpy library.
>>> s.apply(np.log)
London 2.995732
New York 3.044522
Helsinki 2.484907
dtype: float64
"""
return SeriesApply(self, func, convert_dtype, args, kwargs).apply()
def _reduce(
self,
op,
name: str,
*,
axis: Axis = 0,
skipna: bool = True,
numeric_only: bool = False,
filter_type=None,
**kwds,
):
"""
Perform a reduction operation.
If we have an ndarray as a value, then simply perform the operation,
otherwise delegate to the object.
"""
delegate = self._values
if axis is not None:
self._get_axis_number(axis)
if isinstance(delegate, ExtensionArray):
# dispatch to ExtensionArray interface
return delegate._reduce(name, skipna=skipna, **kwds)
else:
# dispatch to numpy arrays
if numeric_only and not is_numeric_dtype(self.dtype):
kwd_name = "numeric_only"
if name in ["any", "all"]:
kwd_name = "bool_only"
# GH#47500 - change to TypeError to match other methods
raise TypeError(
f"Series.{name} does not allow {kwd_name}={numeric_only} "
"with non-numeric dtypes."
)
with np.errstate(all="ignore"):
return op(delegate, skipna=skipna, **kwds)
def _reindex_indexer(
self,
new_index: Index | None,
indexer: npt.NDArray[np.intp] | None,
copy: bool | None,
) -> Series:
# Note: new_index is None iff indexer is None
# if not None, indexer is np.intp
if indexer is None and (
new_index is None or new_index.names == self.index.names
):
if using_copy_on_write():
return self.copy(deep=copy)
if copy or copy is None:
return self.copy(deep=copy)
return self
new_values = algorithms.take_nd(
self._values, indexer, allow_fill=True, fill_value=None
)
return self._constructor(new_values, index=new_index, copy=False)
def _needs_reindex_multi(self, axes, method, level) -> bool:
"""
Check if we do need a multi reindex; this is for compat with
higher dims.
"""
return False
# error: Cannot determine type of 'align'
NDFrame.align, # type: ignore[has-type]
klass=_shared_doc_kwargs["klass"],
axes_single_arg=_shared_doc_kwargs["axes_single_arg"],
)
def align(
self,
other: Series,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value: Hashable = None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> Series:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[True],
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> None:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: Literal[False] = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series:
...
def rename(
self,
index: Renamer | Hashable | None = ...,
*,
axis: Axis | None = ...,
copy: bool = ...,
inplace: bool = ...,
level: Level | None = ...,
errors: IgnoreRaise = ...,
) -> Series | None:
...
def rename(
self,
index: Renamer | Hashable | None = None,
*,
axis: Axis | None = None,
copy: bool = True,
inplace: bool = False,
level: Level | None = None,
errors: IgnoreRaise = "ignore",
) -> Series | None:
"""
Alter Series index labels or name.
Function / dict values must be unique (1-to-1). Labels not contained in
a dict / Series will be left as-is. Extra labels listed don't throw an
error.
Alternatively, change ``Series.name`` with a scalar value.
See the :ref:`user guide <basics.rename>` for more.
Parameters
----------
index : scalar, hashable sequence, dict-like or function optional
Functions or dict-like are transformations to apply to
the index.
Scalar or hashable sequence-like will alter the ``Series.name``
attribute.
axis : {0 or 'index'}
Unused. Parameter needed for compatibility with DataFrame.
copy : bool, default True
Also copy underlying data.
inplace : bool, default False
Whether to return a new Series. If True the value of copy is ignored.
level : int or level name, default None
In case of MultiIndex, only rename labels in the specified level.
errors : {'ignore', 'raise'}, default 'ignore'
If 'raise', raise `KeyError` when a `dict-like mapper` or
`index` contains labels that are not present in the index being transformed.
If 'ignore', existing keys will be renamed and extra keys will be ignored.
Returns
-------
Series or None
Series with index labels or name altered or None if ``inplace=True``.
See Also
--------
DataFrame.rename : Corresponding DataFrame method.
Series.rename_axis : Set the name of the axis.
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.rename("my_name") # scalar, changes Series.name
0 1
1 2
2 3
Name: my_name, dtype: int64
>>> s.rename(lambda x: x ** 2) # function, changes labels
0 1
1 2
4 3
dtype: int64
>>> s.rename({1: 3, 2: 5}) # mapping, changes labels
0 1
3 2
5 3
dtype: int64
"""
if axis is not None:
# Make sure we raise if an invalid 'axis' is passed.
axis = self._get_axis_number(axis)
if callable(index) or is_dict_like(index):
# error: Argument 1 to "_rename" of "NDFrame" has incompatible
# type "Union[Union[Mapping[Any, Hashable], Callable[[Any],
# Hashable]], Hashable, None]"; expected "Union[Mapping[Any,
# Hashable], Callable[[Any], Hashable], None]"
return super()._rename(
index, # type: ignore[arg-type]
copy=copy,
inplace=inplace,
level=level,
errors=errors,
)
else:
return self._set_name(index, inplace=inplace)
"""
Examples
--------
>>> s = pd.Series([1, 2, 3])
>>> s
0 1
1 2
2 3
dtype: int64
>>> s.set_axis(['a', 'b', 'c'], axis=0)
a 1
b 2
c 3
dtype: int64
"""
)
**_shared_doc_kwargs,
extended_summary_sub="",
axis_description_sub="",
see_also_sub="",
)
)
)
# error: Cannot determine type of 'shift'
# ----------------------------------------------------------------------
# Convert to types that support pd.NA
# error: Cannot determine type of 'isna'
# error: Return type "Series" of "isna" incompatible with return type "ndarray
# [Any, dtype[bool_]]" in supertype "IndexOpsMixin"
# error: Cannot determine type of 'isna'
# error: Cannot determine type of 'notna'
# error: Cannot determine type of 'notna'
# ----------------------------------------------------------------------
# Time series-oriented methods
# error: Cannot determine type of 'asfreq'
# error: Cannot determine type of 'resample'
# ----------------------------------------------------------------------
# Add index
# ----------------------------------------------------------------------
# Accessor Methods
# ----------------------------------------------------------------------
# ----------------------------------------------------------------------
# Add plotting methods to Series
# ----------------------------------------------------------------------
# Template-Based Arithmetic/Comparison Methods
Series
The provided code snippet includes necessary dependencies for implementing the `_dtype_to_stata_type_117` function. Write a Python function `def _dtype_to_stata_type_117(dtype: np.dtype, column: Series, force_strl: bool) -> int` to solve the following problem:
Converts dtype types to stata types. Returns the byte of the given ordinal. See TYPE_MAP and comments for an explanation. This is also explained in the dta spec. 1 - 2045 are strings of this length Pandas Stata 32768 - for object strL 65526 - for int8 byte 65527 - for int16 int 65528 - for int32 long 65529 - for float32 float 65530 - for double double If there are dates to convert, then dtype will already have the correct type inserted.
Here is the function:
def _dtype_to_stata_type_117(dtype: np.dtype, column: Series, force_strl: bool) -> int:
"""
Converts dtype types to stata types. Returns the byte of the given ordinal.
See TYPE_MAP and comments for an explanation. This is also explained in
the dta spec.
1 - 2045 are strings of this length
Pandas Stata
32768 - for object strL
65526 - for int8 byte
65527 - for int16 int
65528 - for int32 long
65529 - for float32 float
65530 - for double double
If there are dates to convert, then dtype will already have the correct
type inserted.
"""
# TODO: expand to handle datetime to integer conversion
if force_strl:
return 32768
if dtype.type is np.object_: # try to coerce it to the biggest string
# not memory efficient, what else could we
# do?
itemsize = max_len_string_array(ensure_object(column._values))
itemsize = max(itemsize, 1)
if itemsize <= 2045:
return itemsize
return 32768
elif dtype.type is np.float64:
return 65526
elif dtype.type is np.float32:
return 65527
elif dtype.type is np.int32:
return 65528
elif dtype.type is np.int16:
return 65529
elif dtype.type is np.int8:
return 65530
else: # pragma : no cover
raise NotImplementedError(f"Data type {dtype} not supported.") | Converts dtype types to stata types. Returns the byte of the given ordinal. See TYPE_MAP and comments for an explanation. This is also explained in the dta spec. 1 - 2045 are strings of this length Pandas Stata 32768 - for object strL 65526 - for int8 byte 65527 - for int16 int 65528 - for int32 long 65529 - for float32 float 65530 - for double double If there are dates to convert, then dtype will already have the correct type inserted. |
173,543 | from __future__ import annotations
from collections import abc
import datetime
from io import BytesIO
import os
import struct
import sys
from types import TracebackType
from typing import (
IO,
TYPE_CHECKING,
Any,
AnyStr,
Callable,
Final,
Hashable,
Sequence,
cast,
)
import warnings
from dateutil.relativedelta import relativedelta
import numpy as np
from pandas._libs.lib import infer_dtype
from pandas._libs.writers import max_len_string_array
from pandas._typing import (
CompressionOptions,
FilePath,
ReadBuffer,
StorageOptions,
WriteBuffer,
)
from pandas.errors import (
CategoricalConversionWarning,
InvalidColumnName,
PossiblePrecisionLoss,
ValueLabelTypeMismatch,
)
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._exceptions import find_stack_level
from pandas.core.dtypes.common import (
ensure_object,
is_categorical_dtype,
is_datetime64_dtype,
is_numeric_dtype,
)
from pandas import (
Categorical,
DatetimeIndex,
NaT,
Timestamp,
isna,
to_datetime,
to_timedelta,
)
from pandas.core.arrays.boolean import BooleanDtype
from pandas.core.arrays.integer import IntegerDtype
from pandas.core.frame import DataFrame
from pandas.core.indexes.base import Index
from pandas.core.series import Series
from pandas.core.shared_docs import _shared_docs
from pandas.io.common import get_handle
The provided code snippet includes necessary dependencies for implementing the `_pad_bytes_new` function. Write a Python function `def _pad_bytes_new(name: str | bytes, length: int) -> bytes` to solve the following problem:
Takes a bytes instance and pads it with null bytes until it's length chars.
Here is the function:
def _pad_bytes_new(name: str | bytes, length: int) -> bytes:
"""
Takes a bytes instance and pads it with null bytes until it's length chars.
"""
if isinstance(name, str):
name = bytes(name, "utf-8")
return name + b"\x00" * (length - len(name)) | Takes a bytes instance and pads it with null bytes until it's length chars. |
173,544 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
_writers: MutableMapping[str, ExcelWriter_t] = {}
The provided code snippet includes necessary dependencies for implementing the `register_writer` function. Write a Python function `def register_writer(klass: ExcelWriter_t) -> None` to solve the following problem:
Add engine to the excel writer registry.io.excel. You must use this method to integrate with ``to_excel``. Parameters ---------- klass : ExcelWriter
Here is the function:
def register_writer(klass: ExcelWriter_t) -> None:
"""
Add engine to the excel writer registry.io.excel.
You must use this method to integrate with ``to_excel``.
Parameters
----------
klass : ExcelWriter
"""
if not callable(klass):
raise ValueError("Can only register callables as engines")
engine_name = klass._engine
_writers[engine_name] = klass | Add engine to the excel writer registry.io.excel. You must use this method to integrate with ``to_excel``. Parameters ---------- klass : ExcelWriter |
173,545 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
Literal: _SpecialForm = ...
def import_optional_dependency(
name: str,
extra: str = "",
errors: str = "raise",
min_version: str | None = None,
):
"""
Import an optional dependency.
By default, if a dependency is missing an ImportError with a nice
message will be raised. If a dependency is present, but too old,
we raise.
Parameters
----------
name : str
The module name.
extra : str
Additional text to include in the ImportError message.
errors : str {'raise', 'warn', 'ignore'}
What to do when a dependency is not found or its version is too old.
* raise : Raise an ImportError
* warn : Only applicable when a module's version is to old.
Warns that the version is too old and returns None
* ignore: If the module is not installed, return None, otherwise,
return the module, even if the version is too old.
It's expected that users validate the version locally when
using ``errors="ignore"`` (see. ``io/html.py``)
min_version : str, default None
Specify a minimum version that is different from the global pandas
minimum version required.
Returns
-------
maybe_module : Optional[ModuleType]
The imported module, when found and the version is correct.
None is returned when the package is not found and `errors`
is False, or when the package's version is too old and `errors`
is ``'warn'``.
"""
assert errors in {"warn", "raise", "ignore"}
package_name = INSTALL_MAPPING.get(name)
install_name = package_name if package_name is not None else name
msg = (
f"Missing optional dependency '{install_name}'. {extra} "
f"Use pip or conda to install {install_name}."
)
try:
module = importlib.import_module(name)
except ImportError:
if errors == "raise":
raise ImportError(msg)
return None
# Handle submodules: if we have submodule, grab parent module from sys.modules
parent = name.split(".")[0]
if parent != name:
install_name = parent
module_to_get = sys.modules[install_name]
else:
module_to_get = module
minimum_version = min_version if min_version is not None else VERSIONS.get(parent)
if minimum_version:
version = get_version(module_to_get)
if version and Version(version) < Version(minimum_version):
msg = (
f"Pandas requires version '{minimum_version}' or newer of '{parent}' "
f"(version '{version}' currently installed)."
)
if errors == "warn":
warnings.warn(
msg,
UserWarning,
stacklevel=find_stack_level(),
)
return None
elif errors == "raise":
raise ImportError(msg)
return module
The provided code snippet includes necessary dependencies for implementing the `get_default_engine` function. Write a Python function `def get_default_engine(ext: str, mode: Literal["reader", "writer"] = "reader") -> str` to solve the following problem:
Return the default reader/writer for the given extension. Parameters ---------- ext : str The excel file extension for which to get the default engine. mode : str {'reader', 'writer'} Whether to get the default engine for reading or writing. Either 'reader' or 'writer' Returns ------- str The default engine for the extension.
Here is the function:
def get_default_engine(ext: str, mode: Literal["reader", "writer"] = "reader") -> str:
"""
Return the default reader/writer for the given extension.
Parameters
----------
ext : str
The excel file extension for which to get the default engine.
mode : str {'reader', 'writer'}
Whether to get the default engine for reading or writing.
Either 'reader' or 'writer'
Returns
-------
str
The default engine for the extension.
"""
_default_readers = {
"xlsx": "openpyxl",
"xlsm": "openpyxl",
"xlsb": "pyxlsb",
"xls": "xlrd",
"ods": "odf",
}
_default_writers = {
"xlsx": "openpyxl",
"xlsm": "openpyxl",
"xlsb": "pyxlsb",
"ods": "odf",
}
assert mode in ["reader", "writer"]
if mode == "writer":
# Prefer xlsxwriter over openpyxl if installed
xlsxwriter = import_optional_dependency("xlsxwriter", errors="warn")
if xlsxwriter:
_default_writers["xlsx"] = "xlsxwriter"
return _default_writers[ext]
else:
return _default_readers[ext] | Return the default reader/writer for the given extension. Parameters ---------- ext : str The excel file extension for which to get the default engine. mode : str {'reader', 'writer'} Whether to get the default engine for reading or writing. Either 'reader' or 'writer' Returns ------- str The default engine for the extension. |
173,546 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
_writers: MutableMapping[str, ExcelWriter_t] = {}
def get_writer(engine_name: str) -> ExcelWriter_t:
try:
return _writers[engine_name]
except KeyError as err:
raise ValueError(f"No Excel writer '{engine_name}'") from err | null |
173,547 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
def maybe_convert_usecols(usecols: str | list[int]) -> list[int]:
... | null |
173,548 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
def maybe_convert_usecols(usecols: list[str]) -> list[str]:
... | null |
173,549 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
def maybe_convert_usecols(usecols: usecols_func) -> usecols_func:
... | null |
173,550 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
def maybe_convert_usecols(usecols: None) -> None:
... | null |
173,551 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
def _range2cols(areas: str) -> list[int]:
"""
Convert comma separated list of column names and ranges to indices.
Parameters
----------
areas : str
A string containing a sequence of column ranges (or areas).
Returns
-------
cols : list
A list of 0-based column indices.
Examples
--------
>>> _range2cols('A:E')
[0, 1, 2, 3, 4]
>>> _range2cols('A,C,Z:AB')
[0, 2, 25, 26, 27]
"""
cols: list[int] = []
for rng in areas.split(","):
if ":" in rng:
rngs = rng.split(":")
cols.extend(range(_excel2num(rngs[0]), _excel2num(rngs[1]) + 1))
else:
cols.append(_excel2num(rng))
return cols
The provided code snippet includes necessary dependencies for implementing the `maybe_convert_usecols` function. Write a Python function `def maybe_convert_usecols( usecols: str | list[int] | list[str] | usecols_func | None, ) -> None | list[int] | list[str] | usecols_func` to solve the following problem:
Convert `usecols` into a compatible format for parsing in `parsers.py`. Parameters ---------- usecols : object The use-columns object to potentially convert. Returns ------- converted : object The compatible format of `usecols`.
Here is the function:
def maybe_convert_usecols(
usecols: str | list[int] | list[str] | usecols_func | None,
) -> None | list[int] | list[str] | usecols_func:
"""
Convert `usecols` into a compatible format for parsing in `parsers.py`.
Parameters
----------
usecols : object
The use-columns object to potentially convert.
Returns
-------
converted : object
The compatible format of `usecols`.
"""
if usecols is None:
return usecols
if is_integer(usecols):
raise ValueError(
"Passing an integer for `usecols` is no longer supported. "
"Please pass in a list of int from 0 to `usecols` inclusive instead."
)
if isinstance(usecols, str):
return _range2cols(usecols)
return usecols | Convert `usecols` into a compatible format for parsing in `parsers.py`. Parameters ---------- usecols : object The use-columns object to potentially convert. Returns ------- converted : object The compatible format of `usecols`. |
173,552 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
Literal: _SpecialForm = ...
def validate_freeze_panes(freeze_panes: tuple[int, int]) -> Literal[True]:
... | null |
173,553 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
Literal: _SpecialForm = ...
def validate_freeze_panes(freeze_panes: None) -> Literal[False]:
... | null |
173,554 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
def validate_freeze_panes(freeze_panes: tuple[int, int] | None) -> bool:
if freeze_panes is not None:
if len(freeze_panes) == 2 and all(
isinstance(item, int) for item in freeze_panes
):
return True
raise ValueError(
"freeze_panes must be of form (row, column) "
"where row and column are integers"
)
# freeze_panes wasn't specified, return False so it won't be applied
# to output sheet
return False | null |
173,555 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
The provided code snippet includes necessary dependencies for implementing the `fill_mi_header` function. Write a Python function `def fill_mi_header( row: list[Hashable], control_row: list[bool] ) -> tuple[list[Hashable], list[bool]]` to solve the following problem:
Forward fill blank entries in row but only inside the same parent index. Used for creating headers in Multiindex. Parameters ---------- row : list List of items in a single row. control_row : list of bool Helps to determine if particular column is in same parent index as the previous value. Used to stop propagation of empty cells between different indexes. Returns ------- Returns changed row and control_row
Here is the function:
def fill_mi_header(
row: list[Hashable], control_row: list[bool]
) -> tuple[list[Hashable], list[bool]]:
"""
Forward fill blank entries in row but only inside the same parent index.
Used for creating headers in Multiindex.
Parameters
----------
row : list
List of items in a single row.
control_row : list of bool
Helps to determine if particular column is in same parent index as the
previous value. Used to stop propagation of empty cells between
different indexes.
Returns
-------
Returns changed row and control_row
"""
last = row[0]
for i in range(1, len(row)):
if not control_row[i]:
last = row[i]
if row[i] == "" or row[i] is None:
row[i] = last
else:
control_row[i] = False
last = row[i]
return row, control_row | Forward fill blank entries in row but only inside the same parent index. Used for creating headers in Multiindex. Parameters ---------- row : list List of items in a single row. control_row : list of bool Helps to determine if particular column is in same parent index as the previous value. Used to stop propagation of empty cells between different indexes. Returns ------- Returns changed row and control_row |
173,556 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
class Iterable(Protocol[_T_co]):
def __iter__(self) -> Iterator[_T_co]: ...
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
The provided code snippet includes necessary dependencies for implementing the `pop_header_name` function. Write a Python function `def pop_header_name( row: list[Hashable], index_col: int | Sequence[int] ) -> tuple[Hashable | None, list[Hashable]]` to solve the following problem:
Pop the header name for MultiIndex parsing. Parameters ---------- row : list The data row to parse for the header name. index_col : int, list The index columns for our data. Assumed to be non-null. Returns ------- header_name : str The extracted header name. trimmed_row : list The original data row with the header name removed.
Here is the function:
def pop_header_name(
row: list[Hashable], index_col: int | Sequence[int]
) -> tuple[Hashable | None, list[Hashable]]:
"""
Pop the header name for MultiIndex parsing.
Parameters
----------
row : list
The data row to parse for the header name.
index_col : int, list
The index columns for our data. Assumed to be non-null.
Returns
-------
header_name : str
The extracted header name.
trimmed_row : list
The original data row with the header name removed.
"""
# Pop out header name and fill w/blank.
if is_list_like(index_col):
assert isinstance(index_col, Iterable)
i = max(index_col)
else:
assert not isinstance(index_col, Iterable)
i = index_col
header_name = row[i]
header_name = None if header_name == "" else header_name
return header_name, row[:i] + [""] + row[i + 1 :] | Pop the header name for MultiIndex parsing. Parameters ---------- row : list The data row to parse for the header name. index_col : int, list The index columns for our data. Assumed to be non-null. Returns ------- header_name : str The extracted header name. trimmed_row : list The original data row with the header name removed. |
173,557 | from __future__ import annotations
from typing import (
TYPE_CHECKING,
Any,
Callable,
Hashable,
Iterable,
Literal,
MutableMapping,
Sequence,
TypeVar,
overload,
)
from pandas.compat._optional import import_optional_dependency
from pandas.core.dtypes.common import (
is_integer,
is_list_like,
)
Any = object()
The provided code snippet includes necessary dependencies for implementing the `combine_kwargs` function. Write a Python function `def combine_kwargs(engine_kwargs: dict[str, Any] | None, kwargs: dict) -> dict` to solve the following problem:
Used to combine two sources of kwargs for the backend engine. Use of kwargs is deprecated, this function is solely for use in 1.3 and should be removed in 1.4/2.0. Also _base.ExcelWriter.__new__ ensures either engine_kwargs or kwargs must be None or empty respectively. Parameters ---------- engine_kwargs: dict kwargs to be passed through to the engine. kwargs: dict kwargs to be psased through to the engine (deprecated) Returns ------- engine_kwargs combined with kwargs
Here is the function:
def combine_kwargs(engine_kwargs: dict[str, Any] | None, kwargs: dict) -> dict:
"""
Used to combine two sources of kwargs for the backend engine.
Use of kwargs is deprecated, this function is solely for use in 1.3 and should
be removed in 1.4/2.0. Also _base.ExcelWriter.__new__ ensures either engine_kwargs
or kwargs must be None or empty respectively.
Parameters
----------
engine_kwargs: dict
kwargs to be passed through to the engine.
kwargs: dict
kwargs to be psased through to the engine (deprecated)
Returns
-------
engine_kwargs combined with kwargs
"""
if engine_kwargs is None:
result = {}
else:
result = engine_kwargs.copy()
result.update(kwargs)
return result | Used to combine two sources of kwargs for the backend engine. Use of kwargs is deprecated, this function is solely for use in 1.3 and should be removed in 1.4/2.0. Also _base.ExcelWriter.__new__ ensures either engine_kwargs or kwargs must be None or empty respectively. Parameters ---------- engine_kwargs: dict kwargs to be passed through to the engine. kwargs: dict kwargs to be psased through to the engine (deprecated) Returns ------- engine_kwargs combined with kwargs |
173,558 | from __future__ import annotations
import abc
import datetime
from functools import partial
from io import BytesIO
import os
from textwrap import fill
from types import TracebackType
from typing import (
IO,
Any,
Callable,
Hashable,
Iterable,
List,
Literal,
Mapping,
Sequence,
Union,
cast,
overload,
)
import zipfile
from pandas._config import config
from pandas._libs import lib
from pandas._libs.parsers import STR_NA_VALUES
from pandas._typing import (
DtypeArg,
DtypeBackend,
FilePath,
IntStrT,
ReadBuffer,
StorageOptions,
WriteExcelBuffer,
)
from pandas.compat._optional import (
get_version,
import_optional_dependency,
)
from pandas.errors import EmptyDataError
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_bool,
is_float,
is_integer,
is_list_like,
)
from pandas.core.frame import DataFrame
from pandas.core.shared_docs import _shared_docs
from pandas.util.version import Version
from pandas.io.common import (
IOHandles,
get_handle,
stringify_path,
validate_header_arg,
)
from pandas.io.excel._util import (
fill_mi_header,
get_default_engine,
get_writer,
maybe_convert_usecols,
pop_header_name,
)
from pandas.io.parsers import TextParser
from pandas.io.parsers.readers import validate_integer
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
class Iterable(Protocol[_T_co]):
def __iter__(self) -> Iterator[_T_co]: ...
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
Literal: _SpecialForm = ...
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
StorageOptions = Optional[Dict[str, Any]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
def read_excel(
io,
# sheet name is str or int -> DataFrame
sheet_name: str | int = ...,
*,
header: int | Sequence[int] | None = ...,
names: list[str] | None = ...,
index_col: int | Sequence[int] | None = ...,
usecols: int
| str
| Sequence[int]
| Sequence[str]
| Callable[[str], bool]
| None = ...,
dtype: DtypeArg | None = ...,
engine: Literal["xlrd", "openpyxl", "odf", "pyxlsb"] | None = ...,
converters: dict[str, Callable] | dict[int, Callable] | None = ...,
true_values: Iterable[Hashable] | None = ...,
false_values: Iterable[Hashable] | None = ...,
skiprows: Sequence[int] | int | Callable[[int], object] | None = ...,
nrows: int | None = ...,
na_values=...,
keep_default_na: bool = ...,
na_filter: bool = ...,
verbose: bool = ...,
parse_dates: list | dict | bool = ...,
date_parser: Callable | lib.NoDefault = ...,
date_format: dict[Hashable, str] | str | None = ...,
thousands: str | None = ...,
decimal: str = ...,
comment: str | None = ...,
skipfooter: int = ...,
storage_options: StorageOptions = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
) -> DataFrame:
... | null |
173,559 | from __future__ import annotations
import abc
import datetime
from functools import partial
from io import BytesIO
import os
from textwrap import fill
from types import TracebackType
from typing import (
IO,
Any,
Callable,
Hashable,
Iterable,
List,
Literal,
Mapping,
Sequence,
Union,
cast,
overload,
)
import zipfile
from pandas._config import config
from pandas._libs import lib
from pandas._libs.parsers import STR_NA_VALUES
from pandas._typing import (
DtypeArg,
DtypeBackend,
FilePath,
IntStrT,
ReadBuffer,
StorageOptions,
WriteExcelBuffer,
)
from pandas.compat._optional import (
get_version,
import_optional_dependency,
)
from pandas.errors import EmptyDataError
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_bool,
is_float,
is_integer,
is_list_like,
)
from pandas.core.frame import DataFrame
from pandas.core.shared_docs import _shared_docs
from pandas.util.version import Version
from pandas.io.common import (
IOHandles,
get_handle,
stringify_path,
validate_header_arg,
)
from pandas.io.excel._util import (
fill_mi_header,
get_default_engine,
get_writer,
maybe_convert_usecols,
pop_header_name,
)
from pandas.io.parsers import TextParser
from pandas.io.parsers.readers import validate_integer
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
class Iterable(Protocol[_T_co]):
def __iter__(self) -> Iterator[_T_co]: ...
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
Literal: _SpecialForm = ...
IntStrT = TypeVar("IntStrT", int, str)
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
StorageOptions = Optional[Dict[str, Any]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
def read_excel(
io,
# sheet name is list or None -> dict[IntStrT, DataFrame]
sheet_name: list[IntStrT] | None,
*,
header: int | Sequence[int] | None = ...,
names: list[str] | None = ...,
index_col: int | Sequence[int] | None = ...,
usecols: int
| str
| Sequence[int]
| Sequence[str]
| Callable[[str], bool]
| None = ...,
dtype: DtypeArg | None = ...,
engine: Literal["xlrd", "openpyxl", "odf", "pyxlsb"] | None = ...,
converters: dict[str, Callable] | dict[int, Callable] | None = ...,
true_values: Iterable[Hashable] | None = ...,
false_values: Iterable[Hashable] | None = ...,
skiprows: Sequence[int] | int | Callable[[int], object] | None = ...,
nrows: int | None = ...,
na_values=...,
keep_default_na: bool = ...,
na_filter: bool = ...,
verbose: bool = ...,
parse_dates: list | dict | bool = ...,
date_parser: Callable | lib.NoDefault = ...,
date_format: dict[Hashable, str] | str | None = ...,
thousands: str | None = ...,
decimal: str = ...,
comment: str | None = ...,
skipfooter: int = ...,
storage_options: StorageOptions = ...,
dtype_backend: DtypeBackend | lib.NoDefault = ...,
) -> dict[IntStrT, DataFrame]:
... | null |
173,560 | from __future__ import annotations
import abc
import datetime
from functools import partial
from io import BytesIO
import os
from textwrap import fill
from types import TracebackType
from typing import (
IO,
Any,
Callable,
Hashable,
Iterable,
List,
Literal,
Mapping,
Sequence,
Union,
cast,
overload,
)
import zipfile
from pandas._config import config
from pandas._libs import lib
from pandas._libs.parsers import STR_NA_VALUES
from pandas._typing import (
DtypeArg,
DtypeBackend,
FilePath,
IntStrT,
ReadBuffer,
StorageOptions,
WriteExcelBuffer,
)
from pandas.compat._optional import (
get_version,
import_optional_dependency,
)
from pandas.errors import EmptyDataError
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_bool,
is_float,
is_integer,
is_list_like,
)
from pandas.core.frame import DataFrame
from pandas.core.shared_docs import _shared_docs
from pandas.util.version import Version
from pandas.io.common import (
IOHandles,
get_handle,
stringify_path,
validate_header_arg,
)
from pandas.io.excel._util import (
fill_mi_header,
get_default_engine,
get_writer,
maybe_convert_usecols,
pop_header_name,
)
from pandas.io.parsers import TextParser
from pandas.io.parsers.readers import validate_integer
class ExcelFile:
"""
Class for parsing tabular Excel sheets into DataFrame objects.
See read_excel for more documentation.
Parameters
----------
path_or_buffer : str, bytes, path object (pathlib.Path or py._path.local.LocalPath),
A file-like object, xlrd workbook or openpyxl workbook.
If a string or path object, expected to be a path to a
.xls, .xlsx, .xlsb, .xlsm, .odf, .ods, or .odt file.
engine : str, default None
If io is not a buffer or path, this must be set to identify io.
Supported engines: ``xlrd``, ``openpyxl``, ``odf``, ``pyxlsb``
Engine compatibility :
- ``xlrd`` supports old-style Excel files (.xls).
- ``openpyxl`` supports newer Excel file formats.
- ``odf`` supports OpenDocument file formats (.odf, .ods, .odt).
- ``pyxlsb`` supports Binary Excel files.
.. versionchanged:: 1.2.0
The engine `xlrd <https://xlrd.readthedocs.io/en/latest/>`_
now only supports old-style ``.xls`` files.
When ``engine=None``, the following logic will be
used to determine the engine:
- If ``path_or_buffer`` is an OpenDocument format (.odf, .ods, .odt),
then `odf <https://pypi.org/project/odfpy/>`_ will be used.
- Otherwise if ``path_or_buffer`` is an xls format,
``xlrd`` will be used.
- Otherwise if ``path_or_buffer`` is in xlsb format,
`pyxlsb <https://pypi.org/project/pyxlsb/>`_ will be used.
.. versionadded:: 1.3.0
- Otherwise if `openpyxl <https://pypi.org/project/openpyxl/>`_ is installed,
then ``openpyxl`` will be used.
- Otherwise if ``xlrd >= 2.0`` is installed, a ``ValueError`` will be raised.
.. warning::
Please do not report issues when using ``xlrd`` to read ``.xlsx`` files.
This is not supported, switch to using ``openpyxl`` instead.
"""
from pandas.io.excel._odfreader import ODFReader
from pandas.io.excel._openpyxl import OpenpyxlReader
from pandas.io.excel._pyxlsb import PyxlsbReader
from pandas.io.excel._xlrd import XlrdReader
_engines: Mapping[str, Any] = {
"xlrd": XlrdReader,
"openpyxl": OpenpyxlReader,
"odf": ODFReader,
"pyxlsb": PyxlsbReader,
}
def __init__(
self,
path_or_buffer,
engine: str | None = None,
storage_options: StorageOptions = None,
) -> None:
if engine is not None and engine not in self._engines:
raise ValueError(f"Unknown engine: {engine}")
# First argument can also be bytes, so create a buffer
if isinstance(path_or_buffer, bytes):
path_or_buffer = BytesIO(path_or_buffer)
# Could be a str, ExcelFile, Book, etc.
self.io = path_or_buffer
# Always a string
self._io = stringify_path(path_or_buffer)
# Determine xlrd version if installed
if import_optional_dependency("xlrd", errors="ignore") is None:
xlrd_version = None
else:
import xlrd
xlrd_version = Version(get_version(xlrd))
if engine is None:
# Only determine ext if it is needed
ext: str | None
if xlrd_version is not None and isinstance(path_or_buffer, xlrd.Book):
ext = "xls"
else:
ext = inspect_excel_format(
content_or_path=path_or_buffer, storage_options=storage_options
)
if ext is None:
raise ValueError(
"Excel file format cannot be determined, you must specify "
"an engine manually."
)
engine = config.get_option(f"io.excel.{ext}.reader", silent=True)
if engine == "auto":
engine = get_default_engine(ext, mode="reader")
assert engine is not None
self.engine = engine
self.storage_options = storage_options
self._reader = self._engines[engine](self._io, storage_options=storage_options)
def __fspath__(self):
return self._io
def parse(
self,
sheet_name: str | int | list[int] | list[str] | None = 0,
header: int | Sequence[int] | None = 0,
names=None,
index_col: int | Sequence[int] | None = None,
usecols=None,
converters=None,
true_values: Iterable[Hashable] | None = None,
false_values: Iterable[Hashable] | None = None,
skiprows: Sequence[int] | int | Callable[[int], object] | None = None,
nrows: int | None = None,
na_values=None,
parse_dates: list | dict | bool = False,
date_parser: Callable | lib.NoDefault = lib.no_default,
date_format: str | dict[Hashable, str] | None = None,
thousands: str | None = None,
comment: str | None = None,
skipfooter: int = 0,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
**kwds,
) -> DataFrame | dict[str, DataFrame] | dict[int, DataFrame]:
"""
Parse specified sheet(s) into a DataFrame.
Equivalent to read_excel(ExcelFile, ...) See the read_excel
docstring for more info on accepted parameters.
Returns
-------
DataFrame or dict of DataFrames
DataFrame from the passed in Excel file.
"""
return self._reader.parse(
sheet_name=sheet_name,
header=header,
names=names,
index_col=index_col,
usecols=usecols,
converters=converters,
true_values=true_values,
false_values=false_values,
skiprows=skiprows,
nrows=nrows,
na_values=na_values,
parse_dates=parse_dates,
date_parser=date_parser,
date_format=date_format,
thousands=thousands,
comment=comment,
skipfooter=skipfooter,
dtype_backend=dtype_backend,
**kwds,
)
def book(self):
return self._reader.book
def sheet_names(self):
return self._reader.sheet_names
def close(self) -> None:
"""close io if necessary"""
self._reader.close()
def __enter__(self) -> ExcelFile:
return self
def __exit__(
self,
exc_type: type[BaseException] | None,
exc_value: BaseException | None,
traceback: TracebackType | None,
) -> None:
self.close()
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
class Hashable(Protocol, metaclass=ABCMeta):
# TODO: This is special, in that a subclass of a hashable class may not be hashable
# (for example, list vs. object). It's not obvious how to represent this. This class
# is currently mostly useless for static checking.
def __hash__(self) -> int: ...
class Iterable(Protocol[_T_co]):
def __iter__(self) -> Iterator[_T_co]: ...
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
Literal: _SpecialForm = ...
IntStrT = TypeVar("IntStrT", int, str)
DtypeArg = Union[Dtype, Dict[Hashable, Dtype]]
StorageOptions = Optional[Dict[str, Any]]
DtypeBackend = Literal["pyarrow", "numpy_nullable"]
def check_dtype_backend(dtype_backend) -> None:
if dtype_backend is not lib.no_default:
if dtype_backend not in ["numpy_nullable", "pyarrow"]:
raise ValueError(
f"dtype_backend {dtype_backend} is invalid, only 'numpy_nullable' and "
f"'pyarrow' are allowed.",
)
class DataFrame(NDFrame, OpsMixin):
"""
Two-dimensional, size-mutable, potentially heterogeneous tabular data.
Data structure also contains labeled axes (rows and columns).
Arithmetic operations align on both row and column labels. Can be
thought of as a dict-like container for Series objects. The primary
pandas data structure.
Parameters
----------
data : ndarray (structured or homogeneous), Iterable, dict, or DataFrame
Dict can contain Series, arrays, constants, dataclass or list-like objects. If
data is a dict, column order follows insertion-order. If a dict contains Series
which have an index defined, it is aligned by its index. This alignment also
occurs if data is a Series or a DataFrame itself. Alignment is done on
Series/DataFrame inputs.
If data is a list of dicts, column order follows insertion-order.
index : Index or array-like
Index to use for resulting frame. Will default to RangeIndex if
no indexing information part of input data and no index provided.
columns : Index or array-like
Column labels to use for resulting frame when data does not have them,
defaulting to RangeIndex(0, 1, 2, ..., n). If data contains column labels,
will perform column selection instead.
dtype : dtype, default None
Data type to force. Only a single dtype is allowed. If None, infer.
copy : bool or None, default None
Copy data from inputs.
For dict data, the default of None behaves like ``copy=True``. For DataFrame
or 2d ndarray input, the default of None behaves like ``copy=False``.
If data is a dict containing one or more Series (possibly of different dtypes),
``copy=False`` will ensure that these inputs are not copied.
.. versionchanged:: 1.3.0
See Also
--------
DataFrame.from_records : Constructor from tuples, also record arrays.
DataFrame.from_dict : From dicts of Series, arrays, or dicts.
read_csv : Read a comma-separated values (csv) file into DataFrame.
read_table : Read general delimited file into DataFrame.
read_clipboard : Read text from clipboard into DataFrame.
Notes
-----
Please reference the :ref:`User Guide <basics.dataframe>` for more information.
Examples
--------
Constructing DataFrame from a dictionary.
>>> d = {'col1': [1, 2], 'col2': [3, 4]}
>>> df = pd.DataFrame(data=d)
>>> df
col1 col2
0 1 3
1 2 4
Notice that the inferred dtype is int64.
>>> df.dtypes
col1 int64
col2 int64
dtype: object
To enforce a single dtype:
>>> df = pd.DataFrame(data=d, dtype=np.int8)
>>> df.dtypes
col1 int8
col2 int8
dtype: object
Constructing DataFrame from a dictionary including Series:
>>> d = {'col1': [0, 1, 2, 3], 'col2': pd.Series([2, 3], index=[2, 3])}
>>> pd.DataFrame(data=d, index=[0, 1, 2, 3])
col1 col2
0 0 NaN
1 1 NaN
2 2 2.0
3 3 3.0
Constructing DataFrame from numpy ndarray:
>>> df2 = pd.DataFrame(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]),
... columns=['a', 'b', 'c'])
>>> df2
a b c
0 1 2 3
1 4 5 6
2 7 8 9
Constructing DataFrame from a numpy ndarray that has labeled columns:
>>> data = np.array([(1, 2, 3), (4, 5, 6), (7, 8, 9)],
... dtype=[("a", "i4"), ("b", "i4"), ("c", "i4")])
>>> df3 = pd.DataFrame(data, columns=['c', 'a'])
...
>>> df3
c a
0 3 1
1 6 4
2 9 7
Constructing DataFrame from dataclass:
>>> from dataclasses import make_dataclass
>>> Point = make_dataclass("Point", [("x", int), ("y", int)])
>>> pd.DataFrame([Point(0, 0), Point(0, 3), Point(2, 3)])
x y
0 0 0
1 0 3
2 2 3
Constructing DataFrame from Series/DataFrame:
>>> ser = pd.Series([1, 2, 3], index=["a", "b", "c"])
>>> df = pd.DataFrame(data=ser, index=["a", "c"])
>>> df
0
a 1
c 3
>>> df1 = pd.DataFrame([1, 2, 3], index=["a", "b", "c"], columns=["x"])
>>> df2 = pd.DataFrame(data=df1, index=["a", "c"])
>>> df2
x
a 1
c 3
"""
_internal_names_set = {"columns", "index"} | NDFrame._internal_names_set
_typ = "dataframe"
_HANDLED_TYPES = (Series, Index, ExtensionArray, np.ndarray)
_accessors: set[str] = {"sparse"}
_hidden_attrs: frozenset[str] = NDFrame._hidden_attrs | frozenset([])
_mgr: BlockManager | ArrayManager
def _constructor(self) -> Callable[..., DataFrame]:
return DataFrame
_constructor_sliced: Callable[..., Series] = Series
# ----------------------------------------------------------------------
# Constructors
def __init__(
self,
data=None,
index: Axes | None = None,
columns: Axes | None = None,
dtype: Dtype | None = None,
copy: bool | None = None,
) -> None:
if dtype is not None:
dtype = self._validate_dtype(dtype)
if isinstance(data, DataFrame):
data = data._mgr
if not copy:
# if not copying data, ensure to still return a shallow copy
# to avoid the result sharing the same Manager
data = data.copy(deep=False)
if isinstance(data, (BlockManager, ArrayManager)):
if using_copy_on_write():
data = data.copy(deep=False)
# first check if a Manager is passed without any other arguments
# -> use fastpath (without checking Manager type)
if index is None and columns is None and dtype is None and not copy:
# GH#33357 fastpath
NDFrame.__init__(self, data)
return
manager = get_option("mode.data_manager")
# GH47215
if index is not None and isinstance(index, set):
raise ValueError("index cannot be a set")
if columns is not None and isinstance(columns, set):
raise ValueError("columns cannot be a set")
if copy is None:
if isinstance(data, dict):
# retain pre-GH#38939 default behavior
copy = True
elif (
manager == "array"
and isinstance(data, (np.ndarray, ExtensionArray))
and data.ndim == 2
):
# INFO(ArrayManager) by default copy the 2D input array to get
# contiguous 1D arrays
copy = True
elif using_copy_on_write() and not isinstance(
data, (Index, DataFrame, Series)
):
copy = True
else:
copy = False
if data is None:
index = index if index is not None else default_index(0)
columns = columns if columns is not None else default_index(0)
dtype = dtype if dtype is not None else pandas_dtype(object)
data = []
if isinstance(data, (BlockManager, ArrayManager)):
mgr = self._init_mgr(
data, axes={"index": index, "columns": columns}, dtype=dtype, copy=copy
)
elif isinstance(data, dict):
# GH#38939 de facto copy defaults to False only in non-dict cases
mgr = dict_to_mgr(data, index, columns, dtype=dtype, copy=copy, typ=manager)
elif isinstance(data, ma.MaskedArray):
from numpy.ma import mrecords
# masked recarray
if isinstance(data, mrecords.MaskedRecords):
raise TypeError(
"MaskedRecords are not supported. Pass "
"{name: data[name] for name in data.dtype.names} "
"instead"
)
# a masked array
data = sanitize_masked_array(data)
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
elif isinstance(data, (np.ndarray, Series, Index, ExtensionArray)):
if data.dtype.names:
# i.e. numpy structured array
data = cast(np.ndarray, data)
mgr = rec_array_to_mgr(
data,
index,
columns,
dtype,
copy,
typ=manager,
)
elif getattr(data, "name", None) is not None:
# i.e. Series/Index with non-None name
_copy = copy if using_copy_on_write() else True
mgr = dict_to_mgr(
# error: Item "ndarray" of "Union[ndarray, Series, Index]" has no
# attribute "name"
{data.name: data}, # type: ignore[union-attr]
index,
columns,
dtype=dtype,
typ=manager,
copy=_copy,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
# For data is list-like, or Iterable (will consume into list)
elif is_list_like(data):
if not isinstance(data, abc.Sequence):
if hasattr(data, "__array__"):
# GH#44616 big perf improvement for e.g. pytorch tensor
data = np.asarray(data)
else:
data = list(data)
if len(data) > 0:
if is_dataclass(data[0]):
data = dataclasses_to_dicts(data)
if not isinstance(data, np.ndarray) and treat_as_nested(data):
# exclude ndarray as we may have cast it a few lines above
if columns is not None:
columns = ensure_index(columns)
arrays, columns, index = nested_data_to_arrays(
# error: Argument 3 to "nested_data_to_arrays" has incompatible
# type "Optional[Collection[Any]]"; expected "Optional[Index]"
data,
columns,
index, # type: ignore[arg-type]
dtype,
)
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
typ=manager,
)
else:
mgr = ndarray_to_mgr(
data,
index,
columns,
dtype=dtype,
copy=copy,
typ=manager,
)
else:
mgr = dict_to_mgr(
{},
index,
columns if columns is not None else default_index(0),
dtype=dtype,
typ=manager,
)
# For data is scalar
else:
if index is None or columns is None:
raise ValueError("DataFrame constructor not properly called!")
index = ensure_index(index)
columns = ensure_index(columns)
if not dtype:
dtype, _ = infer_dtype_from_scalar(data, pandas_dtype=True)
# For data is a scalar extension dtype
if isinstance(dtype, ExtensionDtype):
# TODO(EA2D): special case not needed with 2D EAs
values = [
construct_1d_arraylike_from_scalar(data, len(index), dtype)
for _ in range(len(columns))
]
mgr = arrays_to_mgr(values, columns, index, dtype=None, typ=manager)
else:
arr2d = construct_2d_arraylike_from_scalar(
data,
len(index),
len(columns),
dtype,
copy,
)
mgr = ndarray_to_mgr(
arr2d,
index,
columns,
dtype=arr2d.dtype,
copy=False,
typ=manager,
)
# ensure correct Manager type according to settings
mgr = mgr_to_mgr(mgr, typ=manager)
NDFrame.__init__(self, mgr)
# ----------------------------------------------------------------------
def __dataframe__(
self, nan_as_null: bool = False, allow_copy: bool = True
) -> DataFrameXchg:
"""
Return the dataframe interchange object implementing the interchange protocol.
Parameters
----------
nan_as_null : bool, default False
Whether to tell the DataFrame to overwrite null values in the data
with ``NaN`` (or ``NaT``).
allow_copy : bool, default True
Whether to allow memory copying when exporting. If set to False
it would cause non-zero-copy exports to fail.
Returns
-------
DataFrame interchange object
The object which consuming library can use to ingress the dataframe.
Notes
-----
Details on the interchange protocol:
https://data-apis.org/dataframe-protocol/latest/index.html
`nan_as_null` currently has no effect; once support for nullable extension
dtypes is added, this value should be propagated to columns.
"""
from pandas.core.interchange.dataframe import PandasDataFrameXchg
return PandasDataFrameXchg(self, nan_as_null, allow_copy)
# ----------------------------------------------------------------------
def axes(self) -> list[Index]:
"""
Return a list representing the axes of the DataFrame.
It has the row axis labels and column axis labels as the only members.
They are returned in that order.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.axes
[RangeIndex(start=0, stop=2, step=1), Index(['col1', 'col2'],
dtype='object')]
"""
return [self.index, self.columns]
def shape(self) -> tuple[int, int]:
"""
Return a tuple representing the dimensionality of the DataFrame.
See Also
--------
ndarray.shape : Tuple of array dimensions.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df.shape
(2, 2)
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4],
... 'col3': [5, 6]})
>>> df.shape
(2, 3)
"""
return len(self.index), len(self.columns)
def _is_homogeneous_type(self) -> bool:
"""
Whether all the columns in a DataFrame have the same type.
Returns
-------
bool
See Also
--------
Index._is_homogeneous_type : Whether the object has a single
dtype.
MultiIndex._is_homogeneous_type : Whether all the levels of a
MultiIndex have the same dtype.
Examples
--------
>>> DataFrame({"A": [1, 2], "B": [3, 4]})._is_homogeneous_type
True
>>> DataFrame({"A": [1, 2], "B": [3.0, 4.0]})._is_homogeneous_type
False
Items with the same type but different sizes are considered
different types.
>>> DataFrame({
... "A": np.array([1, 2], dtype=np.int32),
... "B": np.array([1, 2], dtype=np.int64)})._is_homogeneous_type
False
"""
if isinstance(self._mgr, ArrayManager):
return len({arr.dtype for arr in self._mgr.arrays}) == 1
if self._mgr.any_extension_types:
return len({block.dtype for block in self._mgr.blocks}) == 1
else:
return not self._is_mixed_type
def _can_fast_transpose(self) -> bool:
"""
Can we transpose this DataFrame without creating any new array objects.
"""
if isinstance(self._mgr, ArrayManager):
return False
blocks = self._mgr.blocks
if len(blocks) != 1:
return False
dtype = blocks[0].dtype
# TODO(EA2D) special case would be unnecessary with 2D EAs
return not is_1d_only_ea_dtype(dtype)
def _values(self) -> np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray:
"""
Analogue to ._values that may return a 2D ExtensionArray.
"""
mgr = self._mgr
if isinstance(mgr, ArrayManager):
if len(mgr.arrays) == 1 and not is_1d_only_ea_dtype(mgr.arrays[0].dtype):
# error: Item "ExtensionArray" of "Union[ndarray, ExtensionArray]"
# has no attribute "reshape"
return mgr.arrays[0].reshape(-1, 1) # type: ignore[union-attr]
return ensure_wrapped_if_datetimelike(self.values)
blocks = mgr.blocks
if len(blocks) != 1:
return ensure_wrapped_if_datetimelike(self.values)
arr = blocks[0].values
if arr.ndim == 1:
# non-2D ExtensionArray
return self.values
# more generally, whatever we allow in NDArrayBackedExtensionBlock
arr = cast("np.ndarray | DatetimeArray | TimedeltaArray | PeriodArray", arr)
return arr.T
# ----------------------------------------------------------------------
# Rendering Methods
def _repr_fits_vertical_(self) -> bool:
"""
Check length against max_rows.
"""
max_rows = get_option("display.max_rows")
return len(self) <= max_rows
def _repr_fits_horizontal_(self, ignore_width: bool = False) -> bool:
"""
Check if full repr fits in horizontal boundaries imposed by the display
options width and max_columns.
In case of non-interactive session, no boundaries apply.
`ignore_width` is here so ipynb+HTML output can behave the way
users expect. display.max_columns remains in effect.
GH3541, GH3573
"""
width, height = console.get_console_size()
max_columns = get_option("display.max_columns")
nb_columns = len(self.columns)
# exceed max columns
if (max_columns and nb_columns > max_columns) or (
(not ignore_width) and width and nb_columns > (width // 2)
):
return False
# used by repr_html under IPython notebook or scripts ignore terminal
# dims
if ignore_width or width is None or not console.in_interactive_session():
return True
if get_option("display.width") is not None or console.in_ipython_frontend():
# check at least the column row for excessive width
max_rows = 1
else:
max_rows = get_option("display.max_rows")
# when auto-detecting, so width=None and not in ipython front end
# check whether repr fits horizontal by actually checking
# the width of the rendered repr
buf = StringIO()
# only care about the stuff we'll actually print out
# and to_string on entire frame may be expensive
d = self
if max_rows is not None: # unlimited rows
# min of two, where one may be None
d = d.iloc[: min(max_rows, len(d))]
else:
return True
d.to_string(buf=buf)
value = buf.getvalue()
repr_width = max(len(line) for line in value.split("\n"))
return repr_width < width
def _info_repr(self) -> bool:
"""
True if the repr should show the info view.
"""
info_repr_option = get_option("display.large_repr") == "info"
return info_repr_option and not (
self._repr_fits_horizontal_() and self._repr_fits_vertical_()
)
def __repr__(self) -> str:
"""
Return a string representation for a particular DataFrame.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
return buf.getvalue()
repr_params = fmt.get_dataframe_repr_params()
return self.to_string(**repr_params)
def _repr_html_(self) -> str | None:
"""
Return a html representation for a particular DataFrame.
Mainly for IPython notebook.
"""
if self._info_repr():
buf = StringIO()
self.info(buf=buf)
# need to escape the <class>, should be the first line.
val = buf.getvalue().replace("<", r"<", 1)
val = val.replace(">", r">", 1)
return f"<pre>{val}</pre>"
if get_option("display.notebook_repr_html"):
max_rows = get_option("display.max_rows")
min_rows = get_option("display.min_rows")
max_cols = get_option("display.max_columns")
show_dimensions = get_option("display.show_dimensions")
formatter = fmt.DataFrameFormatter(
self,
columns=None,
col_space=None,
na_rep="NaN",
formatters=None,
float_format=None,
sparsify=None,
justify=None,
index_names=True,
header=True,
index=True,
bold_rows=True,
escape=True,
max_rows=max_rows,
min_rows=min_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=".",
)
return fmt.DataFrameRenderer(formatter).to_html(notebook=True)
else:
return None
def to_string(
self,
buf: None = ...,
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> str:
...
def to_string(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[str] | None = ...,
col_space: int | list[int] | dict[Hashable, int] | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: fmt.FormattersType | None = ...,
float_format: fmt.FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool = ...,
decimal: str = ...,
line_width: int | None = ...,
min_rows: int | None = ...,
max_colwidth: int | None = ...,
encoding: str | None = ...,
) -> None:
...
header_type="bool or sequence of str",
header="Write out the column names. If a list of strings "
"is given, it is assumed to be aliases for the "
"column names",
col_space_type="int, list or dict of int",
col_space="The minimum width of each column. If a list of ints is given "
"every integers corresponds with one column. If a dict is given, the key "
"references the column, while the value defines the space to use.",
)
def to_string(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[str] | None = None,
col_space: int | list[int] | dict[Hashable, int] | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: fmt.FormattersType | None = None,
float_format: fmt.FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool = False,
decimal: str = ".",
line_width: int | None = None,
min_rows: int | None = None,
max_colwidth: int | None = None,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame to a console-friendly tabular output.
%(shared_params)s
line_width : int, optional
Width to wrap a line in characters.
min_rows : int, optional
The number of rows to display in the console in a truncated repr
(when number of rows is above `max_rows`).
max_colwidth : int, optional
Max width to truncate each column in characters. By default, no limit.
encoding : str, default "utf-8"
Set character encoding.
%(returns)s
See Also
--------
to_html : Convert DataFrame to HTML.
Examples
--------
>>> d = {'col1': [1, 2, 3], 'col2': [4, 5, 6]}
>>> df = pd.DataFrame(d)
>>> print(df.to_string())
col1 col2
0 1 4
1 2 5
2 3 6
"""
from pandas import option_context
with option_context("display.max_colwidth", max_colwidth):
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
formatters=formatters,
float_format=float_format,
sparsify=sparsify,
justify=justify,
index_names=index_names,
header=header,
index=index,
min_rows=min_rows,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
decimal=decimal,
)
return fmt.DataFrameRenderer(formatter).to_string(
buf=buf,
encoding=encoding,
line_width=line_width,
)
# ----------------------------------------------------------------------
def style(self) -> Styler:
"""
Returns a Styler object.
Contains methods for building a styled HTML representation of the DataFrame.
See Also
--------
io.formats.style.Styler : Helps style a DataFrame or Series according to the
data with HTML and CSS.
"""
from pandas.io.formats.style import Styler
return Styler(self)
_shared_docs[
"items"
] = r"""
Iterate over (column name, Series) pairs.
Iterates over the DataFrame columns, returning a tuple with
the column name and the content as a Series.
Yields
------
label : object
The column names for the DataFrame being iterated over.
content : Series
The column entries belonging to each label, as a Series.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as
(index, Series) pairs.
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples
of the values.
Examples
--------
>>> df = pd.DataFrame({'species': ['bear', 'bear', 'marsupial'],
... 'population': [1864, 22000, 80000]},
... index=['panda', 'polar', 'koala'])
>>> df
species population
panda bear 1864
polar bear 22000
koala marsupial 80000
>>> for label, content in df.items():
... print(f'label: {label}')
... print(f'content: {content}', sep='\n')
...
label: species
content:
panda bear
polar bear
koala marsupial
Name: species, dtype: object
label: population
content:
panda 1864
polar 22000
koala 80000
Name: population, dtype: int64
"""
def items(self) -> Iterable[tuple[Hashable, Series]]:
if self.columns.is_unique and hasattr(self, "_item_cache"):
for k in self.columns:
yield k, self._get_item_cache(k)
else:
for i, k in enumerate(self.columns):
yield k, self._ixs(i, axis=1)
def iterrows(self) -> Iterable[tuple[Hashable, Series]]:
"""
Iterate over DataFrame rows as (index, Series) pairs.
Yields
------
index : label or tuple of label
The index of the row. A tuple for a `MultiIndex`.
data : Series
The data of the row as a Series.
See Also
--------
DataFrame.itertuples : Iterate over DataFrame rows as namedtuples of the values.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
1. Because ``iterrows`` returns a Series for each row,
it does **not** preserve dtypes across the rows (dtypes are
preserved across columns for DataFrames). For example,
>>> df = pd.DataFrame([[1, 1.5]], columns=['int', 'float'])
>>> row = next(df.iterrows())[1]
>>> row
int 1.0
float 1.5
Name: 0, dtype: float64
>>> print(row['int'].dtype)
float64
>>> print(df['int'].dtype)
int64
To preserve dtypes while iterating over the rows, it is better
to use :meth:`itertuples` which returns namedtuples of the values
and which is generally faster than ``iterrows``.
2. You should **never modify** something you are iterating over.
This is not guaranteed to work in all cases. Depending on the
data types, the iterator returns a copy and not a view, and writing
to it will have no effect.
"""
columns = self.columns
klass = self._constructor_sliced
using_cow = using_copy_on_write()
for k, v in zip(self.index, self.values):
s = klass(v, index=columns, name=k).__finalize__(self)
if using_cow and self._mgr.is_single_block:
s._mgr.add_references(self._mgr) # type: ignore[arg-type]
yield k, s
def itertuples(
self, index: bool = True, name: str | None = "Pandas"
) -> Iterable[tuple[Any, ...]]:
"""
Iterate over DataFrame rows as namedtuples.
Parameters
----------
index : bool, default True
If True, return the index as the first element of the tuple.
name : str or None, default "Pandas"
The name of the returned namedtuples or None to return regular
tuples.
Returns
-------
iterator
An object to iterate over namedtuples for each row in the
DataFrame with the first field possibly being the index and
following fields being the column values.
See Also
--------
DataFrame.iterrows : Iterate over DataFrame rows as (index, Series)
pairs.
DataFrame.items : Iterate over (column name, Series) pairs.
Notes
-----
The column names will be renamed to positional names if they are
invalid Python identifiers, repeated, or start with an underscore.
Examples
--------
>>> df = pd.DataFrame({'num_legs': [4, 2], 'num_wings': [0, 2]},
... index=['dog', 'hawk'])
>>> df
num_legs num_wings
dog 4 0
hawk 2 2
>>> for row in df.itertuples():
... print(row)
...
Pandas(Index='dog', num_legs=4, num_wings=0)
Pandas(Index='hawk', num_legs=2, num_wings=2)
By setting the `index` parameter to False we can remove the index
as the first element of the tuple:
>>> for row in df.itertuples(index=False):
... print(row)
...
Pandas(num_legs=4, num_wings=0)
Pandas(num_legs=2, num_wings=2)
With the `name` parameter set we set a custom name for the yielded
namedtuples:
>>> for row in df.itertuples(name='Animal'):
... print(row)
...
Animal(Index='dog', num_legs=4, num_wings=0)
Animal(Index='hawk', num_legs=2, num_wings=2)
"""
arrays = []
fields = list(self.columns)
if index:
arrays.append(self.index)
fields.insert(0, "Index")
# use integer indexing because of possible duplicate column names
arrays.extend(self.iloc[:, k] for k in range(len(self.columns)))
if name is not None:
# https://github.com/python/mypy/issues/9046
# error: namedtuple() expects a string literal as the first argument
itertuple = collections.namedtuple( # type: ignore[misc]
name, fields, rename=True
)
return map(itertuple._make, zip(*arrays))
# fallback to regular tuples
return zip(*arrays)
def __len__(self) -> int:
"""
Returns length of info axis, but here we use the index.
"""
return len(self.index)
def dot(self, other: Series) -> Series:
...
def dot(self, other: DataFrame | Index | ArrayLike) -> DataFrame:
...
def dot(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Compute the matrix multiplication between the DataFrame and other.
This method computes the matrix product between the DataFrame and the
values of an other Series, DataFrame or a numpy array.
It can also be called using ``self @ other`` in Python >= 3.5.
Parameters
----------
other : Series, DataFrame or array-like
The other object to compute the matrix product with.
Returns
-------
Series or DataFrame
If other is a Series, return the matrix product between self and
other as a Series. If other is a DataFrame or a numpy.array, return
the matrix product of self and other in a DataFrame of a np.array.
See Also
--------
Series.dot: Similar method for Series.
Notes
-----
The dimensions of DataFrame and other must be compatible in order to
compute the matrix multiplication. In addition, the column names of
DataFrame and the index of other must contain the same values, as they
will be aligned prior to the multiplication.
The dot method for Series computes the inner product, instead of the
matrix product here.
Examples
--------
Here we multiply a DataFrame with a Series.
>>> df = pd.DataFrame([[0, 1, -2, -1], [1, 1, 1, 1]])
>>> s = pd.Series([1, 1, 2, 1])
>>> df.dot(s)
0 -4
1 5
dtype: int64
Here we multiply a DataFrame with another DataFrame.
>>> other = pd.DataFrame([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(other)
0 1
0 1 4
1 2 2
Note that the dot method give the same result as @
>>> df @ other
0 1
0 1 4
1 2 2
The dot method works also if other is an np.array.
>>> arr = np.array([[0, 1], [1, 2], [-1, -1], [2, 0]])
>>> df.dot(arr)
0 1
0 1 4
1 2 2
Note how shuffling of the objects does not change the result.
>>> s2 = s.reindex([1, 0, 2, 3])
>>> df.dot(s2)
0 -4
1 5
dtype: int64
"""
if isinstance(other, (Series, DataFrame)):
common = self.columns.union(other.index)
if len(common) > len(self.columns) or len(common) > len(other.index):
raise ValueError("matrices are not aligned")
left = self.reindex(columns=common, copy=False)
right = other.reindex(index=common, copy=False)
lvals = left.values
rvals = right._values
else:
left = self
lvals = self.values
rvals = np.asarray(other)
if lvals.shape[1] != rvals.shape[0]:
raise ValueError(
f"Dot product shape mismatch, {lvals.shape} vs {rvals.shape}"
)
if isinstance(other, DataFrame):
return self._constructor(
np.dot(lvals, rvals),
index=left.index,
columns=other.columns,
copy=False,
)
elif isinstance(other, Series):
return self._constructor_sliced(
np.dot(lvals, rvals), index=left.index, copy=False
)
elif isinstance(rvals, (np.ndarray, Index)):
result = np.dot(lvals, rvals)
if result.ndim == 2:
return self._constructor(result, index=left.index, copy=False)
else:
return self._constructor_sliced(result, index=left.index, copy=False)
else: # pragma: no cover
raise TypeError(f"unsupported type: {type(other)}")
def __matmul__(self, other: Series) -> Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
...
def __matmul__(self, other: AnyArrayLike | DataFrame) -> DataFrame | Series:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
return self.dot(other)
def __rmatmul__(self, other) -> DataFrame:
"""
Matrix multiplication using binary `@` operator in Python>=3.5.
"""
try:
return self.T.dot(np.transpose(other)).T
except ValueError as err:
if "shape mismatch" not in str(err):
raise
# GH#21581 give exception message for original shapes
msg = f"shapes {np.shape(other)} and {self.shape} not aligned"
raise ValueError(msg) from err
# ----------------------------------------------------------------------
# IO methods (to / from other formats)
def from_dict(
cls,
data: dict,
orient: str = "columns",
dtype: Dtype | None = None,
columns: Axes | None = None,
) -> DataFrame:
"""
Construct DataFrame from dict of array-like or dicts.
Creates DataFrame object from dictionary by columns or by index
allowing dtype specification.
Parameters
----------
data : dict
Of the form {field : array-like} or {field : dict}.
orient : {'columns', 'index', 'tight'}, default 'columns'
The "orientation" of the data. If the keys of the passed dict
should be the columns of the resulting DataFrame, pass 'columns'
(default). Otherwise if the keys should be rows, pass 'index'.
If 'tight', assume a dict with keys ['index', 'columns', 'data',
'index_names', 'column_names'].
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
dtype : dtype, default None
Data type to force after DataFrame construction, otherwise infer.
columns : list, default None
Column labels to use when ``orient='index'``. Raises a ValueError
if used with ``orient='columns'`` or ``orient='tight'``.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_records : DataFrame from structured ndarray, sequence
of tuples or dicts, or DataFrame.
DataFrame : DataFrame object creation using constructor.
DataFrame.to_dict : Convert the DataFrame to a dictionary.
Examples
--------
By default the keys of the dict become the DataFrame columns:
>>> data = {'col_1': [3, 2, 1, 0], 'col_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Specify ``orient='index'`` to create the DataFrame using dictionary
keys as rows:
>>> data = {'row_1': [3, 2, 1, 0], 'row_2': ['a', 'b', 'c', 'd']}
>>> pd.DataFrame.from_dict(data, orient='index')
0 1 2 3
row_1 3 2 1 0
row_2 a b c d
When using the 'index' orientation, the column names can be
specified manually:
>>> pd.DataFrame.from_dict(data, orient='index',
... columns=['A', 'B', 'C', 'D'])
A B C D
row_1 3 2 1 0
row_2 a b c d
Specify ``orient='tight'`` to create the DataFrame using a 'tight'
format:
>>> data = {'index': [('a', 'b'), ('a', 'c')],
... 'columns': [('x', 1), ('y', 2)],
... 'data': [[1, 3], [2, 4]],
... 'index_names': ['n1', 'n2'],
... 'column_names': ['z1', 'z2']}
>>> pd.DataFrame.from_dict(data, orient='tight')
z1 x y
z2 1 2
n1 n2
a b 1 3
c 2 4
"""
index = None
orient = orient.lower()
if orient == "index":
if len(data) > 0:
# TODO speed up Series case
if isinstance(list(data.values())[0], (Series, dict)):
data = _from_nested_dict(data)
else:
index = list(data.keys())
# error: Incompatible types in assignment (expression has type
# "List[Any]", variable has type "Dict[Any, Any]")
data = list(data.values()) # type: ignore[assignment]
elif orient in ("columns", "tight"):
if columns is not None:
raise ValueError(f"cannot use columns parameter with orient='{orient}'")
else: # pragma: no cover
raise ValueError(
f"Expected 'index', 'columns' or 'tight' for orient parameter. "
f"Got '{orient}' instead"
)
if orient != "tight":
return cls(data, index=index, columns=columns, dtype=dtype)
else:
realdata = data["data"]
def create_index(indexlist, namelist):
index: Index
if len(namelist) > 1:
index = MultiIndex.from_tuples(indexlist, names=namelist)
else:
index = Index(indexlist, name=namelist[0])
return index
index = create_index(data["index"], data["index_names"])
columns = create_index(data["columns"], data["column_names"])
return cls(realdata, index=index, columns=columns, dtype=dtype)
def to_numpy(
self,
dtype: npt.DTypeLike | None = None,
copy: bool = False,
na_value: object = lib.no_default,
) -> np.ndarray:
"""
Convert the DataFrame to a NumPy array.
By default, the dtype of the returned array will be the common NumPy
dtype of all types in the DataFrame. For example, if the dtypes are
``float16`` and ``float32``, the results dtype will be ``float32``.
This may require copying data and coercing values, which may be
expensive.
Parameters
----------
dtype : str or numpy.dtype, optional
The dtype to pass to :meth:`numpy.asarray`.
copy : bool, default False
Whether to ensure that the returned value is not a view on
another array. Note that ``copy=False`` does not *ensure* that
``to_numpy()`` is no-copy. Rather, ``copy=True`` ensure that
a copy is made, even if not strictly necessary.
na_value : Any, optional
The value to use for missing values. The default value depends
on `dtype` and the dtypes of the DataFrame columns.
.. versionadded:: 1.1.0
Returns
-------
numpy.ndarray
See Also
--------
Series.to_numpy : Similar method for Series.
Examples
--------
>>> pd.DataFrame({"A": [1, 2], "B": [3, 4]}).to_numpy()
array([[1, 3],
[2, 4]])
With heterogeneous data, the lowest common type will have to
be used.
>>> df = pd.DataFrame({"A": [1, 2], "B": [3.0, 4.5]})
>>> df.to_numpy()
array([[1. , 3. ],
[2. , 4.5]])
For a mix of numeric and non-numeric types, the output array will
have object dtype.
>>> df['C'] = pd.date_range('2000', periods=2)
>>> df.to_numpy()
array([[1, 3.0, Timestamp('2000-01-01 00:00:00')],
[2, 4.5, Timestamp('2000-01-02 00:00:00')]], dtype=object)
"""
if dtype is not None:
dtype = np.dtype(dtype)
result = self._mgr.as_array(dtype=dtype, copy=copy, na_value=na_value)
if result.dtype is not dtype:
result = np.array(result, dtype=dtype, copy=False)
return result
def _create_data_for_split_and_tight_to_dict(
self, are_all_object_dtype_cols: bool, object_dtype_indices: list[int]
) -> list:
"""
Simple helper method to create data for to ``to_dict(orient="split")`` and
``to_dict(orient="tight")`` to create the main output data
"""
if are_all_object_dtype_cols:
data = [
list(map(maybe_box_native, t))
for t in self.itertuples(index=False, name=None)
]
else:
data = [list(t) for t in self.itertuples(index=False, name=None)]
if object_dtype_indices:
# If we have object_dtype_cols, apply maybe_box_naive after list
# comprehension for perf
for row in data:
for i in object_dtype_indices:
row[i] = maybe_box_native(row[i])
return data
def to_dict(
self,
orient: Literal["dict", "list", "series", "split", "tight", "index"] = ...,
into: type[dict] = ...,
) -> dict:
...
def to_dict(self, orient: Literal["records"], into: type[dict] = ...) -> list[dict]:
...
def to_dict(
self,
orient: Literal[
"dict", "list", "series", "split", "tight", "records", "index"
] = "dict",
into: type[dict] = dict,
index: bool = True,
) -> dict | list[dict]:
"""
Convert the DataFrame to a dictionary.
The type of the key-value pairs can be customized with the parameters
(see below).
Parameters
----------
orient : str {'dict', 'list', 'series', 'split', 'tight', 'records', 'index'}
Determines the type of the values of the dictionary.
- 'dict' (default) : dict like {column -> {index -> value}}
- 'list' : dict like {column -> [values]}
- 'series' : dict like {column -> Series(values)}
- 'split' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values]}
- 'tight' : dict like
{'index' -> [index], 'columns' -> [columns], 'data' -> [values],
'index_names' -> [index.names], 'column_names' -> [column.names]}
- 'records' : list like
[{column -> value}, ... , {column -> value}]
- 'index' : dict like {index -> {column -> value}}
.. versionadded:: 1.4.0
'tight' as an allowed value for the ``orient`` argument
into : class, default dict
The collections.abc.Mapping subclass used for all Mappings
in the return value. Can be the actual class or an empty
instance of the mapping type you want. If you want a
collections.defaultdict, you must pass it initialized.
index : bool, default True
Whether to include the index item (and index_names item if `orient`
is 'tight') in the returned dictionary. Can only be ``False``
when `orient` is 'split' or 'tight'.
.. versionadded:: 2.0.0
Returns
-------
dict, list or collections.abc.Mapping
Return a collections.abc.Mapping object representing the DataFrame.
The resulting transformation depends on the `orient` parameter.
See Also
--------
DataFrame.from_dict: Create a DataFrame from a dictionary.
DataFrame.to_json: Convert a DataFrame to JSON format.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2],
... 'col2': [0.5, 0.75]},
... index=['row1', 'row2'])
>>> df
col1 col2
row1 1 0.50
row2 2 0.75
>>> df.to_dict()
{'col1': {'row1': 1, 'row2': 2}, 'col2': {'row1': 0.5, 'row2': 0.75}}
You can specify the return orientation.
>>> df.to_dict('series')
{'col1': row1 1
row2 2
Name: col1, dtype: int64,
'col2': row1 0.50
row2 0.75
Name: col2, dtype: float64}
>>> df.to_dict('split')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]]}
>>> df.to_dict('records')
[{'col1': 1, 'col2': 0.5}, {'col1': 2, 'col2': 0.75}]
>>> df.to_dict('index')
{'row1': {'col1': 1, 'col2': 0.5}, 'row2': {'col1': 2, 'col2': 0.75}}
>>> df.to_dict('tight')
{'index': ['row1', 'row2'], 'columns': ['col1', 'col2'],
'data': [[1, 0.5], [2, 0.75]], 'index_names': [None], 'column_names': [None]}
You can also specify the mapping type.
>>> from collections import OrderedDict, defaultdict
>>> df.to_dict(into=OrderedDict)
OrderedDict([('col1', OrderedDict([('row1', 1), ('row2', 2)])),
('col2', OrderedDict([('row1', 0.5), ('row2', 0.75)]))])
If you want a `defaultdict`, you need to initialize it:
>>> dd = defaultdict(list)
>>> df.to_dict('records', into=dd)
[defaultdict(<class 'list'>, {'col1': 1, 'col2': 0.5}),
defaultdict(<class 'list'>, {'col1': 2, 'col2': 0.75})]
"""
from pandas.core.methods.to_dict import to_dict
return to_dict(self, orient, into, index)
def to_gbq(
self,
destination_table: str,
project_id: str | None = None,
chunksize: int | None = None,
reauth: bool = False,
if_exists: str = "fail",
auth_local_webserver: bool = True,
table_schema: list[dict[str, str]] | None = None,
location: str | None = None,
progress_bar: bool = True,
credentials=None,
) -> None:
"""
Write a DataFrame to a Google BigQuery table.
This function requires the `pandas-gbq package
<https://pandas-gbq.readthedocs.io>`__.
See the `How to authenticate with Google BigQuery
<https://pandas-gbq.readthedocs.io/en/latest/howto/authentication.html>`__
guide for authentication instructions.
Parameters
----------
destination_table : str
Name of table to be written, in the form ``dataset.tablename``.
project_id : str, optional
Google BigQuery Account project ID. Optional when available from
the environment.
chunksize : int, optional
Number of rows to be inserted in each chunk from the dataframe.
Set to ``None`` to load the whole dataframe at once.
reauth : bool, default False
Force Google BigQuery to re-authenticate the user. This is useful
if multiple accounts are used.
if_exists : str, default 'fail'
Behavior when the destination table exists. Value can be one of:
``'fail'``
If table exists raise pandas_gbq.gbq.TableCreationError.
``'replace'``
If table exists, drop it, recreate it, and insert data.
``'append'``
If table exists, insert data. Create if does not exist.
auth_local_webserver : bool, default True
Use the `local webserver flow`_ instead of the `console flow`_
when getting user credentials.
.. _local webserver flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_local_server
.. _console flow:
https://google-auth-oauthlib.readthedocs.io/en/latest/reference/google_auth_oauthlib.flow.html#google_auth_oauthlib.flow.InstalledAppFlow.run_console
*New in version 0.2.0 of pandas-gbq*.
.. versionchanged:: 1.5.0
Default value is changed to ``True``. Google has deprecated the
``auth_local_webserver = False`` `"out of band" (copy-paste)
flow
<https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html?m=1#disallowed-oob>`_.
table_schema : list of dicts, optional
List of BigQuery table fields to which according DataFrame
columns conform to, e.g. ``[{'name': 'col1', 'type':
'STRING'},...]``. If schema is not provided, it will be
generated according to dtypes of DataFrame columns. See
BigQuery API documentation on available names of a field.
*New in version 0.3.1 of pandas-gbq*.
location : str, optional
Location where the load job should run. See the `BigQuery locations
documentation
<https://cloud.google.com/bigquery/docs/dataset-locations>`__ for a
list of available locations. The location must match that of the
target dataset.
*New in version 0.5.0 of pandas-gbq*.
progress_bar : bool, default True
Use the library `tqdm` to show the progress bar for the upload,
chunk by chunk.
*New in version 0.5.0 of pandas-gbq*.
credentials : google.auth.credentials.Credentials, optional
Credentials for accessing Google APIs. Use this parameter to
override default credentials, such as to use Compute Engine
:class:`google.auth.compute_engine.Credentials` or Service
Account :class:`google.oauth2.service_account.Credentials`
directly.
*New in version 0.8.0 of pandas-gbq*.
See Also
--------
pandas_gbq.to_gbq : This function in the pandas-gbq library.
read_gbq : Read a DataFrame from Google BigQuery.
"""
from pandas.io import gbq
gbq.to_gbq(
self,
destination_table,
project_id=project_id,
chunksize=chunksize,
reauth=reauth,
if_exists=if_exists,
auth_local_webserver=auth_local_webserver,
table_schema=table_schema,
location=location,
progress_bar=progress_bar,
credentials=credentials,
)
def from_records(
cls,
data,
index=None,
exclude=None,
columns=None,
coerce_float: bool = False,
nrows: int | None = None,
) -> DataFrame:
"""
Convert structured or record ndarray to DataFrame.
Creates a DataFrame object from a structured ndarray, sequence of
tuples or dicts, or DataFrame.
Parameters
----------
data : structured ndarray, sequence of tuples or dicts, or DataFrame
Structured input data.
index : str, list of fields, array-like
Field of array to use as the index, alternately a specific set of
input labels to use.
exclude : sequence, default None
Columns or fields to exclude.
columns : sequence, default None
Column names to use. If the passed data do not have names
associated with them, this argument provides names for the
columns. Otherwise this argument indicates the order of the columns
in the result (any names not found in the data will become all-NA
columns).
coerce_float : bool, default False
Attempt to convert values of non-string, non-numeric objects (like
decimal.Decimal) to floating point, useful for SQL result sets.
nrows : int, default None
Number of rows to read if data is an iterator.
Returns
-------
DataFrame
See Also
--------
DataFrame.from_dict : DataFrame from dict of array-like or dicts.
DataFrame : DataFrame object creation using constructor.
Examples
--------
Data can be provided as a structured ndarray:
>>> data = np.array([(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')],
... dtype=[('col_1', 'i4'), ('col_2', 'U1')])
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of dicts:
>>> data = [{'col_1': 3, 'col_2': 'a'},
... {'col_1': 2, 'col_2': 'b'},
... {'col_1': 1, 'col_2': 'c'},
... {'col_1': 0, 'col_2': 'd'}]
>>> pd.DataFrame.from_records(data)
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
Data can be provided as a list of tuples with corresponding columns:
>>> data = [(3, 'a'), (2, 'b'), (1, 'c'), (0, 'd')]
>>> pd.DataFrame.from_records(data, columns=['col_1', 'col_2'])
col_1 col_2
0 3 a
1 2 b
2 1 c
3 0 d
"""
if isinstance(data, DataFrame):
if columns is not None:
if is_scalar(columns):
columns = [columns]
data = data[columns]
if index is not None:
data = data.set_index(index)
if exclude is not None:
data = data.drop(columns=exclude)
return data.copy(deep=False)
result_index = None
# Make a copy of the input columns so we can modify it
if columns is not None:
columns = ensure_index(columns)
def maybe_reorder(
arrays: list[ArrayLike], arr_columns: Index, columns: Index, index
) -> tuple[list[ArrayLike], Index, Index | None]:
"""
If our desired 'columns' do not match the data's pre-existing 'arr_columns',
we re-order our arrays. This is like a pre-emptive (cheap) reindex.
"""
if len(arrays):
length = len(arrays[0])
else:
length = 0
result_index = None
if len(arrays) == 0 and index is None and length == 0:
result_index = default_index(0)
arrays, arr_columns = reorder_arrays(arrays, arr_columns, columns, length)
return arrays, arr_columns, result_index
if is_iterator(data):
if nrows == 0:
return cls()
try:
first_row = next(data)
except StopIteration:
return cls(index=index, columns=columns)
dtype = None
if hasattr(first_row, "dtype") and first_row.dtype.names:
dtype = first_row.dtype
values = [first_row]
if nrows is None:
values += data
else:
values.extend(itertools.islice(data, nrows - 1))
if dtype is not None:
data = np.array(values, dtype=dtype)
else:
data = values
if isinstance(data, dict):
if columns is None:
columns = arr_columns = ensure_index(sorted(data))
arrays = [data[k] for k in columns]
else:
arrays = []
arr_columns_list = []
for k, v in data.items():
if k in columns:
arr_columns_list.append(k)
arrays.append(v)
arr_columns = Index(arr_columns_list)
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
elif isinstance(data, (np.ndarray, DataFrame)):
arrays, columns = to_arrays(data, columns)
arr_columns = columns
else:
arrays, arr_columns = to_arrays(data, columns)
if coerce_float:
for i, arr in enumerate(arrays):
if arr.dtype == object:
# error: Argument 1 to "maybe_convert_objects" has
# incompatible type "Union[ExtensionArray, ndarray]";
# expected "ndarray"
arrays[i] = lib.maybe_convert_objects(
arr, # type: ignore[arg-type]
try_float=True,
)
arr_columns = ensure_index(arr_columns)
if columns is None:
columns = arr_columns
else:
arrays, arr_columns, result_index = maybe_reorder(
arrays, arr_columns, columns, index
)
if exclude is None:
exclude = set()
else:
exclude = set(exclude)
if index is not None:
if isinstance(index, str) or not hasattr(index, "__iter__"):
i = columns.get_loc(index)
exclude.add(index)
if len(arrays) > 0:
result_index = Index(arrays[i], name=index)
else:
result_index = Index([], name=index)
else:
try:
index_data = [arrays[arr_columns.get_loc(field)] for field in index]
except (KeyError, TypeError):
# raised by get_loc, see GH#29258
result_index = index
else:
result_index = ensure_index_from_sequences(index_data, names=index)
exclude.update(index)
if any(exclude):
arr_exclude = [x for x in exclude if x in arr_columns]
to_remove = [arr_columns.get_loc(col) for col in arr_exclude]
arrays = [v for i, v in enumerate(arrays) if i not in to_remove]
columns = columns.drop(exclude)
manager = get_option("mode.data_manager")
mgr = arrays_to_mgr(arrays, columns, result_index, typ=manager)
return cls(mgr)
def to_records(
self, index: bool = True, column_dtypes=None, index_dtypes=None
) -> np.recarray:
"""
Convert DataFrame to a NumPy record array.
Index will be included as the first field of the record array if
requested.
Parameters
----------
index : bool, default True
Include index in resulting record array, stored in 'index'
field or using the index label, if set.
column_dtypes : str, type, dict, default None
If a string or type, the data type to store all columns. If
a dictionary, a mapping of column names and indices (zero-indexed)
to specific data types.
index_dtypes : str, type, dict, default None
If a string or type, the data type to store all index levels. If
a dictionary, a mapping of index level names and indices
(zero-indexed) to specific data types.
This mapping is applied only if `index=True`.
Returns
-------
numpy.recarray
NumPy ndarray with the DataFrame labels as fields and each row
of the DataFrame as entries.
See Also
--------
DataFrame.from_records: Convert structured or record ndarray
to DataFrame.
numpy.recarray: An ndarray that allows field access using
attributes, analogous to typed columns in a
spreadsheet.
Examples
--------
>>> df = pd.DataFrame({'A': [1, 2], 'B': [0.5, 0.75]},
... index=['a', 'b'])
>>> df
A B
a 1 0.50
b 2 0.75
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('index', 'O'), ('A', '<i8'), ('B', '<f8')])
If the DataFrame index has no label then the recarray field name
is set to 'index'. If the index has a label then this is used as the
field name:
>>> df.index = df.index.rename("I")
>>> df.to_records()
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i8'), ('B', '<f8')])
The index can be excluded from the record array:
>>> df.to_records(index=False)
rec.array([(1, 0.5 ), (2, 0.75)],
dtype=[('A', '<i8'), ('B', '<f8')])
Data types can be specified for the columns:
>>> df.to_records(column_dtypes={"A": "int32"})
rec.array([('a', 1, 0.5 ), ('b', 2, 0.75)],
dtype=[('I', 'O'), ('A', '<i4'), ('B', '<f8')])
As well as for the index:
>>> df.to_records(index_dtypes="<S2")
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S2'), ('A', '<i8'), ('B', '<f8')])
>>> index_dtypes = f"<S{df.index.str.len().max()}"
>>> df.to_records(index_dtypes=index_dtypes)
rec.array([(b'a', 1, 0.5 ), (b'b', 2, 0.75)],
dtype=[('I', 'S1'), ('A', '<i8'), ('B', '<f8')])
"""
if index:
ix_vals = [
np.asarray(self.index.get_level_values(i))
for i in range(self.index.nlevels)
]
arrays = ix_vals + [
np.asarray(self.iloc[:, i]) for i in range(len(self.columns))
]
index_names = list(self.index.names)
if isinstance(self.index, MultiIndex):
index_names = com.fill_missing_names(index_names)
elif index_names[0] is None:
index_names = ["index"]
names = [str(name) for name in itertools.chain(index_names, self.columns)]
else:
arrays = [np.asarray(self.iloc[:, i]) for i in range(len(self.columns))]
names = [str(c) for c in self.columns]
index_names = []
index_len = len(index_names)
formats = []
for i, v in enumerate(arrays):
index_int = i
# When the names and arrays are collected, we
# first collect those in the DataFrame's index,
# followed by those in its columns.
#
# Thus, the total length of the array is:
# len(index_names) + len(DataFrame.columns).
#
# This check allows us to see whether we are
# handling a name / array in the index or column.
if index_int < index_len:
dtype_mapping = index_dtypes
name = index_names[index_int]
else:
index_int -= index_len
dtype_mapping = column_dtypes
name = self.columns[index_int]
# We have a dictionary, so we get the data type
# associated with the index or column (which can
# be denoted by its name in the DataFrame or its
# position in DataFrame's array of indices or
# columns, whichever is applicable.
if is_dict_like(dtype_mapping):
if name in dtype_mapping:
dtype_mapping = dtype_mapping[name]
elif index_int in dtype_mapping:
dtype_mapping = dtype_mapping[index_int]
else:
dtype_mapping = None
# If no mapping can be found, use the array's
# dtype attribute for formatting.
#
# A valid dtype must either be a type or
# string naming a type.
if dtype_mapping is None:
formats.append(v.dtype)
elif isinstance(dtype_mapping, (type, np.dtype, str)):
# error: Argument 1 to "append" of "list" has incompatible
# type "Union[type, dtype[Any], str]"; expected "dtype[Any]"
formats.append(dtype_mapping) # type: ignore[arg-type]
else:
element = "row" if i < index_len else "column"
msg = f"Invalid dtype {dtype_mapping} specified for {element} {name}"
raise ValueError(msg)
return np.rec.fromarrays(arrays, dtype={"names": names, "formats": formats})
def _from_arrays(
cls,
arrays,
columns,
index,
dtype: Dtype | None = None,
verify_integrity: bool = True,
) -> DataFrame:
"""
Create DataFrame from a list of arrays corresponding to the columns.
Parameters
----------
arrays : list-like of arrays
Each array in the list corresponds to one column, in order.
columns : list-like, Index
The column names for the resulting DataFrame.
index : list-like, Index
The rows labels for the resulting DataFrame.
dtype : dtype, optional
Optional dtype to enforce for all arrays.
verify_integrity : bool, default True
Validate and homogenize all input. If set to False, it is assumed
that all elements of `arrays` are actual arrays how they will be
stored in a block (numpy ndarray or ExtensionArray), have the same
length as and are aligned with the index, and that `columns` and
`index` are ensured to be an Index object.
Returns
-------
DataFrame
"""
if dtype is not None:
dtype = pandas_dtype(dtype)
manager = get_option("mode.data_manager")
columns = ensure_index(columns)
if len(columns) != len(arrays):
raise ValueError("len(columns) must match len(arrays)")
mgr = arrays_to_mgr(
arrays,
columns,
index,
dtype=dtype,
verify_integrity=verify_integrity,
typ=manager,
)
return cls(mgr)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path",
)
def to_stata(
self,
path: FilePath | WriteBuffer[bytes],
*,
convert_dates: dict[Hashable, str] | None = None,
write_index: bool = True,
byteorder: str | None = None,
time_stamp: datetime.datetime | None = None,
data_label: str | None = None,
variable_labels: dict[Hashable, str] | None = None,
version: int | None = 114,
convert_strl: Sequence[Hashable] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
value_labels: dict[Hashable, dict[float, str]] | None = None,
) -> None:
"""
Export DataFrame object to Stata dta format.
Writes the DataFrame to a Stata dataset file.
"dta" files contain a Stata dataset.
Parameters
----------
path : str, path object, or buffer
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function.
convert_dates : dict
Dictionary mapping columns containing datetime types to stata
internal format to use when writing the dates. Options are 'tc',
'td', 'tm', 'tw', 'th', 'tq', 'ty'. Column can be either an integer
or a name. Datetime columns that do not have a conversion type
specified will be converted to 'tc'. Raises NotImplementedError if
a datetime column has timezone information.
write_index : bool
Write the index to Stata dataset.
byteorder : str
Can be ">", "<", "little", or "big". default is `sys.byteorder`.
time_stamp : datetime
A datetime to use as file creation date. Default is the current
time.
data_label : str, optional
A label for the data set. Must be 80 characters or smaller.
variable_labels : dict
Dictionary containing columns as keys and variable labels as
values. Each label must be 80 characters or smaller.
version : {{114, 117, 118, 119, None}}, default 114
Version to use in the output dta file. Set to None to let pandas
decide between 118 or 119 formats depending on the number of
columns in the frame. Version 114 can be read by Stata 10 and
later. Version 117 can be read by Stata 13 or later. Version 118
is supported in Stata 14 and later. Version 119 is supported in
Stata 15 and later. Version 114 limits string variables to 244
characters or fewer while versions 117 and later allow strings
with lengths up to 2,000,000 characters. Versions 118 and 119
support Unicode characters, and version 119 supports more than
32,767 variables.
Version 119 should usually only be used when the number of
variables exceeds the capacity of dta format 118. Exporting
smaller datasets in format 119 may have unintended consequences,
and, as of November 2020, Stata SE cannot read version 119 files.
convert_strl : list, optional
List of column names to convert to string columns to Stata StrL
format. Only available if version is 117. Storing strings in the
StrL format can produce smaller dta files if strings have more than
8 characters and values are repeated.
{compression_options}
.. versionadded:: 1.1.0
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
.. versionadded:: 1.2.0
value_labels : dict of dicts
Dictionary containing columns as keys and dictionaries of column value
to labels as values. Labels for a single variable must be 32,000
characters or smaller.
.. versionadded:: 1.4.0
Raises
------
NotImplementedError
* If datetimes contain timezone information
* Column dtype is not representable in Stata
ValueError
* Columns listed in convert_dates are neither datetime64[ns]
or datetime.datetime
* Column listed in convert_dates is not in DataFrame
* Categorical label contains more than 32,000 characters
See Also
--------
read_stata : Import Stata data files.
io.stata.StataWriter : Low-level writer for Stata data files.
io.stata.StataWriter117 : Low-level writer for version 117 files.
Examples
--------
>>> df = pd.DataFrame({{'animal': ['falcon', 'parrot', 'falcon',
... 'parrot'],
... 'speed': [350, 18, 361, 15]}})
>>> df.to_stata('animals.dta') # doctest: +SKIP
"""
if version not in (114, 117, 118, 119, None):
raise ValueError("Only formats 114, 117, 118 and 119 are supported.")
if version == 114:
if convert_strl is not None:
raise ValueError("strl is not supported in format 114")
from pandas.io.stata import StataWriter as statawriter
elif version == 117:
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriter117 as statawriter,
)
else: # versions 118 and 119
# Incompatible import of "statawriter" (imported name has type
# "Type[StataWriter117]", local name has type "Type[StataWriter]")
from pandas.io.stata import ( # type: ignore[assignment]
StataWriterUTF8 as statawriter,
)
kwargs: dict[str, Any] = {}
if version is None or version >= 117:
# strl conversion is only supported >= 117
kwargs["convert_strl"] = convert_strl
if version is None or version >= 118:
# Specifying the version is only supported for UTF8 (118 or 119)
kwargs["version"] = version
writer = statawriter(
path,
self,
convert_dates=convert_dates,
byteorder=byteorder,
time_stamp=time_stamp,
data_label=data_label,
write_index=write_index,
variable_labels=variable_labels,
compression=compression,
storage_options=storage_options,
value_labels=value_labels,
**kwargs,
)
writer.write_file()
def to_feather(self, path: FilePath | WriteBuffer[bytes], **kwargs) -> None:
"""
Write a DataFrame to the binary Feather format.
Parameters
----------
path : str, path object, file-like object
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If a string or a path,
it will be used as Root Directory path when writing a partitioned dataset.
**kwargs :
Additional keywords passed to :func:`pyarrow.feather.write_feather`.
Starting with pyarrow 0.17, this includes the `compression`,
`compression_level`, `chunksize` and `version` keywords.
.. versionadded:: 1.1.0
Notes
-----
This function writes the dataframe as a `feather file
<https://arrow.apache.org/docs/python/feather.html>`_. Requires a default
index. For saving the DataFrame with your custom index use a method that
supports custom indices e.g. `to_parquet`.
"""
from pandas.io.feather_format import to_feather
to_feather(self, path, **kwargs)
Series.to_markdown,
klass=_shared_doc_kwargs["klass"],
storage_options=_shared_docs["storage_options"],
examples="""Examples
--------
>>> df = pd.DataFrame(
... data={"animal_1": ["elk", "pig"], "animal_2": ["dog", "quetzal"]}
... )
>>> print(df.to_markdown())
| | animal_1 | animal_2 |
|---:|:-----------|:-----------|
| 0 | elk | dog |
| 1 | pig | quetzal |
Output markdown with a tabulate option.
>>> print(df.to_markdown(tablefmt="grid"))
+----+------------+------------+
| | animal_1 | animal_2 |
+====+============+============+
| 0 | elk | dog |
+----+------------+------------+
| 1 | pig | quetzal |
+----+------------+------------+""",
)
def to_markdown(
self,
buf: FilePath | WriteBuffer[str] | None = None,
mode: str = "wt",
index: bool = True,
storage_options: StorageOptions = None,
**kwargs,
) -> str | None:
if "showindex" in kwargs:
raise ValueError("Pass 'index' instead of 'showindex")
kwargs.setdefault("headers", "keys")
kwargs.setdefault("tablefmt", "pipe")
kwargs.setdefault("showindex", index)
tabulate = import_optional_dependency("tabulate")
result = tabulate.tabulate(self, **kwargs)
if buf is None:
return result
with get_handle(buf, mode, storage_options=storage_options) as handles:
handles.handle.write(result)
return None
def to_parquet(
self,
path: None = ...,
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> bytes:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes],
engine: str = ...,
compression: str | None = ...,
index: bool | None = ...,
partition_cols: list[str] | None = ...,
storage_options: StorageOptions = ...,
**kwargs,
) -> None:
...
def to_parquet(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
engine: str = "auto",
compression: str | None = "snappy",
index: bool | None = None,
partition_cols: list[str] | None = None,
storage_options: StorageOptions = None,
**kwargs,
) -> bytes | None:
"""
Write a DataFrame to the binary parquet format.
This function writes the dataframe as a `parquet file
<https://parquet.apache.org/>`_. You can choose different parquet
backends, and have the option of compression. See
:ref:`the user guide <io.parquet>` for more details.
Parameters
----------
path : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a binary ``write()`` function. If None, the result is
returned as bytes. If a string or path, it will be used as Root Directory
path when writing a partitioned dataset.
.. versionchanged:: 1.2.0
Previously this was "fname"
engine : {{'auto', 'pyarrow', 'fastparquet'}}, default 'auto'
Parquet library to use. If 'auto', then the option
``io.parquet.engine`` is used. The default ``io.parquet.engine``
behavior is to try 'pyarrow', falling back to 'fastparquet' if
'pyarrow' is unavailable.
compression : {{'snappy', 'gzip', 'brotli', None}}, default 'snappy'
Name of the compression to use. Use ``None`` for no compression.
index : bool, default None
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``True`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
partition_cols : list, optional, default None
Column names by which to partition the dataset.
Columns are partitioned in the order they are given.
Must be None if path is not a string.
{storage_options}
.. versionadded:: 1.2.0
**kwargs
Additional arguments passed to the parquet library. See
:ref:`pandas io <io.parquet>` for more details.
Returns
-------
bytes if no path argument is provided else None
See Also
--------
read_parquet : Read a parquet file.
DataFrame.to_orc : Write an orc file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
This function requires either the `fastparquet
<https://pypi.org/project/fastparquet>`_ or `pyarrow
<https://arrow.apache.org/docs/python/>`_ library.
Examples
--------
>>> df = pd.DataFrame(data={{'col1': [1, 2], 'col2': [3, 4]}})
>>> df.to_parquet('df.parquet.gzip',
... compression='gzip') # doctest: +SKIP
>>> pd.read_parquet('df.parquet.gzip') # doctest: +SKIP
col1 col2
0 1 3
1 2 4
If you want to get a buffer to the parquet content you can use a io.BytesIO
object, as long as you don't use partition_cols, which creates multiple files.
>>> import io
>>> f = io.BytesIO()
>>> df.to_parquet(f)
>>> f.seek(0)
0
>>> content = f.read()
"""
from pandas.io.parquet import to_parquet
return to_parquet(
self,
path,
engine,
compression=compression,
index=index,
partition_cols=partition_cols,
storage_options=storage_options,
**kwargs,
)
def to_orc(
self,
path: FilePath | WriteBuffer[bytes] | None = None,
*,
engine: Literal["pyarrow"] = "pyarrow",
index: bool | None = None,
engine_kwargs: dict[str, Any] | None = None,
) -> bytes | None:
"""
Write a DataFrame to the ORC format.
.. versionadded:: 1.5.0
Parameters
----------
path : str, file-like object or None, default None
If a string, it will be used as Root Directory path
when writing a partitioned dataset. By file-like object,
we refer to objects with a write() method, such as a file handle
(e.g. via builtin open function). If path is None,
a bytes object is returned.
engine : str, default 'pyarrow'
ORC library to use. Pyarrow must be >= 7.0.0.
index : bool, optional
If ``True``, include the dataframe's index(es) in the file output.
If ``False``, they will not be written to the file.
If ``None``, similar to ``infer`` the dataframe's index(es)
will be saved. However, instead of being saved as values,
the RangeIndex will be stored as a range in the metadata so it
doesn't require much space and is faster. Other indexes will
be included as columns in the file output.
engine_kwargs : dict[str, Any] or None, default None
Additional keyword arguments passed to :func:`pyarrow.orc.write_table`.
Returns
-------
bytes if no path argument is provided else None
Raises
------
NotImplementedError
Dtype of one or more columns is category, unsigned integers, interval,
period or sparse.
ValueError
engine is not pyarrow.
See Also
--------
read_orc : Read a ORC file.
DataFrame.to_parquet : Write a parquet file.
DataFrame.to_csv : Write a csv file.
DataFrame.to_sql : Write to a sql table.
DataFrame.to_hdf : Write to hdf.
Notes
-----
* Before using this function you should read the :ref:`user guide about
ORC <io.orc>` and :ref:`install optional dependencies <install.warn_orc>`.
* This function requires `pyarrow <https://arrow.apache.org/docs/python/>`_
library.
* For supported dtypes please refer to `supported ORC features in Arrow
<https://arrow.apache.org/docs/cpp/orc.html#data-types>`__.
* Currently timezones in datetime columns are not preserved when a
dataframe is converted into ORC files.
Examples
--------
>>> df = pd.DataFrame(data={'col1': [1, 2], 'col2': [4, 3]})
>>> df.to_orc('df.orc') # doctest: +SKIP
>>> pd.read_orc('df.orc') # doctest: +SKIP
col1 col2
0 1 4
1 2 3
If you want to get a buffer to the orc content you can write it to io.BytesIO
>>> import io
>>> b = io.BytesIO(df.to_orc()) # doctest: +SKIP
>>> b.seek(0) # doctest: +SKIP
0
>>> content = b.read() # doctest: +SKIP
"""
from pandas.io.orc import to_orc
return to_orc(
self, path, engine=engine, index=index, engine_kwargs=engine_kwargs
)
def to_html(
self,
buf: FilePath | WriteBuffer[str],
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> None:
...
def to_html(
self,
buf: None = ...,
columns: Sequence[Level] | None = ...,
col_space: ColspaceArgType | None = ...,
header: bool | Sequence[str] = ...,
index: bool = ...,
na_rep: str = ...,
formatters: FormattersType | None = ...,
float_format: FloatFormatType | None = ...,
sparsify: bool | None = ...,
index_names: bool = ...,
justify: str | None = ...,
max_rows: int | None = ...,
max_cols: int | None = ...,
show_dimensions: bool | str = ...,
decimal: str = ...,
bold_rows: bool = ...,
classes: str | list | tuple | None = ...,
escape: bool = ...,
notebook: bool = ...,
border: int | bool | None = ...,
table_id: str | None = ...,
render_links: bool = ...,
encoding: str | None = ...,
) -> str:
...
header_type="bool",
header="Whether to print column labels, default True",
col_space_type="str or int, list or dict of int or str",
col_space="The minimum width of each column in CSS length "
"units. An int is assumed to be px units.",
)
def to_html(
self,
buf: FilePath | WriteBuffer[str] | None = None,
columns: Sequence[Level] | None = None,
col_space: ColspaceArgType | None = None,
header: bool | Sequence[str] = True,
index: bool = True,
na_rep: str = "NaN",
formatters: FormattersType | None = None,
float_format: FloatFormatType | None = None,
sparsify: bool | None = None,
index_names: bool = True,
justify: str | None = None,
max_rows: int | None = None,
max_cols: int | None = None,
show_dimensions: bool | str = False,
decimal: str = ".",
bold_rows: bool = True,
classes: str | list | tuple | None = None,
escape: bool = True,
notebook: bool = False,
border: int | bool | None = None,
table_id: str | None = None,
render_links: bool = False,
encoding: str | None = None,
) -> str | None:
"""
Render a DataFrame as an HTML table.
%(shared_params)s
bold_rows : bool, default True
Make the row labels bold in the output.
classes : str or list or tuple, default None
CSS class(es) to apply to the resulting html table.
escape : bool, default True
Convert the characters <, >, and & to HTML-safe sequences.
notebook : {True, False}, default False
Whether the generated HTML is for IPython Notebook.
border : int
A ``border=border`` attribute is included in the opening
`<table>` tag. Default ``pd.options.display.html.border``.
table_id : str, optional
A css id is included in the opening `<table>` tag if specified.
render_links : bool, default False
Convert URLs to HTML links.
encoding : str, default "utf-8"
Set character encoding.
.. versionadded:: 1.0
%(returns)s
See Also
--------
to_string : Convert DataFrame to a string.
"""
if justify is not None and justify not in fmt._VALID_JUSTIFY_PARAMETERS:
raise ValueError("Invalid value for justify parameter")
formatter = fmt.DataFrameFormatter(
self,
columns=columns,
col_space=col_space,
na_rep=na_rep,
header=header,
index=index,
formatters=formatters,
float_format=float_format,
bold_rows=bold_rows,
sparsify=sparsify,
justify=justify,
index_names=index_names,
escape=escape,
decimal=decimal,
max_rows=max_rows,
max_cols=max_cols,
show_dimensions=show_dimensions,
)
# TODO: a generic formatter wld b in DataFrameFormatter
return fmt.DataFrameRenderer(formatter).to_html(
buf=buf,
classes=classes,
notebook=notebook,
border=border,
encoding=encoding,
table_id=table_id,
render_links=render_links,
)
storage_options=_shared_docs["storage_options"],
compression_options=_shared_docs["compression_options"] % "path_or_buffer",
)
def to_xml(
self,
path_or_buffer: FilePath | WriteBuffer[bytes] | WriteBuffer[str] | None = None,
index: bool = True,
root_name: str | None = "data",
row_name: str | None = "row",
na_rep: str | None = None,
attr_cols: list[str] | None = None,
elem_cols: list[str] | None = None,
namespaces: dict[str | None, str] | None = None,
prefix: str | None = None,
encoding: str = "utf-8",
xml_declaration: bool | None = True,
pretty_print: bool | None = True,
parser: str | None = "lxml",
stylesheet: FilePath | ReadBuffer[str] | ReadBuffer[bytes] | None = None,
compression: CompressionOptions = "infer",
storage_options: StorageOptions = None,
) -> str | None:
"""
Render a DataFrame to an XML document.
.. versionadded:: 1.3.0
Parameters
----------
path_or_buffer : str, path object, file-like object, or None, default None
String, path object (implementing ``os.PathLike[str]``), or file-like
object implementing a ``write()`` function. If None, the result is returned
as a string.
index : bool, default True
Whether to include index in XML document.
root_name : str, default 'data'
The name of root element in XML document.
row_name : str, default 'row'
The name of row element in XML document.
na_rep : str, optional
Missing data representation.
attr_cols : list-like, optional
List of columns to write as attributes in row element.
Hierarchical columns will be flattened with underscore
delimiting the different levels.
elem_cols : list-like, optional
List of columns to write as children in row element. By default,
all columns output as children of row element. Hierarchical
columns will be flattened with underscore delimiting the
different levels.
namespaces : dict, optional
All namespaces to be defined in root element. Keys of dict
should be prefix names and values of dict corresponding URIs.
Default namespaces should be given empty string key. For
example, ::
namespaces = {{"": "https://example.com"}}
prefix : str, optional
Namespace prefix to be used for every element and/or attribute
in document. This should be one of the keys in ``namespaces``
dict.
encoding : str, default 'utf-8'
Encoding of the resulting document.
xml_declaration : bool, default True
Whether to include the XML declaration at start of document.
pretty_print : bool, default True
Whether output should be pretty printed with indentation and
line breaks.
parser : {{'lxml','etree'}}, default 'lxml'
Parser module to use for building of tree. Only 'lxml' and
'etree' are supported. With 'lxml', the ability to use XSLT
stylesheet is supported.
stylesheet : str, path object or file-like object, optional
A URL, file-like object, or a raw string containing an XSLT
script used to transform the raw XML output. Script should use
layout of elements and attributes from original output. This
argument requires ``lxml`` to be installed. Only XSLT 1.0
scripts and not later versions is currently supported.
{compression_options}
.. versionchanged:: 1.4.0 Zstandard support.
{storage_options}
Returns
-------
None or str
If ``io`` is None, returns the resulting XML format as a
string. Otherwise returns None.
See Also
--------
to_json : Convert the pandas object to a JSON string.
to_html : Convert DataFrame to a html.
Examples
--------
>>> df = pd.DataFrame({{'shape': ['square', 'circle', 'triangle'],
... 'degrees': [360, 360, 180],
... 'sides': [4, np.nan, 3]}})
>>> df.to_xml() # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row>
<index>0</index>
<shape>square</shape>
<degrees>360</degrees>
<sides>4.0</sides>
</row>
<row>
<index>1</index>
<shape>circle</shape>
<degrees>360</degrees>
<sides/>
</row>
<row>
<index>2</index>
<shape>triangle</shape>
<degrees>180</degrees>
<sides>3.0</sides>
</row>
</data>
>>> df.to_xml(attr_cols=[
... 'index', 'shape', 'degrees', 'sides'
... ]) # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<data>
<row index="0" shape="square" degrees="360" sides="4.0"/>
<row index="1" shape="circle" degrees="360"/>
<row index="2" shape="triangle" degrees="180" sides="3.0"/>
</data>
>>> df.to_xml(namespaces={{"doc": "https://example.com"}},
... prefix="doc") # doctest: +SKIP
<?xml version='1.0' encoding='utf-8'?>
<doc:data xmlns:doc="https://example.com">
<doc:row>
<doc:index>0</doc:index>
<doc:shape>square</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides>4.0</doc:sides>
</doc:row>
<doc:row>
<doc:index>1</doc:index>
<doc:shape>circle</doc:shape>
<doc:degrees>360</doc:degrees>
<doc:sides/>
</doc:row>
<doc:row>
<doc:index>2</doc:index>
<doc:shape>triangle</doc:shape>
<doc:degrees>180</doc:degrees>
<doc:sides>3.0</doc:sides>
</doc:row>
</doc:data>
"""
from pandas.io.formats.xml import (
EtreeXMLFormatter,
LxmlXMLFormatter,
)
lxml = import_optional_dependency("lxml.etree", errors="ignore")
TreeBuilder: type[EtreeXMLFormatter] | type[LxmlXMLFormatter]
if parser == "lxml":
if lxml is not None:
TreeBuilder = LxmlXMLFormatter
else:
raise ImportError(
"lxml not found, please install or use the etree parser."
)
elif parser == "etree":
TreeBuilder = EtreeXMLFormatter
else:
raise ValueError("Values for parser can only be lxml or etree.")
xml_formatter = TreeBuilder(
self,
path_or_buffer=path_or_buffer,
index=index,
root_name=root_name,
row_name=row_name,
na_rep=na_rep,
attr_cols=attr_cols,
elem_cols=elem_cols,
namespaces=namespaces,
prefix=prefix,
encoding=encoding,
xml_declaration=xml_declaration,
pretty_print=pretty_print,
stylesheet=stylesheet,
compression=compression,
storage_options=storage_options,
)
return xml_formatter.write_output()
# ----------------------------------------------------------------------
def info(
self,
verbose: bool | None = None,
buf: WriteBuffer[str] | None = None,
max_cols: int | None = None,
memory_usage: bool | str | None = None,
show_counts: bool | None = None,
) -> None:
info = DataFrameInfo(
data=self,
memory_usage=memory_usage,
)
info.render(
buf=buf,
max_cols=max_cols,
verbose=verbose,
show_counts=show_counts,
)
def memory_usage(self, index: bool = True, deep: bool = False) -> Series:
"""
Return the memory usage of each column in bytes.
The memory usage can optionally include the contribution of
the index and elements of `object` dtype.
This value is displayed in `DataFrame.info` by default. This can be
suppressed by setting ``pandas.options.display.memory_usage`` to False.
Parameters
----------
index : bool, default True
Specifies whether to include the memory usage of the DataFrame's
index in returned Series. If ``index=True``, the memory usage of
the index is the first item in the output.
deep : bool, default False
If True, introspect the data deeply by interrogating
`object` dtypes for system-level memory consumption, and include
it in the returned values.
Returns
-------
Series
A Series whose index is the original column names and whose values
is the memory usage of each column in bytes.
See Also
--------
numpy.ndarray.nbytes : Total bytes consumed by the elements of an
ndarray.
Series.memory_usage : Bytes consumed by a Series.
Categorical : Memory-efficient array for string values with
many repeated values.
DataFrame.info : Concise summary of a DataFrame.
Notes
-----
See the :ref:`Frequently Asked Questions <df-memory-usage>` for more
details.
Examples
--------
>>> dtypes = ['int64', 'float64', 'complex128', 'object', 'bool']
>>> data = dict([(t, np.ones(shape=5000, dtype=int).astype(t))
... for t in dtypes])
>>> df = pd.DataFrame(data)
>>> df.head()
int64 float64 complex128 object bool
0 1 1.0 1.0+0.0j 1 True
1 1 1.0 1.0+0.0j 1 True
2 1 1.0 1.0+0.0j 1 True
3 1 1.0 1.0+0.0j 1 True
4 1 1.0 1.0+0.0j 1 True
>>> df.memory_usage()
Index 128
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
>>> df.memory_usage(index=False)
int64 40000
float64 40000
complex128 80000
object 40000
bool 5000
dtype: int64
The memory footprint of `object` dtype columns is ignored by default:
>>> df.memory_usage(deep=True)
Index 128
int64 40000
float64 40000
complex128 80000
object 180000
bool 5000
dtype: int64
Use a Categorical for efficient storage of an object-dtype column with
many repeated values.
>>> df['object'].astype('category').memory_usage(deep=True)
5244
"""
result = self._constructor_sliced(
[c.memory_usage(index=False, deep=deep) for col, c in self.items()],
index=self.columns,
dtype=np.intp,
)
if index:
index_memory_usage = self._constructor_sliced(
self.index.memory_usage(deep=deep), index=["Index"]
)
result = index_memory_usage._append(result)
return result
def transpose(self, *args, copy: bool = False) -> DataFrame:
"""
Transpose index and columns.
Reflect the DataFrame over its main diagonal by writing rows as columns
and vice-versa. The property :attr:`.T` is an accessor to the method
:meth:`transpose`.
Parameters
----------
*args : tuple, optional
Accepted for compatibility with NumPy.
copy : bool, default False
Whether to copy the data after transposing, even for DataFrames
with a single dtype.
Note that a copy is always required for mixed dtype DataFrames,
or for DataFrames with any extension types.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
numpy.transpose : Permute the dimensions of a given array.
Notes
-----
Transposing a DataFrame with mixed dtypes will result in a homogeneous
DataFrame with the `object` dtype. In such a case, a copy of the data
is always made.
Examples
--------
**Square DataFrame with homogeneous dtype**
>>> d1 = {'col1': [1, 2], 'col2': [3, 4]}
>>> df1 = pd.DataFrame(data=d1)
>>> df1
col1 col2
0 1 3
1 2 4
>>> df1_transposed = df1.T # or df1.transpose()
>>> df1_transposed
0 1
col1 1 2
col2 3 4
When the dtype is homogeneous in the original DataFrame, we get a
transposed DataFrame with the same dtype:
>>> df1.dtypes
col1 int64
col2 int64
dtype: object
>>> df1_transposed.dtypes
0 int64
1 int64
dtype: object
**Non-square DataFrame with mixed dtypes**
>>> d2 = {'name': ['Alice', 'Bob'],
... 'score': [9.5, 8],
... 'employed': [False, True],
... 'kids': [0, 0]}
>>> df2 = pd.DataFrame(data=d2)
>>> df2
name score employed kids
0 Alice 9.5 False 0
1 Bob 8.0 True 0
>>> df2_transposed = df2.T # or df2.transpose()
>>> df2_transposed
0 1
name Alice Bob
score 9.5 8.0
employed False True
kids 0 0
When the DataFrame has mixed dtypes, we get a transposed DataFrame with
the `object` dtype:
>>> df2.dtypes
name object
score float64
employed bool
kids int64
dtype: object
>>> df2_transposed.dtypes
0 object
1 object
dtype: object
"""
nv.validate_transpose(args, {})
# construct the args
dtypes = list(self.dtypes)
if self._can_fast_transpose:
# Note: tests pass without this, but this improves perf quite a bit.
new_vals = self._values.T
if copy and not using_copy_on_write():
new_vals = new_vals.copy()
result = self._constructor(
new_vals, index=self.columns, columns=self.index, copy=False
)
if using_copy_on_write() and len(self) > 0:
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
elif (
self._is_homogeneous_type and dtypes and is_extension_array_dtype(dtypes[0])
):
# We have EAs with the same dtype. We can preserve that dtype in transpose.
dtype = dtypes[0]
arr_type = dtype.construct_array_type()
values = self.values
new_values = [arr_type._from_sequence(row, dtype=dtype) for row in values]
result = type(self)._from_arrays(
new_values, index=self.columns, columns=self.index
)
else:
new_arr = self.values.T
if copy and not using_copy_on_write():
new_arr = new_arr.copy()
result = self._constructor(
new_arr,
index=self.columns,
columns=self.index,
# We already made a copy (more than one block)
copy=False,
)
return result.__finalize__(self, method="transpose")
def T(self) -> DataFrame:
"""
The transpose of the DataFrame.
Returns
-------
DataFrame
The transposed DataFrame.
See Also
--------
DataFrame.transpose : Transpose index and columns.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.T
0 1
col1 1 2
col2 3 4
"""
return self.transpose()
# ----------------------------------------------------------------------
# Indexing Methods
def _ixs(self, i: int, axis: AxisInt = 0) -> Series:
"""
Parameters
----------
i : int
axis : int
Returns
-------
Series
"""
# irow
if axis == 0:
new_mgr = self._mgr.fast_xs(i)
# if we are a copy, mark as such
copy = isinstance(new_mgr.array, np.ndarray) and new_mgr.array.base is None
result = self._constructor_sliced(new_mgr, name=self.index[i]).__finalize__(
self
)
result._set_is_copy(self, copy=copy)
return result
# icol
else:
label = self.columns[i]
col_mgr = self._mgr.iget(i)
result = self._box_col_values(col_mgr, i)
# this is a cached value, mark it so
result._set_as_cached(label, self)
return result
def _get_column_array(self, i: int) -> ArrayLike:
"""
Get the values of the i'th column (ndarray or ExtensionArray, as stored
in the Block)
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
return self._mgr.iget_values(i)
def _iter_column_arrays(self) -> Iterator[ArrayLike]:
"""
Iterate over the arrays of all columns in order.
This returns the values as stored in the Block (ndarray or ExtensionArray).
Warning! The returned array is a view but doesn't handle Copy-on-Write,
so this should be used with caution (for read-only purposes).
"""
for i in range(len(self.columns)):
yield self._get_column_array(i)
def _getitem_nocopy(self, key: list):
"""
Behaves like __getitem__, but returns a view in cases where __getitem__
would make a copy.
"""
# TODO(CoW): can be removed if/when we are always Copy-on-Write
indexer = self.columns._get_indexer_strict(key, "columns")[1]
new_axis = self.columns[indexer]
new_mgr = self._mgr.reindex_indexer(
new_axis,
indexer,
axis=0,
allow_dups=True,
copy=False,
only_slice=True,
)
return self._constructor(new_mgr)
def __getitem__(self, key):
check_dict_or_set_indexers(key)
key = lib.item_from_zerodim(key)
key = com.apply_if_callable(key, self)
if is_hashable(key) and not is_iterator(key):
# is_iterator to exclude generator e.g. test_getitem_listlike
# shortcut if the key is in columns
is_mi = isinstance(self.columns, MultiIndex)
# GH#45316 Return view if key is not duplicated
# Only use drop_duplicates with duplicates for performance
if not is_mi and (
self.columns.is_unique
and key in self.columns
or key in self.columns.drop_duplicates(keep=False)
):
return self._get_item_cache(key)
elif is_mi and self.columns.is_unique and key in self.columns:
return self._getitem_multilevel(key)
# Do we have a slicer (on rows)?
if isinstance(key, slice):
indexer = self.index._convert_slice_indexer(key, kind="getitem")
if isinstance(indexer, np.ndarray):
# reachable with DatetimeIndex
indexer = lib.maybe_indices_to_slice(
indexer.astype(np.intp, copy=False), len(self)
)
if isinstance(indexer, np.ndarray):
# GH#43223 If we can not convert, use take
return self.take(indexer, axis=0)
return self._slice(indexer, axis=0)
# Do we have a (boolean) DataFrame?
if isinstance(key, DataFrame):
return self.where(key)
# Do we have a (boolean) 1d indexer?
if com.is_bool_indexer(key):
return self._getitem_bool_array(key)
# We are left with two options: a single key, and a collection of keys,
# We interpret tuples as collections only for non-MultiIndex
is_single_key = isinstance(key, tuple) or not is_list_like(key)
if is_single_key:
if self.columns.nlevels > 1:
return self._getitem_multilevel(key)
indexer = self.columns.get_loc(key)
if is_integer(indexer):
indexer = [indexer]
else:
if is_iterator(key):
key = list(key)
indexer = self.columns._get_indexer_strict(key, "columns")[1]
# take() does not accept boolean indexers
if getattr(indexer, "dtype", None) == bool:
indexer = np.where(indexer)[0]
data = self._take_with_is_copy(indexer, axis=1)
if is_single_key:
# What does looking for a single key in a non-unique index return?
# The behavior is inconsistent. It returns a Series, except when
# - the key itself is repeated (test on data.shape, #9519), or
# - we have a MultiIndex on columns (test on self.columns, #21309)
if data.shape[1] == 1 and not isinstance(self.columns, MultiIndex):
# GH#26490 using data[key] can cause RecursionError
return data._get_item_cache(key)
return data
def _getitem_bool_array(self, key):
# also raises Exception if object array with NA values
# warning here just in case -- previously __setitem__ was
# reindexing but __getitem__ was not; it seems more reasonable to
# go with the __setitem__ behavior since that is more consistent
# with all other indexing behavior
if isinstance(key, Series) and not key.index.equals(self.index):
warnings.warn(
"Boolean Series key will be reindexed to match DataFrame index.",
UserWarning,
stacklevel=find_stack_level(),
)
elif len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}."
)
# check_bool_indexer will throw exception if Series key cannot
# be reindexed to match DataFrame rows
key = check_bool_indexer(self.index, key)
if key.all():
return self.copy(deep=None)
indexer = key.nonzero()[0]
return self._take_with_is_copy(indexer, axis=0)
def _getitem_multilevel(self, key):
# self.columns is a MultiIndex
loc = self.columns.get_loc(key)
if isinstance(loc, (slice, np.ndarray)):
new_columns = self.columns[loc]
result_columns = maybe_droplevels(new_columns, key)
if self._is_mixed_type:
result = self.reindex(columns=new_columns)
result.columns = result_columns
else:
new_values = self._values[:, loc]
result = self._constructor(
new_values, index=self.index, columns=result_columns, copy=False
)
if using_copy_on_write() and isinstance(loc, slice):
result._mgr.add_references(self._mgr) # type: ignore[arg-type]
result = result.__finalize__(self)
# If there is only one column being returned, and its name is
# either an empty string, or a tuple with an empty string as its
# first element, then treat the empty string as a placeholder
# and return the column as if the user had provided that empty
# string in the key. If the result is a Series, exclude the
# implied empty string from its name.
if len(result.columns) == 1:
# e.g. test_frame_getitem_multicolumn_empty_level,
# test_frame_mixed_depth_get, test_loc_setitem_single_column_slice
top = result.columns[0]
if isinstance(top, tuple):
top = top[0]
if top == "":
result = result[""]
if isinstance(result, Series):
result = self._constructor_sliced(
result, index=self.index, name=key
)
result._set_is_copy(self)
return result
else:
# loc is neither a slice nor ndarray, so must be an int
return self._ixs(loc, axis=1)
def _get_value(self, index, col, takeable: bool = False) -> Scalar:
"""
Quickly retrieve single value at passed column and index.
Parameters
----------
index : row label
col : column label
takeable : interpret the index/col as indexers, default False
Returns
-------
scalar
Notes
-----
Assumes that both `self.index._index_as_unique` and
`self.columns._index_as_unique`; Caller is responsible for checking.
"""
if takeable:
series = self._ixs(col, axis=1)
return series._values[index]
series = self._get_item_cache(col)
engine = self.index._engine
if not isinstance(self.index, MultiIndex):
# CategoricalIndex: Trying to use the engine fastpath may give incorrect
# results if our categories are integers that dont match our codes
# IntervalIndex: IntervalTree has no get_loc
row = self.index.get_loc(index)
return series._values[row]
# For MultiIndex going through engine effectively restricts us to
# same-length tuples; see test_get_set_value_no_partial_indexing
loc = engine.get_loc(index)
return series._values[loc]
def isetitem(self, loc, value) -> None:
"""
Set the given value in the column with position `loc`.
This is a positional analogue to ``__setitem__``.
Parameters
----------
loc : int or sequence of ints
Index position for the column.
value : scalar or arraylike
Value(s) for the column.
Notes
-----
``frame.isetitem(loc, value)`` is an in-place method as it will
modify the DataFrame in place (not returning a new object). In contrast to
``frame.iloc[:, i] = value`` which will try to update the existing values in
place, ``frame.isetitem(loc, value)`` will not update the values of the column
itself in place, it will instead insert a new array.
In cases where ``frame.columns`` is unique, this is equivalent to
``frame[frame.columns[i]] = value``.
"""
if isinstance(value, DataFrame):
if is_scalar(loc):
loc = [loc]
for i, idx in enumerate(loc):
arraylike = self._sanitize_column(value.iloc[:, i])
self._iset_item_mgr(idx, arraylike, inplace=False)
return
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=False)
def __setitem__(self, key, value):
if not PYPY and using_copy_on_write():
if sys.getrefcount(self) <= 3:
warnings.warn(
_chained_assignment_msg, ChainedAssignmentError, stacklevel=2
)
key = com.apply_if_callable(key, self)
# see if we can slice the rows
if isinstance(key, slice):
slc = self.index._convert_slice_indexer(key, kind="getitem")
return self._setitem_slice(slc, value)
if isinstance(key, DataFrame) or getattr(key, "ndim", None) == 2:
self._setitem_frame(key, value)
elif isinstance(key, (Series, np.ndarray, list, Index)):
self._setitem_array(key, value)
elif isinstance(value, DataFrame):
self._set_item_frame_value(key, value)
elif (
is_list_like(value)
and not self.columns.is_unique
and 1 < len(self.columns.get_indexer_for([key])) == len(value)
):
# Column to set is duplicated
self._setitem_array([key], value)
else:
# set column
self._set_item(key, value)
def _setitem_slice(self, key: slice, value) -> None:
# NB: we can't just use self.loc[key] = value because that
# operates on labels and we need to operate positional for
# backwards-compat, xref GH#31469
self._check_setitem_copy()
self.iloc[key] = value
def _setitem_array(self, key, value):
# also raises Exception if object array with NA values
if com.is_bool_indexer(key):
# bool indexer is indexing along rows
if len(key) != len(self.index):
raise ValueError(
f"Item wrong length {len(key)} instead of {len(self.index)}!"
)
key = check_bool_indexer(self.index, key)
indexer = key.nonzero()[0]
self._check_setitem_copy()
if isinstance(value, DataFrame):
# GH#39931 reindex since iloc does not align
value = value.reindex(self.index.take(indexer))
self.iloc[indexer] = value
else:
# Note: unlike self.iloc[:, indexer] = value, this will
# never try to overwrite values inplace
if isinstance(value, DataFrame):
check_key_length(self.columns, key, value)
for k1, k2 in zip(key, value.columns):
self[k1] = value[k2]
elif not is_list_like(value):
for col in key:
self[col] = value
elif isinstance(value, np.ndarray) and value.ndim == 2:
self._iset_not_inplace(key, value)
elif np.ndim(value) > 1:
# list of lists
value = DataFrame(value).values
return self._setitem_array(key, value)
else:
self._iset_not_inplace(key, value)
def _iset_not_inplace(self, key, value):
# GH#39510 when setting with df[key] = obj with a list-like key and
# list-like value, we iterate over those listlikes and set columns
# one at a time. This is different from dispatching to
# `self.loc[:, key]= value` because loc.__setitem__ may overwrite
# data inplace, whereas this will insert new arrays.
def igetitem(obj, i: int):
# Note: we catch DataFrame obj before getting here, but
# hypothetically would return obj.iloc[:, i]
if isinstance(obj, np.ndarray):
return obj[..., i]
else:
return obj[i]
if self.columns.is_unique:
if np.shape(value)[-1] != len(key):
raise ValueError("Columns must be same length as key")
for i, col in enumerate(key):
self[col] = igetitem(value, i)
else:
ilocs = self.columns.get_indexer_non_unique(key)[0]
if (ilocs < 0).any():
# key entries not in self.columns
raise NotImplementedError
if np.shape(value)[-1] != len(ilocs):
raise ValueError("Columns must be same length as key")
assert np.ndim(value) <= 2
orig_columns = self.columns
# Using self.iloc[:, i] = ... may set values inplace, which
# by convention we do not do in __setitem__
try:
self.columns = Index(range(len(self.columns)))
for i, iloc in enumerate(ilocs):
self[iloc] = igetitem(value, i)
finally:
self.columns = orig_columns
def _setitem_frame(self, key, value):
# support boolean setting with DataFrame input, e.g.
# df[df > df2] = 0
if isinstance(key, np.ndarray):
if key.shape != self.shape:
raise ValueError("Array conditional must be same shape as self")
key = self._constructor(key, **self._construct_axes_dict(), copy=False)
if key.size and not all(is_bool_dtype(dtype) for dtype in key.dtypes):
raise TypeError(
"Must pass DataFrame or 2-d ndarray with boolean values only"
)
self._check_inplace_setting(value)
self._check_setitem_copy()
self._where(-key, value, inplace=True)
def _set_item_frame_value(self, key, value: DataFrame) -> None:
self._ensure_valid_index(value)
# align columns
if key in self.columns:
loc = self.columns.get_loc(key)
cols = self.columns[loc]
len_cols = 1 if is_scalar(cols) or isinstance(cols, tuple) else len(cols)
if len_cols != len(value.columns):
raise ValueError("Columns must be same length as key")
# align right-hand-side columns if self.columns
# is multi-index and self[key] is a sub-frame
if isinstance(self.columns, MultiIndex) and isinstance(
loc, (slice, Series, np.ndarray, Index)
):
cols_droplevel = maybe_droplevels(cols, key)
if len(cols_droplevel) and not cols_droplevel.equals(value.columns):
value = value.reindex(cols_droplevel, axis=1)
for col, col_droplevel in zip(cols, cols_droplevel):
self[col] = value[col_droplevel]
return
if is_scalar(cols):
self[cols] = value[value.columns[0]]
return
# now align rows
arraylike = _reindex_for_setitem(value, self.index)
self._set_item_mgr(key, arraylike)
return
if len(value.columns) != 1:
raise ValueError(
"Cannot set a DataFrame with multiple columns to the single "
f"column {key}"
)
self[key] = value[value.columns[0]]
def _iset_item_mgr(
self, loc: int | slice | np.ndarray, value, inplace: bool = False
) -> None:
# when called from _set_item_mgr loc can be anything returned from get_loc
self._mgr.iset(loc, value, inplace=inplace)
self._clear_item_cache()
def _set_item_mgr(self, key, value: ArrayLike) -> None:
try:
loc = self._info_axis.get_loc(key)
except KeyError:
# This item wasn't present, just insert at end
self._mgr.insert(len(self._info_axis), key, value)
else:
self._iset_item_mgr(loc, value)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _iset_item(self, loc: int, value) -> None:
arraylike = self._sanitize_column(value)
self._iset_item_mgr(loc, arraylike, inplace=True)
# check if we are modifying a copy
# try to set first as we want an invalid
# value exception to occur first
if len(self):
self._check_setitem_copy()
def _set_item(self, key, value) -> None:
"""
Add series to DataFrame in specified column.
If series is a numpy-array (not a Series/TimeSeries), it must be the
same length as the DataFrames index or an error will be thrown.
Series/TimeSeries will be conformed to the DataFrames index to
ensure homogeneity.
"""
value = self._sanitize_column(value)
if (
key in self.columns
and value.ndim == 1
and not is_extension_array_dtype(value)
):
# broadcast across multiple columns if necessary
if not self.columns.is_unique or isinstance(self.columns, MultiIndex):
existing_piece = self[key]
if isinstance(existing_piece, DataFrame):
value = np.tile(value, (len(existing_piece.columns), 1)).T
self._set_item_mgr(key, value)
def _set_value(
self, index: IndexLabel, col, value: Scalar, takeable: bool = False
) -> None:
"""
Put single value at passed column and index.
Parameters
----------
index : Label
row label
col : Label
column label
value : scalar
takeable : bool, default False
Sets whether or not index/col interpreted as indexers
"""
try:
if takeable:
icol = col
iindex = cast(int, index)
else:
icol = self.columns.get_loc(col)
iindex = self.index.get_loc(index)
self._mgr.column_setitem(icol, iindex, value, inplace_only=True)
self._clear_item_cache()
except (KeyError, TypeError, ValueError, LossySetitemError):
# get_loc might raise a KeyError for missing labels (falling back
# to (i)loc will do expansion of the index)
# column_setitem will do validation that may raise TypeError,
# ValueError, or LossySetitemError
# set using a non-recursive method & reset the cache
if takeable:
self.iloc[index, col] = value
else:
self.loc[index, col] = value
self._item_cache.pop(col, None)
except InvalidIndexError as ii_err:
# GH48729: Seems like you are trying to assign a value to a
# row when only scalar options are permitted
raise InvalidIndexError(
f"You can only assign a scalar value not a {type(value)}"
) from ii_err
def _ensure_valid_index(self, value) -> None:
"""
Ensure that if we don't have an index, that we can create one from the
passed value.
"""
# GH5632, make sure that we are a Series convertible
if not len(self.index) and is_list_like(value) and len(value):
if not isinstance(value, DataFrame):
try:
value = Series(value)
except (ValueError, NotImplementedError, TypeError) as err:
raise ValueError(
"Cannot set a frame with no defined index "
"and a value that cannot be converted to a Series"
) from err
# GH31368 preserve name of index
index_copy = value.index.copy()
if self.index.name is not None:
index_copy.name = self.index.name
self._mgr = self._mgr.reindex_axis(index_copy, axis=1, fill_value=np.nan)
def _box_col_values(self, values: SingleDataManager, loc: int) -> Series:
"""
Provide boxed values for a column.
"""
# Lookup in columns so that if e.g. a str datetime was passed
# we attach the Timestamp object as the name.
name = self.columns[loc]
klass = self._constructor_sliced
# We get index=self.index bc values is a SingleDataManager
return klass(values, name=name, fastpath=True).__finalize__(self)
# ----------------------------------------------------------------------
# Lookup Caching
def _clear_item_cache(self) -> None:
self._item_cache.clear()
def _get_item_cache(self, item: Hashable) -> Series:
"""Return the cached item, item represents a label indexer."""
if using_copy_on_write():
loc = self.columns.get_loc(item)
return self._ixs(loc, axis=1)
cache = self._item_cache
res = cache.get(item)
if res is None:
# All places that call _get_item_cache have unique columns,
# pending resolution of GH#33047
loc = self.columns.get_loc(item)
res = self._ixs(loc, axis=1)
cache[item] = res
# for a chain
res._is_copy = self._is_copy
return res
def _reset_cacher(self) -> None:
# no-op for DataFrame
pass
def _maybe_cache_changed(self, item, value: Series, inplace: bool) -> None:
"""
The object has called back to us saying maybe it has changed.
"""
loc = self._info_axis.get_loc(item)
arraylike = value._values
old = self._ixs(loc, axis=1)
if old._values is value._values and inplace:
# GH#46149 avoid making unnecessary copies/block-splitting
return
self._mgr.iset(loc, arraylike, inplace=inplace)
# ----------------------------------------------------------------------
# Unsorted
def query(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> DataFrame:
...
def query(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def query(self, expr: str, *, inplace: bool = ..., **kwargs) -> DataFrame | None:
...
def query(self, expr: str, *, inplace: bool = False, **kwargs) -> DataFrame | None:
"""
Query the columns of a DataFrame with a boolean expression.
Parameters
----------
expr : str
The query string to evaluate.
You can refer to variables
in the environment by prefixing them with an '@' character like
``@a + b``.
You can refer to column names that are not valid Python variable names
by surrounding them in backticks. Thus, column names containing spaces
or punctuations (besides underscores) or starting with digits must be
surrounded by backticks. (For example, a column named "Area (cm^2)" would
be referenced as ```Area (cm^2)```). Column names which are Python keywords
(like "list", "for", "import", etc) cannot be used.
For example, if one of your columns is called ``a a`` and you want
to sum it with ``b``, your query should be ```a a` + b``.
inplace : bool
Whether to modify the DataFrame rather than creating a new one.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by :meth:`DataFrame.query`.
Returns
-------
DataFrame or None
DataFrame resulting from the provided query expression or
None if ``inplace=True``.
See Also
--------
eval : Evaluate a string describing operations on
DataFrame columns.
DataFrame.eval : Evaluate a string describing operations on
DataFrame columns.
Notes
-----
The result of the evaluation of this expression is first passed to
:attr:`DataFrame.loc` and if that fails because of a
multidimensional key (e.g., a DataFrame) then the result will be passed
to :meth:`DataFrame.__getitem__`.
This method uses the top-level :func:`eval` function to
evaluate the passed query.
The :meth:`~pandas.DataFrame.query` method uses a slightly
modified Python syntax by default. For example, the ``&`` and ``|``
(bitwise) operators have the precedence of their boolean cousins,
:keyword:`and` and :keyword:`or`. This *is* syntactically valid Python,
however the semantics are different.
You can change the semantics of the expression by passing the keyword
argument ``parser='python'``. This enforces the same semantics as
evaluation in Python space. Likewise, you can pass ``engine='python'``
to evaluate an expression using Python itself as a backend. This is not
recommended as it is inefficient compared to using ``numexpr`` as the
engine.
The :attr:`DataFrame.index` and
:attr:`DataFrame.columns` attributes of the
:class:`~pandas.DataFrame` instance are placed in the query namespace
by default, which allows you to treat both the index and columns of the
frame as a column in the frame.
The identifier ``index`` is used for the frame index; you can also
use the name of the index to identify it in a query. Please note that
Python keywords may not be used as identifiers.
For further details and examples see the ``query`` documentation in
:ref:`indexing <indexing.query>`.
*Backtick quoted variables*
Backtick quoted variables are parsed as literal Python code and
are converted internally to a Python valid identifier.
This can lead to the following problems.
During parsing a number of disallowed characters inside the backtick
quoted string are replaced by strings that are allowed as a Python identifier.
These characters include all operators in Python, the space character, the
question mark, the exclamation mark, the dollar sign, and the euro sign.
For other characters that fall outside the ASCII range (U+0001..U+007F)
and those that are not further specified in PEP 3131,
the query parser will raise an error.
This excludes whitespace different than the space character,
but also the hashtag (as it is used for comments) and the backtick
itself (backtick can also not be escaped).
In a special case, quotes that make a pair around a backtick can
confuse the parser.
For example, ```it's` > `that's``` will raise an error,
as it forms a quoted string (``'s > `that'``) with a backtick inside.
See also the Python documentation about lexical analysis
(https://docs.python.org/3/reference/lexical_analysis.html)
in combination with the source code in :mod:`pandas.core.computation.parsing`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6),
... 'B': range(10, 0, -2),
... 'C C': range(10, 5, -1)})
>>> df
A B C C
0 1 10 10
1 2 8 9
2 3 6 8
3 4 4 7
4 5 2 6
>>> df.query('A > B')
A B C C
4 5 2 6
The previous expression is equivalent to
>>> df[df.A > df.B]
A B C C
4 5 2 6
For columns with spaces in their name, you can use backtick quoting.
>>> df.query('B == `C C`')
A B C C
0 1 10 10
The previous expression is equivalent to
>>> df[df.B == df['C C']]
A B C C
0 1 10 10
"""
inplace = validate_bool_kwarg(inplace, "inplace")
if not isinstance(expr, str):
msg = f"expr must be a string to be evaluated, {type(expr)} given"
raise ValueError(msg)
kwargs["level"] = kwargs.pop("level", 0) + 1
kwargs["target"] = None
res = self.eval(expr, **kwargs)
try:
result = self.loc[res]
except ValueError:
# when res is multi-dimensional loc raises, but this is sometimes a
# valid query
result = self[res]
if inplace:
self._update_inplace(result)
return None
else:
return result
def eval(self, expr: str, *, inplace: Literal[False] = ..., **kwargs) -> Any:
...
def eval(self, expr: str, *, inplace: Literal[True], **kwargs) -> None:
...
def eval(self, expr: str, *, inplace: bool = False, **kwargs) -> Any | None:
"""
Evaluate a string describing operations on DataFrame columns.
Operates on columns only, not specific rows or elements. This allows
`eval` to run arbitrary code, which can make you vulnerable to code
injection if you pass user input to this function.
Parameters
----------
expr : str
The expression string to evaluate.
inplace : bool, default False
If the expression contains an assignment, whether to perform the
operation inplace and mutate the existing DataFrame. Otherwise,
a new DataFrame is returned.
**kwargs
See the documentation for :func:`eval` for complete details
on the keyword arguments accepted by
:meth:`~pandas.DataFrame.query`.
Returns
-------
ndarray, scalar, pandas object, or None
The result of the evaluation or None if ``inplace=True``.
See Also
--------
DataFrame.query : Evaluates a boolean expression to query the columns
of a frame.
DataFrame.assign : Can evaluate an expression or function to create new
values for a column.
eval : Evaluate a Python expression as a string using various
backends.
Notes
-----
For more details see the API documentation for :func:`~eval`.
For detailed examples see :ref:`enhancing performance with eval
<enhancingperf.eval>`.
Examples
--------
>>> df = pd.DataFrame({'A': range(1, 6), 'B': range(10, 0, -2)})
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
>>> df.eval('A + B')
0 11
1 10
2 9
3 8
4 7
dtype: int64
Assignment is allowed though by default the original DataFrame is not
modified.
>>> df.eval('C = A + B')
A B C
0 1 10 11
1 2 8 10
2 3 6 9
3 4 4 8
4 5 2 7
>>> df
A B
0 1 10
1 2 8
2 3 6
3 4 4
4 5 2
Multiple columns can be assigned to using multi-line expressions:
>>> df.eval(
... '''
... C = A + B
... D = A - B
... '''
... )
A B C D
0 1 10 11 -9
1 2 8 10 -6
2 3 6 9 -3
3 4 4 8 0
4 5 2 7 3
"""
from pandas.core.computation.eval import eval as _eval
inplace = validate_bool_kwarg(inplace, "inplace")
kwargs["level"] = kwargs.pop("level", 0) + 1
index_resolvers = self._get_index_resolvers()
column_resolvers = self._get_cleaned_column_resolvers()
resolvers = column_resolvers, index_resolvers
if "target" not in kwargs:
kwargs["target"] = self
kwargs["resolvers"] = tuple(kwargs.get("resolvers", ())) + resolvers
return _eval(expr, inplace=inplace, **kwargs)
def select_dtypes(self, include=None, exclude=None) -> DataFrame:
"""
Return a subset of the DataFrame's columns based on the column dtypes.
Parameters
----------
include, exclude : scalar or list-like
A selection of dtypes or strings to be included/excluded. At least
one of these parameters must be supplied.
Returns
-------
DataFrame
The subset of the frame including the dtypes in ``include`` and
excluding the dtypes in ``exclude``.
Raises
------
ValueError
* If both of ``include`` and ``exclude`` are empty
* If ``include`` and ``exclude`` have overlapping elements
* If any kind of string dtype is passed in.
See Also
--------
DataFrame.dtypes: Return Series with the data type of each column.
Notes
-----
* To select all *numeric* types, use ``np.number`` or ``'number'``
* To select strings you must use the ``object`` dtype, but note that
this will return *all* object dtype columns
* See the `numpy dtype hierarchy
<https://numpy.org/doc/stable/reference/arrays.scalars.html>`__
* To select datetimes, use ``np.datetime64``, ``'datetime'`` or
``'datetime64'``
* To select timedeltas, use ``np.timedelta64``, ``'timedelta'`` or
``'timedelta64'``
* To select Pandas categorical dtypes, use ``'category'``
* To select Pandas datetimetz dtypes, use ``'datetimetz'`` (new in
0.20.0) or ``'datetime64[ns, tz]'``
Examples
--------
>>> df = pd.DataFrame({'a': [1, 2] * 3,
... 'b': [True, False] * 3,
... 'c': [1.0, 2.0] * 3})
>>> df
a b c
0 1 True 1.0
1 2 False 2.0
2 1 True 1.0
3 2 False 2.0
4 1 True 1.0
5 2 False 2.0
>>> df.select_dtypes(include='bool')
b
0 True
1 False
2 True
3 False
4 True
5 False
>>> df.select_dtypes(include=['float64'])
c
0 1.0
1 2.0
2 1.0
3 2.0
4 1.0
5 2.0
>>> df.select_dtypes(exclude=['int64'])
b c
0 True 1.0
1 False 2.0
2 True 1.0
3 False 2.0
4 True 1.0
5 False 2.0
"""
if not is_list_like(include):
include = (include,) if include is not None else ()
if not is_list_like(exclude):
exclude = (exclude,) if exclude is not None else ()
selection = (frozenset(include), frozenset(exclude))
if not any(selection):
raise ValueError("at least one of include or exclude must be nonempty")
# convert the myriad valid dtypes object to a single representation
def check_int_infer_dtype(dtypes):
converted_dtypes: list[type] = []
for dtype in dtypes:
# Numpy maps int to different types (int32, in64) on Windows and Linux
# see https://github.com/numpy/numpy/issues/9464
if (isinstance(dtype, str) and dtype == "int") or (dtype is int):
converted_dtypes.append(np.int32)
converted_dtypes.append(np.int64)
elif dtype == "float" or dtype is float:
# GH#42452 : np.dtype("float") coerces to np.float64 from Numpy 1.20
converted_dtypes.extend([np.float64, np.float32])
else:
converted_dtypes.append(infer_dtype_from_object(dtype))
return frozenset(converted_dtypes)
include = check_int_infer_dtype(include)
exclude = check_int_infer_dtype(exclude)
for dtypes in (include, exclude):
invalidate_string_dtypes(dtypes)
# can't both include AND exclude!
if not include.isdisjoint(exclude):
raise ValueError(f"include and exclude overlap on {(include & exclude)}")
def dtype_predicate(dtype: DtypeObj, dtypes_set) -> bool:
# GH 46870: BooleanDtype._is_numeric == True but should be excluded
return issubclass(dtype.type, tuple(dtypes_set)) or (
np.number in dtypes_set
and getattr(dtype, "_is_numeric", False)
and not is_bool_dtype(dtype)
)
def predicate(arr: ArrayLike) -> bool:
dtype = arr.dtype
if include:
if not dtype_predicate(dtype, include):
return False
if exclude:
if dtype_predicate(dtype, exclude):
return False
return True
mgr = self._mgr._get_data_subset(predicate).copy(deep=None)
return type(self)(mgr).__finalize__(self)
def insert(
self,
loc: int,
column: Hashable,
value: Scalar | AnyArrayLike,
allow_duplicates: bool | lib.NoDefault = lib.no_default,
) -> None:
"""
Insert column into DataFrame at specified location.
Raises a ValueError if `column` is already contained in the DataFrame,
unless `allow_duplicates` is set to True.
Parameters
----------
loc : int
Insertion index. Must verify 0 <= loc <= len(columns).
column : str, number, or hashable object
Label of the inserted column.
value : Scalar, Series, or array-like
allow_duplicates : bool, optional, default lib.no_default
See Also
--------
Index.insert : Insert new item by index.
Examples
--------
>>> df = pd.DataFrame({'col1': [1, 2], 'col2': [3, 4]})
>>> df
col1 col2
0 1 3
1 2 4
>>> df.insert(1, "newcol", [99, 99])
>>> df
col1 newcol col2
0 1 99 3
1 2 99 4
>>> df.insert(0, "col1", [100, 100], allow_duplicates=True)
>>> df
col1 col1 newcol col2
0 100 1 99 3
1 100 2 99 4
Notice that pandas uses index alignment in case of `value` from type `Series`:
>>> df.insert(0, "col0", pd.Series([5, 6], index=[1, 2]))
>>> df
col0 col1 col1 newcol col2
0 NaN 100 1 99 3
1 5.0 100 2 99 4
"""
if allow_duplicates is lib.no_default:
allow_duplicates = False
if allow_duplicates and not self.flags.allows_duplicate_labels:
raise ValueError(
"Cannot specify 'allow_duplicates=True' when "
"'self.flags.allows_duplicate_labels' is False."
)
if not allow_duplicates and column in self.columns:
# Should this be a different kind of error??
raise ValueError(f"cannot insert {column}, already exists")
if not isinstance(loc, int):
raise TypeError("loc must be int")
value = self._sanitize_column(value)
self._mgr.insert(loc, column, value)
def assign(self, **kwargs) -> DataFrame:
r"""
Assign new columns to a DataFrame.
Returns a new object with all original columns in addition to new ones.
Existing columns that are re-assigned will be overwritten.
Parameters
----------
**kwargs : dict of {str: callable or Series}
The column names are keywords. If the values are
callable, they are computed on the DataFrame and
assigned to the new columns. The callable must not
change input DataFrame (though pandas doesn't check it).
If the values are not callable, (e.g. a Series, scalar, or array),
they are simply assigned.
Returns
-------
DataFrame
A new DataFrame with the new columns in addition to
all the existing columns.
Notes
-----
Assigning multiple columns within the same ``assign`` is possible.
Later items in '\*\*kwargs' may refer to newly created or modified
columns in 'df'; items are computed and assigned into 'df' in order.
Examples
--------
>>> df = pd.DataFrame({'temp_c': [17.0, 25.0]},
... index=['Portland', 'Berkeley'])
>>> df
temp_c
Portland 17.0
Berkeley 25.0
Where the value is a callable, evaluated on `df`:
>>> df.assign(temp_f=lambda x: x.temp_c * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
Alternatively, the same behavior can be achieved by directly
referencing an existing Series or sequence:
>>> df.assign(temp_f=df['temp_c'] * 9 / 5 + 32)
temp_c temp_f
Portland 17.0 62.6
Berkeley 25.0 77.0
You can create multiple columns within the same assign where one
of the columns depends on another one defined within the same assign:
>>> df.assign(temp_f=lambda x: x['temp_c'] * 9 / 5 + 32,
... temp_k=lambda x: (x['temp_f'] + 459.67) * 5 / 9)
temp_c temp_f temp_k
Portland 17.0 62.6 290.15
Berkeley 25.0 77.0 298.15
"""
data = self.copy(deep=None)
for k, v in kwargs.items():
data[k] = com.apply_if_callable(v, data)
return data
def _sanitize_column(self, value) -> ArrayLike:
"""
Ensures new columns (which go into the BlockManager as new blocks) are
always copied and converted into an array.
Parameters
----------
value : scalar, Series, or array-like
Returns
-------
numpy.ndarray or ExtensionArray
"""
self._ensure_valid_index(value)
# We can get there through isetitem with a DataFrame
# or through loc single_block_path
if isinstance(value, DataFrame):
return _reindex_for_setitem(value, self.index)
elif is_dict_like(value):
return _reindex_for_setitem(Series(value), self.index)
if is_list_like(value):
com.require_length_match(value, self.index)
return sanitize_array(value, self.index, copy=True, allow_2d=True)
def _series(self):
return {
item: Series(
self._mgr.iget(idx), index=self.index, name=item, fastpath=True
)
for idx, item in enumerate(self.columns)
}
# ----------------------------------------------------------------------
# Reindexing and alignment
def _reindex_axes(self, axes, level, limit, tolerance, method, fill_value, copy):
frame = self
columns = axes["columns"]
if columns is not None:
frame = frame._reindex_columns(
columns, method, copy, level, fill_value, limit, tolerance
)
index = axes["index"]
if index is not None:
frame = frame._reindex_index(
index, method, copy, level, fill_value, limit, tolerance
)
return frame
def _reindex_index(
self,
new_index,
method,
copy: bool,
level: Level,
fill_value=np.nan,
limit=None,
tolerance=None,
):
new_index, indexer = self.index.reindex(
new_index, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{0: [new_index, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_columns(
self,
new_columns,
method,
copy: bool,
level: Level,
fill_value=None,
limit=None,
tolerance=None,
):
new_columns, indexer = self.columns.reindex(
new_columns, method=method, level=level, limit=limit, tolerance=tolerance
)
return self._reindex_with_indexers(
{1: [new_columns, indexer]},
copy=copy,
fill_value=fill_value,
allow_dups=False,
)
def _reindex_multi(
self, axes: dict[str, Index], copy: bool, fill_value
) -> DataFrame:
"""
We are guaranteed non-Nones in the axes.
"""
new_index, row_indexer = self.index.reindex(axes["index"])
new_columns, col_indexer = self.columns.reindex(axes["columns"])
if row_indexer is not None and col_indexer is not None:
# Fastpath. By doing two 'take's at once we avoid making an
# unnecessary copy.
# We only get here with `not self._is_mixed_type`, which (almost)
# ensures that self.values is cheap. It may be worth making this
# condition more specific.
indexer = row_indexer, col_indexer
new_values = take_2d_multi(self.values, indexer, fill_value=fill_value)
return self._constructor(
new_values, index=new_index, columns=new_columns, copy=False
)
else:
return self._reindex_with_indexers(
{0: [new_index, row_indexer], 1: [new_columns, col_indexer]},
copy=copy,
fill_value=fill_value,
)
def align(
self,
other: DataFrame,
join: AlignJoin = "outer",
axis: Axis | None = None,
level: Level = None,
copy: bool | None = None,
fill_value=None,
method: FillnaOptions | None = None,
limit: int | None = None,
fill_axis: Axis = 0,
broadcast_axis: Axis | None = None,
) -> DataFrame:
return super().align(
other,
join=join,
axis=axis,
level=level,
copy=copy,
fill_value=fill_value,
method=method,
limit=limit,
fill_axis=fill_axis,
broadcast_axis=broadcast_axis,
)
"""
Examples
--------
>>> df = pd.DataFrame({"A": [1, 2, 3], "B": [4, 5, 6]})
Change the row labels.
>>> df.set_axis(['a', 'b', 'c'], axis='index')
A B
a 1 4
b 2 5
c 3 6
Change the column labels.
>>> df.set_axis(['I', 'II'], axis='columns')
I II
0 1 4
1 2 5
2 3 6
"""
)
**_shared_doc_kwargs,
extended_summary_sub=" column or",
axis_description_sub=", and 1 identifies the columns",
see_also_sub=" or columns",
)
)
# ----------------------------------------------------------------------
# Reindex-based selection methods
# ----------------------------------------------------------------------
# Sorting
# error: Signature of "sort_values" incompatible with supertype "NDFrame"
# TODO: Just move the sort_values doc here.
)
# ----------------------------------------------------------------------
# Arithmetic Methods
)
)
)
# ----------------------------------------------------------------------
# Function application
)
# error: Signature of "any" incompatible with supertype "NDFrame" [override]
# error: Missing return statement
)
# ----------------------------------------------------------------------
# Merging / joining methods
# ----------------------------------------------------------------------
# Statistical methods, etc.
# ----------------------------------------------------------------------
# ndarray-like stats methods
# ----------------------------------------------------------------------
# Add index and columns
# ----------------------------------------------------------------------
# Add plotting methods to DataFrame
# ----------------------------------------------------------------------
# Internal Interface Methods
DataFrame
def read_excel(
io,
sheet_name: str | int | list[IntStrT] | None = 0,
*,
header: int | Sequence[int] | None = 0,
names: list[str] | None = None,
index_col: int | Sequence[int] | None = None,
usecols: int
| str
| Sequence[int]
| Sequence[str]
| Callable[[str], bool]
| None = None,
dtype: DtypeArg | None = None,
engine: Literal["xlrd", "openpyxl", "odf", "pyxlsb"] | None = None,
converters: dict[str, Callable] | dict[int, Callable] | None = None,
true_values: Iterable[Hashable] | None = None,
false_values: Iterable[Hashable] | None = None,
skiprows: Sequence[int] | int | Callable[[int], object] | None = None,
nrows: int | None = None,
na_values=None,
keep_default_na: bool = True,
na_filter: bool = True,
verbose: bool = False,
parse_dates: list | dict | bool = False,
date_parser: Callable | lib.NoDefault = lib.no_default,
date_format: dict[Hashable, str] | str | None = None,
thousands: str | None = None,
decimal: str = ".",
comment: str | None = None,
skipfooter: int = 0,
storage_options: StorageOptions = None,
dtype_backend: DtypeBackend | lib.NoDefault = lib.no_default,
) -> DataFrame | dict[IntStrT, DataFrame]:
check_dtype_backend(dtype_backend)
should_close = False
if not isinstance(io, ExcelFile):
should_close = True
io = ExcelFile(io, storage_options=storage_options, engine=engine)
elif engine and engine != io.engine:
raise ValueError(
"Engine should not be specified when passing "
"an ExcelFile - ExcelFile already has the engine set"
)
try:
data = io.parse(
sheet_name=sheet_name,
header=header,
names=names,
index_col=index_col,
usecols=usecols,
dtype=dtype,
converters=converters,
true_values=true_values,
false_values=false_values,
skiprows=skiprows,
nrows=nrows,
na_values=na_values,
keep_default_na=keep_default_na,
na_filter=na_filter,
verbose=verbose,
parse_dates=parse_dates,
date_parser=date_parser,
date_format=date_format,
thousands=thousands,
decimal=decimal,
comment=comment,
skipfooter=skipfooter,
dtype_backend=dtype_backend,
)
finally:
# make sure to close opened file handles
if should_close:
io.close()
return data | null |
173,561 | from __future__ import annotations
import abc
import datetime
from functools import partial
from io import BytesIO
import os
from textwrap import fill
from types import TracebackType
from typing import (
IO,
Any,
Callable,
Hashable,
Iterable,
List,
Literal,
Mapping,
Sequence,
Union,
cast,
overload,
)
import zipfile
from pandas._config import config
from pandas._libs import lib
from pandas._libs.parsers import STR_NA_VALUES
from pandas._typing import (
DtypeArg,
DtypeBackend,
FilePath,
IntStrT,
ReadBuffer,
StorageOptions,
WriteExcelBuffer,
)
from pandas.compat._optional import (
get_version,
import_optional_dependency,
)
from pandas.errors import EmptyDataError
from pandas.util._decorators import (
Appender,
doc,
)
from pandas.util._validators import check_dtype_backend
from pandas.core.dtypes.common import (
is_bool,
is_float,
is_integer,
is_list_like,
)
from pandas.core.frame import DataFrame
from pandas.core.shared_docs import _shared_docs
from pandas.util.version import Version
from pandas.io.common import (
IOHandles,
get_handle,
stringify_path,
validate_header_arg,
)
from pandas.io.excel._util import (
fill_mi_header,
get_default_engine,
get_writer,
maybe_convert_usecols,
pop_header_name,
)
from pandas.io.parsers import TextParser
from pandas.io.parsers.readers import validate_integer
XLS_SIGNATURES = (
b"\x09\x00\x04\x00\x07\x00\x10\x00", # BIFF2
b"\x09\x02\x06\x00\x00\x00\x10\x00", # BIFF3
b"\x09\x04\x06\x00\x00\x00\x10\x00", # BIFF4
b"\xD0\xCF\x11\xE0\xA1\xB1\x1A\xE1", # Compound File Binary
)
ZIP_SIGNATURE = b"PK\x03\x04"
PEEK_SIZE = max(map(len, XLS_SIGNATURES + (ZIP_SIGNATURE,)))
class BytesIO(BufferedIOBase, BinaryIO):
def __init__(self, initial_bytes: bytes = ...) -> None: ...
# BytesIO does not contain a "name" field. This workaround is necessary
# to allow BytesIO sub-classes to add this field, as it is defined
# as a read-only property on IO[].
name: Any
def __enter__(self: _T) -> _T: ...
def getvalue(self) -> bytes: ...
def getbuffer(self) -> memoryview: ...
if sys.version_info >= (3, 7):
def read1(self, __size: Optional[int] = ...) -> bytes: ...
else:
def read1(self, __size: Optional[int]) -> bytes: ... # type: ignore
class ReadBuffer(BaseBuffer, Protocol[AnyStr_co]):
def read(self, __n: int = ...) -> AnyStr_co:
# for BytesIOWrapper, gzip.GzipFile, bz2.BZ2File
...
FilePath = Union[str, "PathLike[str]"]
StorageOptions = Optional[Dict[str, Any]]
)
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[False],
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: Literal[True] = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = ...,
compression: CompressionOptions = ...,
memory_map: bool = ...,
is_text: bool = ...,
errors: str | None = ...,
storage_options: StorageOptions = ...,
) -> IOHandles[str] | IOHandles[bytes]:
...
def get_handle(
path_or_buf: FilePath | BaseBuffer,
mode: str,
*,
encoding: str | None = None,
compression: CompressionOptions = None,
memory_map: bool = False,
is_text: bool = True,
errors: str | None = None,
storage_options: StorageOptions = None,
) -> IOHandles[str] | IOHandles[bytes]:
"""
Get file handle for given path/buffer and mode.
Parameters
----------
path_or_buf : str or file handle
File path or object.
mode : str
Mode to open path_or_buf with.
encoding : str or None
Encoding to use.
{compression_options}
.. versionchanged:: 1.0.0
May now be a dict with key 'method' as compression mode
and other keys as compression options if compression
mode is 'zip'.
.. versionchanged:: 1.1.0
Passing compression options as keys in dict is now
supported for compression modes 'gzip', 'bz2', 'zstd' and 'zip'.
.. versionchanged:: 1.4.0 Zstandard support.
memory_map : bool, default False
See parsers._parser_params for more information. Only used by read_csv.
is_text : bool, default True
Whether the type of the content passed to the file/buffer is string or
bytes. This is not the same as `"b" not in mode`. If a string content is
passed to a binary file/buffer, a wrapper is inserted.
errors : str, default 'strict'
Specifies how encoding and decoding errors are to be handled.
See the errors argument for :func:`open` for a full list
of options.
storage_options: StorageOptions = None
Passed to _get_filepath_or_buffer
.. versionchanged:: 1.2.0
Returns the dataclass IOHandles
"""
# Windows does not default to utf-8. Set to utf-8 for a consistent behavior
encoding = encoding or "utf-8"
errors = errors or "strict"
# read_csv does not know whether the buffer is opened in binary/text mode
if _is_binary_mode(path_or_buf, mode) and "b" not in mode:
mode += "b"
# validate encoding and errors
codecs.lookup(encoding)
if isinstance(errors, str):
codecs.lookup_error(errors)
# open URLs
ioargs = _get_filepath_or_buffer(
path_or_buf,
encoding=encoding,
compression=compression,
mode=mode,
storage_options=storage_options,
)
handle = ioargs.filepath_or_buffer
handles: list[BaseBuffer]
# memory mapping needs to be the first step
# only used for read_csv
handle, memory_map, handles = _maybe_memory_map(handle, memory_map)
is_path = isinstance(handle, str)
compression_args = dict(ioargs.compression)
compression = compression_args.pop("method")
# Only for write methods
if "r" not in mode and is_path:
check_parent_directory(str(handle))
if compression:
if compression != "zstd":
# compression libraries do not like an explicit text-mode
ioargs.mode = ioargs.mode.replace("t", "")
elif compression == "zstd" and "b" not in ioargs.mode:
# python-zstandard defaults to text mode, but we always expect
# compression libraries to use binary mode.
ioargs.mode += "b"
# GZ Compression
if compression == "gzip":
if isinstance(handle, str):
# error: Incompatible types in assignment (expression has type
# "GzipFile", variable has type "Union[str, BaseBuffer]")
handle = gzip.GzipFile( # type: ignore[assignment]
filename=handle,
mode=ioargs.mode,
**compression_args,
)
else:
handle = gzip.GzipFile(
# No overload variant of "GzipFile" matches argument types
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
fileobj=handle, # type: ignore[call-overload]
mode=ioargs.mode,
**compression_args,
)
# BZ Compression
elif compression == "bz2":
# Overload of "BZ2File" to handle pickle protocol 5
# "Union[str, BaseBuffer]", "str", "Dict[str, Any]"
handle = _BZ2File( # type: ignore[call-overload]
handle,
mode=ioargs.mode,
**compression_args,
)
# ZIP Compression
elif compression == "zip":
# error: Argument 1 to "_BytesZipFile" has incompatible type
# "Union[str, BaseBuffer]"; expected "Union[Union[str, PathLike[str]],
# ReadBuffer[bytes], WriteBuffer[bytes]]"
handle = _BytesZipFile(
handle, ioargs.mode, **compression_args # type: ignore[arg-type]
)
if handle.buffer.mode == "r":
handles.append(handle)
zip_names = handle.buffer.namelist()
if len(zip_names) == 1:
handle = handle.buffer.open(zip_names.pop())
elif not zip_names:
raise ValueError(f"Zero files found in ZIP file {path_or_buf}")
else:
raise ValueError(
"Multiple files found in ZIP file. "
f"Only one file per ZIP: {zip_names}"
)
# TAR Encoding
elif compression == "tar":
compression_args.setdefault("mode", ioargs.mode)
if isinstance(handle, str):
handle = _BytesTarFile(name=handle, **compression_args)
else:
# error: Argument "fileobj" to "_BytesTarFile" has incompatible
# type "BaseBuffer"; expected "Union[ReadBuffer[bytes],
# WriteBuffer[bytes], None]"
handle = _BytesTarFile(
fileobj=handle, **compression_args # type: ignore[arg-type]
)
assert isinstance(handle, _BytesTarFile)
if "r" in handle.buffer.mode:
handles.append(handle)
files = handle.buffer.getnames()
if len(files) == 1:
file = handle.buffer.extractfile(files[0])
assert file is not None
handle = file
elif not files:
raise ValueError(f"Zero files found in TAR archive {path_or_buf}")
else:
raise ValueError(
"Multiple files found in TAR archive. "
f"Only one file per TAR archive: {files}"
)
# XZ Compression
elif compression == "xz":
# error: Argument 1 to "LZMAFile" has incompatible type "Union[str,
# BaseBuffer]"; expected "Optional[Union[Union[str, bytes, PathLike[str],
# PathLike[bytes]], IO[bytes]]]"
handle = get_lzma_file()(handle, ioargs.mode) # type: ignore[arg-type]
# Zstd Compression
elif compression == "zstd":
zstd = import_optional_dependency("zstandard")
if "r" in ioargs.mode:
open_args = {"dctx": zstd.ZstdDecompressor(**compression_args)}
else:
open_args = {"cctx": zstd.ZstdCompressor(**compression_args)}
handle = zstd.open(
handle,
mode=ioargs.mode,
**open_args,
)
# Unrecognized Compression
else:
msg = f"Unrecognized compression type: {compression}"
raise ValueError(msg)
assert not isinstance(handle, str)
handles.append(handle)
elif isinstance(handle, str):
# Check whether the filename is to be opened in binary mode.
# Binary mode does not support 'encoding' and 'newline'.
if ioargs.encoding and "b" not in ioargs.mode:
# Encoding
handle = open(
handle,
ioargs.mode,
encoding=ioargs.encoding,
errors=errors,
newline="",
)
else:
# Binary mode
handle = open(handle, ioargs.mode)
handles.append(handle)
# Convert BytesIO or file objects passed with an encoding
is_wrapped = False
if not is_text and ioargs.mode == "rb" and isinstance(handle, TextIOBase):
# not added to handles as it does not open/buffer resources
handle = _BytesIOWrapper(
handle,
encoding=ioargs.encoding,
)
elif is_text and (
compression or memory_map or _is_binary_mode(handle, ioargs.mode)
):
if (
not hasattr(handle, "readable")
or not hasattr(handle, "writable")
or not hasattr(handle, "seekable")
):
handle = _IOWrapper(handle)
# error: Argument 1 to "TextIOWrapper" has incompatible type
# "_IOWrapper"; expected "IO[bytes]"
handle = TextIOWrapper(
handle, # type: ignore[arg-type]
encoding=ioargs.encoding,
errors=errors,
newline="",
)
handles.append(handle)
# only marked as wrapped when the caller provided a handle
is_wrapped = not (
isinstance(ioargs.filepath_or_buffer, str) or ioargs.should_close
)
if "r" in ioargs.mode and not hasattr(handle, "read"):
raise TypeError(
"Expected file path name or file-like object, "
f"got {type(ioargs.filepath_or_buffer)} type"
)
handles.reverse() # close the most recently added buffer first
if ioargs.should_close:
assert not isinstance(ioargs.filepath_or_buffer, str)
handles.append(ioargs.filepath_or_buffer)
return IOHandles(
# error: Argument "handle" to "IOHandles" has incompatible type
# "Union[TextIOWrapper, GzipFile, BaseBuffer, typing.IO[bytes],
# typing.IO[Any]]"; expected "pandas._typing.IO[Any]"
handle=handle, # type: ignore[arg-type]
# error: Argument "created_handles" to "IOHandles" has incompatible type
# "List[BaseBuffer]"; expected "List[Union[IO[bytes], IO[str]]]"
created_handles=handles, # type: ignore[arg-type]
is_wrapped=is_wrapped,
compression=ioargs.compression,
)
The provided code snippet includes necessary dependencies for implementing the `inspect_excel_format` function. Write a Python function `def inspect_excel_format( content_or_path: FilePath | ReadBuffer[bytes], storage_options: StorageOptions = None, ) -> str | None` to solve the following problem:
Inspect the path or content of an excel file and get its format. Adopted from xlrd: https://github.com/python-excel/xlrd. Parameters ---------- content_or_path : str or file-like object Path to file or content of file to inspect. May be a URL. {storage_options} Returns ------- str or None Format of file if it can be determined. Raises ------ ValueError If resulting stream is empty. BadZipFile If resulting stream does not have an XLS signature and is not a valid zipfile.
Here is the function:
def inspect_excel_format(
content_or_path: FilePath | ReadBuffer[bytes],
storage_options: StorageOptions = None,
) -> str | None:
"""
Inspect the path or content of an excel file and get its format.
Adopted from xlrd: https://github.com/python-excel/xlrd.
Parameters
----------
content_or_path : str or file-like object
Path to file or content of file to inspect. May be a URL.
{storage_options}
Returns
-------
str or None
Format of file if it can be determined.
Raises
------
ValueError
If resulting stream is empty.
BadZipFile
If resulting stream does not have an XLS signature and is not a valid zipfile.
"""
if isinstance(content_or_path, bytes):
content_or_path = BytesIO(content_or_path)
with get_handle(
content_or_path, "rb", storage_options=storage_options, is_text=False
) as handle:
stream = handle.handle
stream.seek(0)
buf = stream.read(PEEK_SIZE)
if buf is None:
raise ValueError("stream is empty")
assert isinstance(buf, bytes)
peek = buf
stream.seek(0)
if any(peek.startswith(sig) for sig in XLS_SIGNATURES):
return "xls"
elif not peek.startswith(ZIP_SIGNATURE):
return None
with zipfile.ZipFile(stream) as zf:
# Workaround for some third party files that use forward slashes and
# lower case names.
component_names = [
name.replace("\\", "/").lower() for name in zf.namelist()
]
if "xl/workbook.xml" in component_names:
return "xlsx"
if "xl/workbook.bin" in component_names:
return "xlsb"
if "content.xml" in component_names:
return "ods"
return "zip" | Inspect the path or content of an excel file and get its format. Adopted from xlrd: https://github.com/python-excel/xlrd. Parameters ---------- content_or_path : str or file-like object Path to file or content of file to inspect. May be a URL. {storage_options} Returns ------- str or None Format of file if it can be determined. Raises ------ ValueError If resulting stream is empty. BadZipFile If resulting stream does not have an XLS signature and is not a valid zipfile. |
173,562 | from __future__ import annotations
import sys
def removesuffix(string: str, suffix: str) -> str:
if string.endswith(suffix):
return string[: -len(suffix)]
return string | null |
173,563 | from __future__ import annotations
import sys
def removeprefix(string: str, prefix: str) -> str:
if string.startswith(prefix):
return string[len(prefix) :]
return string | null |
173,564 | from __future__ import annotations
import codecs
import json
import locale
import os
import platform
import struct
import sys
from pandas._typing import JSONSerializable
from pandas.compat._optional import (
VERSIONS,
get_version,
import_optional_dependency,
)
def _get_sys_info() -> dict[str, JSONSerializable]:
"""
Returns system information as a JSON serializable dictionary.
"""
uname_result = platform.uname()
language_code, encoding = locale.getlocale()
return {
"commit": _get_commit_hash(),
"python": ".".join([str(i) for i in sys.version_info]),
"python-bits": struct.calcsize("P") * 8,
"OS": uname_result.system,
"OS-release": uname_result.release,
"Version": uname_result.version,
"machine": uname_result.machine,
"processor": uname_result.processor,
"byteorder": sys.byteorder,
"LC_ALL": os.environ.get("LC_ALL"),
"LANG": os.environ.get("LANG"),
"LOCALE": {"language-code": language_code, "encoding": encoding},
}
def _get_dependency_info() -> dict[str, JSONSerializable]:
"""
Returns dependency information as a JSON serializable dictionary.
"""
deps = [
"pandas",
# required
"numpy",
"pytz",
"dateutil",
# install / build,
"setuptools",
"pip",
"Cython",
# test
"pytest",
"hypothesis",
# docs
"sphinx",
# Other, need a min version
"blosc",
"feather",
"xlsxwriter",
"lxml.etree",
"html5lib",
"pymysql",
"psycopg2",
"jinja2",
# Other, not imported.
"IPython",
"pandas_datareader",
]
deps.extend(list(VERSIONS))
result: dict[str, JSONSerializable] = {}
for modname in deps:
mod = import_optional_dependency(modname, errors="ignore")
result[modname] = get_version(mod) if mod else None
return result
try:
from sys import is_finalizing
except ImportError:
# Emulate it
def _get_emulated_is_finalizing() -> Callable[[], bool]:
L = [] # type: List[None]
atexit.register(lambda: L.append(None))
def is_finalizing() -> bool:
# Not referencing any globals here
return L != []
return is_finalizing
is_finalizing = _get_emulated_is_finalizing()
The provided code snippet includes necessary dependencies for implementing the `show_versions` function. Write a Python function `def show_versions(as_json: str | bool = False) -> None` to solve the following problem:
Provide useful information, important for bug reports. It comprises info about hosting operation system, pandas version, and versions of other installed relative packages. Parameters ---------- as_json : str or bool, default False * If False, outputs info in a human readable form to the console. * If str, it will be considered as a path to a file. Info will be written to that file in JSON format. * If True, outputs info in JSON format to the console.
Here is the function:
def show_versions(as_json: str | bool = False) -> None:
"""
Provide useful information, important for bug reports.
It comprises info about hosting operation system, pandas version,
and versions of other installed relative packages.
Parameters
----------
as_json : str or bool, default False
* If False, outputs info in a human readable form to the console.
* If str, it will be considered as a path to a file.
Info will be written to that file in JSON format.
* If True, outputs info in JSON format to the console.
"""
sys_info = _get_sys_info()
deps = _get_dependency_info()
if as_json:
j = {"system": sys_info, "dependencies": deps}
if as_json is True:
sys.stdout.writelines(json.dumps(j, indent=2))
else:
assert isinstance(as_json, str) # needed for mypy
with codecs.open(as_json, "wb", encoding="utf8") as f:
json.dump(j, f, indent=2)
else:
assert isinstance(sys_info["LOCALE"], dict) # needed for mypy
language_code = sys_info["LOCALE"]["language-code"]
encoding = sys_info["LOCALE"]["encoding"]
sys_info["LOCALE"] = f"{language_code}.{encoding}"
maxlen = max(len(x) for x in deps)
print("\nINSTALLED VERSIONS")
print("------------------")
for k, v in sys_info.items():
print(f"{k:<{maxlen}}: {v}")
print("")
for k, v in deps.items():
print(f"{k:<{maxlen}}: {v}") | Provide useful information, important for bug reports. It comprises info about hosting operation system, pandas version, and versions of other installed relative packages. Parameters ---------- as_json : str or bool, default False * If False, outputs info in a human readable form to the console. * If str, it will be considered as a path to a file. Info will be written to that file in JSON format. * If True, outputs info in JSON format to the console. |
173,565 | from __future__ import annotations
from functools import wraps
import inspect
from textwrap import dedent
from typing import (
Any,
Callable,
Mapping,
cast,
)
import warnings
from pandas._libs.properties import cache_readonly
from pandas._typing import (
F,
T,
)
from pandas.util._exceptions import find_stack_level
def wraps(wrapped: _AnyCallable, assigned: Sequence[str] = ..., updated: Sequence[str] = ...) -> Callable[[_T], _T]: ...
def dedent(text: str) -> str: ...
Any = object()
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
F = TypeVar("F", bound=FuncType)
The provided code snippet includes necessary dependencies for implementing the `deprecate` function. Write a Python function `def deprecate( name: str, alternative: Callable[..., Any], version: str, alt_name: str | None = None, klass: type[Warning] | None = None, stacklevel: int = 2, msg: str | None = None, ) -> Callable[[F], F]` to solve the following problem:
Return a new function that emits a deprecation warning on use. To use this method for a deprecated function, another function `alternative` with the same signature must exist. The deprecated function will emit a deprecation warning, and in the docstring it will contain the deprecation directive with the provided version so it can be detected for future removal. Parameters ---------- name : str Name of function to deprecate. alternative : func Function to use instead. version : str Version of pandas in which the method has been deprecated. alt_name : str, optional Name to use in preference of alternative.__name__. klass : Warning, default FutureWarning stacklevel : int, default 2 msg : str The message to display in the warning. Default is '{name} is deprecated. Use {alt_name} instead.'
Here is the function:
def deprecate(
name: str,
alternative: Callable[..., Any],
version: str,
alt_name: str | None = None,
klass: type[Warning] | None = None,
stacklevel: int = 2,
msg: str | None = None,
) -> Callable[[F], F]:
"""
Return a new function that emits a deprecation warning on use.
To use this method for a deprecated function, another function
`alternative` with the same signature must exist. The deprecated
function will emit a deprecation warning, and in the docstring
it will contain the deprecation directive with the provided version
so it can be detected for future removal.
Parameters
----------
name : str
Name of function to deprecate.
alternative : func
Function to use instead.
version : str
Version of pandas in which the method has been deprecated.
alt_name : str, optional
Name to use in preference of alternative.__name__.
klass : Warning, default FutureWarning
stacklevel : int, default 2
msg : str
The message to display in the warning.
Default is '{name} is deprecated. Use {alt_name} instead.'
"""
alt_name = alt_name or alternative.__name__
klass = klass or FutureWarning
warning_msg = msg or f"{name} is deprecated, use {alt_name} instead."
@wraps(alternative)
def wrapper(*args, **kwargs) -> Callable[..., Any]:
warnings.warn(warning_msg, klass, stacklevel=stacklevel)
return alternative(*args, **kwargs)
# adding deprecated directive to the docstring
msg = msg or f"Use `{alt_name}` instead."
doc_error_msg = (
"deprecate needs a correctly formatted docstring in "
"the target function (should have a one liner short "
"summary, and opening quotes should be in their own "
f"line). Found:\n{alternative.__doc__}"
)
# when python is running in optimized mode (i.e. `-OO`), docstrings are
# removed, so we check that a docstring with correct formatting is used
# but we allow empty docstrings
if alternative.__doc__:
if alternative.__doc__.count("\n") < 3:
raise AssertionError(doc_error_msg)
empty1, summary, empty2, doc_string = alternative.__doc__.split("\n", 3)
if empty1 or empty2 and not summary:
raise AssertionError(doc_error_msg)
wrapper.__doc__ = dedent(
f"""
{summary.strip()}
.. deprecated:: {version}
{msg}
{dedent(doc_string)}"""
)
# error: Incompatible return value type (got "Callable[[VarArg(Any), KwArg(Any)],
# Callable[...,Any]]", expected "Callable[[F], F]")
return wrapper # type: ignore[return-value] | Return a new function that emits a deprecation warning on use. To use this method for a deprecated function, another function `alternative` with the same signature must exist. The deprecated function will emit a deprecation warning, and in the docstring it will contain the deprecation directive with the provided version so it can be detected for future removal. Parameters ---------- name : str Name of function to deprecate. alternative : func Function to use instead. version : str Version of pandas in which the method has been deprecated. alt_name : str, optional Name to use in preference of alternative.__name__. klass : Warning, default FutureWarning stacklevel : int, default 2 msg : str The message to display in the warning. Default is '{name} is deprecated. Use {alt_name} instead.' |
173,566 | from __future__ import annotations
from functools import wraps
import inspect
from textwrap import dedent
from typing import (
Any,
Callable,
Mapping,
cast,
)
import warnings
from pandas._libs.properties import cache_readonly
from pandas._typing import (
F,
T,
)
from pandas.util._exceptions import find_stack_level
def wraps(wrapped: _AnyCallable, assigned: Sequence[str] = ..., updated: Sequence[str] = ...) -> Callable[[_T], _T]: ...
Any = object()
class Mapping(_Collection[_KT], Generic[_KT, _VT_co]):
# TODO: We wish the key type could also be covariant, but that doesn't work,
# see discussion in https: //github.com/python/typing/pull/273.
def __getitem__(self, k: _KT) -> _VT_co: ...
# Mixin methods
def get(self, key: _KT) -> Optional[_VT_co]: ...
def get(self, key: _KT, default: Union[_VT_co, _T]) -> Union[_VT_co, _T]: ...
def items(self) -> AbstractSet[Tuple[_KT, _VT_co]]: ...
def keys(self) -> AbstractSet[_KT]: ...
def values(self) -> ValuesView[_VT_co]: ...
def __contains__(self, o: object) -> bool: ...
def cast(typ: Type[_T], val: Any) -> _T: ...
def cast(typ: str, val: Any) -> Any: ...
def cast(typ: object, val: Any) -> Any: ...
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
F = TypeVar("F", bound=FuncType)
The provided code snippet includes necessary dependencies for implementing the `deprecate_kwarg` function. Write a Python function `def deprecate_kwarg( old_arg_name: str, new_arg_name: str | None, mapping: Mapping[Any, Any] | Callable[[Any], Any] | None = None, stacklevel: int = 2, ) -> Callable[[F], F]` to solve the following problem:
Decorator to deprecate a keyword argument of a function. Parameters ---------- old_arg_name : str Name of argument in function to deprecate new_arg_name : str or None Name of preferred argument in function. Use None to raise warning that ``old_arg_name`` keyword is deprecated. mapping : dict or callable If mapping is present, use it to translate old arguments to new arguments. A callable must do its own value checking; values not found in a dict will be forwarded unchanged. Examples -------- The following deprecates 'cols', using 'columns' instead >>> @deprecate_kwarg(old_arg_name='cols', new_arg_name='columns') ... def f(columns=''): ... print(columns) ... >>> f(columns='should work ok') should work ok >>> f(cols='should raise warning') # doctest: +SKIP FutureWarning: cols is deprecated, use columns instead warnings.warn(msg, FutureWarning) should raise warning >>> f(cols='should error', columns="can\'t pass do both") # doctest: +SKIP TypeError: Can only specify 'cols' or 'columns', not both >>> @deprecate_kwarg('old', 'new', {'yes': True, 'no': False}) ... def f(new=False): ... print('yes!' if new else 'no!') ... >>> f(old='yes') # doctest: +SKIP FutureWarning: old='yes' is deprecated, use new=True instead warnings.warn(msg, FutureWarning) yes! To raise a warning that a keyword will be removed entirely in the future >>> @deprecate_kwarg(old_arg_name='cols', new_arg_name=None) ... def f(cols='', another_param=''): ... print(cols) ... >>> f(cols='should raise warning') # doctest: +SKIP FutureWarning: the 'cols' keyword is deprecated and will be removed in a future version please takes steps to stop use of 'cols' should raise warning >>> f(another_param='should not raise warning') # doctest: +SKIP should not raise warning >>> f(cols='should raise warning', another_param='') # doctest: +SKIP FutureWarning: the 'cols' keyword is deprecated and will be removed in a future version please takes steps to stop use of 'cols' should raise warning
Here is the function:
def deprecate_kwarg(
old_arg_name: str,
new_arg_name: str | None,
mapping: Mapping[Any, Any] | Callable[[Any], Any] | None = None,
stacklevel: int = 2,
) -> Callable[[F], F]:
"""
Decorator to deprecate a keyword argument of a function.
Parameters
----------
old_arg_name : str
Name of argument in function to deprecate
new_arg_name : str or None
Name of preferred argument in function. Use None to raise warning that
``old_arg_name`` keyword is deprecated.
mapping : dict or callable
If mapping is present, use it to translate old arguments to
new arguments. A callable must do its own value checking;
values not found in a dict will be forwarded unchanged.
Examples
--------
The following deprecates 'cols', using 'columns' instead
>>> @deprecate_kwarg(old_arg_name='cols', new_arg_name='columns')
... def f(columns=''):
... print(columns)
...
>>> f(columns='should work ok')
should work ok
>>> f(cols='should raise warning') # doctest: +SKIP
FutureWarning: cols is deprecated, use columns instead
warnings.warn(msg, FutureWarning)
should raise warning
>>> f(cols='should error', columns="can\'t pass do both") # doctest: +SKIP
TypeError: Can only specify 'cols' or 'columns', not both
>>> @deprecate_kwarg('old', 'new', {'yes': True, 'no': False})
... def f(new=False):
... print('yes!' if new else 'no!')
...
>>> f(old='yes') # doctest: +SKIP
FutureWarning: old='yes' is deprecated, use new=True instead
warnings.warn(msg, FutureWarning)
yes!
To raise a warning that a keyword will be removed entirely in the future
>>> @deprecate_kwarg(old_arg_name='cols', new_arg_name=None)
... def f(cols='', another_param=''):
... print(cols)
...
>>> f(cols='should raise warning') # doctest: +SKIP
FutureWarning: the 'cols' keyword is deprecated and will be removed in a
future version please takes steps to stop use of 'cols'
should raise warning
>>> f(another_param='should not raise warning') # doctest: +SKIP
should not raise warning
>>> f(cols='should raise warning', another_param='') # doctest: +SKIP
FutureWarning: the 'cols' keyword is deprecated and will be removed in a
future version please takes steps to stop use of 'cols'
should raise warning
"""
if mapping is not None and not hasattr(mapping, "get") and not callable(mapping):
raise TypeError(
"mapping from old to new argument values must be dict or callable!"
)
def _deprecate_kwarg(func: F) -> F:
@wraps(func)
def wrapper(*args, **kwargs) -> Callable[..., Any]:
old_arg_value = kwargs.pop(old_arg_name, None)
if old_arg_value is not None:
if new_arg_name is None:
msg = (
f"the {repr(old_arg_name)} keyword is deprecated and "
"will be removed in a future version. Please take "
f"steps to stop the use of {repr(old_arg_name)}"
)
warnings.warn(msg, FutureWarning, stacklevel=stacklevel)
kwargs[old_arg_name] = old_arg_value
return func(*args, **kwargs)
elif mapping is not None:
if callable(mapping):
new_arg_value = mapping(old_arg_value)
else:
new_arg_value = mapping.get(old_arg_value, old_arg_value)
msg = (
f"the {old_arg_name}={repr(old_arg_value)} keyword is "
"deprecated, use "
f"{new_arg_name}={repr(new_arg_value)} instead."
)
else:
new_arg_value = old_arg_value
msg = (
f"the {repr(old_arg_name)}' keyword is deprecated, "
f"use {repr(new_arg_name)} instead."
)
warnings.warn(msg, FutureWarning, stacklevel=stacklevel)
if kwargs.get(new_arg_name) is not None:
msg = (
f"Can only specify {repr(old_arg_name)} "
f"or {repr(new_arg_name)}, not both."
)
raise TypeError(msg)
kwargs[new_arg_name] = new_arg_value
return func(*args, **kwargs)
return cast(F, wrapper)
return _deprecate_kwarg | Decorator to deprecate a keyword argument of a function. Parameters ---------- old_arg_name : str Name of argument in function to deprecate new_arg_name : str or None Name of preferred argument in function. Use None to raise warning that ``old_arg_name`` keyword is deprecated. mapping : dict or callable If mapping is present, use it to translate old arguments to new arguments. A callable must do its own value checking; values not found in a dict will be forwarded unchanged. Examples -------- The following deprecates 'cols', using 'columns' instead >>> @deprecate_kwarg(old_arg_name='cols', new_arg_name='columns') ... def f(columns=''): ... print(columns) ... >>> f(columns='should work ok') should work ok >>> f(cols='should raise warning') # doctest: +SKIP FutureWarning: cols is deprecated, use columns instead warnings.warn(msg, FutureWarning) should raise warning >>> f(cols='should error', columns="can\'t pass do both") # doctest: +SKIP TypeError: Can only specify 'cols' or 'columns', not both >>> @deprecate_kwarg('old', 'new', {'yes': True, 'no': False}) ... def f(new=False): ... print('yes!' if new else 'no!') ... >>> f(old='yes') # doctest: +SKIP FutureWarning: old='yes' is deprecated, use new=True instead warnings.warn(msg, FutureWarning) yes! To raise a warning that a keyword will be removed entirely in the future >>> @deprecate_kwarg(old_arg_name='cols', new_arg_name=None) ... def f(cols='', another_param=''): ... print(cols) ... >>> f(cols='should raise warning') # doctest: +SKIP FutureWarning: the 'cols' keyword is deprecated and will be removed in a future version please takes steps to stop use of 'cols' should raise warning >>> f(another_param='should not raise warning') # doctest: +SKIP should not raise warning >>> f(cols='should raise warning', another_param='') # doctest: +SKIP FutureWarning: the 'cols' keyword is deprecated and will be removed in a future version please takes steps to stop use of 'cols' should raise warning |
173,567 | from __future__ import annotations
from functools import wraps
import inspect
from textwrap import dedent
from typing import (
Any,
Callable,
Mapping,
cast,
)
import warnings
from pandas._libs.properties import cache_readonly
from pandas._typing import (
F,
T,
)
from pandas.util._exceptions import find_stack_level
def _format_argument_list(allow_args: list[str]) -> str:
"""
Convert the allow_args argument (either string or integer) of
`deprecate_nonkeyword_arguments` function to a string describing
it to be inserted into warning message.
Parameters
----------
allowed_args : list, tuple or int
The `allowed_args` argument for `deprecate_nonkeyword_arguments`,
but None value is not allowed.
Returns
-------
str
The substring describing the argument list in best way to be
inserted to the warning message.
Examples
--------
`format_argument_list([])` -> ''
`format_argument_list(['a'])` -> "except for the arguments 'a'"
`format_argument_list(['a', 'b'])` -> "except for the arguments 'a' and 'b'"
`format_argument_list(['a', 'b', 'c'])` ->
"except for the arguments 'a', 'b' and 'c'"
"""
if "self" in allow_args:
allow_args.remove("self")
if not allow_args:
return ""
elif len(allow_args) == 1:
return f" except for the argument '{allow_args[0]}'"
else:
last = allow_args[-1]
args = ", ".join(["'" + x + "'" for x in allow_args[:-1]])
return f" except for the arguments {args} and '{last}'"
def future_version_msg(version: str | None) -> str:
"""Specify which version of pandas the deprecation will take place in."""
if version is None:
return "In a future version of pandas"
else:
return f"Starting with pandas version {version}"
def wraps(wrapped: _AnyCallable, assigned: Sequence[str] = ..., updated: Sequence[str] = ...) -> Callable[[_T], _T]: ...
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
F = TypeVar("F", bound=FuncType)
def find_stack_level() -> int:
"""
Find the first place in the stack that is not inside pandas
(tests notwithstanding).
"""
import pandas as pd
pkg_dir = os.path.dirname(pd.__file__)
test_dir = os.path.join(pkg_dir, "tests")
# https://stackoverflow.com/questions/17407119/python-inspect-stack-is-slow
frame = inspect.currentframe()
n = 0
while frame:
fname = inspect.getfile(frame)
if fname.startswith(pkg_dir) and not fname.startswith(test_dir):
frame = frame.f_back
n += 1
else:
break
return n
The provided code snippet includes necessary dependencies for implementing the `deprecate_nonkeyword_arguments` function. Write a Python function `def deprecate_nonkeyword_arguments( version: str | None, allowed_args: list[str] | None = None, name: str | None = None, ) -> Callable[[F], F]` to solve the following problem:
Decorator to deprecate a use of non-keyword arguments of a function. Parameters ---------- version : str, optional The version in which positional arguments will become keyword-only. If None, then the warning message won't specify any particular version. allowed_args : list, optional In case of list, it must be the list of names of some first arguments of the decorated functions that are OK to be given as positional arguments. In case of None value, defaults to list of all arguments not having the default value. name : str, optional The specific name of the function to show in the warning message. If None, then the Qualified name of the function is used.
Here is the function:
def deprecate_nonkeyword_arguments(
version: str | None,
allowed_args: list[str] | None = None,
name: str | None = None,
) -> Callable[[F], F]:
"""
Decorator to deprecate a use of non-keyword arguments of a function.
Parameters
----------
version : str, optional
The version in which positional arguments will become
keyword-only. If None, then the warning message won't
specify any particular version.
allowed_args : list, optional
In case of list, it must be the list of names of some
first arguments of the decorated functions that are
OK to be given as positional arguments. In case of None value,
defaults to list of all arguments not having the
default value.
name : str, optional
The specific name of the function to show in the warning
message. If None, then the Qualified name of the function
is used.
"""
def decorate(func):
old_sig = inspect.signature(func)
if allowed_args is not None:
allow_args = allowed_args
else:
allow_args = [
p.name
for p in old_sig.parameters.values()
if p.kind in (p.POSITIONAL_ONLY, p.POSITIONAL_OR_KEYWORD)
and p.default is p.empty
]
new_params = [
p.replace(kind=p.KEYWORD_ONLY)
if (
p.kind in (p.POSITIONAL_ONLY, p.POSITIONAL_OR_KEYWORD)
and p.name not in allow_args
)
else p
for p in old_sig.parameters.values()
]
new_params.sort(key=lambda p: p.kind)
new_sig = old_sig.replace(parameters=new_params)
num_allow_args = len(allow_args)
msg = (
f"{future_version_msg(version)} all arguments of "
f"{name or func.__qualname__}{{arguments}} will be keyword-only."
)
@wraps(func)
def wrapper(*args, **kwargs):
if len(args) > num_allow_args:
warnings.warn(
msg.format(arguments=_format_argument_list(allow_args)),
FutureWarning,
stacklevel=find_stack_level(),
)
return func(*args, **kwargs)
# error: "Callable[[VarArg(Any), KwArg(Any)], Any]" has no
# attribute "__signature__"
wrapper.__signature__ = new_sig # type: ignore[attr-defined]
return wrapper
return decorate | Decorator to deprecate a use of non-keyword arguments of a function. Parameters ---------- version : str, optional The version in which positional arguments will become keyword-only. If None, then the warning message won't specify any particular version. allowed_args : list, optional In case of list, it must be the list of names of some first arguments of the decorated functions that are OK to be given as positional arguments. In case of None value, defaults to list of all arguments not having the default value. name : str, optional The specific name of the function to show in the warning message. If None, then the Qualified name of the function is used. |
173,568 | from __future__ import annotations
from functools import wraps
import inspect
from textwrap import dedent
from typing import (
Any,
Callable,
Mapping,
cast,
)
import warnings
from pandas._libs.properties import cache_readonly
from pandas._typing import (
F,
T,
)
from pandas.util._exceptions import find_stack_level
def dedent(text: str) -> str: ...
class Callable(BaseTypingInstance):
def py__call__(self, arguments):
"""
def x() -> Callable[[Callable[..., _T]], _T]: ...
"""
# The 0th index are the arguments.
try:
param_values = self._generics_manager[0]
result_values = self._generics_manager[1]
except IndexError:
debug.warning('Callable[...] defined without two arguments')
return NO_VALUES
else:
from jedi.inference.gradual.annotation import infer_return_for_callable
return infer_return_for_callable(arguments, param_values, result_values)
def py__get__(self, instance, class_value):
return ValueSet([self])
F = TypeVar("F", bound=FuncType)
The provided code snippet includes necessary dependencies for implementing the `doc` function. Write a Python function `def doc(*docstrings: None | str | Callable, **params) -> Callable[[F], F]` to solve the following problem:
A decorator take docstring templates, concatenate them and perform string substitution on it. This decorator will add a variable "_docstring_components" to the wrapped callable to keep track the original docstring template for potential usage. If it should be consider as a template, it will be saved as a string. Otherwise, it will be saved as callable, and later user __doc__ and dedent to get docstring. Parameters ---------- *docstrings : None, str, or callable The string / docstring / docstring template to be appended in order after default docstring under callable. **params The string which would be used to format docstring template.
Here is the function:
def doc(*docstrings: None | str | Callable, **params) -> Callable[[F], F]:
"""
A decorator take docstring templates, concatenate them and perform string
substitution on it.
This decorator will add a variable "_docstring_components" to the wrapped
callable to keep track the original docstring template for potential usage.
If it should be consider as a template, it will be saved as a string.
Otherwise, it will be saved as callable, and later user __doc__ and dedent
to get docstring.
Parameters
----------
*docstrings : None, str, or callable
The string / docstring / docstring template to be appended in order
after default docstring under callable.
**params
The string which would be used to format docstring template.
"""
def decorator(decorated: F) -> F:
# collecting docstring and docstring templates
docstring_components: list[str | Callable] = []
if decorated.__doc__:
docstring_components.append(dedent(decorated.__doc__))
for docstring in docstrings:
if docstring is None:
continue
if hasattr(docstring, "_docstring_components"):
docstring_components.extend(
docstring._docstring_components # pyright: ignore[reportGeneralTypeIssues] # noqa: E501
)
elif isinstance(docstring, str) or docstring.__doc__:
docstring_components.append(docstring)
params_applied = [
component.format(**params)
if isinstance(component, str) and len(params) > 0
else component
for component in docstring_components
]
decorated.__doc__ = "".join(
[
component
if isinstance(component, str)
else dedent(component.__doc__ or "")
for component in params_applied
]
)
# error: "F" has no attribute "_docstring_components"
decorated._docstring_components = ( # type: ignore[attr-defined]
docstring_components
)
return decorated
return decorator | A decorator take docstring templates, concatenate them and perform string substitution on it. This decorator will add a variable "_docstring_components" to the wrapped callable to keep track the original docstring template for potential usage. If it should be consider as a template, it will be saved as a string. Otherwise, it will be saved as callable, and later user __doc__ and dedent to get docstring. Parameters ---------- *docstrings : None, str, or callable The string / docstring / docstring template to be appended in order after default docstring under callable. **params The string which would be used to format docstring template. |
173,569 | from __future__ import annotations
from functools import wraps
import inspect
from textwrap import dedent
from typing import (
Any,
Callable,
Mapping,
cast,
)
import warnings
from pandas._libs.properties import cache_readonly
from pandas._typing import (
F,
T,
)
from pandas.util._exceptions import find_stack_level
def indent(text: str | None, indents: int = 1) -> str:
if not text or not isinstance(text, str):
return ""
jointext = "".join(["\n"] + [" "] * indents)
return jointext.join(text.split("\n")) | null |
173,570 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
def _check_arg_length(fname, args, max_fname_arg_count, compat_args):
"""
Checks whether 'args' has length of at most 'compat_args'. Raises
a TypeError if that is not the case, similar to in Python when a
function is called with too many arguments.
"""
if max_fname_arg_count < 0:
raise ValueError("'max_fname_arg_count' must be non-negative")
if len(args) > len(compat_args):
max_arg_count = len(compat_args) + max_fname_arg_count
actual_arg_count = len(args) + max_fname_arg_count
argument = "argument" if max_arg_count == 1 else "arguments"
raise TypeError(
f"{fname}() takes at most {max_arg_count} {argument} "
f"({actual_arg_count} given)"
)
def _check_for_default_values(fname, arg_val_dict, compat_args):
"""
Check that the keys in `arg_val_dict` are mapped to their
default values as specified in `compat_args`.
Note that this function is to be called only when it has been
checked that arg_val_dict.keys() is a subset of compat_args
"""
for key in arg_val_dict:
# try checking equality directly with '=' operator,
# as comparison may have been overridden for the left
# hand object
try:
v1 = arg_val_dict[key]
v2 = compat_args[key]
# check for None-ness otherwise we could end up
# comparing a numpy array vs None
if (v1 is not None and v2 is None) or (v1 is None and v2 is not None):
match = False
else:
match = v1 == v2
if not is_bool(match):
raise ValueError("'match' is not a boolean")
# could not compare them directly, so try comparison
# using the 'is' operator
except ValueError:
match = arg_val_dict[key] is compat_args[key]
if not match:
raise ValueError(
f"the '{key}' parameter is not supported in "
f"the pandas implementation of {fname}()"
)
The provided code snippet includes necessary dependencies for implementing the `validate_args` function. Write a Python function `def validate_args(fname, args, max_fname_arg_count, compat_args) -> None` to solve the following problem:
Checks whether the length of the `*args` argument passed into a function has at most `len(compat_args)` arguments and whether or not all of these elements in `args` are set to their default values. Parameters ---------- fname : str The name of the function being passed the `*args` parameter args : tuple The `*args` parameter passed into a function max_fname_arg_count : int The maximum number of arguments that the function `fname` can accept, excluding those in `args`. Used for displaying appropriate error messages. Must be non-negative. compat_args : dict A dictionary of keys and their associated default values. In order to accommodate buggy behaviour in some versions of `numpy`, where a signature displayed keyword arguments but then passed those arguments **positionally** internally when calling downstream implementations, a dict ensures that the original order of the keyword arguments is enforced. Raises ------ TypeError If `args` contains more values than there are `compat_args` ValueError If `args` contains values that do not correspond to those of the default values specified in `compat_args`
Here is the function:
def validate_args(fname, args, max_fname_arg_count, compat_args) -> None:
"""
Checks whether the length of the `*args` argument passed into a function
has at most `len(compat_args)` arguments and whether or not all of these
elements in `args` are set to their default values.
Parameters
----------
fname : str
The name of the function being passed the `*args` parameter
args : tuple
The `*args` parameter passed into a function
max_fname_arg_count : int
The maximum number of arguments that the function `fname`
can accept, excluding those in `args`. Used for displaying
appropriate error messages. Must be non-negative.
compat_args : dict
A dictionary of keys and their associated default values.
In order to accommodate buggy behaviour in some versions of `numpy`,
where a signature displayed keyword arguments but then passed those
arguments **positionally** internally when calling downstream
implementations, a dict ensures that the original
order of the keyword arguments is enforced.
Raises
------
TypeError
If `args` contains more values than there are `compat_args`
ValueError
If `args` contains values that do not correspond to those
of the default values specified in `compat_args`
"""
_check_arg_length(fname, args, max_fname_arg_count, compat_args)
# We do this so that we can provide a more informative
# error message about the parameters that we are not
# supporting in the pandas implementation of 'fname'
kwargs = dict(zip(compat_args, args))
_check_for_default_values(fname, kwargs, compat_args) | Checks whether the length of the `*args` argument passed into a function has at most `len(compat_args)` arguments and whether or not all of these elements in `args` are set to their default values. Parameters ---------- fname : str The name of the function being passed the `*args` parameter args : tuple The `*args` parameter passed into a function max_fname_arg_count : int The maximum number of arguments that the function `fname` can accept, excluding those in `args`. Used for displaying appropriate error messages. Must be non-negative. compat_args : dict A dictionary of keys and their associated default values. In order to accommodate buggy behaviour in some versions of `numpy`, where a signature displayed keyword arguments but then passed those arguments **positionally** internally when calling downstream implementations, a dict ensures that the original order of the keyword arguments is enforced. Raises ------ TypeError If `args` contains more values than there are `compat_args` ValueError If `args` contains values that do not correspond to those of the default values specified in `compat_args` |
173,571 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
def _check_arg_length(fname, args, max_fname_arg_count, compat_args):
"""
Checks whether 'args' has length of at most 'compat_args'. Raises
a TypeError if that is not the case, similar to in Python when a
function is called with too many arguments.
"""
if max_fname_arg_count < 0:
raise ValueError("'max_fname_arg_count' must be non-negative")
if len(args) > len(compat_args):
max_arg_count = len(compat_args) + max_fname_arg_count
actual_arg_count = len(args) + max_fname_arg_count
argument = "argument" if max_arg_count == 1 else "arguments"
raise TypeError(
f"{fname}() takes at most {max_arg_count} {argument} "
f"({actual_arg_count} given)"
)
def validate_kwargs(fname, kwargs, compat_args) -> None:
"""
Checks whether parameters passed to the **kwargs argument in a
function `fname` are valid parameters as specified in `*compat_args`
and whether or not they are set to their default values.
Parameters
----------
fname : str
The name of the function being passed the `**kwargs` parameter
kwargs : dict
The `**kwargs` parameter passed into `fname`
compat_args: dict
A dictionary of keys that `kwargs` is allowed to have and their
associated default values
Raises
------
TypeError if `kwargs` contains keys not in `compat_args`
ValueError if `kwargs` contains keys in `compat_args` that do not
map to the default values specified in `compat_args`
"""
kwds = kwargs.copy()
_check_for_invalid_keys(fname, kwargs, compat_args)
_check_for_default_values(fname, kwds, compat_args)
The provided code snippet includes necessary dependencies for implementing the `validate_args_and_kwargs` function. Write a Python function `def validate_args_and_kwargs( fname, args, kwargs, max_fname_arg_count, compat_args ) -> None` to solve the following problem:
Checks whether parameters passed to the *args and **kwargs argument in a function `fname` are valid parameters as specified in `*compat_args` and whether or not they are set to their default values. Parameters ---------- fname: str The name of the function being passed the `**kwargs` parameter args: tuple The `*args` parameter passed into a function kwargs: dict The `**kwargs` parameter passed into `fname` max_fname_arg_count: int The minimum number of arguments that the function `fname` requires, excluding those in `args`. Used for displaying appropriate error messages. Must be non-negative. compat_args: dict A dictionary of keys that `kwargs` is allowed to have and their associated default values. Raises ------ TypeError if `args` contains more values than there are `compat_args` OR `kwargs` contains keys not in `compat_args` ValueError if `args` contains values not at the default value (`None`) `kwargs` contains keys in `compat_args` that do not map to the default value as specified in `compat_args` See Also -------- validate_args : Purely args validation. validate_kwargs : Purely kwargs validation.
Here is the function:
def validate_args_and_kwargs(
fname, args, kwargs, max_fname_arg_count, compat_args
) -> None:
"""
Checks whether parameters passed to the *args and **kwargs argument in a
function `fname` are valid parameters as specified in `*compat_args`
and whether or not they are set to their default values.
Parameters
----------
fname: str
The name of the function being passed the `**kwargs` parameter
args: tuple
The `*args` parameter passed into a function
kwargs: dict
The `**kwargs` parameter passed into `fname`
max_fname_arg_count: int
The minimum number of arguments that the function `fname`
requires, excluding those in `args`. Used for displaying
appropriate error messages. Must be non-negative.
compat_args: dict
A dictionary of keys that `kwargs` is allowed to
have and their associated default values.
Raises
------
TypeError if `args` contains more values than there are
`compat_args` OR `kwargs` contains keys not in `compat_args`
ValueError if `args` contains values not at the default value (`None`)
`kwargs` contains keys in `compat_args` that do not map to the default
value as specified in `compat_args`
See Also
--------
validate_args : Purely args validation.
validate_kwargs : Purely kwargs validation.
"""
# Check that the total number of arguments passed in (i.e.
# args and kwargs) does not exceed the length of compat_args
_check_arg_length(
fname, args + tuple(kwargs.values()), max_fname_arg_count, compat_args
)
# Check there is no overlap with the positional and keyword
# arguments, similar to what is done in actual Python functions
args_dict = dict(zip(compat_args, args))
for key in args_dict:
if key in kwargs:
raise TypeError(
f"{fname}() got multiple values for keyword argument '{key}'"
)
kwargs.update(args_dict)
validate_kwargs(fname, kwargs, compat_args) | Checks whether parameters passed to the *args and **kwargs argument in a function `fname` are valid parameters as specified in `*compat_args` and whether or not they are set to their default values. Parameters ---------- fname: str The name of the function being passed the `**kwargs` parameter args: tuple The `*args` parameter passed into a function kwargs: dict The `**kwargs` parameter passed into `fname` max_fname_arg_count: int The minimum number of arguments that the function `fname` requires, excluding those in `args`. Used for displaying appropriate error messages. Must be non-negative. compat_args: dict A dictionary of keys that `kwargs` is allowed to have and their associated default values. Raises ------ TypeError if `args` contains more values than there are `compat_args` OR `kwargs` contains keys not in `compat_args` ValueError if `args` contains values not at the default value (`None`) `kwargs` contains keys in `compat_args` that do not map to the default value as specified in `compat_args` See Also -------- validate_args : Purely args validation. validate_kwargs : Purely kwargs validation. |
173,572 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
def clean_fill_method(method: str | None, allow_nearest: bool = False):
# asfreq is compat for resampling
if method in [None, "asfreq"]:
return None
if isinstance(method, str):
method = method.lower()
if method == "ffill":
method = "pad"
elif method == "bfill":
method = "backfill"
valid_methods = ["pad", "backfill"]
expecting = "pad (ffill) or backfill (bfill)"
if allow_nearest:
valid_methods.append("nearest")
expecting = "pad (ffill), backfill (bfill) or nearest"
if method not in valid_methods:
raise ValueError(f"Invalid fill method. Expecting {expecting}. Got {method}")
return method
The provided code snippet includes necessary dependencies for implementing the `validate_fillna_kwargs` function. Write a Python function `def validate_fillna_kwargs(value, method, validate_scalar_dict_value: bool = True)` to solve the following problem:
Validate the keyword arguments to 'fillna'. This checks that exactly one of 'value' and 'method' is specified. If 'method' is specified, this validates that it's a valid method. Parameters ---------- value, method : object The 'value' and 'method' keyword arguments for 'fillna'. validate_scalar_dict_value : bool, default True Whether to validate that 'value' is a scalar or dict. Specifically, validate that it is not a list or tuple. Returns ------- value, method : object
Here is the function:
def validate_fillna_kwargs(value, method, validate_scalar_dict_value: bool = True):
"""
Validate the keyword arguments to 'fillna'.
This checks that exactly one of 'value' and 'method' is specified.
If 'method' is specified, this validates that it's a valid method.
Parameters
----------
value, method : object
The 'value' and 'method' keyword arguments for 'fillna'.
validate_scalar_dict_value : bool, default True
Whether to validate that 'value' is a scalar or dict. Specifically,
validate that it is not a list or tuple.
Returns
-------
value, method : object
"""
from pandas.core.missing import clean_fill_method
if value is None and method is None:
raise ValueError("Must specify a fill 'value' or 'method'.")
if value is None and method is not None:
method = clean_fill_method(method)
elif value is not None and method is None:
if validate_scalar_dict_value and isinstance(value, (list, tuple)):
raise TypeError(
'"value" parameter must be a scalar or dict, but '
f'you passed a "{type(value).__name__}"'
)
elif value is not None and method is not None:
raise ValueError("Cannot specify both 'value' and 'method'.")
return value, method | Validate the keyword arguments to 'fillna'. This checks that exactly one of 'value' and 'method' is specified. If 'method' is specified, this validates that it's a valid method. Parameters ---------- value, method : object The 'value' and 'method' keyword arguments for 'fillna'. validate_scalar_dict_value : bool, default True Whether to validate that 'value' is a scalar or dict. Specifically, validate that it is not a list or tuple. Returns ------- value, method : object |
173,573 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
BoolishT = TypeVar("BoolishT", bool, int)
def validate_ascending(ascending: BoolishT) -> BoolishT:
... | null |
173,574 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
BoolishT = TypeVar("BoolishT", bool, int)
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co:
def __getitem__(self, s: slice) -> Sequence[_T_co]:
def index(self, value: Any, start: int = ..., stop: int = ...) -> int:
def count(self, value: Any) -> int:
def __contains__(self, x: object) -> bool:
def __iter__(self) -> Iterator[_T_co]:
def __reversed__(self) -> Iterator[_T_co]:
def validate_ascending(ascending: Sequence[BoolishT]) -> list[BoolishT]:
... | null |
173,575 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
BoolishT = TypeVar("BoolishT", bool, int)
def validate_bool_kwarg(
value: BoolishNoneT, arg_name, none_allowed: bool = True, int_allowed: bool = False
) -> BoolishNoneT:
"""
Ensure that argument passed in arg_name can be interpreted as boolean.
Parameters
----------
value : bool
Value to be validated.
arg_name : str
Name of the argument. To be reflected in the error message.
none_allowed : bool, default True
Whether to consider None to be a valid boolean.
int_allowed : bool, default False
Whether to consider integer value to be a valid boolean.
Returns
-------
value
The same value as input.
Raises
------
ValueError
If the value is not a valid boolean.
"""
good_value = is_bool(value)
if none_allowed:
good_value = good_value or value is None
if int_allowed:
good_value = good_value or isinstance(value, int)
if not good_value:
raise ValueError(
f'For argument "{arg_name}" expected type bool, received '
f"type {type(value).__name__}."
)
return value
class Sequence(_Collection[_T_co], Reversible[_T_co], Generic[_T_co]):
def __getitem__(self, i: int) -> _T_co: ...
def __getitem__(self, s: slice) -> Sequence[_T_co]: ...
# Mixin methods
def index(self, value: Any, start: int = ..., stop: int = ...) -> int: ...
def count(self, value: Any) -> int: ...
def __contains__(self, x: object) -> bool: ...
def __iter__(self) -> Iterator[_T_co]: ...
def __reversed__(self) -> Iterator[_T_co]: ...
The provided code snippet includes necessary dependencies for implementing the `validate_ascending` function. Write a Python function `def validate_ascending( ascending: bool | int | Sequence[BoolishT], ) -> bool | int | list[BoolishT]` to solve the following problem:
Validate ``ascending`` kwargs for ``sort_index`` method.
Here is the function:
def validate_ascending(
ascending: bool | int | Sequence[BoolishT],
) -> bool | int | list[BoolishT]:
"""Validate ``ascending`` kwargs for ``sort_index`` method."""
kwargs = {"none_allowed": False, "int_allowed": True}
if not isinstance(ascending, Sequence):
return validate_bool_kwarg(ascending, "ascending", **kwargs)
return [validate_bool_kwarg(item, "ascending", **kwargs) for item in ascending] | Validate ``ascending`` kwargs for ``sort_index`` method. |
173,576 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
The provided code snippet includes necessary dependencies for implementing the `validate_endpoints` function. Write a Python function `def validate_endpoints(closed: str | None) -> tuple[bool, bool]` to solve the following problem:
Check that the `closed` argument is among [None, "left", "right"] Parameters ---------- closed : {None, "left", "right"} Returns ------- left_closed : bool right_closed : bool Raises ------ ValueError : if argument is not among valid values
Here is the function:
def validate_endpoints(closed: str | None) -> tuple[bool, bool]:
"""
Check that the `closed` argument is among [None, "left", "right"]
Parameters
----------
closed : {None, "left", "right"}
Returns
-------
left_closed : bool
right_closed : bool
Raises
------
ValueError : if argument is not among valid values
"""
left_closed = False
right_closed = False
if closed is None:
left_closed = True
right_closed = True
elif closed == "left":
left_closed = True
elif closed == "right":
right_closed = True
else:
raise ValueError("Closed has to be either 'left', 'right' or None")
return left_closed, right_closed | Check that the `closed` argument is among [None, "left", "right"] Parameters ---------- closed : {None, "left", "right"} Returns ------- left_closed : bool right_closed : bool Raises ------ ValueError : if argument is not among valid values |
173,577 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
The provided code snippet includes necessary dependencies for implementing the `validate_inclusive` function. Write a Python function `def validate_inclusive(inclusive: str | None) -> tuple[bool, bool]` to solve the following problem:
Check that the `inclusive` argument is among {"both", "neither", "left", "right"}. Parameters ---------- inclusive : {"both", "neither", "left", "right"} Returns ------- left_right_inclusive : tuple[bool, bool] Raises ------ ValueError : if argument is not among valid values
Here is the function:
def validate_inclusive(inclusive: str | None) -> tuple[bool, bool]:
"""
Check that the `inclusive` argument is among {"both", "neither", "left", "right"}.
Parameters
----------
inclusive : {"both", "neither", "left", "right"}
Returns
-------
left_right_inclusive : tuple[bool, bool]
Raises
------
ValueError : if argument is not among valid values
"""
left_right_inclusive: tuple[bool, bool] | None = None
if isinstance(inclusive, str):
left_right_inclusive = {
"both": (True, True),
"left": (True, False),
"right": (False, True),
"neither": (False, False),
}.get(inclusive)
if left_right_inclusive is None:
raise ValueError(
"Inclusive has to be either 'both', 'neither', 'left' or 'right'"
)
return left_right_inclusive | Check that the `inclusive` argument is among {"both", "neither", "left", "right"}. Parameters ---------- inclusive : {"both", "neither", "left", "right"} Returns ------- left_right_inclusive : tuple[bool, bool] Raises ------ ValueError : if argument is not among valid values |
173,578 | from __future__ import annotations
from typing import (
Iterable,
Sequence,
TypeVar,
overload,
)
import numpy as np
from pandas._libs import lib
from pandas.core.dtypes.common import (
is_bool,
is_integer,
)
The provided code snippet includes necessary dependencies for implementing the `validate_insert_loc` function. Write a Python function `def validate_insert_loc(loc: int, length: int) -> int` to solve the following problem:
Check that we have an integer between -length and length, inclusive. Standardize negative loc to within [0, length]. The exceptions we raise on failure match np.insert.
Here is the function:
def validate_insert_loc(loc: int, length: int) -> int:
"""
Check that we have an integer between -length and length, inclusive.
Standardize negative loc to within [0, length].
The exceptions we raise on failure match np.insert.
"""
if not is_integer(loc):
raise TypeError(f"loc must be an integer between -{length} and {length}")
if loc < 0:
loc += length
if not 0 <= loc <= length:
raise IndexError(f"loc must be an integer between -{length} and {length}")
return loc | Check that we have an integer between -length and length, inclusive. Standardize negative loc to within [0, length]. The exceptions we raise on failure match np.insert. |
173,579 | from __future__ import annotations
import contextlib
import inspect
import os
import re
from typing import Generator
import warnings
class Generator(Iterator[_T_co], Generic[_T_co, _T_contra, _V_co]):
def __next__(self) -> _T_co: ...
def send(self, __value: _T_contra) -> _T_co: ...
def throw(
self, __typ: Type[BaseException], __val: Union[BaseException, object] = ..., __tb: Optional[TracebackType] = ...
) -> _T_co: ...
def throw(self, __typ: BaseException, __val: None = ..., __tb: Optional[TracebackType] = ...) -> _T_co: ...
def close(self) -> None: ...
def __iter__(self) -> Generator[_T_co, _T_contra, _V_co]: ...
def gi_code(self) -> CodeType: ...
def gi_frame(self) -> FrameType: ...
def gi_running(self) -> bool: ...
def gi_yieldfrom(self) -> Optional[Generator[Any, Any, Any]]: ...
The provided code snippet includes necessary dependencies for implementing the `rewrite_exception` function. Write a Python function `def rewrite_exception(old_name: str, new_name: str) -> Generator[None, None, None]` to solve the following problem:
Rewrite the message of an exception.
Here is the function:
def rewrite_exception(old_name: str, new_name: str) -> Generator[None, None, None]:
"""
Rewrite the message of an exception.
"""
try:
yield
except Exception as err:
if not err.args:
raise
msg = str(err.args[0])
msg = msg.replace(old_name, new_name)
args: tuple[str, ...] = (msg,)
if len(err.args) > 1:
args = args + err.args[1:]
err.args = args
raise | Rewrite the message of an exception. |
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