response
stringlengths
1
33.1k
instruction
stringlengths
22
582k
Make a fixture attribute an alias of another fixture's attribute by default. Parameters ---------- attr_name : str The name of the attribute to alias. Returns ------- p : classproperty A class property that does the property aliasing. Examples -------- >>> class C(object): ... attr = 1 ... >>> class D(C)...
def alias(attr_name): """Make a fixture attribute an alias of another fixture's attribute by default. Parameters ---------- attr_name : str The name of the attribute to alias. Returns ------- p : classproperty A class property that does the property aliasing. Examp...
Equivalent to dts.get_loc(dt, method='ffill'), but with reasonable microperformance.
def fast_get_loc_ffilled(dts, dt): """ Equivalent to dts.get_loc(dt, method='ffill'), but with reasonable microperformance. """ ix = dts.searchsorted(dt, side='right') - 1 if ix < 0: raise KeyError(dt) return ix
Get the argument names of a function >>> def f(x, y=2): ... pass >>> keywords(f) ['x', 'y'] Notes ----- Taken from odo.utils
def keywords(func): """Get the argument names of a function >>> def f(x, y=2): ... pass >>> keywords(f) ['x', 'y'] Notes ----- Taken from odo.utils """ if isinstance(func, type): return keywords(func.__init__) elif isinstance(func, partial): return keyw...
Return a dict of valid kwargs for `f` from a subset of `kwargs` Examples -------- >>> def f(a, b=1, c=2): ... return a + b + c ... >>> raw_kwargs = dict(a=1, b=3, d=4) >>> f(**raw_kwargs) Traceback (most recent call last): ... TypeError: f() got an unexpected keyword argument 'd' >>> kwargs = filter_kwargs(f, ...
def filter_kwargs(f, kwargs): """Return a dict of valid kwargs for `f` from a subset of `kwargs` Examples -------- >>> def f(a, b=1, c=2): ... return a + b + c ... >>> raw_kwargs = dict(a=1, b=3, d=4) >>> f(**raw_kwargs) Traceback (most recent call last): ... TypeErr...
Format the path for final display. Parameters ---------- path : iterable of str The path to the values that are not equal. Returns ------- fmtd : str The formatted path to put into the error message.
def _fmt_path(path): """Format the path for final display. Parameters ---------- path : iterable of str The path to the values that are not equal. Returns ------- fmtd : str The formatted path to put into the error message. """ if not path: return '' ret...
Format the message for final display. Parameters ---------- msg : str The message to show to the user to provide additional context. returns ------- fmtd : str The formatted message to put into the error message.
def _fmt_msg(msg): """Format the message for final display. Parameters ---------- msg : str The message to show to the user to provide additional context. returns ------- fmtd : str The formatted message to put into the error message. """ if not msg: return ...
Assert that ``subcls`` is a subclass of ``cls``. Parameters ---------- subcls : type The type to check. cls : type The type to check ``subcls`` against. msg : str, optional An extra assertion message to print if this fails.
def assert_is_subclass(subcls, cls, msg=''): """Assert that ``subcls`` is a subclass of ``cls``. Parameters ---------- subcls : type The type to check. cls : type The type to check ``subcls`` against. msg : str, optional An extra assertion message to print if this fails....
Assert that ``not_subcls`` is not a subclass of ``cls``. Parameters ---------- not_subcls : type The type to check. cls : type The type to check ``not_subcls`` against. msg : str, optional An extra assertion message to print if this fails.
def assert_is_not_subclass(not_subcls, cls, msg=''): """Assert that ``not_subcls`` is not a subclass of ``cls``. Parameters ---------- not_subcls : type The type to check. cls : type The type to check ``not_subcls`` against. msg : str, optional An extra assertion message...
Assert that ``expected`` matches the result. Parameters ---------- result : str The string to search. expected : str or compiled regex The pattern to search for in ``result``. msg : str, optional An extra assertion message to print if this fails.
def assert_regex(result, expected, msg=''): """Assert that ``expected`` matches the result. Parameters ---------- result : str The string to search. expected : str or compiled regex The pattern to search for in ``result``. msg : str, optional An extra assertion message t...
Assert that some exception is raised in a context and that the message matches some pattern. Parameters ---------- exc : type or tuple[type] The exception type or types to expect. pattern : str or compiled regex The pattern to search for in the str of the raised exception. msg : str, optional An extra asse...
def assert_raises_regex(exc, pattern, msg=''): """Assert that some exception is raised in a context and that the message matches some pattern. Parameters ---------- exc : type or tuple[type] The exception type or types to expect. pattern : str or compiled regex The pattern to se...
Assert that some exception is raised in a context and that the message exactly matches some string. Parameters ---------- exc : type or tuple[type] The exception type or types to expect. expected_str : str The expected result of ``str(exception)``. msg : str, optional An extra assertion message to print if...
def assert_raises_str(exc, expected_str, msg=''): """Assert that some exception is raised in a context and that the message exactly matches some string. Parameters ---------- exc : type or tuple[type] The exception type or types to expect. expected_str : str The expected result ...
Create an assertion error formatted for use in ``assert_equal``. Parameters ---------- assertion_message : str The concrete reason for the failure. path : tuple[str] The path leading up to the failure. msg : str The user supplied message. Returns ------- exception_instance : AssertionError The new exc...
def make_assert_equal_assertion_error(assertion_message, path, msg): """Create an assertion error formatted for use in ``assert_equal``. Parameters ---------- assertion_message : str The concrete reason for the failure. path : tuple[str] The path leading up to the failure. msg :...
Assert that two objects are equal using the ``==`` operator. Parameters ---------- result : object The result that came from the function under test. expected : object The expected result. Raises ------ AssertionError Raised when ``result`` is not equal to ``expected``.
def assert_equal(result, expected, path=(), msg='', **kwargs): """Assert that two objects are equal using the ``==`` operator. Parameters ---------- result : object The result that came from the function under test. expected : object The expected result. Raises ------ A...
Compare two sets. This is used to check dictionary keys and sets. Parameters ---------- result : set expected : set msg : str path : tuple type : str The type of an element. For dict we use ``'key'`` and for set we use ``'element'``.
def _check_sets(result, expected, msg, path, type_): """Compare two sets. This is used to check dictionary keys and sets. Parameters ---------- result : set expected : set msg : str path : tuple type : str The type of an element. For dict we use ``'key'`` and for set we use ...
Register a new check for an ndframe object. Parameters ---------- type_ : type The class to register an ``assert_equal`` dispatch for. assert_eq : callable[type_, type_] The function which checks that if the two ndframes are equal. Returns ------- assert_ndframe_equal : callable[type_, type_] The wrapped ...
def _register_assert_equal_wrapper(type_, assert_eq): """Register a new check for an ndframe object. Parameters ---------- type_ : type The class to register an ``assert_equal`` dispatch for. assert_eq : callable[type_, type_] The function which checks that if the two ndframes are e...
Branch for comparing python datetime (which includes pandas Timestamp) and np.datetime64 as equal. Returns raises unless ``allow_datetime_coercions`` is passed as True.
def assert_timestamp_and_datetime_equal(result, expected, path=(), msg='', allow_datetime_coercions=False, compare_nat_e...
Assertion helper for comparing very long strings (e.g. error messages).
def assert_messages_equal(result, expected, msg=''): """Assertion helper for comparing very long strings (e.g. error messages). """ # The arg here is "keepends" which keeps trailing newlines (which # matters for checking trailing whitespace). You can't pass keepends by # name :(. left_lines = re...
Get the index of the first difference between two strings.
def index_of_first_difference(left, right): """Get the index of the first difference between two strings.""" difflocs = (i for (i, (lc, rc)) in enumerate(zip_longest(left, right)) if lc != rc) try: return next(difflocs) except StopIteration: raise ValueError("Left was equ...
Decorator for API methods that should only be called during or before TradingAlgorithm.initialize. `exception` will be raised if the method is called after initialize. Examples -------- @require_not_initialized(SomeException("Don't do that!")) def method(self): # Do stuff that should only be allowed during initia...
def require_not_initialized(exception): """ Decorator for API methods that should only be called during or before TradingAlgorithm.initialize. `exception` will be raised if the method is called after initialize. Examples -------- @require_not_initialized(SomeException("Don't do that!")) ...
Decorator for API methods that should only be called after TradingAlgorithm.initialize. `exception` will be raised if the method is called before initialize has completed. Examples -------- @require_initialized(SomeException("Don't do that!")) def method(self): # Do stuff that should only be allowed after initial...
def require_initialized(exception): """ Decorator for API methods that should only be called after TradingAlgorithm.initialize. `exception` will be raised if the method is called before initialize has completed. Examples -------- @require_initialized(SomeException("Don't do that!")) de...
Decorator for API methods that cannot be called from within TradingAlgorithm.before_trading_start. `exception` will be raised if the method is called inside `before_trading_start`. Examples -------- @disallowed_in_before_trading_start(SomeException("Don't do that!")) def method(self): # Do stuff that is not allow...
def disallowed_in_before_trading_start(exception): """ Decorator for API methods that cannot be called from within TradingAlgorithm.before_trading_start. `exception` will be raised if the method is called inside `before_trading_start`. Examples -------- @disallowed_in_before_trading_start(...
Checks for the presence of an extra to the argument list. Raises expections if this is unexpected or if it is missing and expected.
def _expect_extra(expected, present, exc_unexpected, exc_missing, exc_args): """ Checks for the presence of an extra to the argument list. Raises expections if this is unexpected or if it is missing and expected. """ if present: if not expected: raise exc_unexpected(*exc_args)...
Checks the callable_ to make sure that it satisfies the given expectations. expected_args should be an iterable of Arguments in the order you expect to receive them. expect_starargs means that the function should or should not take a *args param. expect_kwargs says the callable should or should not take **kwargs param...
def verify_callable_argspec(callable_, expected_args=Argument.ignore, expect_starargs=Argument.ignore, expect_kwargs=Argument.ignore): """ Checks the callable_ to make sure that it satisfies the given expectations. expec...
Optionally show a progress bar for the given iterator. Parameters ---------- it : iterable The underlying iterator. show_progress : bool Should progress be shown. **kwargs Forwarded to the click progress bar. Returns ------- itercontext : context manager A context manager whose enter is the actual ite...
def maybe_show_progress(it, show_progress, **kwargs): """Optionally show a progress bar for the given iterator. Parameters ---------- it : iterable The underlying iterator. show_progress : bool Should progress be shown. **kwargs Forwarded to the click progress bar. ...
Compute the start and end dates to run a pipeline for. Parameters ---------- sessions : DatetimeIndex The available dates. start_date : pd.Timestamp The first date in the pipeline. end_date : pd.Timestamp The last date in the pipeline. chunksize : int or None The size of the chunks to run. Setting this...
def compute_date_range_chunks(sessions, start_date, end_date, chunksize): """Compute the start and end dates to run a pipeline for. Parameters ---------- sessions : DatetimeIndex The available dates. start_date : pd.Timestamp The first date in the pipeline. end_date : pd.Timesta...
Used to mark a function as deprecated. Parameters ---------- msg : str The message to display in the deprecation warning. stacklevel : int How far up the stack the warning needs to go, before showing the relevant calling lines. Examples -------- @deprecated(msg='function_a is deprecated! Use function_b in...
def deprecated(msg=None, stacklevel=2): """ Used to mark a function as deprecated. Parameters ---------- msg : str The message to display in the deprecation warning. stacklevel : int How far up the stack the warning needs to go, before showing the relevant calling lines....
Construct a new enum object. Parameters ---------- *options : iterable of str The names of the fields for the enum. Returns ------- enum A new enum collection. Examples -------- >>> e = enum('a', 'b', 'c') >>> e <enum: ('a', 'b', 'c')> >>> e.a 0 >>> e.b 1 >>> e.a in e True >>> tuple(e) (0, 1, 2) Notes -----...
def enum(option, *options): """ Construct a new enum object. Parameters ---------- *options : iterable of str The names of the fields for the enum. Returns ------- enum A new enum collection. Examples -------- >>> e = enum('a', 'b', 'c') >>> e <enum...
Converts a UTC tz-naive timestamp to a tz-aware timestamp.
def naive_to_utc(ts): """ Converts a UTC tz-naive timestamp to a tz-aware timestamp. """ # Drop the nanoseconds field. warn=False suppresses the warning # that we are losing the nanoseconds; however, this is intended. return pd.Timestamp(ts.to_pydatetime(warn=False), tz='UTC')
Normalize a time. If the time is tz-naive, assume it is UTC.
def ensure_utc(time, tz='UTC'): """ Normalize a time. If the time is tz-naive, assume it is UTC. """ if not time.tzinfo: time = time.replace(tzinfo=pytz.timezone(tz)) return time.replace(tzinfo=pytz.utc)
Builds the offset argument for event rules.
def _build_offset(offset, kwargs, default): """ Builds the offset argument for event rules. """ # Filter down to just kwargs that were actually passed. kwargs = {k: v for k, v in six.iteritems(kwargs) if v is not None} if offset is None: if not kwargs: return default # use ...
Builds the date argument for event rules.
def _build_date(date, kwargs): """ Builds the date argument for event rules. """ if date is None: if not kwargs: raise ValueError('Must pass a date or kwargs') else: return datetime.date(**kwargs) elif kwargs: raise ValueError('Cannot pass kwargs a...
Builds the time argument for event rules.
def _build_time(time, kwargs): """ Builds the time argument for event rules. """ tz = kwargs.pop('tz', 'UTC') if time: if kwargs: raise ValueError('Cannot pass kwargs and a time') else: return ensure_utc(time, tz) elif not kwargs: raise ValueErr...
A preprocessor that coerces integral floats to ints. Receipt of non-integral floats raises a TypeError.
def lossless_float_to_int(funcname, func, argname, arg): """ A preprocessor that coerces integral floats to ints. Receipt of non-integral floats raises a TypeError. """ if not isinstance(arg, float): return arg arg_as_int = int(arg) if arg == arg_as_int: warnings.warn( ...
Constructs an event rule from the factory api.
def make_eventrule(date_rule, time_rule, cal, half_days=True): """ Constructs an event rule from the factory api. """ _check_if_not_called(date_rule) _check_if_not_called(time_rule) if half_days: inner_rule = date_rule & time_rule else: inner_rule = date_rule & time_rule & ...
creates trade_count trades for each sid in sids list. first trade will be on sim_params.start_session, and daily thereafter for each sid. Thus, two sids should result in two trades per day.
def create_daily_trade_source(sids, sim_params, asset_finder, trading_calendar): """ creates trade_count trades for each sid in sids list. first trade will be on sim_params.start_session, and daily thereafter for e...
Yield classes in the order that methods should be looked up from the base classes of an object.
def bases_mro(bases): """ Yield classes in the order that methods should be looked up from the base classes of an object. """ for base in bases: for class_ in base.__mro__: yield class_
Checks if `name` is a `final` object in the given `mro`. We need to check the mro because we need to directly go into the __dict__ of the classes. Because `final` objects are descriptor, we need to grab them _BEFORE_ the `__call__` is invoked.
def is_final(name, mro): """ Checks if `name` is a `final` object in the given `mro`. We need to check the mro because we need to directly go into the __dict__ of the classes. Because `final` objects are descriptor, we need to grab them _BEFORE_ the `__call__` is invoked. """ return any(isin...
Adds a suffix to ``word`` if some sequence has anything other than exactly one element. Parameters ---------- word : str The string to add the suffix to. seq : sequence The sequence to check the length of. suffix : str, optional. The suffix to add to ``word`` Returns ------- maybe_plural : str ``word`...
def s(word, seq, suffix='s'): """Adds a suffix to ``word`` if some sequence has anything other than exactly one element. Parameters ---------- word : str The string to add the suffix to. seq : sequence The sequence to check the length of. suffix : str, optional. The ...
Selects a singular or plural word based on the length of a sequence. Parameters ---------- singlular : str The string to use when ``len(seq) == 1``. plural : str The string to use when ``len(seq) != 1``. seq : sequence The sequence to check the length of. Returns ------- maybe_plural : str Either ``si...
def plural(singular, plural, seq): """Selects a singular or plural word based on the length of a sequence. Parameters ---------- singlular : str The string to use when ``len(seq) == 1``. plural : str The string to use when ``len(seq) != 1``. seq : sequence The sequence t...
Format a bulleted list of values. Parameters ---------- items : sequence The items to make a list. indent : int, optional The number of spaces to add before each bullet. bullet_type : str, optional The bullet type to use. Returns ------- formatted_list : str The formatted list as a single string.
def bulleted_list(items, indent=0, bullet_type='-'): """Format a bulleted list of values. Parameters ---------- items : sequence The items to make a list. indent : int, optional The number of spaces to add before each bullet. bullet_type : str, optional The bullet type t...
Apply a function to arguments. Parameters ---------- f : callable The function to call. *args, **kwargs **kwargs Arguments to feed to the callable. Returns ------- a : any The result of ``f(*args, **kwargs)`` Examples -------- >>> from toolz.curried.operator import add, sub >>> fs = add(1), sub(1) >>> tu...
def apply(f, *args, **kwargs): """Apply a function to arguments. Parameters ---------- f : callable The function to call. *args, **kwargs **kwargs Arguments to feed to the callable. Returns ------- a : any The result of ``f(*args, **kwargs)`` Examples ...
Parameters ---------- funcs : iterable[function] Sequence of functions to map over `seq`. seq : iterable Sequence over which to map funcs. Yields ------ elem : object Concatenated result of mapping each ``func`` over ``seq``. Examples -------- >>> list(mapall([lambda x: x + 1, lambda x: x - 1], [1, 2, 3])...
def mapall(funcs, seq): """ Parameters ---------- funcs : iterable[function] Sequence of functions to map over `seq`. seq : iterable Sequence over which to map funcs. Yields ------ elem : object Concatenated result of mapping each ``func`` over ``seq``. Exam...
Check if all values in a sequence are equal. Returns True on empty sequences. Examples -------- >>> same(1, 1, 1, 1) True >>> same(1, 2, 1) False >>> same() True
def same(*values): """ Check if all values in a sequence are equal. Returns True on empty sequences. Examples -------- >>> same(1, 1, 1, 1) True >>> same(1, 2, 1) False >>> same() True """ if not values: return True first, rest = values[0], values[1:] ...
Parameters ---------- *dicts : iterable[dict] A sequence of dicts all sharing the same keys. Returns ------- zipped : dict A dict whose keys are the union of all keys in *dicts, and whose values are tuples of length len(dicts) containing the result of looking up each key in each dict. Raises ------ Va...
def dzip_exact(*dicts): """ Parameters ---------- *dicts : iterable[dict] A sequence of dicts all sharing the same keys. Returns ------- zipped : dict A dict whose keys are the union of all keys in *dicts, and whose values are tuples of length len(dicts) containing t...
Helper for unzip which checks the lengths of each element in it. Parameters ---------- it : iterable[tuple] An iterable of tuples. ``unzip`` should map ensure that these are already tuples. elem_len : int or None The expected element length. If this is None it is infered from the length of the first ele...
def _gen_unzip(it, elem_len): """Helper for unzip which checks the lengths of each element in it. Parameters ---------- it : iterable[tuple] An iterable of tuples. ``unzip`` should map ensure that these are already tuples. elem_len : int or None The expected element length. I...
Unzip a length n sequence of length m sequences into m seperate length n sequences. Parameters ---------- seq : iterable[iterable] The sequence to unzip. elem_len : int, optional The expected length of each element of ``seq``. If not provided this will be infered from the length of the first element of ``se...
def unzip(seq, elem_len=None): """Unzip a length n sequence of length m sequences into m seperate length n sequences. Parameters ---------- seq : iterable[iterable] The sequence to unzip. elem_len : int, optional The expected length of each element of ``seq``. If not provided thi...
Perform a chained application of ``getattr`` on ``value`` with the values in ``attrs``. If ``default`` is supplied, return it if any of the attribute lookups fail. Parameters ---------- value : object Root of the lookup chain. attrs : iterable[str] Sequence of attributes to look up. default : object, optional...
def getattrs(value, attrs, default=_no_default): """ Perform a chained application of ``getattr`` on ``value`` with the values in ``attrs``. If ``default`` is supplied, return it if any of the attribute lookups fail. Parameters ---------- value : object Root of the lookup chain. ...
Decorator factory for setting attributes on a function. Doesn't change the behavior of the wrapped function. Examples -------- >>> @set_attribute('__name__', 'foo') ... def bar(): ... return 3 ... >>> bar() 3 >>> bar.__name__ 'foo'
def set_attribute(name, value): """ Decorator factory for setting attributes on a function. Doesn't change the behavior of the wrapped function. Examples -------- >>> @set_attribute('__name__', 'foo') ... def bar(): ... return 3 ... >>> bar() 3 >>> bar.__name__ ...
Fold a function over a sequence with right associativity. Parameters ---------- f : callable[any, any] The function to reduce the sequence with. The first argument will be the element of the sequence; the second argument will be the accumulator. seq : iterable[any] The sequence to reduce. default : any...
def foldr(f, seq, default=_no_default): """Fold a function over a sequence with right associativity. Parameters ---------- f : callable[any, any] The function to reduce the sequence with. The first argument will be the element of the sequence; the second argument will be the acc...
Invert a dictionary into a dictionary of sets. >>> invert({'a': 1, 'b': 2, 'c': 1}) # doctest: +SKIP {1: {'a', 'c'}, 2: {'b'}}
def invert(d): """ Invert a dictionary into a dictionary of sets. >>> invert({'a': 1, 'b': 2, 'c': 1}) # doctest: +SKIP {1: {'a', 'c'}, 2: {'b'}} """ out = {} for k, v in iteritems(d): try: out[v].add(k) except KeyError: out[v] = {k} return out
Get the items from a dict, sorted by key. Example ------- >>> keysorted({'c': 1, 'b': 2, 'a': 3}) [('a', 3), ('b', 2), ('c', 1)]
def keysorted(d): """Get the items from a dict, sorted by key. Example ------- >>> keysorted({'c': 1, 'b': 2, 'a': 3}) [('a', 3), ('b', 2), ('c', 1)] """ return sorted(iteritems(d), key=itemgetter(0))
Check that all axes of a pandas object are unique. Parameters ---------- obj : pd.Series / pd.DataFrame / pd.Panel The object to validate. Returns ------- obj : pd.Series / pd.DataFrame / pd.Panel The validated object, unchanged. Raises ------ ValueError If any axis has duplicate entries.
def verify_indices_all_unique(obj): """ Check that all axes of a pandas object are unique. Parameters ---------- obj : pd.Series / pd.DataFrame / pd.Panel The object to validate. Returns ------- obj : pd.Series / pd.DataFrame / pd.Panel The validated object, unchanged. ...
Modify a preprocessor to explicitly allow `None`. Parameters ---------- preprocessor : callable[callable, str, any -> any] A preprocessor to delegate to when `arg is not None`. Returns ------- optional_preprocessor : callable[callable, str, any -> any] A preprocessor that delegates to `preprocessor` when `arg...
def optionally(preprocessor): """Modify a preprocessor to explicitly allow `None`. Parameters ---------- preprocessor : callable[callable, str, any -> any] A preprocessor to delegate to when `arg is not None`. Returns ------- optional_preprocessor : callable[callable, str, any -> a...
Argument preprocessor that converts the input into a numpy dtype. Examples -------- >>> import numpy as np >>> from zipline.utils.preprocess import preprocess >>> @preprocess(dtype=ensure_dtype) ... def foo(dtype): ... return dtype ... >>> foo(float) dtype('float64')
def ensure_dtype(func, argname, arg): """ Argument preprocessor that converts the input into a numpy dtype. Examples -------- >>> import numpy as np >>> from zipline.utils.preprocess import preprocess >>> @preprocess(dtype=ensure_dtype) ... def foo(dtype): ... return dtype ....
Argument preprocessor that converts the input into a tzinfo object. Examples -------- >>> from zipline.utils.preprocess import preprocess >>> @preprocess(tz=ensure_timezone) ... def foo(tz): ... return tz >>> foo('utc') <UTC>
def ensure_timezone(func, argname, arg): """Argument preprocessor that converts the input into a tzinfo object. Examples -------- >>> from zipline.utils.preprocess import preprocess >>> @preprocess(tz=ensure_timezone) ... def foo(tz): ... return tz >>> foo('utc') <UTC> """ ...
Argument preprocessor that converts the input into a pandas Timestamp object. Examples -------- >>> from zipline.utils.preprocess import preprocess >>> @preprocess(ts=ensure_timestamp) ... def foo(ts): ... return ts >>> foo('2014-01-01') Timestamp('2014-01-01 00:00:00')
def ensure_timestamp(func, argname, arg): """Argument preprocessor that converts the input into a pandas Timestamp object. Examples -------- >>> from zipline.utils.preprocess import preprocess >>> @preprocess(ts=ensure_timestamp) ... def foo(ts): ... return ts >>> foo('2014-01-0...
Preprocessing decorator that verifies inputs have expected numpy dtypes. Examples -------- >>> from numpy import dtype, arange, int8, float64 >>> @expect_dtypes(x=dtype(int8)) ... def foo(x, y): ... return x, y ... >>> foo(arange(3, dtype=int8), 'foo') (array([0, 1, 2], dtype=int8), 'foo') >>> foo(arange(3, dtype=f...
def expect_dtypes(__funcname=_qualified_name, **named): """ Preprocessing decorator that verifies inputs have expected numpy dtypes. Examples -------- >>> from numpy import dtype, arange, int8, float64 >>> @expect_dtypes(x=dtype(int8)) ... def foo(x, y): ... return x, y ... >...
Preprocessing decorator that verifies inputs have expected dtype kinds. Examples -------- >>> from numpy import int64, int32, float32 >>> @expect_kinds(x='i') ... def foo(x): ... return x ... >>> foo(int64(2)) 2 >>> foo(int32(2)) 2 >>> foo(float32(2)) # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS Traceback (most rece...
def expect_kinds(**named): """ Preprocessing decorator that verifies inputs have expected dtype kinds. Examples -------- >>> from numpy import int64, int32, float32 >>> @expect_kinds(x='i') ... def foo(x): ... return x ... >>> foo(int64(2)) 2 >>> foo(int32(2)) 2 ...
Preprocessing decorator that verifies inputs have expected types. Examples -------- >>> @expect_types(x=int, y=str) ... def foo(x, y): ... return x, y ... >>> foo(2, '3') (2, '3') >>> foo(2.0, '3') # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS Traceback (most recent call last): ... TypeError: ...foo() expected a v...
def expect_types(__funcname=_qualified_name, **named): """ Preprocessing decorator that verifies inputs have expected types. Examples -------- >>> @expect_types(x=int, y=str) ... def foo(x, y): ... return x, y ... >>> foo(2, '3') (2, '3') >>> foo(2.0, '3') # doctest: +NO...
Factory for making preprocessing functions that check a predicate on the input value. Parameters ---------- exc_type : Exception The exception type to raise if the predicate fails. template : str A template string to use to create error messages. Should have %-style named template parameters for 'funcname'...
def make_check(exc_type, template, pred, actual, funcname): """ Factory for making preprocessing functions that check a predicate on the input value. Parameters ---------- exc_type : Exception The exception type to raise if the predicate fails. template : str A template stri...
Helper for use with `expect_types` when an input can be `type_` or `None`. Returns an object such that both `None` and instances of `type_` pass checks of the form `isinstance(obj, optional(type_))`. Parameters ---------- type_ : type Type for which to produce an option. Examples -------- >>> isinstance({}, optio...
def optional(type_): """ Helper for use with `expect_types` when an input can be `type_` or `None`. Returns an object such that both `None` and instances of `type_` pass checks of the form `isinstance(obj, optional(type_))`. Parameters ---------- type_ : type Type for which to produ...
Preprocessing decorator that verifies inputs are elements of some expected collection. Examples -------- >>> @expect_element(x=('a', 'b')) ... def foo(x): ... return x.upper() ... >>> foo('a') 'A' >>> foo('b') 'B' >>> foo('c') # doctest: +NORMALIZE_WHITESPACE +ELLIPSIS Traceback (most recent call last): ... Val...
def expect_element(__funcname=_qualified_name, **named): """ Preprocessing decorator that verifies inputs are elements of some expected collection. Examples -------- >>> @expect_element(x=('a', 'b')) ... def foo(x): ... return x.upper() ... >>> foo('a') 'A' >>> foo('b...
Preprocessing decorator verifying that inputs fall INCLUSIVELY between bounds. Bounds should be passed as a pair of ``(min_value, max_value)``. ``None`` may be passed as ``min_value`` or ``max_value`` to signify that the input is only bounded above or below. Examples -------- >>> @expect_bounded(x=(1, 5)) ... def fo...
def expect_bounded(__funcname=_qualified_name, **named): """ Preprocessing decorator verifying that inputs fall INCLUSIVELY between bounds. Bounds should be passed as a pair of ``(min_value, max_value)``. ``None`` may be passed as ``min_value`` or ``max_value`` to signify that the input is onl...
Preprocessing decorator verifying that inputs fall EXCLUSIVELY between bounds. Bounds should be passed as a pair of ``(min_value, max_value)``. ``None`` may be passed as ``min_value`` or ``max_value`` to signify that the input is only bounded above or below. Examples -------- >>> @expect_strictly_bounded(x=(1, 5)) ....
def expect_strictly_bounded(__funcname=_qualified_name, **named): """ Preprocessing decorator verifying that inputs fall EXCLUSIVELY between bounds. Bounds should be passed as a pair of ``(min_value, max_value)``. ``None`` may be passed as ``min_value`` or ``max_value`` to signify that the inp...
Preprocessing decorator that verifies inputs are numpy arrays with a specific dimensionality. Examples -------- >>> from numpy import array >>> @expect_dimensions(x=1, y=2) ... def foo(x, y): ... return x[0] + y[0, 0] ... >>> foo(array([1, 1]), array([[1, 1], [2, 2]])) 2 >>> foo(array([1, 1]), array([1, 1])) # doc...
def expect_dimensions(__funcname=_qualified_name, **dimensions): """ Preprocessing decorator that verifies inputs are numpy arrays with a specific dimensionality. Examples -------- >>> from numpy import array >>> @expect_dimensions(x=1, y=2) ... def foo(x, y): ... return x[0] + y...
A preprocessing decorator that coerces inputs of a given type by passing them to a callable. Parameters ---------- from : type or tuple or types Inputs types on which to call ``to``. to : function Coercion function to call on inputs. **to_kwargs Additional keywords to forward to every call to ``to``. Exam...
def coerce(from_, to, **to_kwargs): """ A preprocessing decorator that coerces inputs of a given type by passing them to a callable. Parameters ---------- from : type or tuple or types Inputs types on which to call ``to``. to : function Coercion function to call on inputs. ...
Preprocessing decorator that applies type coercions. Parameters ---------- **kwargs : dict[str -> (type, callable)] Keyword arguments mapping function parameter names to pairs of (from_type, to_type). Examples -------- >>> @coerce_types(x=(float, int), y=(int, str)) ... def func(x, y): ... return (x, y)...
def coerce_types(**kwargs): """ Preprocessing decorator that applies type coercions. Parameters ---------- **kwargs : dict[str -> (type, callable)] Keyword arguments mapping function parameter names to pairs of (from_type, to_type). Examples -------- >>> @coerce_types...
Validate that a dictionary has an expected set of keys.
def validate_keys(dict_, expected, funcname): """Validate that a dictionary has an expected set of keys. """ expected = set(expected) received = set(dict_) missing = expected - received if missing: raise ValueError( "Missing keys in {}:\n" "Expected Keys: {}\n" ...
Check if a and b are equal with some tolerance. Parameters ---------- a, b : float The floats to check for equality. atol : float, optional The absolute tolerance. rtol : float, optional The relative tolerance. equal_nan : bool, optional Should NaN compare equal? See Also -------- numpy.isclose Notes...
def tolerant_equals(a, b, atol=10e-7, rtol=10e-7, equal_nan=False): """Check if a and b are equal with some tolerance. Parameters ---------- a, b : float The floats to check for equality. atol : float, optional The absolute tolerance. rtol : float, optional The relative ...
Round a to the nearest integer if that integer is within an epsilon of a.
def round_if_near_integer(a, epsilon=1e-4): """ Round a to the nearest integer if that integer is within an epsilon of a. """ if abs(a - round(a)) <= epsilon: return round(a) else: return a
Compute the number of decimal places in a number. Examples -------- >>> number_of_decimal_places(1) 0 >>> number_of_decimal_places(3.14) 2 >>> number_of_decimal_places('3.14') 2
def number_of_decimal_places(n): """ Compute the number of decimal places in a number. Examples -------- >>> number_of_decimal_places(1) 0 >>> number_of_decimal_places(3.14) 2 >>> number_of_decimal_places('3.14') 2 """ decimal = Decimal(str(n)) return -decimal.as_tup...
Users should only access the lru_cache through its public API: cache_info, cache_clear The internals of the lru_cache are encapsulated for thread safety and to allow the implementation to change.
def _weak_lru_cache(maxsize=100): """ Users should only access the lru_cache through its public API: cache_info, cache_clear The internals of the lru_cache are encapsulated for thread safety and to allow the implementation to change. """ def decorating_function( user_function, tu...
Weak least-recently-used cache decorator. If *maxsize* is set to None, the LRU features are disabled and the cache can grow without bound. Arguments to the cached function must be hashable. Any that are weak- referenceable will be stored by weak reference. Once any of the args have been garbage collected, the entry ...
def weak_lru_cache(maxsize=100): """Weak least-recently-used cache decorator. If *maxsize* is set to None, the LRU features are disabled and the cache can grow without bound. Arguments to the cached function must be hashable. Any that are weak- referenceable will be stored by weak reference. Once...
Compose multiple classes together. Parameters ---------- *mcls : tuple[type] The classes that you would like to compose Returns ------- cls : type A type that subclasses all of the types in ``mcls``. Notes ----- A common use case for this is to build composed metaclasses, for example, imagine you have some s...
def compose_types(a, *cs): """Compose multiple classes together. Parameters ---------- *mcls : tuple[type] The classes that you would like to compose Returns ------- cls : type A type that subclasses all of the types in ``mcls``. Notes ----- A common use case f...
Make a class inheriting from ``bases`` whose metaclass inherits from all of ``metaclasses``. Like :func:`six.with_metaclass`, but allows multiple metaclasses. Parameters ---------- metaclasses : iterable[type] A tuple of types to use as metaclasses. *bases : tuple[type] A tuple of types to use as bases. Retu...
def with_metaclasses(metaclasses, *bases): """Make a class inheriting from ``bases`` whose metaclass inherits from all of ``metaclasses``. Like :func:`six.with_metaclass`, but allows multiple metaclasses. Parameters ---------- metaclasses : iterable[type] A tuple of types to use as met...
Retrieve NaT with the same units as ``dtype``. Parameters ---------- dtype : dtype-coercable The dtype to lookup the NaT value for. Returns ------- NaT : dtype The NaT value for the given dtype.
def NaT_for_dtype(dtype): """Retrieve NaT with the same units as ``dtype``. Parameters ---------- dtype : dtype-coercable The dtype to lookup the NaT value for. Returns ------- NaT : dtype The NaT value for the given dtype. """ return NaTmap[np.dtype(dtype)]
Make a function that checks whether a scalar or array is of a given kind (e.g. float, int, datetime, timedelta).
def make_kind_check(python_types, numpy_kind): """ Make a function that checks whether a scalar or array is of a given kind (e.g. float, int, datetime, timedelta). """ def check(value): if hasattr(value, 'dtype'): return value.dtype.kind == numpy_kind return isinstance(va...
Make a value with the specified numpy dtype. Only datetime64[ns] and datetime64[D] are supported for datetime dtypes.
def coerce_to_dtype(dtype, value): """ Make a value with the specified numpy dtype. Only datetime64[ns] and datetime64[D] are supported for datetime dtypes. """ name = dtype.name if name.startswith('datetime64'): if name == 'datetime64[D]': return make_datetime64D(value) ...
Get the default fill value for `dtype`.
def default_missing_value_for_dtype(dtype): """ Get the default fill value for `dtype`. """ try: return _FILLVALUE_DEFAULTS[dtype] except KeyError: raise NoDefaultMissingValue( "No default value registered for dtype %s." % dtype )
Restride `array` to repeat `count` times along the first axis. Parameters ---------- array : np.array The array to restride. count : int Number of times to repeat `array`. Returns ------- result : array Array of shape (count,) + array.shape, composed of `array` repeated `count` times along the first a...
def repeat_first_axis(array, count): """ Restride `array` to repeat `count` times along the first axis. Parameters ---------- array : np.array The array to restride. count : int Number of times to repeat `array`. Returns ------- result : array Array of shape...
Restride `array` to repeat `count` times along the last axis. Parameters ---------- array : np.array The array to restride. count : int Number of times to repeat `array`. Returns ------- result : array Array of shape array.shape + (count,) composed of `array` repeated `count` times along the last axis...
def repeat_last_axis(array, count): """ Restride `array` to repeat `count` times along the last axis. Parameters ---------- array : np.array The array to restride. count : int Number of times to repeat `array`. Returns ------- result : array Array of shape a...
Restride an array of shape (X_0, ... X_N) into an array of shape (length, X_0 - length + 1, ... X_N) where each slice at index i along the first axis is equivalent to result[i] = array[length * i:length * (i + 1)] Parameters ---------- array : np.ndarray The base array. length : int Length of ...
def rolling_window(array, length): """ Restride an array of shape (X_0, ... X_N) into an array of shape (length, X_0 - length + 1, ... X_N) where each slice at index i along the first axis is equivalent to result[i] = array[length * i:length * (i + 1)] Parameters --...
Check if a value is np.NaT.
def isnat(obj): """ Check if a value is np.NaT. """ if obj.dtype.kind not in ('m', 'M'): raise ValueError("%s is not a numpy datetime or timedelta") return obj.view(int64_dtype) == iNaT
Generic is_missing function that handles NaN and NaT.
def is_missing(data, missing_value): """ Generic is_missing function that handles NaN and NaT. """ if is_float(data) and isnan(missing_value): return isnan(data) elif is_datetime(data) and isnat(missing_value): return isnat(data) elif is_object(data) and missing_value is None: ...
Check if two scalar values are "the same". Returns True if `x == y`, or if x and y are both NaN or both NaT.
def same(x, y): """ Check if two scalar values are "the same". Returns True if `x == y`, or if x and y are both NaN or both NaT. """ if is_float(x) and isnan(x) and is_float(y) and isnan(y): return True elif is_datetime(x) and isnat(x) and is_datetime(y) and isnat(y): return Tru...
Simple of numpy.busday_count that returns `float` arrays rather than int arrays, and handles `NaT`s by returning `NaN`s where the inputs were `NaT`. Doesn't support custom weekdays or calendars, but probably should in the future. See Also -------- np.busday_count
def busday_count_mask_NaT(begindates, enddates, out=None): """ Simple of numpy.busday_count that returns `float` arrays rather than int arrays, and handles `NaT`s by returning `NaN`s where the inputs were `NaT`. Doesn't support custom weekdays or calendars, but probably should in the future. S...
Helper for building a WarningContext that ignores warnings from numpy's nanfunctions.
def ignore_nanwarnings(): """ Helper for building a WarningContext that ignores warnings from numpy's nanfunctions. """ return WarningContext( ( ('ignore',), {'category': RuntimeWarning, 'module': 'numpy.lib.nanfunctions'}, ) )
Check if each element of ``array`` is in choices. Parameters ---------- array : np.ndarray choices : object Object implementing __contains__. Returns ------- was_element : np.ndarray[bool] Array indicating whether each element of ``array`` was in ``choices``.
def vectorized_is_element(array, choices): """ Check if each element of ``array`` is in choices. Parameters ---------- array : np.ndarray choices : object Object implementing __contains__. Returns ------- was_element : np.ndarray[bool] Array indicating whether each ...
Convert an array of shape (N,) into an array of shape (N, 1). This is equivalent to `a[:, np.newaxis]`. Parameters ---------- a : np.ndarray Example ------- >>> import numpy as np >>> a = np.arange(5) >>> a array([0, 1, 2, 3, 4]) >>> as_column(a) array([[0], [1], [2], [3], [4]]) >>> as_co...
def as_column(a): """ Convert an array of shape (N,) into an array of shape (N, 1). This is equivalent to `a[:, np.newaxis]`. Parameters ---------- a : np.ndarray Example ------- >>> import numpy as np >>> a = np.arange(5) >>> a array([0, 1, 2, 3, 4]) >>> as_column...
Compute indices of values in ``a`` that differ from the previous value. Parameters ---------- a : np.ndarray The array on which to indices of change. include_first : bool Whether or not to consider the first index of the array as "changed". Example ------- >>> import numpy as np >>> changed_locations(np.array...
def changed_locations(a, include_first): """ Compute indices of values in ``a`` that differ from the previous value. Parameters ---------- a : np.ndarray The array on which to indices of change. include_first : bool Whether or not to consider the first index of the array as "cha...
Compare datetime64 ndarrays, treating NaT values as equal.
def compare_datetime_arrays(x, y): """ Compare datetime64 ndarrays, treating NaT values as equal. """ return array_equal(x.view('int64'), y.view('int64'))
Convert an array of dtype S to an object array containing `str`.
def bytes_array_to_native_str_object_array(a): """Convert an array of dtype S to an object array containing `str`. """ if six.PY2: return a.astype(object) else: return a.astype(str).astype(object)
Take a DataFrame and return a triple of (df.index, df.columns, df.values)
def explode(df): """ Take a DataFrame and return a triple of (df.index, df.columns, df.values) """ return df.index, df.columns, df.values
Convert a time into microseconds since midnight. Parameters ---------- time : datetime.time The time to convert. Returns ------- us : int The number of microseconds since midnight. Notes ----- This does not account for leap seconds or daylight savings.
def _time_to_micros(time): """Convert a time into microseconds since midnight. Parameters ---------- time : datetime.time The time to convert. Returns ------- us : int The number of microseconds since midnight. Notes ----- This does not account for leap seconds or...
Return a mask of all of the datetimes in ``dts`` that are between ``start`` and ``end``. Parameters ---------- dts : pd.DatetimeIndex The index to mask. start : time Mask away times less than the start. end : time Mask away times greater than the end. include_start : bool, optional Inclusive on ``start`...
def mask_between_time(dts, start, end, include_start=True, include_end=True): """Return a mask of all of the datetimes in ``dts`` that are between ``start`` and ``end``. Parameters ---------- dts : pd.DatetimeIndex The index to mask. start : time Mask away times less than the sta...
Find the index of ``dt`` in ``dts``. This function should be used instead of `dts.get_loc(dt)` if the index is large enough that we don't want to initialize a hash table in ``dts``. In particular, this should always be used on minutely trading calendars. Parameters ---------- dts : pd.DatetimeIndex Index in which...
def find_in_sorted_index(dts, dt): """ Find the index of ``dt`` in ``dts``. This function should be used instead of `dts.get_loc(dt)` if the index is large enough that we don't want to initialize a hash table in ``dts``. In particular, this should always be used on minutely trading calendars. ...
Find values in ``dts`` closest but not equal to ``dt``. Returns a pair of (last_before, first_after). When ``dt`` is less than any element in ``dts``, ``last_before`` is None. When ``dt`` is greater any element in ``dts``, ``first_after`` is None. ``dts`` must be unique and sorted in increasing order. Parameters --...
def nearest_unequal_elements(dts, dt): """ Find values in ``dts`` closest but not equal to ``dt``. Returns a pair of (last_before, first_after). When ``dt`` is less than any element in ``dts``, ``last_before`` is None. When ``dt`` is greater any element in ``dts``, ``first_after`` is None. ``...
Convert a pd.Timedelta to a number of seconds as an int.
def timedelta_to_integral_seconds(delta): """ Convert a pd.Timedelta to a number of seconds as an int. """ return int(delta.total_seconds())
Convert a pd.Timedelta to a number of minutes as an int.
def timedelta_to_integral_minutes(delta): """ Convert a pd.Timedelta to a number of minutes as an int. """ return timedelta_to_integral_seconds(delta) // 60
Clear cached attributes from a pandas DataFrame. By default pandas memoizes indexers (`iloc`, `loc`, `ix`, etc.) objects on DataFrames, resulting in refcycles that can lead to unexpectedly long-lived DataFrames. This function attempts to clear those cycles by deleting the cached indexers from the frame. Parameters --...
def clear_dataframe_indexer_caches(df): """ Clear cached attributes from a pandas DataFrame. By default pandas memoizes indexers (`iloc`, `loc`, `ix`, etc.) objects on DataFrames, resulting in refcycles that can lead to unexpectedly long-lived DataFrames. This function attempts to clear those cycle...