id int64 0 190k | prompt stringlengths 21 13.4M | docstring stringlengths 1 12k ⌀ |
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173,680 | import codecs
import warnings
import re
from contextlib import contextmanager
from parso.normalizer import Normalizer, NormalizerConfig, Issue, Rule
from parso.python.tokenize import _get_token_collection
def _iter_definition_exprs_from_lists(exprlist):
def check_expr(child):
if child.type == 'atom':
if child.children[0] == '(':
testlist_comp = child.children[1]
if testlist_comp.type == 'testlist_comp':
yield from _iter_definition_exprs_from_lists(testlist_comp)
return
else:
# It's a paren that doesn't do anything, like 1 + (1)
yield from check_expr(testlist_comp)
return
elif child.children[0] == '[':
yield testlist_comp
return
yield child
if exprlist.type in _STAR_EXPR_PARENTS:
for child in exprlist.children[::2]:
yield from check_expr(child)
else:
yield from check_expr(exprlist)
def _get_for_stmt_definition_exprs(for_stmt):
exprlist = for_stmt.children[1]
return list(_iter_definition_exprs_from_lists(exprlist)) | null |
173,681 | import codecs
import warnings
import re
from contextlib import contextmanager
from parso.normalizer import Normalizer, NormalizerConfig, Issue, Rule
from parso.python.tokenize import _get_token_collection
_COMP_FOR_TYPES = ('comp_for', 'sync_comp_for')
def _is_argument_comprehension(argument):
return argument.children[1].type in _COMP_FOR_TYPES | null |
173,682 | import codecs
import warnings
import re
from contextlib import contextmanager
from parso.normalizer import Normalizer, NormalizerConfig, Issue, Rule
from parso.python.tokenize import _get_token_collection
def _any_fstring_error(version, node):
if version < (3, 9) or node is None:
return False
if node.type == "error_node":
return any(child.type == "fstring_start" for child in node.children)
elif node.type == "fstring":
return True
else:
return node.search_ancestor("fstring") | null |
173,683 | import re
from codecs import BOM_UTF8
from typing import Tuple
from parso.python.tokenize import group
class PrefixPart:
def __init__(self, leaf, typ, value, spacing='', start_pos=None):
def end_pos(self) -> Tuple[int, int]:
def create_spacing_part(self):
def __repr__(self):
def search_ancestor(self, *node_types):
_regex = group(
_comment, _backslash, _newline, _form_feed, _only_spacing, _bom,
capture=True
)
_regex = re.compile(group(_spacing, capture=True) + _regex)
_types = {
'#': 'comment',
'\\': 'backslash',
'\f': 'formfeed',
'\n': 'newline',
'\r': 'newline',
unicode_bom: 'bom'
}
def group(*choices, capture=False, **kwargs):
def split_prefix(leaf, start_pos):
line, column = start_pos
start = 0
value = spacing = ''
bom = False
while start != len(leaf.prefix):
match = _regex.match(leaf.prefix, start)
spacing = match.group(1)
value = match.group(2)
if not value:
break
type_ = _types[value[0]]
yield PrefixPart(
leaf, type_, value, spacing,
start_pos=(line, column + start - int(bom) + len(spacing))
)
if type_ == 'bom':
bom = True
start = match.end(0)
if value.endswith('\n') or value.endswith('\r'):
line += 1
column = -start
if value:
spacing = ''
yield PrefixPart(
leaf, 'spacing', spacing,
start_pos=(line, column + start)
) | null |
173,684 | from __future__ import absolute_import
import sys
import re
import itertools as _itertools
from codecs import BOM_UTF8
from typing import NamedTuple, Tuple, Iterator, Iterable, List, Dict, \
Pattern, Set
from parso.python.token import PythonTokenTypes
from parso.utils import split_lines, PythonVersionInfo, parse_version_string
class PythonToken(Token):
def __repr__(self):
return ('TokenInfo(type=%s, string=%r, start_pos=%r, prefix=%r)' %
self._replace(type=self.type.name))
def tokenize_lines(
lines: Iterable[str],
*,
version_info: PythonVersionInfo,
indents: List[int] = None,
start_pos: Tuple[int, int] = (1, 0),
is_first_token=True,
) -> Iterator[PythonToken]:
"""
A heavily modified Python standard library tokenizer.
Additionally to the default information, yields also the prefix of each
token. This idea comes from lib2to3. The prefix contains all information
that is irrelevant for the parser like newlines in parentheses or comments.
"""
def dedent_if_necessary(start):
while start < indents[-1]:
if start > indents[-2]:
yield PythonToken(ERROR_DEDENT, '', (lnum, start), '')
indents[-1] = start
break
indents.pop()
yield PythonToken(DEDENT, '', spos, '')
pseudo_token, single_quoted, triple_quoted, endpats, whitespace, \
fstring_pattern_map, always_break_tokens, = \
_get_token_collection(version_info)
paren_level = 0 # count parentheses
if indents is None:
indents = [0]
max_ = 0
numchars = '0123456789'
contstr = ''
contline: str
contstr_start: Tuple[int, int]
endprog: Pattern
# We start with a newline. This makes indent at the first position
# possible. It's not valid Python, but still better than an INDENT in the
# second line (and not in the first). This makes quite a few things in
# Jedi's fast parser possible.
new_line = True
prefix = '' # Should never be required, but here for safety
additional_prefix = ''
lnum = start_pos[0] - 1
fstring_stack: List[FStringNode] = []
for line in lines: # loop over lines in stream
lnum += 1
pos = 0
max_ = len(line)
if is_first_token:
if line.startswith(BOM_UTF8_STRING):
additional_prefix = BOM_UTF8_STRING
line = line[1:]
max_ = len(line)
# Fake that the part before was already parsed.
line = '^' * start_pos[1] + line
pos = start_pos[1]
max_ += start_pos[1]
is_first_token = False
if contstr: # continued string
endmatch = endprog.match(line) # noqa: F821
if endmatch:
pos = endmatch.end(0)
yield PythonToken(
STRING, contstr + line[:pos],
contstr_start, prefix) # noqa: F821
contstr = ''
contline = ''
else:
contstr = contstr + line
contline = contline + line
continue
while pos < max_:
if fstring_stack:
tos = fstring_stack[-1]
if not tos.is_in_expr():
string, pos = _find_fstring_string(endpats, fstring_stack, line, lnum, pos)
if string:
yield PythonToken(
FSTRING_STRING, string,
tos.last_string_start_pos,
# Never has a prefix because it can start anywhere and
# include whitespace.
prefix=''
)
tos.previous_lines = ''
continue
if pos == max_:
break
rest = line[pos:]
fstring_end_token, additional_prefix, quote_length = _close_fstring_if_necessary(
fstring_stack,
rest,
lnum,
pos,
additional_prefix,
)
pos += quote_length
if fstring_end_token is not None:
yield fstring_end_token
continue
# in an f-string, match until the end of the string
if fstring_stack:
string_line = line
for fstring_stack_node in fstring_stack:
quote = fstring_stack_node.quote
end_match = endpats[quote].match(line, pos)
if end_match is not None:
end_match_string = end_match.group(0)
if len(end_match_string) - len(quote) + pos < len(string_line):
string_line = line[:pos] + end_match_string[:-len(quote)]
pseudomatch = pseudo_token.match(string_line, pos)
else:
pseudomatch = pseudo_token.match(line, pos)
if pseudomatch:
prefix = additional_prefix + pseudomatch.group(1)
additional_prefix = ''
start, pos = pseudomatch.span(2)
spos = (lnum, start)
token = pseudomatch.group(2)
if token == '':
assert prefix
additional_prefix = prefix
# This means that we have a line with whitespace/comments at
# the end, which just results in an endmarker.
break
initial = token[0]
else:
match = whitespace.match(line, pos)
initial = line[match.end()]
start = match.end()
spos = (lnum, start)
if new_line and initial not in '\r\n#' and (initial != '\\' or pseudomatch is None):
new_line = False
if paren_level == 0 and not fstring_stack:
indent_start = start
if indent_start > indents[-1]:
yield PythonToken(INDENT, '', spos, '')
indents.append(indent_start)
yield from dedent_if_necessary(indent_start)
if not pseudomatch: # scan for tokens
match = whitespace.match(line, pos)
if new_line and paren_level == 0 and not fstring_stack:
yield from dedent_if_necessary(match.end())
pos = match.end()
new_line = False
yield PythonToken(
ERRORTOKEN, line[pos], (lnum, pos),
additional_prefix + match.group(0)
)
additional_prefix = ''
pos += 1
continue
if (initial in numchars # ordinary number
or (initial == '.' and token != '.' and token != '...')):
yield PythonToken(NUMBER, token, spos, prefix)
elif pseudomatch.group(3) is not None: # ordinary name
if token in always_break_tokens and (fstring_stack or paren_level):
fstring_stack[:] = []
paren_level = 0
# We only want to dedent if the token is on a new line.
m = re.match(r'[ \f\t]*$', line[:start])
if m is not None:
yield from dedent_if_necessary(m.end())
if token.isidentifier():
yield PythonToken(NAME, token, spos, prefix)
else:
yield from _split_illegal_unicode_name(token, spos, prefix)
elif initial in '\r\n':
if any(not f.allow_multiline() for f in fstring_stack):
fstring_stack.clear()
if not new_line and paren_level == 0 and not fstring_stack:
yield PythonToken(NEWLINE, token, spos, prefix)
else:
additional_prefix = prefix + token
new_line = True
elif initial == '#': # Comments
assert not token.endswith("\n") and not token.endswith("\r")
if fstring_stack and fstring_stack[-1].is_in_expr():
# `#` is not allowed in f-string expressions
yield PythonToken(ERRORTOKEN, initial, spos, prefix)
pos = start + 1
else:
additional_prefix = prefix + token
elif token in triple_quoted:
endprog = endpats[token]
endmatch = endprog.match(line, pos)
if endmatch: # all on one line
pos = endmatch.end(0)
token = line[start:pos]
yield PythonToken(STRING, token, spos, prefix)
else:
contstr_start = spos # multiple lines
contstr = line[start:]
contline = line
break
# Check up to the first 3 chars of the token to see if
# they're in the single_quoted set. If so, they start
# a string.
# We're using the first 3, because we're looking for
# "rb'" (for example) at the start of the token. If
# we switch to longer prefixes, this needs to be
# adjusted.
# Note that initial == token[:1].
# Also note that single quote checking must come after
# triple quote checking (above).
elif initial in single_quoted or \
token[:2] in single_quoted or \
token[:3] in single_quoted:
if token[-1] in '\r\n': # continued string
# This means that a single quoted string ends with a
# backslash and is continued.
contstr_start = lnum, start
endprog = (endpats.get(initial) or endpats.get(token[1])
or endpats.get(token[2]))
contstr = line[start:]
contline = line
break
else: # ordinary string
yield PythonToken(STRING, token, spos, prefix)
elif token in fstring_pattern_map: # The start of an fstring.
fstring_stack.append(FStringNode(fstring_pattern_map[token]))
yield PythonToken(FSTRING_START, token, spos, prefix)
elif initial == '\\' and line[start:] in ('\\\n', '\\\r\n', '\\\r'): # continued stmt
additional_prefix += prefix + line[start:]
break
else:
if token in '([{':
if fstring_stack:
fstring_stack[-1].open_parentheses(token)
else:
paren_level += 1
elif token in ')]}':
if fstring_stack:
fstring_stack[-1].close_parentheses(token)
else:
if paren_level:
paren_level -= 1
elif token.startswith(':') and fstring_stack \
and fstring_stack[-1].parentheses_count \
- fstring_stack[-1].format_spec_count == 1:
# `:` and `:=` both count
fstring_stack[-1].format_spec_count += 1
token = ':'
pos = start + 1
yield PythonToken(OP, token, spos, prefix)
if contstr:
yield PythonToken(ERRORTOKEN, contstr, contstr_start, prefix)
if contstr.endswith('\n') or contstr.endswith('\r'):
new_line = True
if fstring_stack:
tos = fstring_stack[-1]
if tos.previous_lines:
yield PythonToken(
FSTRING_STRING, tos.previous_lines,
tos.last_string_start_pos,
# Never has a prefix because it can start anywhere and
# include whitespace.
prefix=''
)
end_pos = lnum, max_
# As the last position we just take the maximally possible position. We
# remove -1 for the last new line.
for indent in indents[1:]:
indents.pop()
yield PythonToken(DEDENT, '', end_pos, '')
yield PythonToken(ENDMARKER, '', end_pos, additional_prefix)
class Tuple(BaseTypingInstance):
def _is_homogenous(self):
# To specify a variable-length tuple of homogeneous type, Tuple[T, ...]
# is used.
return self._generics_manager.is_homogenous_tuple()
def py__simple_getitem__(self, index):
if self._is_homogenous():
return self._generics_manager.get_index_and_execute(0)
else:
if isinstance(index, int):
return self._generics_manager.get_index_and_execute(index)
debug.dbg('The getitem type on Tuple was %s' % index)
return NO_VALUES
def py__iter__(self, contextualized_node=None):
if self._is_homogenous():
yield LazyKnownValues(self._generics_manager.get_index_and_execute(0))
else:
for v in self._generics_manager.to_tuple():
yield LazyKnownValues(v.execute_annotation())
def py__getitem__(self, index_value_set, contextualized_node):
if self._is_homogenous():
return self._generics_manager.get_index_and_execute(0)
return ValueSet.from_sets(
self._generics_manager.to_tuple()
).execute_annotation()
def _get_wrapped_value(self):
tuple_, = self.inference_state.builtins_module \
.py__getattribute__('tuple').execute_annotation()
return tuple_
def name(self):
return self._wrapped_value.name
def infer_type_vars(self, value_set):
# Circular
from jedi.inference.gradual.annotation import merge_pairwise_generics, merge_type_var_dicts
value_set = value_set.filter(
lambda x: x.py__name__().lower() == 'tuple',
)
if self._is_homogenous():
# The parameter annotation is of the form `Tuple[T, ...]`,
# so we treat the incoming tuple like a iterable sequence
# rather than a positional container of elements.
return self._class_value.get_generics()[0].infer_type_vars(
value_set.merge_types_of_iterate(),
)
else:
# The parameter annotation has only explicit type parameters
# (e.g: `Tuple[T]`, `Tuple[T, U]`, `Tuple[T, U, V]`, etc.) so we
# treat the incoming values as needing to match the annotation
# exactly, just as we would for non-tuple annotations.
type_var_dict = {}
for element in value_set:
try:
method = element.get_annotated_class_object
except AttributeError:
# This might still happen, because the tuple name matching
# above is not 100% correct, so just catch the remaining
# cases here.
continue
py_class = method()
merge_type_var_dicts(
type_var_dict,
merge_pairwise_generics(self._class_value, py_class),
)
return type_var_dict
class Iterator(Iterable[_T_co], Protocol[_T_co]):
def __next__(self) -> _T_co: ...
def __iter__(self) -> Iterator[_T_co]: ...
def split_lines(string: str, keepends: bool = False) -> Sequence[str]:
r"""
Intended for Python code. In contrast to Python's :py:meth:`str.splitlines`,
looks at form feeds and other special characters as normal text. Just
splits ``\n`` and ``\r\n``.
Also different: Returns ``[""]`` for an empty string input.
In Python 2.7 form feeds are used as normal characters when using
str.splitlines. However in Python 3 somewhere there was a decision to split
also on form feeds.
"""
if keepends:
lst = string.splitlines(True)
# We have to merge lines that were broken by form feed characters.
merge = []
for i, line in enumerate(lst):
try:
last_chr = line[-1]
except IndexError:
pass
else:
if last_chr in _NON_LINE_BREAKS:
merge.append(i)
for index in reversed(merge):
try:
lst[index] = lst[index] + lst[index + 1]
del lst[index + 1]
except IndexError:
# index + 1 can be empty and therefore there's no need to
# merge.
pass
# The stdlib's implementation of the end is inconsistent when calling
# it with/without keepends. One time there's an empty string in the
# end, one time there's none.
if string.endswith('\n') or string.endswith('\r') or string == '':
lst.append('')
return lst
else:
return re.split(r'\n|\r\n|\r', string)
class PythonVersionInfo(_PythonVersionInfo):
def __gt__(self, other):
if isinstance(other, tuple):
if len(other) != 2:
raise ValueError("Can only compare to tuples of length 2.")
return (self.major, self.minor) > other
super().__gt__(other)
return (self.major, self.minor)
def __eq__(self, other):
if isinstance(other, tuple):
if len(other) != 2:
raise ValueError("Can only compare to tuples of length 2.")
return (self.major, self.minor) == other
super().__eq__(other)
def __ne__(self, other):
return not self.__eq__(other)
The provided code snippet includes necessary dependencies for implementing the `tokenize` function. Write a Python function `def tokenize( code: str, *, version_info: PythonVersionInfo, start_pos: Tuple[int, int] = (1, 0) ) -> Iterator[PythonToken]` to solve the following problem:
Generate tokens from a the source code (string).
Here is the function:
def tokenize(
code: str, *, version_info: PythonVersionInfo, start_pos: Tuple[int, int] = (1, 0)
) -> Iterator[PythonToken]:
"""Generate tokens from a the source code (string)."""
lines = split_lines(code, keepends=True)
return tokenize_lines(lines, version_info=version_info, start_pos=start_pos) | Generate tokens from a the source code (string). |
173,685 | from __future__ import absolute_import
import sys
import re
import itertools as _itertools
from codecs import BOM_UTF8
from typing import NamedTuple, Tuple, Iterator, Iterable, List, Dict, \
Pattern, Set
from parso.python.token import PythonTokenTypes
from parso.utils import split_lines, PythonVersionInfo, parse_version_string
The provided code snippet includes necessary dependencies for implementing the `_print_tokens` function. Write a Python function `def _print_tokens(func)` to solve the following problem:
A small helper function to help debug the tokenize_lines function.
Here is the function:
def _print_tokens(func):
"""
A small helper function to help debug the tokenize_lines function.
"""
def wrapper(*args, **kwargs):
for token in func(*args, **kwargs):
print(token) # This print is intentional for debugging!
yield token
return wrapper | A small helper function to help debug the tokenize_lines function. |
173,686 | from typing import Dict, Type
from parso import tree
from parso.pgen2.generator import ReservedString
def _token_to_transition(grammar, type_, value):
# Map from token to label
if type_.value.contains_syntax:
# Check for reserved words (keywords)
try:
return grammar.reserved_syntax_strings[value]
except KeyError:
pass
return type_ | null |
173,687 | import hashlib
import os
from typing import Generic, TypeVar, Union, Dict, Optional, Any
from pathlib import Path
from parso._compatibility import is_pypy
from parso.pgen2 import generate_grammar
from parso.utils import split_lines, python_bytes_to_unicode, \
PythonVersionInfo, parse_version_string
from parso.python.diff import DiffParser
from parso.python.tokenize import tokenize_lines, tokenize
from parso.python.token import PythonTokenTypes
from parso.cache import parser_cache, load_module, try_to_save_module
from parso.parser import BaseParser
from parso.python.parser import Parser as PythonParser
from parso.python.errors import ErrorFinderConfig
from parso.python import pep8
from parso.file_io import FileIO, KnownContentFileIO
from parso.normalizer import RefactoringNormalizer, NormalizerConfig
_loaded_grammars: Dict[str, 'Grammar'] = {}
class PythonGrammar(Grammar):
_error_normalizer_config = ErrorFinderConfig()
_token_namespace = PythonTokenTypes
_start_nonterminal = 'file_input'
def __init__(self, version_info: PythonVersionInfo, bnf_text: str):
super().__init__(
bnf_text,
tokenizer=self._tokenize_lines,
parser=PythonParser,
diff_parser=DiffParser
)
self.version_info = version_info
def _tokenize_lines(self, lines, **kwargs):
return tokenize_lines(lines, version_info=self.version_info, **kwargs)
def _tokenize(self, code):
# Used by Jedi.
return tokenize(code, version_info=self.version_info)
def parse_version_string(version: str = None) -> PythonVersionInfo:
"""
Checks for a valid version number (e.g. `3.8` or `3.10.1` or `3`) and
returns a corresponding version info that is always two characters long in
decimal.
"""
if version is None:
version = '%s.%s' % sys.version_info[:2]
if not isinstance(version, str):
raise TypeError('version must be a string like "3.8"')
return _parse_version(version)
The provided code snippet includes necessary dependencies for implementing the `load_grammar` function. Write a Python function `def load_grammar(*, version: str = None, path: str = None)` to solve the following problem:
Loads a :py:class:`parso.Grammar`. The default version is the current Python version. :param str version: A python version string, e.g. ``version='3.8'``. :param str path: A path to a grammar file
Here is the function:
def load_grammar(*, version: str = None, path: str = None):
"""
Loads a :py:class:`parso.Grammar`. The default version is the current Python
version.
:param str version: A python version string, e.g. ``version='3.8'``.
:param str path: A path to a grammar file
"""
version_info = parse_version_string(version)
file = path or os.path.join(
'python',
'grammar%s%s.txt' % (version_info.major, version_info.minor)
)
global _loaded_grammars
path = os.path.join(os.path.dirname(__file__), file)
try:
return _loaded_grammars[path]
except KeyError:
try:
with open(path) as f:
bnf_text = f.read()
grammar = PythonGrammar(version_info, bnf_text)
return _loaded_grammars.setdefault(path, grammar)
except FileNotFoundError:
message = "Python version %s.%s is currently not supported." % (
version_info.major, version_info.minor
)
raise NotImplementedError(message) | Loads a :py:class:`parso.Grammar`. The default version is the current Python version. :param str version: A python version string, e.g. ``version='3.8'``. :param str path: A path to a grammar file |
173,688 | import time
import os
import sys
import hashlib
import gc
import shutil
import platform
import logging
import warnings
import pickle
from pathlib import Path
from typing import Dict, Any
class Path(PurePath):
def __new__(cls: Type[_P], *args: Union[str, _PathLike], **kwargs: Any) -> _P: ...
def __enter__(self: _P) -> _P: ...
def __exit__(
self, exc_type: Optional[Type[BaseException]], exc_value: Optional[BaseException], traceback: Optional[TracebackType]
) -> Optional[bool]: ...
def cwd(cls: Type[_P]) -> _P: ...
def stat(self) -> os.stat_result: ...
def chmod(self, mode: int) -> None: ...
def exists(self) -> bool: ...
def glob(self: _P, pattern: str) -> Generator[_P, None, None]: ...
def group(self) -> str: ...
def is_dir(self) -> bool: ...
def is_file(self) -> bool: ...
if sys.version_info >= (3, 7):
def is_mount(self) -> bool: ...
def is_symlink(self) -> bool: ...
def is_socket(self) -> bool: ...
def is_fifo(self) -> bool: ...
def is_block_device(self) -> bool: ...
def is_char_device(self) -> bool: ...
def iterdir(self: _P) -> Generator[_P, None, None]: ...
def lchmod(self, mode: int) -> None: ...
def lstat(self) -> os.stat_result: ...
def mkdir(self, mode: int = ..., parents: bool = ..., exist_ok: bool = ...) -> None: ...
# Adapted from builtins.open
# Text mode: always returns a TextIOWrapper
def open(
self,
mode: OpenTextMode = ...,
buffering: int = ...,
encoding: Optional[str] = ...,
errors: Optional[str] = ...,
newline: Optional[str] = ...,
) -> TextIOWrapper: ...
# Unbuffered binary mode: returns a FileIO
def open(
self, mode: OpenBinaryMode, buffering: Literal[0], encoding: None = ..., errors: None = ..., newline: None = ...
) -> FileIO: ...
# Buffering is on: return BufferedRandom, BufferedReader, or BufferedWriter
def open(
self,
mode: OpenBinaryModeUpdating,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedRandom: ...
def open(
self,
mode: OpenBinaryModeWriting,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedWriter: ...
def open(
self,
mode: OpenBinaryModeReading,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedReader: ...
# Buffering cannot be determined: fall back to BinaryIO
def open(
self, mode: OpenBinaryMode, buffering: int, encoding: None = ..., errors: None = ..., newline: None = ...
) -> BinaryIO: ...
# Fallback if mode is not specified
def open(
self,
mode: str,
buffering: int = ...,
encoding: Optional[str] = ...,
errors: Optional[str] = ...,
newline: Optional[str] = ...,
) -> IO[Any]: ...
def owner(self) -> str: ...
if sys.version_info >= (3, 9):
def readlink(self: _P) -> _P: ...
if sys.version_info >= (3, 8):
def rename(self: _P, target: Union[str, PurePath]) -> _P: ...
def replace(self: _P, target: Union[str, PurePath]) -> _P: ...
else:
def rename(self, target: Union[str, PurePath]) -> None: ...
def replace(self, target: Union[str, PurePath]) -> None: ...
def resolve(self: _P, strict: bool = ...) -> _P: ...
def rglob(self: _P, pattern: str) -> Generator[_P, None, None]: ...
def rmdir(self) -> None: ...
def symlink_to(self, target: Union[str, Path], target_is_directory: bool = ...) -> None: ...
def touch(self, mode: int = ..., exist_ok: bool = ...) -> None: ...
if sys.version_info >= (3, 8):
def unlink(self, missing_ok: bool = ...) -> None: ...
else:
def unlink(self) -> None: ...
def home(cls: Type[_P]) -> _P: ...
def absolute(self: _P) -> _P: ...
def expanduser(self: _P) -> _P: ...
def read_bytes(self) -> bytes: ...
def read_text(self, encoding: Optional[str] = ..., errors: Optional[str] = ...) -> str: ...
def samefile(self, other_path: Union[str, bytes, int, Path]) -> bool: ...
def write_bytes(self, data: bytes) -> int: ...
def write_text(self, data: str, encoding: Optional[str] = ..., errors: Optional[str] = ...) -> int: ...
if sys.version_info >= (3, 8):
def link_to(self, target: Union[str, bytes, os.PathLike[str]]) -> None: ...
def _get_default_cache_path():
if platform.system().lower() == 'windows':
dir_ = Path(os.getenv('LOCALAPPDATA') or '~', 'Parso', 'Parso')
elif platform.system().lower() == 'darwin':
dir_ = Path('~', 'Library', 'Caches', 'Parso')
else:
dir_ = Path(os.getenv('XDG_CACHE_HOME') or '~/.cache', 'parso')
return dir_.expanduser() | null |
173,689 | import time
import os
import sys
import hashlib
import gc
import shutil
import platform
import logging
import warnings
import pickle
from pathlib import Path
from typing import Dict, Any
parser_cache: Dict[str, Any] = {}
def _load_from_file_system(hashed_grammar, path, p_time, cache_path=None):
cache_path = _get_hashed_path(hashed_grammar, path, cache_path=cache_path)
try:
if p_time > os.path.getmtime(cache_path):
# Cache is outdated
return None
with open(cache_path, 'rb') as f:
gc.disable()
try:
module_cache_item = pickle.load(f)
finally:
gc.enable()
except FileNotFoundError:
return None
else:
_set_cache_item(hashed_grammar, path, module_cache_item)
LOG.debug('pickle loaded: %s', path)
return module_cache_item.node
The provided code snippet includes necessary dependencies for implementing the `load_module` function. Write a Python function `def load_module(hashed_grammar, file_io, cache_path=None)` to solve the following problem:
Returns a module or None, if it fails.
Here is the function:
def load_module(hashed_grammar, file_io, cache_path=None):
"""
Returns a module or None, if it fails.
"""
p_time = file_io.get_last_modified()
if p_time is None:
return None
try:
module_cache_item = parser_cache[hashed_grammar][file_io.path]
if p_time <= module_cache_item.change_time:
module_cache_item.last_used = time.time()
return module_cache_item.node
except KeyError:
return _load_from_file_system(
hashed_grammar,
file_io.path,
p_time,
cache_path=cache_path
) | Returns a module or None, if it fails. |
173,690 | import time
import os
import sys
import hashlib
import gc
import shutil
import platform
import logging
import warnings
import pickle
from pathlib import Path
from typing import Dict, Any
class _NodeCacheItem:
def __init__(self, node, lines, change_time=None):
def _set_cache_item(hashed_grammar, path, module_cache_item):
def _save_to_file_system(hashed_grammar, path, item, cache_path=None):
def _remove_cache_and_update_lock(cache_path=None):
def try_to_save_module(hashed_grammar, file_io, module, lines, pickling=True, cache_path=None):
path = file_io.path
try:
p_time = None if path is None else file_io.get_last_modified()
except OSError:
p_time = None
pickling = False
item = _NodeCacheItem(module, lines, p_time)
_set_cache_item(hashed_grammar, path, item)
if pickling and path is not None:
try:
_save_to_file_system(hashed_grammar, path, item, cache_path=cache_path)
except PermissionError:
# It's not really a big issue if the cache cannot be saved to the
# file system. It's still in RAM in that case. However we should
# still warn the user that this is happening.
warnings.warn(
'Tried to save a file to %s, but got permission denied.' % path,
Warning
)
else:
_remove_cache_and_update_lock(cache_path=cache_path) | null |
173,691 | from ast import literal_eval
from typing import TypeVar, Generic, Mapping, Sequence, Set, Union
from parso.pgen2.grammar_parser import GrammarParser, NFAState
def _dump_nfa(start, finish):
print("Dump of NFA for", start.from_rule)
todo = [start]
for i, state in enumerate(todo):
print(" State", i, state is finish and "(final)" or "")
for arc in state.arcs:
label, next_ = arc.nonterminal_or_string, arc.next
if next_ in todo:
j = todo.index(next_)
else:
j = len(todo)
todo.append(next_)
if label is None:
print(" -> %d" % j)
else:
print(" %s -> %d" % (label, j)) | null |
173,692 | from ast import literal_eval
from typing import TypeVar, Generic, Mapping, Sequence, Set, Union
from parso.pgen2.grammar_parser import GrammarParser, NFAState
def _dump_dfas(dfas):
print("Dump of DFA for", dfas[0].from_rule)
for i, state in enumerate(dfas):
print(" State", i, state.is_final and "(final)" or "")
for nonterminal, next_ in state.arcs.items():
print(" %s -> %d" % (nonterminal, dfas.index(next_))) | null |
173,693 | from ast import literal_eval
from typing import TypeVar, Generic, Mapping, Sequence, Set, Union
from parso.pgen2.grammar_parser import GrammarParser, NFAState
class Grammar(Generic[_TokenTypeT]):
"""
Once initialized, this class supplies the grammar tables for the
parsing engine implemented by parse.py. The parsing engine
accesses the instance variables directly.
The only important part in this parsers are dfas and transitions between
dfas.
"""
def __init__(self,
start_nonterminal: str,
rule_to_dfas: Mapping[str, Sequence['DFAState[_TokenTypeT]']],
reserved_syntax_strings: Mapping[str, 'ReservedString']):
self.nonterminal_to_dfas = rule_to_dfas
self.reserved_syntax_strings = reserved_syntax_strings
self.start_nonterminal = start_nonterminal
class DFAPlan:
"""
Plans are used for the parser to create stack nodes and do the proper
DFA state transitions.
"""
def __init__(self, next_dfa: 'DFAState', dfa_pushes: Sequence['DFAState'] = []):
self.next_dfa = next_dfa
self.dfa_pushes = dfa_pushes
def __repr__(self):
return '%s(%s, %s)' % (self.__class__.__name__, self.next_dfa, self.dfa_pushes)
class ReservedString:
"""
Most grammars will have certain keywords and operators that are mentioned
in the grammar as strings (e.g. "if") and not token types (e.g. NUMBER).
This class basically is the former.
"""
def __init__(self, value: str):
self.value = value
def __repr__(self):
return '%s(%s)' % (self.__class__.__name__, self.value)
def _simplify_dfas(dfas):
"""
This is not theoretically optimal, but works well enough.
Algorithm: repeatedly look for two states that have the same
set of arcs (same labels pointing to the same nodes) and
unify them, until things stop changing.
dfas is a list of DFAState instances
"""
changes = True
while changes:
changes = False
for i, state_i in enumerate(dfas):
for j in range(i + 1, len(dfas)):
state_j = dfas[j]
if state_i == state_j:
del dfas[j]
for state in dfas:
state.unifystate(state_j, state_i)
changes = True
break
def _make_dfas(start, finish):
"""
Uses the powerset construction algorithm to create DFA states from sets of
NFA states.
Also does state reduction if some states are not needed.
"""
# To turn an NFA into a DFA, we define the states of the DFA
# to correspond to *sets* of states of the NFA. Then do some
# state reduction.
assert isinstance(start, NFAState)
assert isinstance(finish, NFAState)
def addclosure(nfa_state, base_nfa_set):
assert isinstance(nfa_state, NFAState)
if nfa_state in base_nfa_set:
return
base_nfa_set.add(nfa_state)
for nfa_arc in nfa_state.arcs:
if nfa_arc.nonterminal_or_string is None:
addclosure(nfa_arc.next, base_nfa_set)
base_nfa_set = set()
addclosure(start, base_nfa_set)
states = [DFAState(start.from_rule, base_nfa_set, finish)]
for state in states: # NB states grows while we're iterating
arcs = {}
# Find state transitions and store them in arcs.
for nfa_state in state.nfa_set:
for nfa_arc in nfa_state.arcs:
if nfa_arc.nonterminal_or_string is not None:
nfa_set = arcs.setdefault(nfa_arc.nonterminal_or_string, set())
addclosure(nfa_arc.next, nfa_set)
# Now create the dfa's with no None's in arcs anymore. All Nones have
# been eliminated and state transitions (arcs) are properly defined, we
# just need to create the dfa's.
for nonterminal_or_string, nfa_set in arcs.items():
for nested_state in states:
if nested_state.nfa_set == nfa_set:
# The DFA state already exists for this rule.
break
else:
nested_state = DFAState(start.from_rule, nfa_set, finish)
states.append(nested_state)
state.add_arc(nested_state, nonterminal_or_string)
return states # List of DFAState instances; first one is start
def _make_transition(token_namespace, reserved_syntax_strings, label):
"""
Creates a reserved string ("if", "for", "*", ...) or returns the token type
(NUMBER, STRING, ...) for a given grammar terminal.
"""
if label[0].isalpha():
# A named token (e.g. NAME, NUMBER, STRING)
return getattr(token_namespace, label)
else:
# Either a keyword or an operator
assert label[0] in ('"', "'"), label
assert not label.startswith('"""') and not label.startswith("'''")
value = literal_eval(label)
try:
return reserved_syntax_strings[value]
except KeyError:
r = reserved_syntax_strings[value] = ReservedString(value)
return r
def _calculate_tree_traversal(nonterminal_to_dfas):
"""
By this point we know how dfas can move around within a stack node, but we
don't know how we can add a new stack node (nonterminal transitions).
"""
# Map from grammar rule (nonterminal) name to a set of tokens.
first_plans = {}
nonterminals = list(nonterminal_to_dfas.keys())
nonterminals.sort()
for nonterminal in nonterminals:
if nonterminal not in first_plans:
_calculate_first_plans(nonterminal_to_dfas, first_plans, nonterminal)
# Now that we have calculated the first terminals, we are sure that
# there is no left recursion.
for dfas in nonterminal_to_dfas.values():
for dfa_state in dfas:
transitions = dfa_state.transitions
for nonterminal, next_dfa in dfa_state.nonterminal_arcs.items():
for transition, pushes in first_plans[nonterminal].items():
if transition in transitions:
prev_plan = transitions[transition]
# Make sure these are sorted so that error messages are
# at least deterministic
choices = sorted([
(
prev_plan.dfa_pushes[0].from_rule
if prev_plan.dfa_pushes
else prev_plan.next_dfa.from_rule
),
(
pushes[0].from_rule
if pushes else next_dfa.from_rule
),
])
raise ValueError(
"Rule %s is ambiguous; given a %s token, we "
"can't determine if we should evaluate %s or %s."
% (
(
dfa_state.from_rule,
transition,
) + tuple(choices)
)
)
transitions[transition] = DFAPlan(next_dfa, pushes)
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: ...
class GrammarParser:
"""
The parser for Python grammar files.
"""
def __init__(self, bnf_grammar: str):
self._bnf_grammar = bnf_grammar
self.generator = tokenize(
bnf_grammar,
version_info=parse_version_string('3.9')
)
self._gettoken() # Initialize lookahead
def parse(self) -> Iterator[Tuple[NFAState, NFAState]]:
# grammar: (NEWLINE | rule)* ENDMARKER
while self.type != PythonTokenTypes.ENDMARKER:
while self.type == PythonTokenTypes.NEWLINE:
self._gettoken()
# rule: NAME ':' rhs NEWLINE
self._current_rule_name = self._expect(PythonTokenTypes.NAME)
self._expect(PythonTokenTypes.OP, ':')
a, z = self._parse_rhs()
self._expect(PythonTokenTypes.NEWLINE)
yield a, z
def _parse_rhs(self):
# rhs: items ('|' items)*
a, z = self._parse_items()
if self.value != "|":
return a, z
else:
aa = NFAState(self._current_rule_name)
zz = NFAState(self._current_rule_name)
while True:
# Add the possibility to go into the state of a and come back
# to finish.
aa.add_arc(a)
z.add_arc(zz)
if self.value != "|":
break
self._gettoken()
a, z = self._parse_items()
return aa, zz
def _parse_items(self):
# items: item+
a, b = self._parse_item()
while self.type in (PythonTokenTypes.NAME, PythonTokenTypes.STRING) \
or self.value in ('(', '['):
c, d = self._parse_item()
# Need to end on the next item.
b.add_arc(c)
b = d
return a, b
def _parse_item(self):
# item: '[' rhs ']' | atom ['+' | '*']
if self.value == "[":
self._gettoken()
a, z = self._parse_rhs()
self._expect(PythonTokenTypes.OP, ']')
# Make it also possible that there is no token and change the
# state.
a.add_arc(z)
return a, z
else:
a, z = self._parse_atom()
value = self.value
if value not in ("+", "*"):
return a, z
self._gettoken()
# Make it clear that we can go back to the old state and repeat.
z.add_arc(a)
if value == "+":
return a, z
else:
# The end state is the same as the beginning, nothing must
# change.
return a, a
def _parse_atom(self):
# atom: '(' rhs ')' | NAME | STRING
if self.value == "(":
self._gettoken()
a, z = self._parse_rhs()
self._expect(PythonTokenTypes.OP, ')')
return a, z
elif self.type in (PythonTokenTypes.NAME, PythonTokenTypes.STRING):
a = NFAState(self._current_rule_name)
z = NFAState(self._current_rule_name)
# Make it clear that the state transition requires that value.
a.add_arc(z, self.value)
self._gettoken()
return a, z
else:
self._raise_error("expected (...) or NAME or STRING, got %s/%s",
self.type, self.value)
def _expect(self, type_, value=None):
if self.type != type_:
self._raise_error("expected %s, got %s [%s]",
type_, self.type, self.value)
if value is not None and self.value != value:
self._raise_error("expected %s, got %s", value, self.value)
value = self.value
self._gettoken()
return value
def _gettoken(self):
tup = next(self.generator)
self.type, self.value, self.begin, prefix = tup
def _raise_error(self, msg, *args):
if args:
try:
msg = msg % args
except:
msg = " ".join([msg] + list(map(str, args)))
line = self._bnf_grammar.splitlines()[self.begin[0] - 1]
raise SyntaxError(msg, ('<grammar>', self.begin[0],
self.begin[1], line))
The provided code snippet includes necessary dependencies for implementing the `generate_grammar` function. Write a Python function `def generate_grammar(bnf_grammar: str, token_namespace) -> Grammar` to solve the following problem:
``bnf_text`` is a grammar in extended BNF (using * for repetition, + for at-least-once repetition, [] for optional parts, | for alternatives and () for grouping). It's not EBNF according to ISO/IEC 14977. It's a dialect Python uses in its own parser.
Here is the function:
def generate_grammar(bnf_grammar: str, token_namespace) -> Grammar:
"""
``bnf_text`` is a grammar in extended BNF (using * for repetition, + for
at-least-once repetition, [] for optional parts, | for alternatives and ()
for grouping).
It's not EBNF according to ISO/IEC 14977. It's a dialect Python uses in its
own parser.
"""
rule_to_dfas = {}
start_nonterminal = None
for nfa_a, nfa_z in GrammarParser(bnf_grammar).parse():
# _dump_nfa(nfa_a, nfa_z)
dfas = _make_dfas(nfa_a, nfa_z)
# _dump_dfas(dfas)
# oldlen = len(dfas)
_simplify_dfas(dfas)
# newlen = len(dfas)
rule_to_dfas[nfa_a.from_rule] = dfas
# print(nfa_a.from_rule, oldlen, newlen)
if start_nonterminal is None:
start_nonterminal = nfa_a.from_rule
reserved_strings: Mapping[str, ReservedString] = {}
for nonterminal, dfas in rule_to_dfas.items():
for dfa_state in dfas:
for terminal_or_nonterminal, next_dfa in dfa_state.arcs.items():
if terminal_or_nonterminal in rule_to_dfas:
dfa_state.nonterminal_arcs[terminal_or_nonterminal] = next_dfa
else:
transition = _make_transition(
token_namespace,
reserved_strings,
terminal_or_nonterminal
)
dfa_state.transitions[transition] = DFAPlan(next_dfa)
_calculate_tree_traversal(rule_to_dfas)
return Grammar(start_nonterminal, rule_to_dfas, reserved_strings) # type: ignore | ``bnf_text`` is a grammar in extended BNF (using * for repetition, + for at-least-once repetition, [] for optional parts, | for alternatives and () for grouping). It's not EBNF according to ISO/IEC 14977. It's a dialect Python uses in its own parser. |
173,694 | from __future__ import annotations
import re
from typing import Any
TOKENS = {
'class': RE_CLASS,
'param': RE_PARAM,
'empty': RE_EMPTY,
'lstrt': RE_LSTRT,
'dstrt': RE_DSTRT,
'tstrt': RE_TSTRT,
'lend': RE_LEND,
'dend': RE_DEND,
'tend': RE_TEND,
'sqstr': RE_SQSTR,
'sep': RE_SEP,
'dsep': RE_DSEP,
'int': RE_INT,
'kword': RE_KWORD,
'dqstr': RE_DQSTR
}
Any = object()
The provided code snippet includes necessary dependencies for implementing the `pretty` function. Write a Python function `def pretty(obj: Any) -> str` to solve the following problem:
Make the object output string pretty.
Here is the function:
def pretty(obj: Any) -> str: # pragma: no cover
"""Make the object output string pretty."""
sel = str(obj)
index = 0
end = len(sel) - 1
indent = 0
output = []
while index <= end:
m = None
for k, v in TOKENS.items():
m = v.match(sel, index)
if m:
name = k
index = m.end(0)
if name in ('class', 'lstrt', 'dstrt', 'tstrt'):
indent += 4
output.append('{}\n{}'.format(m.group(0), " " * indent))
elif name in ('param', 'int', 'kword', 'sqstr', 'dqstr', 'empty'):
output.append(m.group(0))
elif name in ('lend', 'dend', 'tend'):
indent -= 4
output.append(m.group(0))
elif name in ('sep',):
output.append('{}\n{}'.format(m.group(1), " " * indent))
elif name in ('dsep',):
output.append('{} '.format(m.group(1)))
break
return ''.join(output) | Make the object output string pretty. |
173,695 | from __future__ import annotations
import re
from functools import lru_cache
from . import util
from . import css_match as cm
from . import css_types as ct
from .util import SelectorSyntaxError
import warnings
from typing import Optional, Match, Any, Iterator, cast
def _cached_css_compile(
pattern: str,
namespaces: Optional[ct.Namespaces],
custom: Optional[ct.CustomSelectors],
flags: int
) -> cm.SoupSieve:
"""Cached CSS compile."""
custom_selectors = process_custom(custom)
return cm.SoupSieve(
pattern,
CSSParser(
pattern,
custom=custom_selectors,
flags=flags
).process_selectors(),
namespaces,
custom,
flags
)
The provided code snippet includes necessary dependencies for implementing the `_purge_cache` function. Write a Python function `def _purge_cache() -> None` to solve the following problem:
Purge the cache.
Here is the function:
def _purge_cache() -> None:
"""Purge the cache."""
_cached_css_compile.cache_clear() | Purge the cache. |
173,696 | from __future__ import annotations
import re
from functools import lru_cache
from . import util
from . import css_match as cm
from . import css_types as ct
from .util import SelectorSyntaxError
import warnings
from typing import Optional, Match, Any, Iterator, cast
The provided code snippet includes necessary dependencies for implementing the `escape` function. Write a Python function `def escape(ident: str) -> str` to solve the following problem:
Escape identifier.
Here is the function:
def escape(ident: str) -> str:
"""Escape identifier."""
string = []
length = len(ident)
start_dash = length > 0 and ident[0] == '-'
if length == 1 and start_dash:
# Need to escape identifier that is a single `-` with no other characters
string.append('\\{}'.format(ident))
else:
for index, c in enumerate(ident):
codepoint = ord(c)
if codepoint == 0x00:
string.append('\ufffd')
elif (0x01 <= codepoint <= 0x1F) or codepoint == 0x7F:
string.append('\\{:x} '.format(codepoint))
elif (index == 0 or (start_dash and index == 1)) and (0x30 <= codepoint <= 0x39):
string.append('\\{:x} '.format(codepoint))
elif (
codepoint in (0x2D, 0x5F) or codepoint >= 0x80 or (0x30 <= codepoint <= 0x39) or
(0x30 <= codepoint <= 0x39) or (0x41 <= codepoint <= 0x5A) or (0x61 <= codepoint <= 0x7A)
):
string.append(c)
else:
string.append('\\{}'.format(c))
return ''.join(string) | Escape identifier. |
173,697 | from __future__ import annotations
from functools import wraps, lru_cache
import warnings
import re
from typing import Callable, Any, Optional
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])
Any = object()
The provided code snippet includes necessary dependencies for implementing the `deprecated` function. Write a Python function `def deprecated(message: str, stacklevel: int = 2) -> Callable[..., Any]` to solve the following problem:
Raise a `DeprecationWarning` when wrapped function/method is called. Usage: @deprecated("This method will be removed in version X; use Y instead.") def some_method()" pass
Here is the function:
def deprecated(message: str, stacklevel: int = 2) -> Callable[..., Any]: # pragma: no cover
"""
Raise a `DeprecationWarning` when wrapped function/method is called.
Usage:
@deprecated("This method will be removed in version X; use Y instead.")
def some_method()"
pass
"""
def _wrapper(func: Callable[..., Any]) -> Callable[..., Any]:
@wraps(func)
def _deprecated_func(*args: Any, **kwargs: Any) -> Any:
warnings.warn(
f"'{func.__name__}' is deprecated. {message}",
category=DeprecationWarning,
stacklevel=stacklevel
)
return func(*args, **kwargs)
return _deprecated_func
return _wrapper | Raise a `DeprecationWarning` when wrapped function/method is called. Usage: @deprecated("This method will be removed in version X; use Y instead.") def some_method()" pass |
173,698 | from __future__ import annotations
from functools import wraps, lru_cache
import warnings
import re
from typing import Callable, Any, Optional
The provided code snippet includes necessary dependencies for implementing the `warn_deprecated` function. Write a Python function `def warn_deprecated(message: str, stacklevel: int = 2) -> None` to solve the following problem:
Warn deprecated.
Here is the function:
def warn_deprecated(message: str, stacklevel: int = 2) -> None: # pragma: no cover
"""Warn deprecated."""
warnings.warn(
message,
category=DeprecationWarning,
stacklevel=stacklevel
) | Warn deprecated. |
173,699 | from __future__ import annotations
from functools import wraps, lru_cache
import warnings
import re
from typing import Callable, Any, Optional
RE_PATTERN_LINE_SPLIT = re.compile(r'(?:\r\n|(?!\r\n)[\n\r])|$')
The provided code snippet includes necessary dependencies for implementing the `get_pattern_context` function. Write a Python function `def get_pattern_context(pattern: str, index: int) -> tuple[str, int, int]` to solve the following problem:
Get the pattern context.
Here is the function:
def get_pattern_context(pattern: str, index: int) -> tuple[str, int, int]:
"""Get the pattern context."""
last = 0
current_line = 1
col = 1
text = [] # type: list[str]
line = 1
offset = None # type: Optional[int]
# Split pattern by newline and handle the text before the newline
for m in RE_PATTERN_LINE_SPLIT.finditer(pattern):
linetext = pattern[last:m.start(0)]
if not len(m.group(0)) and not len(text):
indent = ''
offset = -1
col = index - last + 1
elif last <= index < m.end(0):
indent = '--> '
offset = (-1 if index > m.start(0) else 0) + 3
col = index - last + 1
else:
indent = ' '
offset = None
if len(text):
# Regardless of whether we are presented with `\r\n`, `\r`, or `\n`,
# we will render the output with just `\n`. We will still log the column
# correctly though.
text.append('\n')
text.append('{}{}'.format(indent, linetext))
if offset is not None:
text.append('\n')
text.append(' ' * (col + offset) + '^')
line = current_line
current_line += 1
last = m.end(0)
return ''.join(text), line, col | Get the pattern context. |
173,700 | from __future__ import annotations
from collections import namedtuple
import re
RE_VER = re.compile(
r'''(?x)
(?P<major>\d+)(?:\.(?P<minor>\d+))?(?:\.(?P<micro>\d+))?
(?:(?P<type>a|b|rc)(?P<pre>\d+))?
(?:\.post(?P<post>\d+))?
(?:\.dev(?P<dev>\d+))?
'''
)
PRE_REL_MAP = {"a": 'alpha', "b": 'beta', "rc": 'candidate'}
class Version(namedtuple("Version", ["major", "minor", "micro", "release", "pre", "post", "dev"])):
"""
Get the version (PEP 440).
A biased approach to the PEP 440 semantic version.
Provides a tuple structure which is sorted for comparisons `v1 > v2` etc.
(major, minor, micro, release type, pre-release build, post-release build, development release build)
Release types are named in is such a way they are comparable with ease.
Accessors to check if a development, pre-release, or post-release build. Also provides accessor to get
development status for setup files.
How it works (currently):
- You must specify a release type as either `final`, `alpha`, `beta`, or `candidate`.
- To define a development release, you can use either `.dev`, `.dev-alpha`, `.dev-beta`, or `.dev-candidate`.
The dot is used to ensure all development specifiers are sorted before `alpha`.
You can specify a `dev` number for development builds, but do not have to as implicit development releases
are allowed.
- You must specify a `pre` value greater than zero if using a prerelease as this project (not PEP 440) does not
allow implicit prereleases.
- You can optionally set `post` to a value greater than zero to make the build a post release. While post releases
are technically allowed in prereleases, it is strongly discouraged, so we are rejecting them. It should be
noted that we do not allow `post0` even though PEP 440 does not restrict this. This project specifically
does not allow implicit post releases.
- It should be noted that we do not support epochs `1!` or local versions `+some-custom.version-1`.
Acceptable version releases:
```
Version(1, 0, 0, "final") 1.0
Version(1, 2, 0, "final") 1.2
Version(1, 2, 3, "final") 1.2.3
Version(1, 2, 0, ".dev-alpha", pre=4) 1.2a4
Version(1, 2, 0, ".dev-beta", pre=4) 1.2b4
Version(1, 2, 0, ".dev-candidate", pre=4) 1.2rc4
Version(1, 2, 0, "final", post=1) 1.2.post1
Version(1, 2, 3, ".dev") 1.2.3.dev0
Version(1, 2, 3, ".dev", dev=1) 1.2.3.dev1
```
"""
def __new__(
cls,
major: int, minor: int, micro: int, release: str = "final",
pre: int = 0, post: int = 0, dev: int = 0
) -> Version:
"""Validate version info."""
# Ensure all parts are positive integers.
for value in (major, minor, micro, pre, post):
if not (isinstance(value, int) and value >= 0):
raise ValueError("All version parts except 'release' should be integers.")
if release not in REL_MAP:
raise ValueError("'{}' is not a valid release type.".format(release))
# Ensure valid pre-release (we do not allow implicit pre-releases).
if ".dev-candidate" < release < "final":
if pre == 0:
raise ValueError("Implicit pre-releases not allowed.")
elif dev:
raise ValueError("Version is not a development release.")
elif post:
raise ValueError("Post-releases are not allowed with pre-releases.")
# Ensure valid development or development/pre release
elif release < "alpha":
if release > ".dev" and pre == 0:
raise ValueError("Implicit pre-release not allowed.")
elif post:
raise ValueError("Post-releases are not allowed with pre-releases.")
# Ensure a valid normal release
else:
if pre:
raise ValueError("Version is not a pre-release.")
elif dev:
raise ValueError("Version is not a development release.")
return super(Version, cls).__new__(cls, major, minor, micro, release, pre, post, dev)
def _is_pre(self) -> bool:
"""Is prerelease."""
return bool(self.pre > 0)
def _is_dev(self) -> bool:
"""Is development."""
return bool(self.release < "alpha")
def _is_post(self) -> bool:
"""Is post."""
return bool(self.post > 0)
def _get_dev_status(self) -> str: # pragma: no cover
"""Get development status string."""
return DEV_STATUS[self.release]
def _get_canonical(self) -> str:
"""Get the canonical output string."""
# Assemble major, minor, micro version and append `pre`, `post`, or `dev` if needed..
if self.micro == 0:
ver = "{}.{}".format(self.major, self.minor)
else:
ver = "{}.{}.{}".format(self.major, self.minor, self.micro)
if self._is_pre():
ver += '{}{}'.format(REL_MAP[self.release], self.pre)
if self._is_post():
ver += ".post{}".format(self.post)
if self._is_dev():
ver += ".dev{}".format(self.dev)
return ver
The provided code snippet includes necessary dependencies for implementing the `parse_version` function. Write a Python function `def parse_version(ver: str) -> Version` to solve the following problem:
Parse version into a comparable Version tuple.
Here is the function:
def parse_version(ver: str) -> Version:
"""Parse version into a comparable Version tuple."""
m = RE_VER.match(ver)
if m is None:
raise ValueError("'{}' is not a valid version".format(ver))
# Handle major, minor, micro
major = int(m.group('major'))
minor = int(m.group('minor')) if m.group('minor') else 0
micro = int(m.group('micro')) if m.group('micro') else 0
# Handle pre releases
if m.group('type'):
release = PRE_REL_MAP[m.group('type')]
pre = int(m.group('pre'))
else:
release = "final"
pre = 0
# Handle development releases
dev = m.group('dev') if m.group('dev') else 0
if m.group('dev'):
dev = int(m.group('dev'))
release = '.dev-' + release if pre else '.dev'
else:
dev = 0
# Handle post
post = int(m.group('post')) if m.group('post') else 0
return Version(major, minor, micro, release, pre, post, dev) | Parse version into a comparable Version tuple. |
173,701 | from __future__ import annotations
import copyreg
from .pretty import pretty
from typing import Any, Iterator, Hashable, Optional, Pattern, Iterable, Mapping
def _pickle(p: Any) -> Any:
return p.__base__(), tuple([getattr(p, s) for s in p.__slots__[:-1]])
Any = object()
The provided code snippet includes necessary dependencies for implementing the `pickle_register` function. Write a Python function `def pickle_register(obj: Any) -> None` to solve the following problem:
Allow object to be pickled.
Here is the function:
def pickle_register(obj: Any) -> None:
"""Allow object to be pickled."""
copyreg.pickle(obj, _pickle) | Allow object to be pickled. |
173,702 | import hashlib
import hmac
import typing as _t
from .encoding import _base64_alphabet
from .encoding import base64_decode
from .encoding import base64_encode
from .encoding import want_bytes
from .exc import BadSignature
_t_secret_key = _t.Union[_t.Iterable[_t_str_bytes], _t_str_bytes]
def want_bytes(
s: _t_str_bytes, encoding: str = "utf-8", errors: str = "strict"
) -> bytes:
if isinstance(s, str):
s = s.encode(encoding, errors)
return s
def _make_keys_list(secret_key: _t_secret_key) -> _t.List[bytes]:
if isinstance(secret_key, (str, bytes)):
return [want_bytes(secret_key)]
return [want_bytes(s) for s in secret_key] | null |
173,703 | import base64
import string
import struct
import typing as _t
from .exc import BadData
_t_str_bytes = _t.Union[str, bytes]
def want_bytes(
s: _t_str_bytes, encoding: str = "utf-8", errors: str = "strict"
) -> bytes:
if isinstance(s, str):
s = s.encode(encoding, errors)
return s
The provided code snippet includes necessary dependencies for implementing the `base64_encode` function. Write a Python function `def base64_encode(string: _t_str_bytes) -> bytes` to solve the following problem:
Base64 encode a string of bytes or text. The resulting bytes are safe to use in URLs.
Here is the function:
def base64_encode(string: _t_str_bytes) -> bytes:
"""Base64 encode a string of bytes or text. The resulting bytes are
safe to use in URLs.
"""
string = want_bytes(string)
return base64.urlsafe_b64encode(string).rstrip(b"=") | Base64 encode a string of bytes or text. The resulting bytes are safe to use in URLs. |
173,704 | import base64
import string
import struct
import typing as _t
from .exc import BadData
_t_str_bytes = _t.Union[str, bytes]
def want_bytes(
s: _t_str_bytes, encoding: str = "utf-8", errors: str = "strict"
) -> bytes:
if isinstance(s, str):
s = s.encode(encoding, errors)
return s
class BadData(Exception):
"""Raised if bad data of any sort was encountered. This is the base
for all exceptions that ItsDangerous defines.
.. versionadded:: 0.15
"""
def __init__(self, message: str):
super().__init__(message)
self.message = message
def __str__(self) -> str:
return self.message
The provided code snippet includes necessary dependencies for implementing the `base64_decode` function. Write a Python function `def base64_decode(string: _t_str_bytes) -> bytes` to solve the following problem:
Base64 decode a URL-safe string of bytes or text. The result is bytes.
Here is the function:
def base64_decode(string: _t_str_bytes) -> bytes:
"""Base64 decode a URL-safe string of bytes or text. The result is
bytes.
"""
string = want_bytes(string, encoding="ascii", errors="ignore")
string += b"=" * (-len(string) % 4)
try:
return base64.urlsafe_b64decode(string)
except (TypeError, ValueError) as e:
raise BadData("Invalid base64-encoded data") from e | Base64 decode a URL-safe string of bytes or text. The result is bytes. |
173,705 | import base64
import string
import struct
import typing as _t
from .exc import BadData
_int_to_bytes = _int64_struct.pack
def int_to_bytes(num: int) -> bytes:
return _int_to_bytes(num).lstrip(b"\x00") | null |
173,706 | import base64
import string
import struct
import typing as _t
from .exc import BadData
_bytes_to_int = _t.cast("_t.Callable[[bytes], _t.Tuple[int]]", _int64_struct.unpack)
def bytes_to_int(bytestr: bytes) -> int:
return _bytes_to_int(bytestr.rjust(8, b"\x00"))[0] | null |
173,707 | import json
import typing as _t
from .encoding import want_bytes
from .exc import BadPayload
from .exc import BadSignature
from .signer import _make_keys_list
from .signer import Signer
The provided code snippet includes necessary dependencies for implementing the `is_text_serializer` function. Write a Python function `def is_text_serializer(serializer: _t.Any) -> bool` to solve the following problem:
Checks whether a serializer generates text or binary.
Here is the function:
def is_text_serializer(serializer: _t.Any) -> bool:
"""Checks whether a serializer generates text or binary."""
return isinstance(serializer.dumps({}), str) | Checks whether a serializer generates text or binary. |
173,708 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
class __diag__(__config_flags):
_type_desc = "diagnostic"
warn_multiple_tokens_in_named_alternation = False
warn_ungrouped_named_tokens_in_collection = False
warn_name_set_on_empty_Forward = False
warn_on_parse_using_empty_Forward = False
warn_on_assignment_to_Forward = False
warn_on_multiple_string_args_to_oneof = False
warn_on_match_first_with_lshift_operator = False
enable_debug_on_named_expressions = False
_all_names = [__ for __ in locals() if not __.startswith("_")]
_warning_names = [name for name in _all_names if name.startswith("warn")]
_debug_names = [name for name in _all_names if name.startswith("enable_debug")]
def enable_all_warnings(cls) -> None:
for name in cls._warning_names:
cls.enable(name)
class Diagnostics(Enum):
"""
Diagnostic configuration (all default to disabled)
- ``warn_multiple_tokens_in_named_alternation`` - flag to enable warnings when a results
name is defined on a :class:`MatchFirst` or :class:`Or` expression with one or more :class:`And` subexpressions
- ``warn_ungrouped_named_tokens_in_collection`` - flag to enable warnings when a results
name is defined on a containing expression with ungrouped subexpressions that also
have results names
- ``warn_name_set_on_empty_Forward`` - flag to enable warnings when a :class:`Forward` is defined
with a results name, but has no contents defined
- ``warn_on_parse_using_empty_Forward`` - flag to enable warnings when a :class:`Forward` is
defined in a grammar but has never had an expression attached to it
- ``warn_on_assignment_to_Forward`` - flag to enable warnings when a :class:`Forward` is defined
but is overwritten by assigning using ``'='`` instead of ``'<<='`` or ``'<<'``
- ``warn_on_multiple_string_args_to_oneof`` - flag to enable warnings when :class:`one_of` is
incorrectly called with multiple str arguments
- ``enable_debug_on_named_expressions`` - flag to auto-enable debug on all subsequent
calls to :class:`ParserElement.set_name`
Diagnostics are enabled/disabled by calling :class:`enable_diag` and :class:`disable_diag`.
All warnings can be enabled by calling :class:`enable_all_warnings`.
"""
warn_multiple_tokens_in_named_alternation = 0
warn_ungrouped_named_tokens_in_collection = 1
warn_name_set_on_empty_Forward = 2
warn_on_parse_using_empty_Forward = 3
warn_on_assignment_to_Forward = 4
warn_on_multiple_string_args_to_oneof = 5
warn_on_match_first_with_lshift_operator = 6
enable_debug_on_named_expressions = 7
The provided code snippet includes necessary dependencies for implementing the `enable_diag` function. Write a Python function `def enable_diag(diag_enum: Diagnostics) -> None` to solve the following problem:
Enable a global pyparsing diagnostic flag (see :class:`Diagnostics`).
Here is the function:
def enable_diag(diag_enum: Diagnostics) -> None:
"""
Enable a global pyparsing diagnostic flag (see :class:`Diagnostics`).
"""
__diag__.enable(diag_enum.name) | Enable a global pyparsing diagnostic flag (see :class:`Diagnostics`). |
173,709 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
class __diag__(__config_flags):
_type_desc = "diagnostic"
warn_multiple_tokens_in_named_alternation = False
warn_ungrouped_named_tokens_in_collection = False
warn_name_set_on_empty_Forward = False
warn_on_parse_using_empty_Forward = False
warn_on_assignment_to_Forward = False
warn_on_multiple_string_args_to_oneof = False
warn_on_match_first_with_lshift_operator = False
enable_debug_on_named_expressions = False
_all_names = [__ for __ in locals() if not __.startswith("_")]
_warning_names = [name for name in _all_names if name.startswith("warn")]
_debug_names = [name for name in _all_names if name.startswith("enable_debug")]
def enable_all_warnings(cls) -> None:
for name in cls._warning_names:
cls.enable(name)
class Diagnostics(Enum):
"""
Diagnostic configuration (all default to disabled)
- ``warn_multiple_tokens_in_named_alternation`` - flag to enable warnings when a results
name is defined on a :class:`MatchFirst` or :class:`Or` expression with one or more :class:`And` subexpressions
- ``warn_ungrouped_named_tokens_in_collection`` - flag to enable warnings when a results
name is defined on a containing expression with ungrouped subexpressions that also
have results names
- ``warn_name_set_on_empty_Forward`` - flag to enable warnings when a :class:`Forward` is defined
with a results name, but has no contents defined
- ``warn_on_parse_using_empty_Forward`` - flag to enable warnings when a :class:`Forward` is
defined in a grammar but has never had an expression attached to it
- ``warn_on_assignment_to_Forward`` - flag to enable warnings when a :class:`Forward` is defined
but is overwritten by assigning using ``'='`` instead of ``'<<='`` or ``'<<'``
- ``warn_on_multiple_string_args_to_oneof`` - flag to enable warnings when :class:`one_of` is
incorrectly called with multiple str arguments
- ``enable_debug_on_named_expressions`` - flag to auto-enable debug on all subsequent
calls to :class:`ParserElement.set_name`
Diagnostics are enabled/disabled by calling :class:`enable_diag` and :class:`disable_diag`.
All warnings can be enabled by calling :class:`enable_all_warnings`.
"""
warn_multiple_tokens_in_named_alternation = 0
warn_ungrouped_named_tokens_in_collection = 1
warn_name_set_on_empty_Forward = 2
warn_on_parse_using_empty_Forward = 3
warn_on_assignment_to_Forward = 4
warn_on_multiple_string_args_to_oneof = 5
warn_on_match_first_with_lshift_operator = 6
enable_debug_on_named_expressions = 7
The provided code snippet includes necessary dependencies for implementing the `disable_diag` function. Write a Python function `def disable_diag(diag_enum: Diagnostics) -> None` to solve the following problem:
Disable a global pyparsing diagnostic flag (see :class:`Diagnostics`).
Here is the function:
def disable_diag(diag_enum: Diagnostics) -> None:
"""
Disable a global pyparsing diagnostic flag (see :class:`Diagnostics`).
"""
__diag__.disable(diag_enum.name) | Disable a global pyparsing diagnostic flag (see :class:`Diagnostics`). |
173,710 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
class __diag__(__config_flags):
_type_desc = "diagnostic"
warn_multiple_tokens_in_named_alternation = False
warn_ungrouped_named_tokens_in_collection = False
warn_name_set_on_empty_Forward = False
warn_on_parse_using_empty_Forward = False
warn_on_assignment_to_Forward = False
warn_on_multiple_string_args_to_oneof = False
warn_on_match_first_with_lshift_operator = False
enable_debug_on_named_expressions = False
_all_names = [__ for __ in locals() if not __.startswith("_")]
_warning_names = [name for name in _all_names if name.startswith("warn")]
_debug_names = [name for name in _all_names if name.startswith("enable_debug")]
def enable_all_warnings(cls) -> None:
for name in cls._warning_names:
cls.enable(name)
The provided code snippet includes necessary dependencies for implementing the `enable_all_warnings` function. Write a Python function `def enable_all_warnings() -> None` to solve the following problem:
Enable all global pyparsing diagnostic warnings (see :class:`Diagnostics`).
Here is the function:
def enable_all_warnings() -> None:
"""
Enable all global pyparsing diagnostic warnings (see :class:`Diagnostics`).
"""
__diag__.enable_all_warnings() | Enable all global pyparsing diagnostic warnings (see :class:`Diagnostics`). |
173,711 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
import typing
def _should_enable_warnings(
cmd_line_warn_options: typing.Iterable[str], warn_env_var: typing.Optional[str]
) -> bool:
enable = bool(warn_env_var)
for warn_opt in cmd_line_warn_options:
w_action, w_message, w_category, w_module, w_line = (warn_opt + "::::").split(
":"
)[:5]
if not w_action.lower().startswith("i") and (
not (w_message or w_category or w_module) or w_module == "pyparsing"
):
enable = True
elif w_action.lower().startswith("i") and w_module in ("pyparsing", ""):
enable = False
return enable | null |
173,712 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
ParseAction = Union[
Callable[[], Any],
Callable[[ParseResults], Any],
Callable[[int, ParseResults], Any],
Callable[[str, int, ParseResults], Any],
]
ParseCondition = Union[
Callable[[], bool],
Callable[[ParseResults], bool],
Callable[[int, ParseResults], bool],
Callable[[str, int, ParseResults], bool],
]
def _trim_arity(func, max_limit=3):
"""decorator to trim function calls to match the arity of the target"""
global _trim_arity_call_line
if func in _single_arg_builtins:
return lambda s, l, t: func(t)
limit = 0
found_arity = False
def extract_tb(tb, limit=0):
frames = traceback.extract_tb(tb, limit=limit)
frame_summary = frames[-1]
return [frame_summary[:2]]
# synthesize what would be returned by traceback.extract_stack at the call to
# user's parse action 'func', so that we don't incur call penalty at parse time
# fmt: off
LINE_DIFF = 7
# IF ANY CODE CHANGES, EVEN JUST COMMENTS OR BLANK LINES, BETWEEN THE NEXT LINE AND
# THE CALL TO FUNC INSIDE WRAPPER, LINE_DIFF MUST BE MODIFIED!!!!
_trim_arity_call_line = (_trim_arity_call_line or traceback.extract_stack(limit=2)[-1])
pa_call_line_synth = (_trim_arity_call_line[0], _trim_arity_call_line[1] + LINE_DIFF)
def wrapper(*args):
nonlocal found_arity, limit
while 1:
try:
ret = func(*args[limit:])
found_arity = True
return ret
except TypeError as te:
# re-raise TypeErrors if they did not come from our arity testing
if found_arity:
raise
else:
tb = te.__traceback__
trim_arity_type_error = (
extract_tb(tb, limit=2)[-1][:2] == pa_call_line_synth
)
del tb
if trim_arity_type_error:
if limit < max_limit:
limit += 1
continue
raise
# fmt: on
# copy func name to wrapper for sensible debug output
# (can't use functools.wraps, since that messes with function signature)
func_name = getattr(func, "__name__", getattr(func, "__class__").__name__)
wrapper.__name__ = func_name
wrapper.__doc__ = func.__doc__
return wrapper
def wraps(wrapped: _AnyCallable, assigned: Sequence[str] = ..., updated: Sequence[str] = ...) -> Callable[[_T], _T]: ...
class ParseException(ParseBaseException):
"""
Exception thrown when a parse expression doesn't match the input string
Example::
try:
Word(nums).set_name("integer").parse_string("ABC")
except ParseException as pe:
print(pe)
print("column: {}".format(pe.column))
prints::
Expected integer (at char 0), (line:1, col:1)
column: 1
"""
class ParseFatalException(ParseBaseException):
"""
User-throwable exception thrown when inconsistent parse content
is found; stops all parsing immediately
"""
The provided code snippet includes necessary dependencies for implementing the `condition_as_parse_action` function. Write a Python function `def condition_as_parse_action( fn: ParseCondition, message: str = None, fatal: bool = False ) -> ParseAction` to solve the following problem:
Function to convert a simple predicate function that returns ``True`` or ``False`` into a parse action. Can be used in places when a parse action is required and :class:`ParserElement.add_condition` cannot be used (such as when adding a condition to an operator level in :class:`infix_notation`). Optional keyword arguments: - ``message`` - define a custom message to be used in the raised exception - ``fatal`` - if True, will raise :class:`ParseFatalException` to stop parsing immediately; otherwise will raise :class:`ParseException`
Here is the function:
def condition_as_parse_action(
fn: ParseCondition, message: str = None, fatal: bool = False
) -> ParseAction:
"""
Function to convert a simple predicate function that returns ``True`` or ``False``
into a parse action. Can be used in places when a parse action is required
and :class:`ParserElement.add_condition` cannot be used (such as when adding a condition
to an operator level in :class:`infix_notation`).
Optional keyword arguments:
- ``message`` - define a custom message to be used in the raised exception
- ``fatal`` - if True, will raise :class:`ParseFatalException` to stop parsing immediately;
otherwise will raise :class:`ParseException`
"""
msg = message if message is not None else "failed user-defined condition"
exc_type = ParseFatalException if fatal else ParseException
fn = _trim_arity(fn)
@wraps(fn)
def pa(s, l, t):
if not bool(fn(s, l, t)):
raise exc_type(s, l, msg)
return pa | Function to convert a simple predicate function that returns ``True`` or ``False`` into a parse action. Can be used in places when a parse action is required and :class:`ParserElement.add_condition` cannot be used (such as when adding a condition to an operator level in :class:`infix_notation`). Optional keyword arguments: - ``message`` - define a custom message to be used in the raised exception - ``fatal`` - if True, will raise :class:`ParseFatalException` to stop parsing immediately; otherwise will raise :class:`ParseException` |
173,713 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
def _default_start_debug_action(
instring: str, loc: int, expr: "ParserElement", cache_hit: bool = False
):
cache_hit_str = "*" if cache_hit else ""
print(
(
"{}Match {} at loc {}({},{})\n {}\n {}^".format(
cache_hit_str,
expr,
loc,
lineno(loc, instring),
col(loc, instring),
line(loc, instring),
" " * (col(loc, instring) - 1),
)
)
) | null |
173,714 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
class ParseResults:
"""Structured parse results, to provide multiple means of access to
the parsed data:
- as a list (``len(results)``)
- by list index (``results[0], results[1]``, etc.)
- by attribute (``results.<results_name>`` - see :class:`ParserElement.set_results_name`)
Example::
integer = Word(nums)
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
# date_str = (integer("year") + '/'
# + integer("month") + '/'
# + integer("day"))
# parse_string returns a ParseResults object
result = date_str.parse_string("1999/12/31")
def test(s, fn=repr):
print("{} -> {}".format(s, fn(eval(s))))
test("list(result)")
test("result[0]")
test("result['month']")
test("result.day")
test("'month' in result")
test("'minutes' in result")
test("result.dump()", str)
prints::
list(result) -> ['1999', '/', '12', '/', '31']
result[0] -> '1999'
result['month'] -> '12'
result.day -> '31'
'month' in result -> True
'minutes' in result -> False
result.dump() -> ['1999', '/', '12', '/', '31']
- day: '31'
- month: '12'
- year: '1999'
"""
_null_values: Tuple[Any, ...] = (None, [], "", ())
__slots__ = [
"_name",
"_parent",
"_all_names",
"_modal",
"_toklist",
"_tokdict",
"__weakref__",
]
class List(list):
"""
Simple wrapper class to distinguish parsed list results that should be preserved
as actual Python lists, instead of being converted to :class:`ParseResults`:
LBRACK, RBRACK = map(pp.Suppress, "[]")
element = pp.Forward()
item = ppc.integer
element_list = LBRACK + pp.delimited_list(element) + RBRACK
# add parse actions to convert from ParseResults to actual Python collection types
def as_python_list(t):
return pp.ParseResults.List(t.as_list())
element_list.add_parse_action(as_python_list)
element <<= item | element_list
element.run_tests('''
100
[2,3,4]
[[2, 1],3,4]
[(2, 1),3,4]
(2,3,4)
''', post_parse=lambda s, r: (r[0], type(r[0])))
prints:
100
(100, <class 'int'>)
[2,3,4]
([2, 3, 4], <class 'list'>)
[[2, 1],3,4]
([[2, 1], 3, 4], <class 'list'>)
(Used internally by :class:`Group` when `aslist=True`.)
"""
def __new__(cls, contained=None):
if contained is None:
contained = []
if not isinstance(contained, list):
raise TypeError(
"{} may only be constructed with a list,"
" not {}".format(cls.__name__, type(contained).__name__)
)
return list.__new__(cls)
def __new__(cls, toklist=None, name=None, **kwargs):
if isinstance(toklist, ParseResults):
return toklist
self = object.__new__(cls)
self._name = None
self._parent = None
self._all_names = set()
if toklist is None:
self._toklist = []
elif isinstance(toklist, (list, _generator_type)):
self._toklist = (
[toklist[:]]
if isinstance(toklist, ParseResults.List)
else list(toklist)
)
else:
self._toklist = [toklist]
self._tokdict = dict()
return self
# Performance tuning: we construct a *lot* of these, so keep this
# constructor as small and fast as possible
def __init__(
self, toklist=None, name=None, asList=True, modal=True, isinstance=isinstance
):
self._modal = modal
if name is not None and name != "":
if isinstance(name, int):
name = str(name)
if not modal:
self._all_names = {name}
self._name = name
if toklist not in self._null_values:
if isinstance(toklist, (str_type, type)):
toklist = [toklist]
if asList:
if isinstance(toklist, ParseResults):
self[name] = _ParseResultsWithOffset(
ParseResults(toklist._toklist), 0
)
else:
self[name] = _ParseResultsWithOffset(
ParseResults(toklist[0]), 0
)
self[name]._name = name
else:
try:
self[name] = toklist[0]
except (KeyError, TypeError, IndexError):
if toklist is not self:
self[name] = toklist
else:
self._name = name
def __getitem__(self, i):
if isinstance(i, (int, slice)):
return self._toklist[i]
else:
if i not in self._all_names:
return self._tokdict[i][-1][0]
else:
return ParseResults([v[0] for v in self._tokdict[i]])
def __setitem__(self, k, v, isinstance=isinstance):
if isinstance(v, _ParseResultsWithOffset):
self._tokdict[k] = self._tokdict.get(k, list()) + [v]
sub = v[0]
elif isinstance(k, (int, slice)):
self._toklist[k] = v
sub = v
else:
self._tokdict[k] = self._tokdict.get(k, list()) + [
_ParseResultsWithOffset(v, 0)
]
sub = v
if isinstance(sub, ParseResults):
sub._parent = wkref(self)
def __delitem__(self, i):
if isinstance(i, (int, slice)):
mylen = len(self._toklist)
del self._toklist[i]
# convert int to slice
if isinstance(i, int):
if i < 0:
i += mylen
i = slice(i, i + 1)
# get removed indices
removed = list(range(*i.indices(mylen)))
removed.reverse()
# fixup indices in token dictionary
for name, occurrences in self._tokdict.items():
for j in removed:
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(
value, position - (position > j)
)
else:
del self._tokdict[i]
def __contains__(self, k) -> bool:
return k in self._tokdict
def __len__(self) -> int:
return len(self._toklist)
def __bool__(self) -> bool:
return not not (self._toklist or self._tokdict)
def __iter__(self) -> Iterator:
return iter(self._toklist)
def __reversed__(self) -> Iterator:
return iter(self._toklist[::-1])
def keys(self):
return iter(self._tokdict)
def values(self):
return (self[k] for k in self.keys())
def items(self):
return ((k, self[k]) for k in self.keys())
def haskeys(self) -> bool:
"""
Since ``keys()`` returns an iterator, this method is helpful in bypassing
code that looks for the existence of any defined results names."""
return bool(self._tokdict)
def pop(self, *args, **kwargs):
"""
Removes and returns item at specified index (default= ``last``).
Supports both ``list`` and ``dict`` semantics for ``pop()``. If
passed no argument or an integer argument, it will use ``list``
semantics and pop tokens from the list of parsed tokens. If passed
a non-integer argument (most likely a string), it will use ``dict``
semantics and pop the corresponding value from any defined results
names. A second default return value argument is supported, just as in
``dict.pop()``.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
def remove_first(tokens):
tokens.pop(0)
numlist.add_parse_action(remove_first)
print(numlist.parse_string("0 123 321")) # -> ['123', '321']
label = Word(alphas)
patt = label("LABEL") + Word(nums)[1, ...]
print(patt.parse_string("AAB 123 321").dump())
# Use pop() in a parse action to remove named result (note that corresponding value is not
# removed from list form of results)
def remove_LABEL(tokens):
tokens.pop("LABEL")
return tokens
patt.add_parse_action(remove_LABEL)
print(patt.parse_string("AAB 123 321").dump())
prints::
['AAB', '123', '321']
- LABEL: 'AAB'
['AAB', '123', '321']
"""
if not args:
args = [-1]
for k, v in kwargs.items():
if k == "default":
args = (args[0], v)
else:
raise TypeError(
"pop() got an unexpected keyword argument {!r}".format(k)
)
if isinstance(args[0], int) or len(args) == 1 or args[0] in self:
index = args[0]
ret = self[index]
del self[index]
return ret
else:
defaultvalue = args[1]
return defaultvalue
def get(self, key, default_value=None):
"""
Returns named result matching the given key, or if there is no
such name, then returns the given ``default_value`` or ``None`` if no
``default_value`` is specified.
Similar to ``dict.get()``.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string("1999/12/31")
print(result.get("year")) # -> '1999'
print(result.get("hour", "not specified")) # -> 'not specified'
print(result.get("hour")) # -> None
"""
if key in self:
return self[key]
else:
return default_value
def insert(self, index, ins_string):
"""
Inserts new element at location index in the list of parsed tokens.
Similar to ``list.insert()``.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
# use a parse action to insert the parse location in the front of the parsed results
def insert_locn(locn, tokens):
tokens.insert(0, locn)
numlist.add_parse_action(insert_locn)
print(numlist.parse_string("0 123 321")) # -> [0, '0', '123', '321']
"""
self._toklist.insert(index, ins_string)
# fixup indices in token dictionary
for name, occurrences in self._tokdict.items():
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(
value, position + (position > index)
)
def append(self, item):
"""
Add single element to end of ``ParseResults`` list of elements.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
# use a parse action to compute the sum of the parsed integers, and add it to the end
def append_sum(tokens):
tokens.append(sum(map(int, tokens)))
numlist.add_parse_action(append_sum)
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321', 444]
"""
self._toklist.append(item)
def extend(self, itemseq):
"""
Add sequence of elements to end of ``ParseResults`` list of elements.
Example::
patt = Word(alphas)[1, ...]
# use a parse action to append the reverse of the matched strings, to make a palindrome
def make_palindrome(tokens):
tokens.extend(reversed([t[::-1] for t in tokens]))
return ''.join(tokens)
patt.add_parse_action(make_palindrome)
print(patt.parse_string("lskdj sdlkjf lksd")) # -> 'lskdjsdlkjflksddsklfjkldsjdksl'
"""
if isinstance(itemseq, ParseResults):
self.__iadd__(itemseq)
else:
self._toklist.extend(itemseq)
def clear(self):
"""
Clear all elements and results names.
"""
del self._toklist[:]
self._tokdict.clear()
def __getattr__(self, name):
try:
return self[name]
except KeyError:
if name.startswith("__"):
raise AttributeError(name)
return ""
def __add__(self, other) -> "ParseResults":
ret = self.copy()
ret += other
return ret
def __iadd__(self, other) -> "ParseResults":
if other._tokdict:
offset = len(self._toklist)
addoffset = lambda a: offset if a < 0 else a + offset
otheritems = other._tokdict.items()
otherdictitems = [
(k, _ParseResultsWithOffset(v[0], addoffset(v[1])))
for k, vlist in otheritems
for v in vlist
]
for k, v in otherdictitems:
self[k] = v
if isinstance(v[0], ParseResults):
v[0]._parent = wkref(self)
self._toklist += other._toklist
self._all_names |= other._all_names
return self
def __radd__(self, other) -> "ParseResults":
if isinstance(other, int) and other == 0:
# useful for merging many ParseResults using sum() builtin
return self.copy()
else:
# this may raise a TypeError - so be it
return other + self
def __repr__(self) -> str:
return "{}({!r}, {})".format(type(self).__name__, self._toklist, self.as_dict())
def __str__(self) -> str:
return (
"["
+ ", ".join(
[
str(i) if isinstance(i, ParseResults) else repr(i)
for i in self._toklist
]
)
+ "]"
)
def _asStringList(self, sep=""):
out = []
for item in self._toklist:
if out and sep:
out.append(sep)
if isinstance(item, ParseResults):
out += item._asStringList()
else:
out.append(str(item))
return out
def as_list(self) -> list:
"""
Returns the parse results as a nested list of matching tokens, all converted to strings.
Example::
patt = Word(alphas)[1, ...]
result = patt.parse_string("sldkj lsdkj sldkj")
# even though the result prints in string-like form, it is actually a pyparsing ParseResults
print(type(result), result) # -> <class 'pyparsing.ParseResults'> ['sldkj', 'lsdkj', 'sldkj']
# Use as_list() to create an actual list
result_list = result.as_list()
print(type(result_list), result_list) # -> <class 'list'> ['sldkj', 'lsdkj', 'sldkj']
"""
return [
res.as_list() if isinstance(res, ParseResults) else res
for res in self._toklist
]
def as_dict(self) -> dict:
"""
Returns the named parse results as a nested dictionary.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string('12/31/1999')
print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]})
result_dict = result.as_dict()
print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'}
# even though a ParseResults supports dict-like access, sometime you just need to have a dict
import json
print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable
print(json.dumps(result.as_dict())) # -> {"month": "31", "day": "1999", "year": "12"}
"""
def to_item(obj):
if isinstance(obj, ParseResults):
return obj.as_dict() if obj.haskeys() else [to_item(v) for v in obj]
else:
return obj
return dict((k, to_item(v)) for k, v in self.items())
def copy(self) -> "ParseResults":
"""
Returns a new copy of a :class:`ParseResults` object.
"""
ret = ParseResults(self._toklist)
ret._tokdict = self._tokdict.copy()
ret._parent = self._parent
ret._all_names |= self._all_names
ret._name = self._name
return ret
def get_name(self):
r"""
Returns the results name for this token expression. Useful when several
different expressions might match at a particular location.
Example::
integer = Word(nums)
ssn_expr = Regex(r"\d\d\d-\d\d-\d\d\d\d")
house_number_expr = Suppress('#') + Word(nums, alphanums)
user_data = (Group(house_number_expr)("house_number")
| Group(ssn_expr)("ssn")
| Group(integer)("age"))
user_info = user_data[1, ...]
result = user_info.parse_string("22 111-22-3333 #221B")
for item in result:
print(item.get_name(), ':', item[0])
prints::
age : 22
ssn : 111-22-3333
house_number : 221B
"""
if self._name:
return self._name
elif self._parent:
par = self._parent()
def find_in_parent(sub):
return next(
(
k
for k, vlist in par._tokdict.items()
for v, loc in vlist
if sub is v
),
None,
)
return find_in_parent(self) if par else None
elif (
len(self) == 1
and len(self._tokdict) == 1
and next(iter(self._tokdict.values()))[0][1] in (0, -1)
):
return next(iter(self._tokdict.keys()))
else:
return None
def dump(self, indent="", full=True, include_list=True, _depth=0) -> str:
"""
Diagnostic method for listing out the contents of
a :class:`ParseResults`. Accepts an optional ``indent`` argument so
that this string can be embedded in a nested display of other data.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string('1999/12/31')
print(result.dump())
prints::
['1999', '/', '12', '/', '31']
- day: '31'
- month: '12'
- year: '1999'
"""
out = []
NL = "\n"
out.append(indent + str(self.as_list()) if include_list else "")
if full:
if self.haskeys():
items = sorted((str(k), v) for k, v in self.items())
for k, v in items:
if out:
out.append(NL)
out.append("{}{}- {}: ".format(indent, (" " * _depth), k))
if isinstance(v, ParseResults):
if v:
out.append(
v.dump(
indent=indent,
full=full,
include_list=include_list,
_depth=_depth + 1,
)
)
else:
out.append(str(v))
else:
out.append(repr(v))
if any(isinstance(vv, ParseResults) for vv in self):
v = self
for i, vv in enumerate(v):
if isinstance(vv, ParseResults):
out.append(
"\n{}{}[{}]:\n{}{}{}".format(
indent,
(" " * (_depth)),
i,
indent,
(" " * (_depth + 1)),
vv.dump(
indent=indent,
full=full,
include_list=include_list,
_depth=_depth + 1,
),
)
)
else:
out.append(
"\n%s%s[%d]:\n%s%s%s"
% (
indent,
(" " * (_depth)),
i,
indent,
(" " * (_depth + 1)),
str(vv),
)
)
return "".join(out)
def pprint(self, *args, **kwargs):
"""
Pretty-printer for parsed results as a list, using the
`pprint <https://docs.python.org/3/library/pprint.html>`_ module.
Accepts additional positional or keyword args as defined for
`pprint.pprint <https://docs.python.org/3/library/pprint.html#pprint.pprint>`_ .
Example::
ident = Word(alphas, alphanums)
num = Word(nums)
func = Forward()
term = ident | num | Group('(' + func + ')')
func <<= ident + Group(Optional(delimited_list(term)))
result = func.parse_string("fna a,b,(fnb c,d,200),100")
result.pprint(width=40)
prints::
['fna',
['a',
'b',
['(', 'fnb', ['c', 'd', '200'], ')'],
'100']]
"""
pprint.pprint(self.as_list(), *args, **kwargs)
# add support for pickle protocol
def __getstate__(self):
return (
self._toklist,
(
self._tokdict.copy(),
self._parent is not None and self._parent() or None,
self._all_names,
self._name,
),
)
def __setstate__(self, state):
self._toklist, (self._tokdict, par, inAccumNames, self._name) = state
self._all_names = set(inAccumNames)
if par is not None:
self._parent = wkref(par)
else:
self._parent = None
def __getnewargs__(self):
return self._toklist, self._name
def __dir__(self):
return dir(type(self)) + list(self.keys())
def from_dict(cls, other, name=None) -> "ParseResults":
"""
Helper classmethod to construct a ``ParseResults`` from a ``dict``, preserving the
name-value relations as results names. If an optional ``name`` argument is
given, a nested ``ParseResults`` will be returned.
"""
def is_iterable(obj):
try:
iter(obj)
except Exception:
return False
else:
return not isinstance(obj, str_type)
ret = cls([])
for k, v in other.items():
if isinstance(v, Mapping):
ret += cls.from_dict(v, name=k)
else:
ret += cls([v], name=k, asList=is_iterable(v))
if name is not None:
ret = cls([ret], name=name)
return ret
asList = as_list
asDict = as_dict
getName = get_name
def _default_success_debug_action(
instring: str,
startloc: int,
endloc: int,
expr: "ParserElement",
toks: ParseResults,
cache_hit: bool = False,
):
cache_hit_str = "*" if cache_hit else ""
print("{}Matched {} -> {}".format(cache_hit_str, expr, toks.as_list())) | null |
173,715 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
def _default_exception_debug_action(
instring: str,
loc: int,
expr: "ParserElement",
exc: Exception,
cache_hit: bool = False,
):
cache_hit_str = "*" if cache_hit else ""
print(
"{}Match {} failed, {} raised: {}".format(
cache_hit_str, expr, type(exc).__name__, exc
)
) | null |
173,716 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
The provided code snippet includes necessary dependencies for implementing the `null_debug_action` function. Write a Python function `def null_debug_action(*args)` to solve the following problem:
Do-nothing' debug action, to suppress debugging output during parsing.
Here is the function:
def null_debug_action(*args):
"""'Do-nothing' debug action, to suppress debugging output during parsing.""" | Do-nothing' debug action, to suppress debugging output during parsing. |
173,717 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
if sys.version_info >= (3, 8):
from functools import cached_property
else:
ParseAction = Union[
Callable[[], Any],
Callable[[ParseResults], Any],
Callable[[int, ParseResults], Any],
Callable[[str, int, ParseResults], Any],
]
def _trim_arity(func, max_limit=3):
"""decorator to trim function calls to match the arity of the target"""
global _trim_arity_call_line
if func in _single_arg_builtins:
return lambda s, l, t: func(t)
limit = 0
found_arity = False
def extract_tb(tb, limit=0):
frames = traceback.extract_tb(tb, limit=limit)
frame_summary = frames[-1]
return [frame_summary[:2]]
# synthesize what would be returned by traceback.extract_stack at the call to
# user's parse action 'func', so that we don't incur call penalty at parse time
# fmt: off
LINE_DIFF = 7
# IF ANY CODE CHANGES, EVEN JUST COMMENTS OR BLANK LINES, BETWEEN THE NEXT LINE AND
# THE CALL TO FUNC INSIDE WRAPPER, LINE_DIFF MUST BE MODIFIED!!!!
_trim_arity_call_line = (_trim_arity_call_line or traceback.extract_stack(limit=2)[-1])
pa_call_line_synth = (_trim_arity_call_line[0], _trim_arity_call_line[1] + LINE_DIFF)
def wrapper(*args):
nonlocal found_arity, limit
while 1:
try:
ret = func(*args[limit:])
found_arity = True
return ret
except TypeError as te:
# re-raise TypeErrors if they did not come from our arity testing
if found_arity:
raise
else:
tb = te.__traceback__
trim_arity_type_error = (
extract_tb(tb, limit=2)[-1][:2] == pa_call_line_synth
)
del tb
if trim_arity_type_error:
if limit < max_limit:
limit += 1
continue
raise
# fmt: on
# copy func name to wrapper for sensible debug output
# (can't use functools.wraps, since that messes with function signature)
func_name = getattr(func, "__name__", getattr(func, "__class__").__name__)
wrapper.__name__ = func_name
wrapper.__doc__ = func.__doc__
return wrapper
import sys
The provided code snippet includes necessary dependencies for implementing the `trace_parse_action` function. Write a Python function `def trace_parse_action(f: ParseAction) -> ParseAction` to solve the following problem:
Decorator for debugging parse actions. When the parse action is called, this decorator will print ``">> entering method-name(line:<current_source_line>, <parse_location>, <matched_tokens>)"``. When the parse action completes, the decorator will print ``"<<"`` followed by the returned value, or any exception that the parse action raised. Example:: wd = Word(alphas) @trace_parse_action def remove_duplicate_chars(tokens): return ''.join(sorted(set(''.join(tokens)))) wds = wd[1, ...].set_parse_action(remove_duplicate_chars) print(wds.parse_string("slkdjs sld sldd sdlf sdljf")) prints:: >>entering remove_duplicate_chars(line: 'slkdjs sld sldd sdlf sdljf', 0, (['slkdjs', 'sld', 'sldd', 'sdlf', 'sdljf'], {})) <<leaving remove_duplicate_chars (ret: 'dfjkls') ['dfjkls']
Here is the function:
def trace_parse_action(f: ParseAction) -> ParseAction:
"""Decorator for debugging parse actions.
When the parse action is called, this decorator will print
``">> entering method-name(line:<current_source_line>, <parse_location>, <matched_tokens>)"``.
When the parse action completes, the decorator will print
``"<<"`` followed by the returned value, or any exception that the parse action raised.
Example::
wd = Word(alphas)
@trace_parse_action
def remove_duplicate_chars(tokens):
return ''.join(sorted(set(''.join(tokens))))
wds = wd[1, ...].set_parse_action(remove_duplicate_chars)
print(wds.parse_string("slkdjs sld sldd sdlf sdljf"))
prints::
>>entering remove_duplicate_chars(line: 'slkdjs sld sldd sdlf sdljf', 0, (['slkdjs', 'sld', 'sldd', 'sdlf', 'sdljf'], {}))
<<leaving remove_duplicate_chars (ret: 'dfjkls')
['dfjkls']
"""
f = _trim_arity(f)
def z(*paArgs):
thisFunc = f.__name__
s, l, t = paArgs[-3:]
if len(paArgs) > 3:
thisFunc = paArgs[0].__class__.__name__ + "." + thisFunc
sys.stderr.write(
">>entering {}(line: {!r}, {}, {!r})\n".format(thisFunc, line(l, s), l, t)
)
try:
ret = f(*paArgs)
except Exception as exc:
sys.stderr.write("<<leaving {} (exception: {})\n".format(thisFunc, exc))
raise
sys.stderr.write("<<leaving {} (ret: {!r})\n".format(thisFunc, ret))
return ret
z.__name__ = f.__name__
return z | Decorator for debugging parse actions. When the parse action is called, this decorator will print ``">> entering method-name(line:<current_source_line>, <parse_location>, <matched_tokens>)"``. When the parse action completes, the decorator will print ``"<<"`` followed by the returned value, or any exception that the parse action raised. Example:: wd = Word(alphas) @trace_parse_action def remove_duplicate_chars(tokens): return ''.join(sorted(set(''.join(tokens)))) wds = wd[1, ...].set_parse_action(remove_duplicate_chars) print(wds.parse_string("slkdjs sld sldd sdlf sdljf")) prints:: >>entering remove_duplicate_chars(line: 'slkdjs sld sldd sdlf sdljf', 0, (['slkdjs', 'sld', 'sldd', 'sdlf', 'sdljf'], {})) <<leaving remove_duplicate_chars (ret: 'dfjkls') ['dfjkls'] |
173,718 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
_reBracketExpr = (
Literal("[")
+ Opt("^").set_results_name("negate")
+ Group(OneOrMore(_charRange | _singleChar)).set_results_name("body")
+ "]"
)
class ParseResults:
"""Structured parse results, to provide multiple means of access to
the parsed data:
- as a list (``len(results)``)
- by list index (``results[0], results[1]``, etc.)
- by attribute (``results.<results_name>`` - see :class:`ParserElement.set_results_name`)
Example::
integer = Word(nums)
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
# date_str = (integer("year") + '/'
# + integer("month") + '/'
# + integer("day"))
# parse_string returns a ParseResults object
result = date_str.parse_string("1999/12/31")
def test(s, fn=repr):
print("{} -> {}".format(s, fn(eval(s))))
test("list(result)")
test("result[0]")
test("result['month']")
test("result.day")
test("'month' in result")
test("'minutes' in result")
test("result.dump()", str)
prints::
list(result) -> ['1999', '/', '12', '/', '31']
result[0] -> '1999'
result['month'] -> '12'
result.day -> '31'
'month' in result -> True
'minutes' in result -> False
result.dump() -> ['1999', '/', '12', '/', '31']
- day: '31'
- month: '12'
- year: '1999'
"""
_null_values: Tuple[Any, ...] = (None, [], "", ())
__slots__ = [
"_name",
"_parent",
"_all_names",
"_modal",
"_toklist",
"_tokdict",
"__weakref__",
]
class List(list):
"""
Simple wrapper class to distinguish parsed list results that should be preserved
as actual Python lists, instead of being converted to :class:`ParseResults`:
LBRACK, RBRACK = map(pp.Suppress, "[]")
element = pp.Forward()
item = ppc.integer
element_list = LBRACK + pp.delimited_list(element) + RBRACK
# add parse actions to convert from ParseResults to actual Python collection types
def as_python_list(t):
return pp.ParseResults.List(t.as_list())
element_list.add_parse_action(as_python_list)
element <<= item | element_list
element.run_tests('''
100
[2,3,4]
[[2, 1],3,4]
[(2, 1),3,4]
(2,3,4)
''', post_parse=lambda s, r: (r[0], type(r[0])))
prints:
100
(100, <class 'int'>)
[2,3,4]
([2, 3, 4], <class 'list'>)
[[2, 1],3,4]
([[2, 1], 3, 4], <class 'list'>)
(Used internally by :class:`Group` when `aslist=True`.)
"""
def __new__(cls, contained=None):
if contained is None:
contained = []
if not isinstance(contained, list):
raise TypeError(
"{} may only be constructed with a list,"
" not {}".format(cls.__name__, type(contained).__name__)
)
return list.__new__(cls)
def __new__(cls, toklist=None, name=None, **kwargs):
if isinstance(toklist, ParseResults):
return toklist
self = object.__new__(cls)
self._name = None
self._parent = None
self._all_names = set()
if toklist is None:
self._toklist = []
elif isinstance(toklist, (list, _generator_type)):
self._toklist = (
[toklist[:]]
if isinstance(toklist, ParseResults.List)
else list(toklist)
)
else:
self._toklist = [toklist]
self._tokdict = dict()
return self
# Performance tuning: we construct a *lot* of these, so keep this
# constructor as small and fast as possible
def __init__(
self, toklist=None, name=None, asList=True, modal=True, isinstance=isinstance
):
self._modal = modal
if name is not None and name != "":
if isinstance(name, int):
name = str(name)
if not modal:
self._all_names = {name}
self._name = name
if toklist not in self._null_values:
if isinstance(toklist, (str_type, type)):
toklist = [toklist]
if asList:
if isinstance(toklist, ParseResults):
self[name] = _ParseResultsWithOffset(
ParseResults(toklist._toklist), 0
)
else:
self[name] = _ParseResultsWithOffset(
ParseResults(toklist[0]), 0
)
self[name]._name = name
else:
try:
self[name] = toklist[0]
except (KeyError, TypeError, IndexError):
if toklist is not self:
self[name] = toklist
else:
self._name = name
def __getitem__(self, i):
if isinstance(i, (int, slice)):
return self._toklist[i]
else:
if i not in self._all_names:
return self._tokdict[i][-1][0]
else:
return ParseResults([v[0] for v in self._tokdict[i]])
def __setitem__(self, k, v, isinstance=isinstance):
if isinstance(v, _ParseResultsWithOffset):
self._tokdict[k] = self._tokdict.get(k, list()) + [v]
sub = v[0]
elif isinstance(k, (int, slice)):
self._toklist[k] = v
sub = v
else:
self._tokdict[k] = self._tokdict.get(k, list()) + [
_ParseResultsWithOffset(v, 0)
]
sub = v
if isinstance(sub, ParseResults):
sub._parent = wkref(self)
def __delitem__(self, i):
if isinstance(i, (int, slice)):
mylen = len(self._toklist)
del self._toklist[i]
# convert int to slice
if isinstance(i, int):
if i < 0:
i += mylen
i = slice(i, i + 1)
# get removed indices
removed = list(range(*i.indices(mylen)))
removed.reverse()
# fixup indices in token dictionary
for name, occurrences in self._tokdict.items():
for j in removed:
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(
value, position - (position > j)
)
else:
del self._tokdict[i]
def __contains__(self, k) -> bool:
return k in self._tokdict
def __len__(self) -> int:
return len(self._toklist)
def __bool__(self) -> bool:
return not not (self._toklist or self._tokdict)
def __iter__(self) -> Iterator:
return iter(self._toklist)
def __reversed__(self) -> Iterator:
return iter(self._toklist[::-1])
def keys(self):
return iter(self._tokdict)
def values(self):
return (self[k] for k in self.keys())
def items(self):
return ((k, self[k]) for k in self.keys())
def haskeys(self) -> bool:
"""
Since ``keys()`` returns an iterator, this method is helpful in bypassing
code that looks for the existence of any defined results names."""
return bool(self._tokdict)
def pop(self, *args, **kwargs):
"""
Removes and returns item at specified index (default= ``last``).
Supports both ``list`` and ``dict`` semantics for ``pop()``. If
passed no argument or an integer argument, it will use ``list``
semantics and pop tokens from the list of parsed tokens. If passed
a non-integer argument (most likely a string), it will use ``dict``
semantics and pop the corresponding value from any defined results
names. A second default return value argument is supported, just as in
``dict.pop()``.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
def remove_first(tokens):
tokens.pop(0)
numlist.add_parse_action(remove_first)
print(numlist.parse_string("0 123 321")) # -> ['123', '321']
label = Word(alphas)
patt = label("LABEL") + Word(nums)[1, ...]
print(patt.parse_string("AAB 123 321").dump())
# Use pop() in a parse action to remove named result (note that corresponding value is not
# removed from list form of results)
def remove_LABEL(tokens):
tokens.pop("LABEL")
return tokens
patt.add_parse_action(remove_LABEL)
print(patt.parse_string("AAB 123 321").dump())
prints::
['AAB', '123', '321']
- LABEL: 'AAB'
['AAB', '123', '321']
"""
if not args:
args = [-1]
for k, v in kwargs.items():
if k == "default":
args = (args[0], v)
else:
raise TypeError(
"pop() got an unexpected keyword argument {!r}".format(k)
)
if isinstance(args[0], int) or len(args) == 1 or args[0] in self:
index = args[0]
ret = self[index]
del self[index]
return ret
else:
defaultvalue = args[1]
return defaultvalue
def get(self, key, default_value=None):
"""
Returns named result matching the given key, or if there is no
such name, then returns the given ``default_value`` or ``None`` if no
``default_value`` is specified.
Similar to ``dict.get()``.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string("1999/12/31")
print(result.get("year")) # -> '1999'
print(result.get("hour", "not specified")) # -> 'not specified'
print(result.get("hour")) # -> None
"""
if key in self:
return self[key]
else:
return default_value
def insert(self, index, ins_string):
"""
Inserts new element at location index in the list of parsed tokens.
Similar to ``list.insert()``.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
# use a parse action to insert the parse location in the front of the parsed results
def insert_locn(locn, tokens):
tokens.insert(0, locn)
numlist.add_parse_action(insert_locn)
print(numlist.parse_string("0 123 321")) # -> [0, '0', '123', '321']
"""
self._toklist.insert(index, ins_string)
# fixup indices in token dictionary
for name, occurrences in self._tokdict.items():
for k, (value, position) in enumerate(occurrences):
occurrences[k] = _ParseResultsWithOffset(
value, position + (position > index)
)
def append(self, item):
"""
Add single element to end of ``ParseResults`` list of elements.
Example::
numlist = Word(nums)[...]
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321']
# use a parse action to compute the sum of the parsed integers, and add it to the end
def append_sum(tokens):
tokens.append(sum(map(int, tokens)))
numlist.add_parse_action(append_sum)
print(numlist.parse_string("0 123 321")) # -> ['0', '123', '321', 444]
"""
self._toklist.append(item)
def extend(self, itemseq):
"""
Add sequence of elements to end of ``ParseResults`` list of elements.
Example::
patt = Word(alphas)[1, ...]
# use a parse action to append the reverse of the matched strings, to make a palindrome
def make_palindrome(tokens):
tokens.extend(reversed([t[::-1] for t in tokens]))
return ''.join(tokens)
patt.add_parse_action(make_palindrome)
print(patt.parse_string("lskdj sdlkjf lksd")) # -> 'lskdjsdlkjflksddsklfjkldsjdksl'
"""
if isinstance(itemseq, ParseResults):
self.__iadd__(itemseq)
else:
self._toklist.extend(itemseq)
def clear(self):
"""
Clear all elements and results names.
"""
del self._toklist[:]
self._tokdict.clear()
def __getattr__(self, name):
try:
return self[name]
except KeyError:
if name.startswith("__"):
raise AttributeError(name)
return ""
def __add__(self, other) -> "ParseResults":
ret = self.copy()
ret += other
return ret
def __iadd__(self, other) -> "ParseResults":
if other._tokdict:
offset = len(self._toklist)
addoffset = lambda a: offset if a < 0 else a + offset
otheritems = other._tokdict.items()
otherdictitems = [
(k, _ParseResultsWithOffset(v[0], addoffset(v[1])))
for k, vlist in otheritems
for v in vlist
]
for k, v in otherdictitems:
self[k] = v
if isinstance(v[0], ParseResults):
v[0]._parent = wkref(self)
self._toklist += other._toklist
self._all_names |= other._all_names
return self
def __radd__(self, other) -> "ParseResults":
if isinstance(other, int) and other == 0:
# useful for merging many ParseResults using sum() builtin
return self.copy()
else:
# this may raise a TypeError - so be it
return other + self
def __repr__(self) -> str:
return "{}({!r}, {})".format(type(self).__name__, self._toklist, self.as_dict())
def __str__(self) -> str:
return (
"["
+ ", ".join(
[
str(i) if isinstance(i, ParseResults) else repr(i)
for i in self._toklist
]
)
+ "]"
)
def _asStringList(self, sep=""):
out = []
for item in self._toklist:
if out and sep:
out.append(sep)
if isinstance(item, ParseResults):
out += item._asStringList()
else:
out.append(str(item))
return out
def as_list(self) -> list:
"""
Returns the parse results as a nested list of matching tokens, all converted to strings.
Example::
patt = Word(alphas)[1, ...]
result = patt.parse_string("sldkj lsdkj sldkj")
# even though the result prints in string-like form, it is actually a pyparsing ParseResults
print(type(result), result) # -> <class 'pyparsing.ParseResults'> ['sldkj', 'lsdkj', 'sldkj']
# Use as_list() to create an actual list
result_list = result.as_list()
print(type(result_list), result_list) # -> <class 'list'> ['sldkj', 'lsdkj', 'sldkj']
"""
return [
res.as_list() if isinstance(res, ParseResults) else res
for res in self._toklist
]
def as_dict(self) -> dict:
"""
Returns the named parse results as a nested dictionary.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string('12/31/1999')
print(type(result), repr(result)) # -> <class 'pyparsing.ParseResults'> (['12', '/', '31', '/', '1999'], {'day': [('1999', 4)], 'year': [('12', 0)], 'month': [('31', 2)]})
result_dict = result.as_dict()
print(type(result_dict), repr(result_dict)) # -> <class 'dict'> {'day': '1999', 'year': '12', 'month': '31'}
# even though a ParseResults supports dict-like access, sometime you just need to have a dict
import json
print(json.dumps(result)) # -> Exception: TypeError: ... is not JSON serializable
print(json.dumps(result.as_dict())) # -> {"month": "31", "day": "1999", "year": "12"}
"""
def to_item(obj):
if isinstance(obj, ParseResults):
return obj.as_dict() if obj.haskeys() else [to_item(v) for v in obj]
else:
return obj
return dict((k, to_item(v)) for k, v in self.items())
def copy(self) -> "ParseResults":
"""
Returns a new copy of a :class:`ParseResults` object.
"""
ret = ParseResults(self._toklist)
ret._tokdict = self._tokdict.copy()
ret._parent = self._parent
ret._all_names |= self._all_names
ret._name = self._name
return ret
def get_name(self):
r"""
Returns the results name for this token expression. Useful when several
different expressions might match at a particular location.
Example::
integer = Word(nums)
ssn_expr = Regex(r"\d\d\d-\d\d-\d\d\d\d")
house_number_expr = Suppress('#') + Word(nums, alphanums)
user_data = (Group(house_number_expr)("house_number")
| Group(ssn_expr)("ssn")
| Group(integer)("age"))
user_info = user_data[1, ...]
result = user_info.parse_string("22 111-22-3333 #221B")
for item in result:
print(item.get_name(), ':', item[0])
prints::
age : 22
ssn : 111-22-3333
house_number : 221B
"""
if self._name:
return self._name
elif self._parent:
par = self._parent()
def find_in_parent(sub):
return next(
(
k
for k, vlist in par._tokdict.items()
for v, loc in vlist
if sub is v
),
None,
)
return find_in_parent(self) if par else None
elif (
len(self) == 1
and len(self._tokdict) == 1
and next(iter(self._tokdict.values()))[0][1] in (0, -1)
):
return next(iter(self._tokdict.keys()))
else:
return None
def dump(self, indent="", full=True, include_list=True, _depth=0) -> str:
"""
Diagnostic method for listing out the contents of
a :class:`ParseResults`. Accepts an optional ``indent`` argument so
that this string can be embedded in a nested display of other data.
Example::
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
result = date_str.parse_string('1999/12/31')
print(result.dump())
prints::
['1999', '/', '12', '/', '31']
- day: '31'
- month: '12'
- year: '1999'
"""
out = []
NL = "\n"
out.append(indent + str(self.as_list()) if include_list else "")
if full:
if self.haskeys():
items = sorted((str(k), v) for k, v in self.items())
for k, v in items:
if out:
out.append(NL)
out.append("{}{}- {}: ".format(indent, (" " * _depth), k))
if isinstance(v, ParseResults):
if v:
out.append(
v.dump(
indent=indent,
full=full,
include_list=include_list,
_depth=_depth + 1,
)
)
else:
out.append(str(v))
else:
out.append(repr(v))
if any(isinstance(vv, ParseResults) for vv in self):
v = self
for i, vv in enumerate(v):
if isinstance(vv, ParseResults):
out.append(
"\n{}{}[{}]:\n{}{}{}".format(
indent,
(" " * (_depth)),
i,
indent,
(" " * (_depth + 1)),
vv.dump(
indent=indent,
full=full,
include_list=include_list,
_depth=_depth + 1,
),
)
)
else:
out.append(
"\n%s%s[%d]:\n%s%s%s"
% (
indent,
(" " * (_depth)),
i,
indent,
(" " * (_depth + 1)),
str(vv),
)
)
return "".join(out)
def pprint(self, *args, **kwargs):
"""
Pretty-printer for parsed results as a list, using the
`pprint <https://docs.python.org/3/library/pprint.html>`_ module.
Accepts additional positional or keyword args as defined for
`pprint.pprint <https://docs.python.org/3/library/pprint.html#pprint.pprint>`_ .
Example::
ident = Word(alphas, alphanums)
num = Word(nums)
func = Forward()
term = ident | num | Group('(' + func + ')')
func <<= ident + Group(Optional(delimited_list(term)))
result = func.parse_string("fna a,b,(fnb c,d,200),100")
result.pprint(width=40)
prints::
['fna',
['a',
'b',
['(', 'fnb', ['c', 'd', '200'], ')'],
'100']]
"""
pprint.pprint(self.as_list(), *args, **kwargs)
# add support for pickle protocol
def __getstate__(self):
return (
self._toklist,
(
self._tokdict.copy(),
self._parent is not None and self._parent() or None,
self._all_names,
self._name,
),
)
def __setstate__(self, state):
self._toklist, (self._tokdict, par, inAccumNames, self._name) = state
self._all_names = set(inAccumNames)
if par is not None:
self._parent = wkref(par)
else:
self._parent = None
def __getnewargs__(self):
return self._toklist, self._name
def __dir__(self):
return dir(type(self)) + list(self.keys())
def from_dict(cls, other, name=None) -> "ParseResults":
"""
Helper classmethod to construct a ``ParseResults`` from a ``dict``, preserving the
name-value relations as results names. If an optional ``name`` argument is
given, a nested ``ParseResults`` will be returned.
"""
def is_iterable(obj):
try:
iter(obj)
except Exception:
return False
else:
return not isinstance(obj, str_type)
ret = cls([])
for k, v in other.items():
if isinstance(v, Mapping):
ret += cls.from_dict(v, name=k)
else:
ret += cls([v], name=k, asList=is_iterable(v))
if name is not None:
ret = cls([ret], name=name)
return ret
asList = as_list
asDict = as_dict
getName = get_name
The provided code snippet includes necessary dependencies for implementing the `srange` function. Write a Python function `def srange(s: str) -> str` to solve the following problem:
r"""Helper to easily define string ranges for use in :class:`Word` construction. Borrows syntax from regexp ``'[]'`` string range definitions:: srange("[0-9]") -> "0123456789" srange("[a-z]") -> "abcdefghijklmnopqrstuvwxyz" srange("[a-z$_]") -> "abcdefghijklmnopqrstuvwxyz$_" The input string must be enclosed in []'s, and the returned string is the expanded character set joined into a single string. The values enclosed in the []'s may be: - a single character - an escaped character with a leading backslash (such as ``\-`` or ``\]``) - an escaped hex character with a leading ``'\x'`` (``\x21``, which is a ``'!'`` character) (``\0x##`` is also supported for backwards compatibility) - an escaped octal character with a leading ``'\0'`` (``\041``, which is a ``'!'`` character) - a range of any of the above, separated by a dash (``'a-z'``, etc.) - any combination of the above (``'aeiouy'``, ``'a-zA-Z0-9_$'``, etc.)
Here is the function:
def srange(s: str) -> str:
r"""Helper to easily define string ranges for use in :class:`Word`
construction. Borrows syntax from regexp ``'[]'`` string range
definitions::
srange("[0-9]") -> "0123456789"
srange("[a-z]") -> "abcdefghijklmnopqrstuvwxyz"
srange("[a-z$_]") -> "abcdefghijklmnopqrstuvwxyz$_"
The input string must be enclosed in []'s, and the returned string
is the expanded character set joined into a single string. The
values enclosed in the []'s may be:
- a single character
- an escaped character with a leading backslash (such as ``\-``
or ``\]``)
- an escaped hex character with a leading ``'\x'``
(``\x21``, which is a ``'!'`` character) (``\0x##``
is also supported for backwards compatibility)
- an escaped octal character with a leading ``'\0'``
(``\041``, which is a ``'!'`` character)
- a range of any of the above, separated by a dash (``'a-z'``,
etc.)
- any combination of the above (``'aeiouy'``,
``'a-zA-Z0-9_$'``, etc.)
"""
_expanded = (
lambda p: p
if not isinstance(p, ParseResults)
else "".join(chr(c) for c in range(ord(p[0]), ord(p[1]) + 1))
)
try:
return "".join(_expanded(part) for part in _reBracketExpr.parse_string(s).body)
except Exception:
return "" | r"""Helper to easily define string ranges for use in :class:`Word` construction. Borrows syntax from regexp ``'[]'`` string range definitions:: srange("[0-9]") -> "0123456789" srange("[a-z]") -> "abcdefghijklmnopqrstuvwxyz" srange("[a-z$_]") -> "abcdefghijklmnopqrstuvwxyz$_" The input string must be enclosed in []'s, and the returned string is the expanded character set joined into a single string. The values enclosed in the []'s may be: - a single character - an escaped character with a leading backslash (such as ``\-`` or ``\]``) - an escaped hex character with a leading ``'\x'`` (``\x21``, which is a ``'!'`` character) (``\0x##`` is also supported for backwards compatibility) - an escaped octal character with a leading ``'\0'`` (``\041``, which is a ``'!'`` character) - a range of any of the above, separated by a dash (``'a-z'``, etc.) - any combination of the above (``'aeiouy'``, ``'a-zA-Z0-9_$'``, etc.) |
173,719 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
ParseAction = Union[
Callable[[], Any],
Callable[[ParseResults], Any],
Callable[[int, ParseResults], Any],
Callable[[str, int, ParseResults], Any],
]
The provided code snippet includes necessary dependencies for implementing the `token_map` function. Write a Python function `def token_map(func, *args) -> ParseAction` to solve the following problem:
Helper to define a parse action by mapping a function to all elements of a :class:`ParseResults` list. If any additional args are passed, they are forwarded to the given function as additional arguments after the token, as in ``hex_integer = Word(hexnums).set_parse_action(token_map(int, 16))``, which will convert the parsed data to an integer using base 16. Example (compare the last to example in :class:`ParserElement.transform_string`:: hex_ints = Word(hexnums)[1, ...].set_parse_action(token_map(int, 16)) hex_ints.run_tests(''' 00 11 22 aa FF 0a 0d 1a ''') upperword = Word(alphas).set_parse_action(token_map(str.upper)) upperword[1, ...].run_tests(''' my kingdom for a horse ''') wd = Word(alphas).set_parse_action(token_map(str.title)) wd[1, ...].set_parse_action(' '.join).run_tests(''' now is the winter of our discontent made glorious summer by this sun of york ''') prints:: 00 11 22 aa FF 0a 0d 1a [0, 17, 34, 170, 255, 10, 13, 26] my kingdom for a horse ['MY', 'KINGDOM', 'FOR', 'A', 'HORSE'] now is the winter of our discontent made glorious summer by this sun of york ['Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York']
Here is the function:
def token_map(func, *args) -> ParseAction:
"""Helper to define a parse action by mapping a function to all
elements of a :class:`ParseResults` list. If any additional args are passed,
they are forwarded to the given function as additional arguments
after the token, as in
``hex_integer = Word(hexnums).set_parse_action(token_map(int, 16))``,
which will convert the parsed data to an integer using base 16.
Example (compare the last to example in :class:`ParserElement.transform_string`::
hex_ints = Word(hexnums)[1, ...].set_parse_action(token_map(int, 16))
hex_ints.run_tests('''
00 11 22 aa FF 0a 0d 1a
''')
upperword = Word(alphas).set_parse_action(token_map(str.upper))
upperword[1, ...].run_tests('''
my kingdom for a horse
''')
wd = Word(alphas).set_parse_action(token_map(str.title))
wd[1, ...].set_parse_action(' '.join).run_tests('''
now is the winter of our discontent made glorious summer by this sun of york
''')
prints::
00 11 22 aa FF 0a 0d 1a
[0, 17, 34, 170, 255, 10, 13, 26]
my kingdom for a horse
['MY', 'KINGDOM', 'FOR', 'A', 'HORSE']
now is the winter of our discontent made glorious summer by this sun of york
['Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York']
"""
def pa(s, l, t):
return [func(tokn, *args) for tokn in t]
func_name = getattr(func, "__name__", getattr(func, "__class__").__name__)
pa.__name__ = func_name
return pa | Helper to define a parse action by mapping a function to all elements of a :class:`ParseResults` list. If any additional args are passed, they are forwarded to the given function as additional arguments after the token, as in ``hex_integer = Word(hexnums).set_parse_action(token_map(int, 16))``, which will convert the parsed data to an integer using base 16. Example (compare the last to example in :class:`ParserElement.transform_string`:: hex_ints = Word(hexnums)[1, ...].set_parse_action(token_map(int, 16)) hex_ints.run_tests(''' 00 11 22 aa FF 0a 0d 1a ''') upperword = Word(alphas).set_parse_action(token_map(str.upper)) upperword[1, ...].run_tests(''' my kingdom for a horse ''') wd = Word(alphas).set_parse_action(token_map(str.title)) wd[1, ...].set_parse_action(' '.join).run_tests(''' now is the winter of our discontent made glorious summer by this sun of york ''') prints:: 00 11 22 aa FF 0a 0d 1a [0, 17, 34, 170, 255, 10, 13, 26] my kingdom for a horse ['MY', 'KINGDOM', 'FOR', 'A', 'HORSE'] now is the winter of our discontent made glorious summer by this sun of york ['Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York'] |
173,720 | import os
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
from abc import ABC, abstractmethod
from enum import Enum
import string
import copy
import warnings
import re
import sys
from collections.abc import Iterable
import traceback
import types
from operator import itemgetter
from functools import wraps
from threading import RLock
from pathlib import Path
from .util import (
_FifoCache,
_UnboundedCache,
__config_flags,
_collapse_string_to_ranges,
_escape_regex_range_chars,
_bslash,
_flatten,
LRUMemo as _LRUMemo,
UnboundedMemo as _UnboundedMemo,
)
from .exceptions import *
from .actions import *
from .results import ParseResults, _ParseResultsWithOffset
from .unicode import pyparsing_unicode
if sys.version_info >= (3, 8):
from functools import cached_property
else:
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
import sys
The provided code snippet includes necessary dependencies for implementing the `autoname_elements` function. Write a Python function `def autoname_elements() -> None` to solve the following problem:
Utility to simplify mass-naming of parser elements, for generating railroad diagram with named subdiagrams.
Here is the function:
def autoname_elements() -> None:
"""
Utility to simplify mass-naming of parser elements, for
generating railroad diagram with named subdiagrams.
"""
for name, var in sys._getframe().f_back.f_locals.items():
if isinstance(var, ParserElement) and not var.customName:
var.set_name(name) | Utility to simplify mass-naming of parser elements, for generating railroad diagram with named subdiagrams. |
173,721 | from .exceptions import ParseException
from .util import col
class ParseException(ParseBaseException):
"""
Exception thrown when a parse expression doesn't match the input string
Example::
try:
Word(nums).set_name("integer").parse_string("ABC")
except ParseException as pe:
print(pe)
print("column: {}".format(pe.column))
prints::
Expected integer (at char 0), (line:1, col:1)
column: 1
"""
def col(loc: int, strg: str) -> int:
"""
Returns current column within a string, counting newlines as line separators.
The first column is number 1.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See
:class:`ParserElement.parseString` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
"""
s = strg
return 1 if 0 < loc < len(s) and s[loc - 1] == "\n" else loc - s.rfind("\n", 0, loc)
The provided code snippet includes necessary dependencies for implementing the `match_only_at_col` function. Write a Python function `def match_only_at_col(n)` to solve the following problem:
Helper method for defining parse actions that require matching at a specific column in the input text.
Here is the function:
def match_only_at_col(n):
"""
Helper method for defining parse actions that require matching at
a specific column in the input text.
"""
def verify_col(strg, locn, toks):
if col(locn, strg) != n:
raise ParseException(strg, locn, "matched token not at column {}".format(n))
return verify_col | Helper method for defining parse actions that require matching at a specific column in the input text. |
173,722 | from .exceptions import ParseException
from .util import col
The provided code snippet includes necessary dependencies for implementing the `replace_with` function. Write a Python function `def replace_with(repl_str)` to solve the following problem:
Helper method for common parse actions that simply return a literal value. Especially useful when used with :class:`transform_string<ParserElement.transform_string>` (). Example:: num = Word(nums).set_parse_action(lambda toks: int(toks[0])) na = one_of("N/A NA").set_parse_action(replace_with(math.nan)) term = na | num term[1, ...].parse_string("324 234 N/A 234") # -> [324, 234, nan, 234]
Here is the function:
def replace_with(repl_str):
"""
Helper method for common parse actions that simply return
a literal value. Especially useful when used with
:class:`transform_string<ParserElement.transform_string>` ().
Example::
num = Word(nums).set_parse_action(lambda toks: int(toks[0]))
na = one_of("N/A NA").set_parse_action(replace_with(math.nan))
term = na | num
term[1, ...].parse_string("324 234 N/A 234") # -> [324, 234, nan, 234]
"""
return lambda s, l, t: [repl_str] | Helper method for common parse actions that simply return a literal value. Especially useful when used with :class:`transform_string<ParserElement.transform_string>` (). Example:: num = Word(nums).set_parse_action(lambda toks: int(toks[0])) na = one_of("N/A NA").set_parse_action(replace_with(math.nan)) term = na | num term[1, ...].parse_string("324 234 N/A 234") # -> [324, 234, nan, 234] |
173,723 | from .exceptions import ParseException
from .util import col
The provided code snippet includes necessary dependencies for implementing the `remove_quotes` function. Write a Python function `def remove_quotes(s, l, t)` to solve the following problem:
Helper parse action for removing quotation marks from parsed quoted strings. Example:: # by default, quotation marks are included in parsed results quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["'Now is the Winter of our Discontent'"] # use remove_quotes to strip quotation marks from parsed results quoted_string.set_parse_action(remove_quotes) quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["Now is the Winter of our Discontent"]
Here is the function:
def remove_quotes(s, l, t):
"""
Helper parse action for removing quotation marks from parsed
quoted strings.
Example::
# by default, quotation marks are included in parsed results
quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["'Now is the Winter of our Discontent'"]
# use remove_quotes to strip quotation marks from parsed results
quoted_string.set_parse_action(remove_quotes)
quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["Now is the Winter of our Discontent"]
"""
return t[0][1:-1] | Helper parse action for removing quotation marks from parsed quoted strings. Example:: # by default, quotation marks are included in parsed results quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["'Now is the Winter of our Discontent'"] # use remove_quotes to strip quotation marks from parsed results quoted_string.set_parse_action(remove_quotes) quoted_string.parse_string("'Now is the Winter of our Discontent'") # -> ["Now is the Winter of our Discontent"] |
173,724 | from .exceptions import ParseException
from .util import col
def with_attribute(*args, **attr_dict):
"""
Helper to create a validating parse action to be used with start
tags created with :class:`make_xml_tags` or
:class:`make_html_tags`. Use ``with_attribute`` to qualify
a starting tag with a required attribute value, to avoid false
matches on common tags such as ``<TD>`` or ``<DIV>``.
Call ``with_attribute`` with a series of attribute names and
values. Specify the list of filter attributes names and values as:
- keyword arguments, as in ``(align="right")``, or
- as an explicit dict with ``**`` operator, when an attribute
name is also a Python reserved word, as in ``**{"class":"Customer", "align":"right"}``
- a list of name-value tuples, as in ``(("ns1:class", "Customer"), ("ns2:align", "right"))``
For attribute names with a namespace prefix, you must use the second
form. Attribute names are matched insensitive to upper/lower case.
If just testing for ``class`` (with or without a namespace), use
:class:`with_class`.
To verify that the attribute exists, but without specifying a value,
pass ``with_attribute.ANY_VALUE`` as the value.
Example::
html = '''
<div>
Some text
<div type="grid">1 4 0 1 0</div>
<div type="graph">1,3 2,3 1,1</div>
<div>this has no type</div>
</div>
'''
div,div_end = make_html_tags("div")
# only match div tag having a type attribute with value "grid"
div_grid = div().set_parse_action(with_attribute(type="grid"))
grid_expr = div_grid + SkipTo(div | div_end)("body")
for grid_header in grid_expr.search_string(html):
print(grid_header.body)
# construct a match with any div tag having a type attribute, regardless of the value
div_any_type = div().set_parse_action(with_attribute(type=with_attribute.ANY_VALUE))
div_expr = div_any_type + SkipTo(div | div_end)("body")
for div_header in div_expr.search_string(html):
print(div_header.body)
prints::
1 4 0 1 0
1 4 0 1 0
1,3 2,3 1,1
"""
if args:
attrs = args[:]
else:
attrs = attr_dict.items()
attrs = [(k, v) for k, v in attrs]
def pa(s, l, tokens):
for attrName, attrValue in attrs:
if attrName not in tokens:
raise ParseException(s, l, "no matching attribute " + attrName)
if attrValue != with_attribute.ANY_VALUE and tokens[attrName] != attrValue:
raise ParseException(
s,
l,
"attribute {!r} has value {!r}, must be {!r}".format(
attrName, tokens[attrName], attrValue
),
)
return pa
with_attribute.ANY_VALUE = object()
The provided code snippet includes necessary dependencies for implementing the `with_class` function. Write a Python function `def with_class(classname, namespace="")` to solve the following problem:
Simplified version of :class:`with_attribute` when matching on a div class - made difficult because ``class`` is a reserved word in Python. Example:: html = ''' <div> Some text <div class="grid">1 4 0 1 0</div> <div class="graph">1,3 2,3 1,1</div> <div>this <div> has no class</div> </div> ''' div,div_end = make_html_tags("div") div_grid = div().set_parse_action(with_class("grid")) grid_expr = div_grid + SkipTo(div | div_end)("body") for grid_header in grid_expr.search_string(html): print(grid_header.body) div_any_type = div().set_parse_action(with_class(withAttribute.ANY_VALUE)) div_expr = div_any_type + SkipTo(div | div_end)("body") for div_header in div_expr.search_string(html): print(div_header.body) prints:: 1 4 0 1 0 1 4 0 1 0 1,3 2,3 1,1
Here is the function:
def with_class(classname, namespace=""):
"""
Simplified version of :class:`with_attribute` when
matching on a div class - made difficult because ``class`` is
a reserved word in Python.
Example::
html = '''
<div>
Some text
<div class="grid">1 4 0 1 0</div>
<div class="graph">1,3 2,3 1,1</div>
<div>this <div> has no class</div>
</div>
'''
div,div_end = make_html_tags("div")
div_grid = div().set_parse_action(with_class("grid"))
grid_expr = div_grid + SkipTo(div | div_end)("body")
for grid_header in grid_expr.search_string(html):
print(grid_header.body)
div_any_type = div().set_parse_action(with_class(withAttribute.ANY_VALUE))
div_expr = div_any_type + SkipTo(div | div_end)("body")
for div_header in div_expr.search_string(html):
print(div_header.body)
prints::
1 4 0 1 0
1 4 0 1 0
1,3 2,3 1,1
"""
classattr = "{}:class".format(namespace) if namespace else "class"
return with_attribute(**{classattr: classname}) | Simplified version of :class:`with_attribute` when matching on a div class - made difficult because ``class`` is a reserved word in Python. Example:: html = ''' <div> Some text <div class="grid">1 4 0 1 0</div> <div class="graph">1,3 2,3 1,1</div> <div>this <div> has no class</div> </div> ''' div,div_end = make_html_tags("div") div_grid = div().set_parse_action(with_class("grid")) grid_expr = div_grid + SkipTo(div | div_end)("body") for grid_header in grid_expr.search_string(html): print(grid_header.body) div_any_type = div().set_parse_action(with_class(withAttribute.ANY_VALUE)) div_expr = div_any_type + SkipTo(div | div_end)("body") for div_header in div_expr.search_string(html): print(div_header.body) prints:: 1 4 0 1 0 1 4 0 1 0 1,3 2,3 1,1 |
173,725 | import warnings
import types
import collections
import itertools
from functools import lru_cache
from typing import List, Union, Iterable
import collections
try:
# Python 3
from collections.abc import Iterable
from collections.abc import MutableMapping
except ImportError:
# Python 2.7
from collections import Iterable
from collections import MutableMapping
try:
from collections import OrderedDict as _OrderedDict
except ImportError:
try:
from ordereddict import OrderedDict as _OrderedDict
except ImportError:
_OrderedDict = None
import itertools
try:
# Python 3
from itertools import filterfalse
except ImportError:
from itertools import ifilterfalse as filterfalse
Union: _SpecialForm = ...
class Iterable(Protocol[_T_co]):
def __iter__(self) -> Iterator[_T_co]: ...
def _collapse_string_to_ranges(
s: Union[str, Iterable[str]], re_escape: bool = True
) -> str:
def is_consecutive(c):
c_int = ord(c)
is_consecutive.prev, prev = c_int, is_consecutive.prev
if c_int - prev > 1:
is_consecutive.value = next(is_consecutive.counter)
return is_consecutive.value
is_consecutive.prev = 0
is_consecutive.counter = itertools.count()
is_consecutive.value = -1
def escape_re_range_char(c):
return "\\" + c if c in r"\^-][" else c
def no_escape_re_range_char(c):
return c
if not re_escape:
escape_re_range_char = no_escape_re_range_char
ret = []
s = "".join(sorted(set(s)))
if len(s) > 3:
for _, chars in itertools.groupby(s, key=is_consecutive):
first = last = next(chars)
last = collections.deque(
itertools.chain(iter([last]), chars), maxlen=1
).pop()
if first == last:
ret.append(escape_re_range_char(first))
else:
sep = "" if ord(last) == ord(first) + 1 else "-"
ret.append(
"{}{}{}".format(
escape_re_range_char(first), sep, escape_re_range_char(last)
)
)
else:
ret = [escape_re_range_char(c) for c in s]
return "".join(ret) | null |
173,726 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
import copy
str_type: Tuple[type, ...] = (str, bytes)
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
class Opt(ParseElementEnhance):
"""
Optional matching of the given expression.
Parameters:
- ``expr`` - expression that must match zero or more times
- ``default`` (optional) - value to be returned if the optional expression is not found.
Example::
# US postal code can be a 5-digit zip, plus optional 4-digit qualifier
zip = Combine(Word(nums, exact=5) + Opt('-' + Word(nums, exact=4)))
zip.run_tests('''
# traditional ZIP code
12345
# ZIP+4 form
12101-0001
# invalid ZIP
98765-
''')
prints::
# traditional ZIP code
12345
['12345']
# ZIP+4 form
12101-0001
['12101-0001']
# invalid ZIP
98765-
^
FAIL: Expected end of text (at char 5), (line:1, col:6)
"""
__optionalNotMatched = _NullToken()
def __init__(
self, expr: Union[ParserElement, str], default: Any = __optionalNotMatched
):
super().__init__(expr, savelist=False)
self.saveAsList = self.expr.saveAsList
self.defaultValue = default
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
self_expr = self.expr
try:
loc, tokens = self_expr._parse(instring, loc, doActions, callPreParse=False)
except (ParseException, IndexError):
default_value = self.defaultValue
if default_value is not self.__optionalNotMatched:
if self_expr.resultsName:
tokens = ParseResults([default_value])
tokens[self_expr.resultsName] = default_value
else:
tokens = [default_value]
else:
tokens = []
return loc, tokens
def _generateDefaultName(self):
inner = str(self.expr)
# strip off redundant inner {}'s
while len(inner) > 1 and inner[0 :: len(inner) - 1] == "{}":
inner = inner[1:-1]
return "[" + inner + "]"
Optional = Opt
class Combine(TokenConverter):
"""Converter to concatenate all matching tokens to a single string.
By default, the matching patterns must also be contiguous in the
input string; this can be disabled by specifying
``'adjacent=False'`` in the constructor.
Example::
real = Word(nums) + '.' + Word(nums)
print(real.parse_string('3.1416')) # -> ['3', '.', '1416']
# will also erroneously match the following
print(real.parse_string('3. 1416')) # -> ['3', '.', '1416']
real = Combine(Word(nums) + '.' + Word(nums))
print(real.parse_string('3.1416')) # -> ['3.1416']
# no match when there are internal spaces
print(real.parse_string('3. 1416')) # -> Exception: Expected W:(0123...)
"""
def __init__(
self,
expr: ParserElement,
join_string: str = "",
adjacent: bool = True,
*,
joinString: typing.Optional[str] = None,
):
super().__init__(expr)
joinString = joinString if joinString is not None else join_string
# suppress whitespace-stripping in contained parse expressions, but re-enable it on the Combine itself
if adjacent:
self.leave_whitespace()
self.adjacent = adjacent
self.skipWhitespace = True
self.joinString = joinString
self.callPreparse = True
def ignore(self, other) -> ParserElement:
if self.adjacent:
ParserElement.ignore(self, other)
else:
super().ignore(other)
return self
def postParse(self, instring, loc, tokenlist):
retToks = tokenlist.copy()
del retToks[:]
retToks += ParseResults(
["".join(tokenlist._asStringList(self.joinString))], modal=self.modalResults
)
if self.resultsName and retToks.haskeys():
return [retToks]
else:
return retToks
class Suppress(TokenConverter):
"""Converter for ignoring the results of a parsed expression.
Example::
source = "a, b, c,d"
wd = Word(alphas)
wd_list1 = wd + (',' + wd)[...]
print(wd_list1.parse_string(source))
# often, delimiters that are useful during parsing are just in the
# way afterward - use Suppress to keep them out of the parsed output
wd_list2 = wd + (Suppress(',') + wd)[...]
print(wd_list2.parse_string(source))
# Skipped text (using '...') can be suppressed as well
source = "lead in START relevant text END trailing text"
start_marker = Keyword("START")
end_marker = Keyword("END")
find_body = Suppress(...) + start_marker + ... + end_marker
print(find_body.parse_string(source)
prints::
['a', ',', 'b', ',', 'c', ',', 'd']
['a', 'b', 'c', 'd']
['START', 'relevant text ', 'END']
(See also :class:`delimited_list`.)
"""
def __init__(self, expr: Union[ParserElement, str], savelist: bool = False):
if expr is ...:
expr = _PendingSkip(NoMatch())
super().__init__(expr)
def __add__(self, other) -> "ParserElement":
if isinstance(self.expr, _PendingSkip):
return Suppress(SkipTo(other)) + other
else:
return super().__add__(other)
def __sub__(self, other) -> "ParserElement":
if isinstance(self.expr, _PendingSkip):
return Suppress(SkipTo(other)) - other
else:
return super().__sub__(other)
def postParse(self, instring, loc, tokenlist):
return []
def suppress(self) -> ParserElement:
return self
The provided code snippet includes necessary dependencies for implementing the `delimited_list` function. Write a Python function `def delimited_list( expr: Union[str, ParserElement], delim: Union[str, ParserElement] = ",", combine: bool = False, min: typing.Optional[int] = None, max: typing.Optional[int] = None, *, allow_trailing_delim: bool = False, ) -> ParserElement` to solve the following problem:
Helper to define a delimited list of expressions - the delimiter defaults to ','. By default, the list elements and delimiters can have intervening whitespace, and comments, but this can be overridden by passing ``combine=True`` in the constructor. If ``combine`` is set to ``True``, the matching tokens are returned as a single token string, with the delimiters included; otherwise, the matching tokens are returned as a list of tokens, with the delimiters suppressed. If ``allow_trailing_delim`` is set to True, then the list may end with a delimiter. Example:: delimited_list(Word(alphas)).parse_string("aa,bb,cc") # -> ['aa', 'bb', 'cc'] delimited_list(Word(hexnums), delim=':', combine=True).parse_string("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE']
Here is the function:
def delimited_list(
expr: Union[str, ParserElement],
delim: Union[str, ParserElement] = ",",
combine: bool = False,
min: typing.Optional[int] = None,
max: typing.Optional[int] = None,
*,
allow_trailing_delim: bool = False,
) -> ParserElement:
"""Helper to define a delimited list of expressions - the delimiter
defaults to ','. By default, the list elements and delimiters can
have intervening whitespace, and comments, but this can be
overridden by passing ``combine=True`` in the constructor. If
``combine`` is set to ``True``, the matching tokens are
returned as a single token string, with the delimiters included;
otherwise, the matching tokens are returned as a list of tokens,
with the delimiters suppressed.
If ``allow_trailing_delim`` is set to True, then the list may end with
a delimiter.
Example::
delimited_list(Word(alphas)).parse_string("aa,bb,cc") # -> ['aa', 'bb', 'cc']
delimited_list(Word(hexnums), delim=':', combine=True).parse_string("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE']
"""
if isinstance(expr, str_type):
expr = ParserElement._literalStringClass(expr)
dlName = "{expr} [{delim} {expr}]...{end}".format(
expr=str(expr.copy().streamline()),
delim=str(delim),
end=" [{}]".format(str(delim)) if allow_trailing_delim else "",
)
if not combine:
delim = Suppress(delim)
if min is not None:
if min < 1:
raise ValueError("min must be greater than 0")
min -= 1
if max is not None:
if min is not None and max <= min:
raise ValueError("max must be greater than, or equal to min")
max -= 1
delimited_list_expr = expr + (delim + expr)[min, max]
if allow_trailing_delim:
delimited_list_expr += Opt(delim)
if combine:
return Combine(delimited_list_expr).set_name(dlName)
else:
return delimited_list_expr.set_name(dlName) | Helper to define a delimited list of expressions - the delimiter defaults to ','. By default, the list elements and delimiters can have intervening whitespace, and comments, but this can be overridden by passing ``combine=True`` in the constructor. If ``combine`` is set to ``True``, the matching tokens are returned as a single token string, with the delimiters included; otherwise, the matching tokens are returned as a list of tokens, with the delimiters suppressed. If ``allow_trailing_delim`` is set to True, then the list may end with a delimiter. Example:: delimited_list(Word(alphas)).parse_string("aa,bb,cc") # -> ['aa', 'bb', 'cc'] delimited_list(Word(hexnums), delim=':', combine=True).parse_string("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE'] |
173,727 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
import copy
nums = "0123456789"
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class Empty(Token):
"""
An empty token, will always match.
"""
def __init__(self):
super().__init__()
self.mayReturnEmpty = True
self.mayIndexError = False
ParserElement._literalStringClass = Literal
class Word(Token):
"""Token for matching words composed of allowed character sets.
Parameters:
- ``init_chars`` - string of all characters that should be used to
match as a word; "ABC" will match "AAA", "ABAB", "CBAC", etc.;
if ``body_chars`` is also specified, then this is the string of
initial characters
- ``body_chars`` - string of characters that
can be used for matching after a matched initial character as
given in ``init_chars``; if omitted, same as the initial characters
(default=``None``)
- ``min`` - minimum number of characters to match (default=1)
- ``max`` - maximum number of characters to match (default=0)
- ``exact`` - exact number of characters to match (default=0)
- ``as_keyword`` - match as a keyword (default=``False``)
- ``exclude_chars`` - characters that might be
found in the input ``body_chars`` string but which should not be
accepted for matching ;useful to define a word of all
printables except for one or two characters, for instance
(default=``None``)
:class:`srange` is useful for defining custom character set strings
for defining :class:`Word` expressions, using range notation from
regular expression character sets.
A common mistake is to use :class:`Word` to match a specific literal
string, as in ``Word("Address")``. Remember that :class:`Word`
uses the string argument to define *sets* of matchable characters.
This expression would match "Add", "AAA", "dAred", or any other word
made up of the characters 'A', 'd', 'r', 'e', and 's'. To match an
exact literal string, use :class:`Literal` or :class:`Keyword`.
pyparsing includes helper strings for building Words:
- :class:`alphas`
- :class:`nums`
- :class:`alphanums`
- :class:`hexnums`
- :class:`alphas8bit` (alphabetic characters in ASCII range 128-255
- accented, tilded, umlauted, etc.)
- :class:`punc8bit` (non-alphabetic characters in ASCII range
128-255 - currency, symbols, superscripts, diacriticals, etc.)
- :class:`printables` (any non-whitespace character)
``alphas``, ``nums``, and ``printables`` are also defined in several
Unicode sets - see :class:`pyparsing_unicode``.
Example::
# a word composed of digits
integer = Word(nums) # equivalent to Word("0123456789") or Word(srange("0-9"))
# a word with a leading capital, and zero or more lowercase
capital_word = Word(alphas.upper(), alphas.lower())
# hostnames are alphanumeric, with leading alpha, and '-'
hostname = Word(alphas, alphanums + '-')
# roman numeral (not a strict parser, accepts invalid mix of characters)
roman = Word("IVXLCDM")
# any string of non-whitespace characters, except for ','
csv_value = Word(printables, exclude_chars=",")
"""
def __init__(
self,
init_chars: str = "",
body_chars: typing.Optional[str] = None,
min: int = 1,
max: int = 0,
exact: int = 0,
as_keyword: bool = False,
exclude_chars: typing.Optional[str] = None,
*,
initChars: typing.Optional[str] = None,
bodyChars: typing.Optional[str] = None,
asKeyword: bool = False,
excludeChars: typing.Optional[str] = None,
):
initChars = initChars or init_chars
bodyChars = bodyChars or body_chars
asKeyword = asKeyword or as_keyword
excludeChars = excludeChars or exclude_chars
super().__init__()
if not initChars:
raise ValueError(
"invalid {}, initChars cannot be empty string".format(
type(self).__name__
)
)
initChars = set(initChars)
self.initChars = initChars
if excludeChars:
excludeChars = set(excludeChars)
initChars -= excludeChars
if bodyChars:
bodyChars = set(bodyChars) - excludeChars
self.initCharsOrig = "".join(sorted(initChars))
if bodyChars:
self.bodyCharsOrig = "".join(sorted(bodyChars))
self.bodyChars = set(bodyChars)
else:
self.bodyCharsOrig = "".join(sorted(initChars))
self.bodyChars = set(initChars)
self.maxSpecified = max > 0
if min < 1:
raise ValueError(
"cannot specify a minimum length < 1; use Opt(Word()) if zero-length word is permitted"
)
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = _MAX_INT
if exact > 0:
self.maxLen = exact
self.minLen = exact
self.errmsg = "Expected " + self.name
self.mayIndexError = False
self.asKeyword = asKeyword
# see if we can make a regex for this Word
if " " not in self.initChars | self.bodyChars and (min == 1 and exact == 0):
if self.bodyChars == self.initChars:
if max == 0:
repeat = "+"
elif max == 1:
repeat = ""
else:
repeat = "{{{},{}}}".format(
self.minLen, "" if self.maxLen == _MAX_INT else self.maxLen
)
self.reString = "[{}]{}".format(
_collapse_string_to_ranges(self.initChars),
repeat,
)
elif len(self.initChars) == 1:
if max == 0:
repeat = "*"
else:
repeat = "{{0,{}}}".format(max - 1)
self.reString = "{}[{}]{}".format(
re.escape(self.initCharsOrig),
_collapse_string_to_ranges(self.bodyChars),
repeat,
)
else:
if max == 0:
repeat = "*"
elif max == 2:
repeat = ""
else:
repeat = "{{0,{}}}".format(max - 1)
self.reString = "[{}][{}]{}".format(
_collapse_string_to_ranges(self.initChars),
_collapse_string_to_ranges(self.bodyChars),
repeat,
)
if self.asKeyword:
self.reString = r"\b" + self.reString + r"\b"
try:
self.re = re.compile(self.reString)
except re.error:
self.re = None
else:
self.re_match = self.re.match
self.__class__ = _WordRegex
def _generateDefaultName(self):
def charsAsStr(s):
max_repr_len = 16
s = _collapse_string_to_ranges(s, re_escape=False)
if len(s) > max_repr_len:
return s[: max_repr_len - 3] + "..."
else:
return s
if self.initChars != self.bodyChars:
base = "W:({}, {})".format(
charsAsStr(self.initChars), charsAsStr(self.bodyChars)
)
else:
base = "W:({})".format(charsAsStr(self.initChars))
# add length specification
if self.minLen > 1 or self.maxLen != _MAX_INT:
if self.minLen == self.maxLen:
if self.minLen == 1:
return base[2:]
else:
return base + "{{{}}}".format(self.minLen)
elif self.maxLen == _MAX_INT:
return base + "{{{},...}}".format(self.minLen)
else:
return base + "{{{},{}}}".format(self.minLen, self.maxLen)
return base
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] not in self.initChars:
raise ParseException(instring, loc, self.errmsg, self)
start = loc
loc += 1
instrlen = len(instring)
bodychars = self.bodyChars
maxloc = start + self.maxLen
maxloc = min(maxloc, instrlen)
while loc < maxloc and instring[loc] in bodychars:
loc += 1
throwException = False
if loc - start < self.minLen:
throwException = True
elif self.maxSpecified and loc < instrlen and instring[loc] in bodychars:
throwException = True
elif self.asKeyword:
if (
start > 0
and instring[start - 1] in bodychars
or loc < instrlen
and instring[loc] in bodychars
):
throwException = True
if throwException:
raise ParseException(instring, loc, self.errmsg, self)
return loc, instring[start:loc]
Optional = Opt
class Forward(ParseElementEnhance):
"""
Forward declaration of an expression to be defined later -
used for recursive grammars, such as algebraic infix notation.
When the expression is known, it is assigned to the ``Forward``
variable using the ``'<<'`` operator.
Note: take care when assigning to ``Forward`` not to overlook
precedence of operators.
Specifically, ``'|'`` has a lower precedence than ``'<<'``, so that::
fwd_expr << a | b | c
will actually be evaluated as::
(fwd_expr << a) | b | c
thereby leaving b and c out as parseable alternatives. It is recommended that you
explicitly group the values inserted into the ``Forward``::
fwd_expr << (a | b | c)
Converting to use the ``'<<='`` operator instead will avoid this problem.
See :class:`ParseResults.pprint` for an example of a recursive
parser created using ``Forward``.
"""
def __init__(self, other: typing.Optional[Union[ParserElement, str]] = None):
self.caller_frame = traceback.extract_stack(limit=2)[0]
super().__init__(other, savelist=False)
self.lshift_line = None
def __lshift__(self, other):
if hasattr(self, "caller_frame"):
del self.caller_frame
if isinstance(other, str_type):
other = self._literalStringClass(other)
self.expr = other
self.mayIndexError = self.expr.mayIndexError
self.mayReturnEmpty = self.expr.mayReturnEmpty
self.set_whitespace_chars(
self.expr.whiteChars, copy_defaults=self.expr.copyDefaultWhiteChars
)
self.skipWhitespace = self.expr.skipWhitespace
self.saveAsList = self.expr.saveAsList
self.ignoreExprs.extend(self.expr.ignoreExprs)
self.lshift_line = traceback.extract_stack(limit=2)[-2]
return self
def __ilshift__(self, other):
return self << other
def __or__(self, other):
caller_line = traceback.extract_stack(limit=2)[-2]
if (
__diag__.warn_on_match_first_with_lshift_operator
and caller_line == self.lshift_line
and Diagnostics.warn_on_match_first_with_lshift_operator
not in self.suppress_warnings_
):
warnings.warn(
"using '<<' operator with '|' is probably an error, use '<<='",
stacklevel=2,
)
ret = super().__or__(other)
return ret
def __del__(self):
# see if we are getting dropped because of '=' reassignment of var instead of '<<=' or '<<'
if (
self.expr is None
and __diag__.warn_on_assignment_to_Forward
and Diagnostics.warn_on_assignment_to_Forward not in self.suppress_warnings_
):
warnings.warn_explicit(
"Forward defined here but no expression attached later using '<<=' or '<<'",
UserWarning,
filename=self.caller_frame.filename,
lineno=self.caller_frame.lineno,
)
def parseImpl(self, instring, loc, doActions=True):
if (
self.expr is None
and __diag__.warn_on_parse_using_empty_Forward
and Diagnostics.warn_on_parse_using_empty_Forward
not in self.suppress_warnings_
):
# walk stack until parse_string, scan_string, search_string, or transform_string is found
parse_fns = [
"parse_string",
"scan_string",
"search_string",
"transform_string",
]
tb = traceback.extract_stack(limit=200)
for i, frm in enumerate(reversed(tb), start=1):
if frm.name in parse_fns:
stacklevel = i + 1
break
else:
stacklevel = 2
warnings.warn(
"Forward expression was never assigned a value, will not parse any input",
stacklevel=stacklevel,
)
if not ParserElement._left_recursion_enabled:
return super().parseImpl(instring, loc, doActions)
# ## Bounded Recursion algorithm ##
# Recursion only needs to be processed at ``Forward`` elements, since they are
# the only ones that can actually refer to themselves. The general idea is
# to handle recursion stepwise: We start at no recursion, then recurse once,
# recurse twice, ..., until more recursion offers no benefit (we hit the bound).
#
# The "trick" here is that each ``Forward`` gets evaluated in two contexts
# - to *match* a specific recursion level, and
# - to *search* the bounded recursion level
# and the two run concurrently. The *search* must *match* each recursion level
# to find the best possible match. This is handled by a memo table, which
# provides the previous match to the next level match attempt.
#
# See also "Left Recursion in Parsing Expression Grammars", Medeiros et al.
#
# There is a complication since we not only *parse* but also *transform* via
# actions: We do not want to run the actions too often while expanding. Thus,
# we expand using `doActions=False` and only run `doActions=True` if the next
# recursion level is acceptable.
with ParserElement.recursion_lock:
memo = ParserElement.recursion_memos
try:
# we are parsing at a specific recursion expansion - use it as-is
prev_loc, prev_result = memo[loc, self, doActions]
if isinstance(prev_result, Exception):
raise prev_result
return prev_loc, prev_result.copy()
except KeyError:
act_key = (loc, self, True)
peek_key = (loc, self, False)
# we are searching for the best recursion expansion - keep on improving
# both `doActions` cases must be tracked separately here!
prev_loc, prev_peek = memo[peek_key] = (
loc - 1,
ParseException(
instring, loc, "Forward recursion without base case", self
),
)
if doActions:
memo[act_key] = memo[peek_key]
while True:
try:
new_loc, new_peek = super().parseImpl(instring, loc, False)
except ParseException:
# we failed before getting any match – do not hide the error
if isinstance(prev_peek, Exception):
raise
new_loc, new_peek = prev_loc, prev_peek
# the match did not get better: we are done
if new_loc <= prev_loc:
if doActions:
# replace the match for doActions=False as well,
# in case the action did backtrack
prev_loc, prev_result = memo[peek_key] = memo[act_key]
del memo[peek_key], memo[act_key]
return prev_loc, prev_result.copy()
del memo[peek_key]
return prev_loc, prev_peek.copy()
# the match did get better: see if we can improve further
else:
if doActions:
try:
memo[act_key] = super().parseImpl(instring, loc, True)
except ParseException as e:
memo[peek_key] = memo[act_key] = (new_loc, e)
raise
prev_loc, prev_peek = memo[peek_key] = new_loc, new_peek
def leave_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = False
return self
def ignore_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = True
return self
def streamline(self) -> ParserElement:
if not self.streamlined:
self.streamlined = True
if self.expr is not None:
self.expr.streamline()
return self
def validate(self, validateTrace=None) -> None:
if validateTrace is None:
validateTrace = []
if self not in validateTrace:
tmp = validateTrace[:] + [self]
if self.expr is not None:
self.expr.validate(tmp)
self._checkRecursion([])
def _generateDefaultName(self):
# Avoid infinite recursion by setting a temporary _defaultName
self._defaultName = ": ..."
# Use the string representation of main expression.
retString = "..."
try:
if self.expr is not None:
retString = str(self.expr)[:1000]
else:
retString = "None"
finally:
return self.__class__.__name__ + ": " + retString
def copy(self) -> ParserElement:
if self.expr is not None:
return super().copy()
else:
ret = Forward()
ret <<= self
return ret
def _setResultsName(self, name, list_all_matches=False):
if (
__diag__.warn_name_set_on_empty_Forward
and Diagnostics.warn_name_set_on_empty_Forward
not in self.suppress_warnings_
):
if self.expr is None:
warnings.warn(
"{}: setting results name {!r} on {} expression "
"that has no contained expression".format(
"warn_name_set_on_empty_Forward", name, type(self).__name__
),
stacklevel=3,
)
return super()._setResultsName(name, list_all_matches)
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
The provided code snippet includes necessary dependencies for implementing the `counted_array` function. Write a Python function `def counted_array( expr: ParserElement, int_expr: typing.Optional[ParserElement] = None, *, intExpr: typing.Optional[ParserElement] = None, ) -> ParserElement` to solve the following problem:
Helper to define a counted list of expressions. This helper defines a pattern of the form:: integer expr expr expr... where the leading integer tells how many expr expressions follow. The matched tokens returns the array of expr tokens as a list - the leading count token is suppressed. If ``int_expr`` is specified, it should be a pyparsing expression that produces an integer value. Example:: counted_array(Word(alphas)).parse_string('2 ab cd ef') # -> ['ab', 'cd'] # in this parser, the leading integer value is given in binary, # '10' indicating that 2 values are in the array binary_constant = Word('01').set_parse_action(lambda t: int(t[0], 2)) counted_array(Word(alphas), int_expr=binary_constant).parse_string('10 ab cd ef') # -> ['ab', 'cd'] # if other fields must be parsed after the count but before the # list items, give the fields results names and they will # be preserved in the returned ParseResults: count_with_metadata = integer + Word(alphas)("type") typed_array = counted_array(Word(alphanums), int_expr=count_with_metadata)("items") result = typed_array.parse_string("3 bool True True False") print(result.dump()) # prints # ['True', 'True', 'False'] # - items: ['True', 'True', 'False'] # - type: 'bool'
Here is the function:
def counted_array(
expr: ParserElement,
int_expr: typing.Optional[ParserElement] = None,
*,
intExpr: typing.Optional[ParserElement] = None,
) -> ParserElement:
"""Helper to define a counted list of expressions.
This helper defines a pattern of the form::
integer expr expr expr...
where the leading integer tells how many expr expressions follow.
The matched tokens returns the array of expr tokens as a list - the
leading count token is suppressed.
If ``int_expr`` is specified, it should be a pyparsing expression
that produces an integer value.
Example::
counted_array(Word(alphas)).parse_string('2 ab cd ef') # -> ['ab', 'cd']
# in this parser, the leading integer value is given in binary,
# '10' indicating that 2 values are in the array
binary_constant = Word('01').set_parse_action(lambda t: int(t[0], 2))
counted_array(Word(alphas), int_expr=binary_constant).parse_string('10 ab cd ef') # -> ['ab', 'cd']
# if other fields must be parsed after the count but before the
# list items, give the fields results names and they will
# be preserved in the returned ParseResults:
count_with_metadata = integer + Word(alphas)("type")
typed_array = counted_array(Word(alphanums), int_expr=count_with_metadata)("items")
result = typed_array.parse_string("3 bool True True False")
print(result.dump())
# prints
# ['True', 'True', 'False']
# - items: ['True', 'True', 'False']
# - type: 'bool'
"""
intExpr = intExpr or int_expr
array_expr = Forward()
def count_field_parse_action(s, l, t):
nonlocal array_expr
n = t[0]
array_expr <<= (expr * n) if n else Empty()
# clear list contents, but keep any named results
del t[:]
if intExpr is None:
intExpr = Word(nums).set_parse_action(lambda t: int(t[0]))
else:
intExpr = intExpr.copy()
intExpr.set_name("arrayLen")
intExpr.add_parse_action(count_field_parse_action, call_during_try=True)
return (intExpr + array_expr).set_name("(len) " + str(expr) + "...") | Helper to define a counted list of expressions. This helper defines a pattern of the form:: integer expr expr expr... where the leading integer tells how many expr expressions follow. The matched tokens returns the array of expr tokens as a list - the leading count token is suppressed. If ``int_expr`` is specified, it should be a pyparsing expression that produces an integer value. Example:: counted_array(Word(alphas)).parse_string('2 ab cd ef') # -> ['ab', 'cd'] # in this parser, the leading integer value is given in binary, # '10' indicating that 2 values are in the array binary_constant = Word('01').set_parse_action(lambda t: int(t[0], 2)) counted_array(Word(alphas), int_expr=binary_constant).parse_string('10 ab cd ef') # -> ['ab', 'cd'] # if other fields must be parsed after the count but before the # list items, give the fields results names and they will # be preserved in the returned ParseResults: count_with_metadata = integer + Word(alphas)("type") typed_array = counted_array(Word(alphanums), int_expr=count_with_metadata)("items") result = typed_array.parse_string("3 bool True True False") print(result.dump()) # prints # ['True', 'True', 'False'] # - items: ['True', 'True', 'False'] # - type: 'bool' |
173,728 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class Empty(Token):
"""
An empty token, will always match.
"""
def __init__(self):
super().__init__()
self.mayReturnEmpty = True
self.mayIndexError = False
class Literal(Token):
"""
Token to exactly match a specified string.
Example::
Literal('blah').parse_string('blah') # -> ['blah']
Literal('blah').parse_string('blahfooblah') # -> ['blah']
Literal('blah').parse_string('bla') # -> Exception: Expected "blah"
For case-insensitive matching, use :class:`CaselessLiteral`.
For keyword matching (force word break before and after the matched string),
use :class:`Keyword` or :class:`CaselessKeyword`.
"""
def __init__(self, match_string: str = "", *, matchString: str = ""):
super().__init__()
match_string = matchString or match_string
self.match = match_string
self.matchLen = len(match_string)
try:
self.firstMatchChar = match_string[0]
except IndexError:
raise ValueError("null string passed to Literal; use Empty() instead")
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = False
self.mayIndexError = False
# Performance tuning: modify __class__ to select
# a parseImpl optimized for single-character check
if self.matchLen == 1 and type(self) is Literal:
self.__class__ = _SingleCharLiteral
def _generateDefaultName(self):
return repr(self.match)
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] == self.firstMatchChar and instring.startswith(
self.match, loc
):
return loc + self.matchLen, self.match
raise ParseException(instring, loc, self.errmsg, self)
ParserElement._literalStringClass = Literal
class And(ParseExpression):
"""
Requires all given :class:`ParseExpression` s to be found in the given order.
Expressions may be separated by whitespace.
May be constructed using the ``'+'`` operator.
May also be constructed using the ``'-'`` operator, which will
suppress backtracking.
Example::
integer = Word(nums)
name_expr = Word(alphas)[1, ...]
expr = And([integer("id"), name_expr("name"), integer("age")])
# more easily written as:
expr = integer("id") + name_expr("name") + integer("age")
"""
class _ErrorStop(Empty):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.leave_whitespace()
def _generateDefaultName(self):
return "-"
def __init__(
self, exprs_arg: typing.Iterable[ParserElement], savelist: bool = True
):
exprs: List[ParserElement] = list(exprs_arg)
if exprs and Ellipsis in exprs:
tmp = []
for i, expr in enumerate(exprs):
if expr is Ellipsis:
if i < len(exprs) - 1:
skipto_arg: ParserElement = (Empty() + exprs[i + 1]).exprs[-1]
tmp.append(SkipTo(skipto_arg)("_skipped*"))
else:
raise Exception(
"cannot construct And with sequence ending in ..."
)
else:
tmp.append(expr)
exprs[:] = tmp
super().__init__(exprs, savelist)
if self.exprs:
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
if not isinstance(self.exprs[0], White):
self.set_whitespace_chars(
self.exprs[0].whiteChars,
copy_defaults=self.exprs[0].copyDefaultWhiteChars,
)
self.skipWhitespace = self.exprs[0].skipWhitespace
else:
self.skipWhitespace = False
else:
self.mayReturnEmpty = True
self.callPreparse = True
def streamline(self) -> ParserElement:
# collapse any _PendingSkip's
if self.exprs:
if any(
isinstance(e, ParseExpression)
and e.exprs
and isinstance(e.exprs[-1], _PendingSkip)
for e in self.exprs[:-1]
):
for i, e in enumerate(self.exprs[:-1]):
if e is None:
continue
if (
isinstance(e, ParseExpression)
and e.exprs
and isinstance(e.exprs[-1], _PendingSkip)
):
e.exprs[-1] = e.exprs[-1] + self.exprs[i + 1]
self.exprs[i + 1] = None
self.exprs = [e for e in self.exprs if e is not None]
super().streamline()
# link any IndentedBlocks to the prior expression
for prev, cur in zip(self.exprs, self.exprs[1:]):
# traverse cur or any first embedded expr of cur looking for an IndentedBlock
# (but watch out for recursive grammar)
seen = set()
while cur:
if id(cur) in seen:
break
seen.add(id(cur))
if isinstance(cur, IndentedBlock):
prev.add_parse_action(
lambda s, l, t, cur_=cur: setattr(
cur_, "parent_anchor", col(l, s)
)
)
break
subs = cur.recurse()
cur = next(iter(subs), None)
self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs)
return self
def parseImpl(self, instring, loc, doActions=True):
# pass False as callPreParse arg to _parse for first element, since we already
# pre-parsed the string as part of our And pre-parsing
loc, resultlist = self.exprs[0]._parse(
instring, loc, doActions, callPreParse=False
)
errorStop = False
for e in self.exprs[1:]:
# if isinstance(e, And._ErrorStop):
if type(e) is And._ErrorStop:
errorStop = True
continue
if errorStop:
try:
loc, exprtokens = e._parse(instring, loc, doActions)
except ParseSyntaxException:
raise
except ParseBaseException as pe:
pe.__traceback__ = None
raise ParseSyntaxException._from_exception(pe)
except IndexError:
raise ParseSyntaxException(
instring, len(instring), self.errmsg, self
)
else:
loc, exprtokens = e._parse(instring, loc, doActions)
if exprtokens or exprtokens.haskeys():
resultlist += exprtokens
return loc, resultlist
def __iadd__(self, other):
if isinstance(other, str_type):
other = self._literalStringClass(other)
return self.append(other) # And([self, other])
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.exprs:
e._checkRecursion(subRecCheckList)
if not e.mayReturnEmpty:
break
def _generateDefaultName(self):
inner = " ".join(str(e) for e in self.exprs)
# strip off redundant inner {}'s
while len(inner) > 1 and inner[0 :: len(inner) - 1] == "{}":
inner = inner[1:-1]
return "{" + inner + "}"
class Forward(ParseElementEnhance):
"""
Forward declaration of an expression to be defined later -
used for recursive grammars, such as algebraic infix notation.
When the expression is known, it is assigned to the ``Forward``
variable using the ``'<<'`` operator.
Note: take care when assigning to ``Forward`` not to overlook
precedence of operators.
Specifically, ``'|'`` has a lower precedence than ``'<<'``, so that::
fwd_expr << a | b | c
will actually be evaluated as::
(fwd_expr << a) | b | c
thereby leaving b and c out as parseable alternatives. It is recommended that you
explicitly group the values inserted into the ``Forward``::
fwd_expr << (a | b | c)
Converting to use the ``'<<='`` operator instead will avoid this problem.
See :class:`ParseResults.pprint` for an example of a recursive
parser created using ``Forward``.
"""
def __init__(self, other: typing.Optional[Union[ParserElement, str]] = None):
self.caller_frame = traceback.extract_stack(limit=2)[0]
super().__init__(other, savelist=False)
self.lshift_line = None
def __lshift__(self, other):
if hasattr(self, "caller_frame"):
del self.caller_frame
if isinstance(other, str_type):
other = self._literalStringClass(other)
self.expr = other
self.mayIndexError = self.expr.mayIndexError
self.mayReturnEmpty = self.expr.mayReturnEmpty
self.set_whitespace_chars(
self.expr.whiteChars, copy_defaults=self.expr.copyDefaultWhiteChars
)
self.skipWhitespace = self.expr.skipWhitespace
self.saveAsList = self.expr.saveAsList
self.ignoreExprs.extend(self.expr.ignoreExprs)
self.lshift_line = traceback.extract_stack(limit=2)[-2]
return self
def __ilshift__(self, other):
return self << other
def __or__(self, other):
caller_line = traceback.extract_stack(limit=2)[-2]
if (
__diag__.warn_on_match_first_with_lshift_operator
and caller_line == self.lshift_line
and Diagnostics.warn_on_match_first_with_lshift_operator
not in self.suppress_warnings_
):
warnings.warn(
"using '<<' operator with '|' is probably an error, use '<<='",
stacklevel=2,
)
ret = super().__or__(other)
return ret
def __del__(self):
# see if we are getting dropped because of '=' reassignment of var instead of '<<=' or '<<'
if (
self.expr is None
and __diag__.warn_on_assignment_to_Forward
and Diagnostics.warn_on_assignment_to_Forward not in self.suppress_warnings_
):
warnings.warn_explicit(
"Forward defined here but no expression attached later using '<<=' or '<<'",
UserWarning,
filename=self.caller_frame.filename,
lineno=self.caller_frame.lineno,
)
def parseImpl(self, instring, loc, doActions=True):
if (
self.expr is None
and __diag__.warn_on_parse_using_empty_Forward
and Diagnostics.warn_on_parse_using_empty_Forward
not in self.suppress_warnings_
):
# walk stack until parse_string, scan_string, search_string, or transform_string is found
parse_fns = [
"parse_string",
"scan_string",
"search_string",
"transform_string",
]
tb = traceback.extract_stack(limit=200)
for i, frm in enumerate(reversed(tb), start=1):
if frm.name in parse_fns:
stacklevel = i + 1
break
else:
stacklevel = 2
warnings.warn(
"Forward expression was never assigned a value, will not parse any input",
stacklevel=stacklevel,
)
if not ParserElement._left_recursion_enabled:
return super().parseImpl(instring, loc, doActions)
# ## Bounded Recursion algorithm ##
# Recursion only needs to be processed at ``Forward`` elements, since they are
# the only ones that can actually refer to themselves. The general idea is
# to handle recursion stepwise: We start at no recursion, then recurse once,
# recurse twice, ..., until more recursion offers no benefit (we hit the bound).
#
# The "trick" here is that each ``Forward`` gets evaluated in two contexts
# - to *match* a specific recursion level, and
# - to *search* the bounded recursion level
# and the two run concurrently. The *search* must *match* each recursion level
# to find the best possible match. This is handled by a memo table, which
# provides the previous match to the next level match attempt.
#
# See also "Left Recursion in Parsing Expression Grammars", Medeiros et al.
#
# There is a complication since we not only *parse* but also *transform* via
# actions: We do not want to run the actions too often while expanding. Thus,
# we expand using `doActions=False` and only run `doActions=True` if the next
# recursion level is acceptable.
with ParserElement.recursion_lock:
memo = ParserElement.recursion_memos
try:
# we are parsing at a specific recursion expansion - use it as-is
prev_loc, prev_result = memo[loc, self, doActions]
if isinstance(prev_result, Exception):
raise prev_result
return prev_loc, prev_result.copy()
except KeyError:
act_key = (loc, self, True)
peek_key = (loc, self, False)
# we are searching for the best recursion expansion - keep on improving
# both `doActions` cases must be tracked separately here!
prev_loc, prev_peek = memo[peek_key] = (
loc - 1,
ParseException(
instring, loc, "Forward recursion without base case", self
),
)
if doActions:
memo[act_key] = memo[peek_key]
while True:
try:
new_loc, new_peek = super().parseImpl(instring, loc, False)
except ParseException:
# we failed before getting any match – do not hide the error
if isinstance(prev_peek, Exception):
raise
new_loc, new_peek = prev_loc, prev_peek
# the match did not get better: we are done
if new_loc <= prev_loc:
if doActions:
# replace the match for doActions=False as well,
# in case the action did backtrack
prev_loc, prev_result = memo[peek_key] = memo[act_key]
del memo[peek_key], memo[act_key]
return prev_loc, prev_result.copy()
del memo[peek_key]
return prev_loc, prev_peek.copy()
# the match did get better: see if we can improve further
else:
if doActions:
try:
memo[act_key] = super().parseImpl(instring, loc, True)
except ParseException as e:
memo[peek_key] = memo[act_key] = (new_loc, e)
raise
prev_loc, prev_peek = memo[peek_key] = new_loc, new_peek
def leave_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = False
return self
def ignore_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = True
return self
def streamline(self) -> ParserElement:
if not self.streamlined:
self.streamlined = True
if self.expr is not None:
self.expr.streamline()
return self
def validate(self, validateTrace=None) -> None:
if validateTrace is None:
validateTrace = []
if self not in validateTrace:
tmp = validateTrace[:] + [self]
if self.expr is not None:
self.expr.validate(tmp)
self._checkRecursion([])
def _generateDefaultName(self):
# Avoid infinite recursion by setting a temporary _defaultName
self._defaultName = ": ..."
# Use the string representation of main expression.
retString = "..."
try:
if self.expr is not None:
retString = str(self.expr)[:1000]
else:
retString = "None"
finally:
return self.__class__.__name__ + ": " + retString
def copy(self) -> ParserElement:
if self.expr is not None:
return super().copy()
else:
ret = Forward()
ret <<= self
return ret
def _setResultsName(self, name, list_all_matches=False):
if (
__diag__.warn_name_set_on_empty_Forward
and Diagnostics.warn_name_set_on_empty_Forward
not in self.suppress_warnings_
):
if self.expr is None:
warnings.warn(
"{}: setting results name {!r} on {} expression "
"that has no contained expression".format(
"warn_name_set_on_empty_Forward", name, type(self).__name__
),
stacklevel=3,
)
return super()._setResultsName(name, list_all_matches)
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
def _flatten(ll: list) -> list:
ret = []
for i in ll:
if isinstance(i, list):
ret.extend(_flatten(i))
else:
ret.append(i)
return ret
The provided code snippet includes necessary dependencies for implementing the `match_previous_literal` function. Write a Python function `def match_previous_literal(expr: ParserElement) -> ParserElement` to solve the following problem:
Helper to define an expression that is indirectly defined from the tokens matched in a previous expression, that is, it looks for a 'repeat' of a previous expression. For example:: first = Word(nums) second = match_previous_literal(first) match_expr = first + ":" + second will match ``"1:1"``, but not ``"1:2"``. Because this matches a previous literal, will also match the leading ``"1:1"`` in ``"1:10"``. If this is not desired, use :class:`match_previous_expr`. Do *not* use with packrat parsing enabled.
Here is the function:
def match_previous_literal(expr: ParserElement) -> ParserElement:
"""Helper to define an expression that is indirectly defined from
the tokens matched in a previous expression, that is, it looks for
a 'repeat' of a previous expression. For example::
first = Word(nums)
second = match_previous_literal(first)
match_expr = first + ":" + second
will match ``"1:1"``, but not ``"1:2"``. Because this
matches a previous literal, will also match the leading
``"1:1"`` in ``"1:10"``. If this is not desired, use
:class:`match_previous_expr`. Do *not* use with packrat parsing
enabled.
"""
rep = Forward()
def copy_token_to_repeater(s, l, t):
if t:
if len(t) == 1:
rep << t[0]
else:
# flatten t tokens
tflat = _flatten(t.as_list())
rep << And(Literal(tt) for tt in tflat)
else:
rep << Empty()
expr.add_parse_action(copy_token_to_repeater, callDuringTry=True)
rep.set_name("(prev) " + str(expr))
return rep | Helper to define an expression that is indirectly defined from the tokens matched in a previous expression, that is, it looks for a 'repeat' of a previous expression. For example:: first = Word(nums) second = match_previous_literal(first) match_expr = first + ":" + second will match ``"1:1"``, but not ``"1:2"``. Because this matches a previous literal, will also match the leading ``"1:1"`` in ``"1:10"``. If this is not desired, use :class:`match_previous_expr`. Do *not* use with packrat parsing enabled. |
173,729 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
import copy
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
class Forward(ParseElementEnhance):
"""
Forward declaration of an expression to be defined later -
used for recursive grammars, such as algebraic infix notation.
When the expression is known, it is assigned to the ``Forward``
variable using the ``'<<'`` operator.
Note: take care when assigning to ``Forward`` not to overlook
precedence of operators.
Specifically, ``'|'`` has a lower precedence than ``'<<'``, so that::
fwd_expr << a | b | c
will actually be evaluated as::
(fwd_expr << a) | b | c
thereby leaving b and c out as parseable alternatives. It is recommended that you
explicitly group the values inserted into the ``Forward``::
fwd_expr << (a | b | c)
Converting to use the ``'<<='`` operator instead will avoid this problem.
See :class:`ParseResults.pprint` for an example of a recursive
parser created using ``Forward``.
"""
def __init__(self, other: typing.Optional[Union[ParserElement, str]] = None):
self.caller_frame = traceback.extract_stack(limit=2)[0]
super().__init__(other, savelist=False)
self.lshift_line = None
def __lshift__(self, other):
if hasattr(self, "caller_frame"):
del self.caller_frame
if isinstance(other, str_type):
other = self._literalStringClass(other)
self.expr = other
self.mayIndexError = self.expr.mayIndexError
self.mayReturnEmpty = self.expr.mayReturnEmpty
self.set_whitespace_chars(
self.expr.whiteChars, copy_defaults=self.expr.copyDefaultWhiteChars
)
self.skipWhitespace = self.expr.skipWhitespace
self.saveAsList = self.expr.saveAsList
self.ignoreExprs.extend(self.expr.ignoreExprs)
self.lshift_line = traceback.extract_stack(limit=2)[-2]
return self
def __ilshift__(self, other):
return self << other
def __or__(self, other):
caller_line = traceback.extract_stack(limit=2)[-2]
if (
__diag__.warn_on_match_first_with_lshift_operator
and caller_line == self.lshift_line
and Diagnostics.warn_on_match_first_with_lshift_operator
not in self.suppress_warnings_
):
warnings.warn(
"using '<<' operator with '|' is probably an error, use '<<='",
stacklevel=2,
)
ret = super().__or__(other)
return ret
def __del__(self):
# see if we are getting dropped because of '=' reassignment of var instead of '<<=' or '<<'
if (
self.expr is None
and __diag__.warn_on_assignment_to_Forward
and Diagnostics.warn_on_assignment_to_Forward not in self.suppress_warnings_
):
warnings.warn_explicit(
"Forward defined here but no expression attached later using '<<=' or '<<'",
UserWarning,
filename=self.caller_frame.filename,
lineno=self.caller_frame.lineno,
)
def parseImpl(self, instring, loc, doActions=True):
if (
self.expr is None
and __diag__.warn_on_parse_using_empty_Forward
and Diagnostics.warn_on_parse_using_empty_Forward
not in self.suppress_warnings_
):
# walk stack until parse_string, scan_string, search_string, or transform_string is found
parse_fns = [
"parse_string",
"scan_string",
"search_string",
"transform_string",
]
tb = traceback.extract_stack(limit=200)
for i, frm in enumerate(reversed(tb), start=1):
if frm.name in parse_fns:
stacklevel = i + 1
break
else:
stacklevel = 2
warnings.warn(
"Forward expression was never assigned a value, will not parse any input",
stacklevel=stacklevel,
)
if not ParserElement._left_recursion_enabled:
return super().parseImpl(instring, loc, doActions)
# ## Bounded Recursion algorithm ##
# Recursion only needs to be processed at ``Forward`` elements, since they are
# the only ones that can actually refer to themselves. The general idea is
# to handle recursion stepwise: We start at no recursion, then recurse once,
# recurse twice, ..., until more recursion offers no benefit (we hit the bound).
#
# The "trick" here is that each ``Forward`` gets evaluated in two contexts
# - to *match* a specific recursion level, and
# - to *search* the bounded recursion level
# and the two run concurrently. The *search* must *match* each recursion level
# to find the best possible match. This is handled by a memo table, which
# provides the previous match to the next level match attempt.
#
# See also "Left Recursion in Parsing Expression Grammars", Medeiros et al.
#
# There is a complication since we not only *parse* but also *transform* via
# actions: We do not want to run the actions too often while expanding. Thus,
# we expand using `doActions=False` and only run `doActions=True` if the next
# recursion level is acceptable.
with ParserElement.recursion_lock:
memo = ParserElement.recursion_memos
try:
# we are parsing at a specific recursion expansion - use it as-is
prev_loc, prev_result = memo[loc, self, doActions]
if isinstance(prev_result, Exception):
raise prev_result
return prev_loc, prev_result.copy()
except KeyError:
act_key = (loc, self, True)
peek_key = (loc, self, False)
# we are searching for the best recursion expansion - keep on improving
# both `doActions` cases must be tracked separately here!
prev_loc, prev_peek = memo[peek_key] = (
loc - 1,
ParseException(
instring, loc, "Forward recursion without base case", self
),
)
if doActions:
memo[act_key] = memo[peek_key]
while True:
try:
new_loc, new_peek = super().parseImpl(instring, loc, False)
except ParseException:
# we failed before getting any match – do not hide the error
if isinstance(prev_peek, Exception):
raise
new_loc, new_peek = prev_loc, prev_peek
# the match did not get better: we are done
if new_loc <= prev_loc:
if doActions:
# replace the match for doActions=False as well,
# in case the action did backtrack
prev_loc, prev_result = memo[peek_key] = memo[act_key]
del memo[peek_key], memo[act_key]
return prev_loc, prev_result.copy()
del memo[peek_key]
return prev_loc, prev_peek.copy()
# the match did get better: see if we can improve further
else:
if doActions:
try:
memo[act_key] = super().parseImpl(instring, loc, True)
except ParseException as e:
memo[peek_key] = memo[act_key] = (new_loc, e)
raise
prev_loc, prev_peek = memo[peek_key] = new_loc, new_peek
def leave_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = False
return self
def ignore_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = True
return self
def streamline(self) -> ParserElement:
if not self.streamlined:
self.streamlined = True
if self.expr is not None:
self.expr.streamline()
return self
def validate(self, validateTrace=None) -> None:
if validateTrace is None:
validateTrace = []
if self not in validateTrace:
tmp = validateTrace[:] + [self]
if self.expr is not None:
self.expr.validate(tmp)
self._checkRecursion([])
def _generateDefaultName(self):
# Avoid infinite recursion by setting a temporary _defaultName
self._defaultName = ": ..."
# Use the string representation of main expression.
retString = "..."
try:
if self.expr is not None:
retString = str(self.expr)[:1000]
else:
retString = "None"
finally:
return self.__class__.__name__ + ": " + retString
def copy(self) -> ParserElement:
if self.expr is not None:
return super().copy()
else:
ret = Forward()
ret <<= self
return ret
def _setResultsName(self, name, list_all_matches=False):
if (
__diag__.warn_name_set_on_empty_Forward
and Diagnostics.warn_name_set_on_empty_Forward
not in self.suppress_warnings_
):
if self.expr is None:
warnings.warn(
"{}: setting results name {!r} on {} expression "
"that has no contained expression".format(
"warn_name_set_on_empty_Forward", name, type(self).__name__
),
stacklevel=3,
)
return super()._setResultsName(name, list_all_matches)
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
def _flatten(ll: list) -> list:
ret = []
for i in ll:
if isinstance(i, list):
ret.extend(_flatten(i))
else:
ret.append(i)
return ret
The provided code snippet includes necessary dependencies for implementing the `match_previous_expr` function. Write a Python function `def match_previous_expr(expr: ParserElement) -> ParserElement` to solve the following problem:
Helper to define an expression that is indirectly defined from the tokens matched in a previous expression, that is, it looks for a 'repeat' of a previous expression. For example:: first = Word(nums) second = match_previous_expr(first) match_expr = first + ":" + second will match ``"1:1"``, but not ``"1:2"``. Because this matches by expressions, will *not* match the leading ``"1:1"`` in ``"1:10"``; the expressions are evaluated first, and then compared, so ``"1"`` is compared with ``"10"``. Do *not* use with packrat parsing enabled.
Here is the function:
def match_previous_expr(expr: ParserElement) -> ParserElement:
"""Helper to define an expression that is indirectly defined from
the tokens matched in a previous expression, that is, it looks for
a 'repeat' of a previous expression. For example::
first = Word(nums)
second = match_previous_expr(first)
match_expr = first + ":" + second
will match ``"1:1"``, but not ``"1:2"``. Because this
matches by expressions, will *not* match the leading ``"1:1"``
in ``"1:10"``; the expressions are evaluated first, and then
compared, so ``"1"`` is compared with ``"10"``. Do *not* use
with packrat parsing enabled.
"""
rep = Forward()
e2 = expr.copy()
rep <<= e2
def copy_token_to_repeater(s, l, t):
matchTokens = _flatten(t.as_list())
def must_match_these_tokens(s, l, t):
theseTokens = _flatten(t.as_list())
if theseTokens != matchTokens:
raise ParseException(
s, l, "Expected {}, found{}".format(matchTokens, theseTokens)
)
rep.set_parse_action(must_match_these_tokens, callDuringTry=True)
expr.add_parse_action(copy_token_to_repeater, callDuringTry=True)
rep.set_name("(prev) " + str(expr))
return rep | Helper to define an expression that is indirectly defined from the tokens matched in a previous expression, that is, it looks for a 'repeat' of a previous expression. For example:: first = Word(nums) second = match_previous_expr(first) match_expr = first + ":" + second will match ``"1:1"``, but not ``"1:2"``. Because this matches by expressions, will *not* match the leading ``"1:1"`` in ``"1:10"``; the expressions are evaluated first, and then compared, so ``"1"`` is compared with ``"10"``. Do *not* use with packrat parsing enabled. |
173,730 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
import warnings
import re
str_type: Tuple[type, ...] = (str, bytes)
class __diag__(__config_flags):
_type_desc = "diagnostic"
warn_multiple_tokens_in_named_alternation = False
warn_ungrouped_named_tokens_in_collection = False
warn_name_set_on_empty_Forward = False
warn_on_parse_using_empty_Forward = False
warn_on_assignment_to_Forward = False
warn_on_multiple_string_args_to_oneof = False
warn_on_match_first_with_lshift_operator = False
enable_debug_on_named_expressions = False
_all_names = [__ for __ in locals() if not __.startswith("_")]
_warning_names = [name for name in _all_names if name.startswith("warn")]
_debug_names = [name for name in _all_names if name.startswith("enable_debug")]
def enable_all_warnings(cls) -> None:
for name in cls._warning_names:
cls.enable(name)
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class NoMatch(Token):
"""
A token that will never match.
"""
def __init__(self):
super().__init__()
self.mayReturnEmpty = True
self.mayIndexError = False
self.errmsg = "Unmatchable token"
def parseImpl(self, instring, loc, doActions=True):
raise ParseException(instring, loc, self.errmsg, self)
class Literal(Token):
"""
Token to exactly match a specified string.
Example::
Literal('blah').parse_string('blah') # -> ['blah']
Literal('blah').parse_string('blahfooblah') # -> ['blah']
Literal('blah').parse_string('bla') # -> Exception: Expected "blah"
For case-insensitive matching, use :class:`CaselessLiteral`.
For keyword matching (force word break before and after the matched string),
use :class:`Keyword` or :class:`CaselessKeyword`.
"""
def __init__(self, match_string: str = "", *, matchString: str = ""):
super().__init__()
match_string = matchString or match_string
self.match = match_string
self.matchLen = len(match_string)
try:
self.firstMatchChar = match_string[0]
except IndexError:
raise ValueError("null string passed to Literal; use Empty() instead")
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = False
self.mayIndexError = False
# Performance tuning: modify __class__ to select
# a parseImpl optimized for single-character check
if self.matchLen == 1 and type(self) is Literal:
self.__class__ = _SingleCharLiteral
def _generateDefaultName(self):
return repr(self.match)
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] == self.firstMatchChar and instring.startswith(
self.match, loc
):
return loc + self.matchLen, self.match
raise ParseException(instring, loc, self.errmsg, self)
ParserElement._literalStringClass = Literal
class Keyword(Token):
"""
Token to exactly match a specified string as a keyword, that is,
it must be immediately followed by a non-keyword character. Compare
with :class:`Literal`:
- ``Literal("if")`` will match the leading ``'if'`` in
``'ifAndOnlyIf'``.
- ``Keyword("if")`` will not; it will only match the leading
``'if'`` in ``'if x=1'``, or ``'if(y==2)'``
Accepts two optional constructor arguments in addition to the
keyword string:
- ``identChars`` is a string of characters that would be valid
identifier characters, defaulting to all alphanumerics + "_" and
"$"
- ``caseless`` allows case-insensitive matching, default is ``False``.
Example::
Keyword("start").parse_string("start") # -> ['start']
Keyword("start").parse_string("starting") # -> Exception
For case-insensitive matching, use :class:`CaselessKeyword`.
"""
DEFAULT_KEYWORD_CHARS = alphanums + "_$"
def __init__(
self,
match_string: str = "",
ident_chars: typing.Optional[str] = None,
caseless: bool = False,
*,
matchString: str = "",
identChars: typing.Optional[str] = None,
):
super().__init__()
identChars = identChars or ident_chars
if identChars is None:
identChars = Keyword.DEFAULT_KEYWORD_CHARS
match_string = matchString or match_string
self.match = match_string
self.matchLen = len(match_string)
try:
self.firstMatchChar = match_string[0]
except IndexError:
raise ValueError("null string passed to Keyword; use Empty() instead")
self.errmsg = "Expected {} {}".format(type(self).__name__, self.name)
self.mayReturnEmpty = False
self.mayIndexError = False
self.caseless = caseless
if caseless:
self.caselessmatch = match_string.upper()
identChars = identChars.upper()
self.identChars = set(identChars)
def _generateDefaultName(self):
return repr(self.match)
def parseImpl(self, instring, loc, doActions=True):
errmsg = self.errmsg
errloc = loc
if self.caseless:
if instring[loc : loc + self.matchLen].upper() == self.caselessmatch:
if loc == 0 or instring[loc - 1].upper() not in self.identChars:
if (
loc >= len(instring) - self.matchLen
or instring[loc + self.matchLen].upper() not in self.identChars
):
return loc + self.matchLen, self.match
else:
# followed by keyword char
errmsg += ", was immediately followed by keyword character"
errloc = loc + self.matchLen
else:
# preceded by keyword char
errmsg += ", keyword was immediately preceded by keyword character"
errloc = loc - 1
# else no match just raise plain exception
else:
if (
instring[loc] == self.firstMatchChar
and self.matchLen == 1
or instring.startswith(self.match, loc)
):
if loc == 0 or instring[loc - 1] not in self.identChars:
if (
loc >= len(instring) - self.matchLen
or instring[loc + self.matchLen] not in self.identChars
):
return loc + self.matchLen, self.match
else:
# followed by keyword char
errmsg += (
", keyword was immediately followed by keyword character"
)
errloc = loc + self.matchLen
else:
# preceded by keyword char
errmsg += ", keyword was immediately preceded by keyword character"
errloc = loc - 1
# else no match just raise plain exception
raise ParseException(instring, errloc, errmsg, self)
def set_default_keyword_chars(chars) -> None:
"""
Overrides the default characters used by :class:`Keyword` expressions.
"""
Keyword.DEFAULT_KEYWORD_CHARS = chars
setDefaultKeywordChars = set_default_keyword_chars
class CaselessLiteral(Literal):
"""
Token to match a specified string, ignoring case of letters.
Note: the matched results will always be in the case of the given
match string, NOT the case of the input text.
Example::
CaselessLiteral("CMD")[1, ...].parse_string("cmd CMD Cmd10")
# -> ['CMD', 'CMD', 'CMD']
(Contrast with example for :class:`CaselessKeyword`.)
"""
def __init__(self, match_string: str = "", *, matchString: str = ""):
match_string = matchString or match_string
super().__init__(match_string.upper())
# Preserve the defining literal.
self.returnString = match_string
self.errmsg = "Expected " + self.name
def parseImpl(self, instring, loc, doActions=True):
if instring[loc : loc + self.matchLen].upper() == self.match:
return loc + self.matchLen, self.returnString
raise ParseException(instring, loc, self.errmsg, self)
class CaselessKeyword(Keyword):
"""
Caseless version of :class:`Keyword`.
Example::
CaselessKeyword("CMD")[1, ...].parse_string("cmd CMD Cmd10")
# -> ['CMD', 'CMD']
(Contrast with example for :class:`CaselessLiteral`.)
"""
def __init__(
self,
match_string: str = "",
ident_chars: typing.Optional[str] = None,
*,
matchString: str = "",
identChars: typing.Optional[str] = None,
):
identChars = identChars or ident_chars
match_string = matchString or match_string
super().__init__(match_string, identChars, caseless=True)
class Regex(Token):
r"""Token for matching strings that match a given regular
expression. Defined with string specifying the regular expression in
a form recognized by the stdlib Python `re module <https://docs.python.org/3/library/re.html>`_.
If the given regex contains named groups (defined using ``(?P<name>...)``),
these will be preserved as named :class:`ParseResults`.
If instead of the Python stdlib ``re`` module you wish to use a different RE module
(such as the ``regex`` module), you can do so by building your ``Regex`` object with
a compiled RE that was compiled using ``regex``.
Example::
realnum = Regex(r"[+-]?\d+\.\d*")
# ref: https://stackoverflow.com/questions/267399/how-do-you-match-only-valid-roman-numerals-with-a-regular-expression
roman = Regex(r"M{0,4}(CM|CD|D?{0,3})(XC|XL|L?X{0,3})(IX|IV|V?I{0,3})")
# named fields in a regex will be returned as named results
date = Regex(r'(?P<year>\d{4})-(?P<month>\d\d?)-(?P<day>\d\d?)')
# the Regex class will accept re's compiled using the regex module
import regex
parser = pp.Regex(regex.compile(r'[0-9]'))
"""
def __init__(
self,
pattern: Any,
flags: Union[re.RegexFlag, int] = 0,
as_group_list: bool = False,
as_match: bool = False,
*,
asGroupList: bool = False,
asMatch: bool = False,
):
"""The parameters ``pattern`` and ``flags`` are passed
to the ``re.compile()`` function as-is. See the Python
`re module <https://docs.python.org/3/library/re.html>`_ module for an
explanation of the acceptable patterns and flags.
"""
super().__init__()
asGroupList = asGroupList or as_group_list
asMatch = asMatch or as_match
if isinstance(pattern, str_type):
if not pattern:
raise ValueError("null string passed to Regex; use Empty() instead")
self._re = None
self.reString = self.pattern = pattern
self.flags = flags
elif hasattr(pattern, "pattern") and hasattr(pattern, "match"):
self._re = pattern
self.pattern = self.reString = pattern.pattern
self.flags = flags
else:
raise TypeError(
"Regex may only be constructed with a string or a compiled RE object"
)
self.errmsg = "Expected " + self.name
self.mayIndexError = False
self.asGroupList = asGroupList
self.asMatch = asMatch
if self.asGroupList:
self.parseImpl = self.parseImplAsGroupList
if self.asMatch:
self.parseImpl = self.parseImplAsMatch
def re(self):
if self._re:
return self._re
else:
try:
return re.compile(self.pattern, self.flags)
except re.error:
raise ValueError(
"invalid pattern ({!r}) passed to Regex".format(self.pattern)
)
def re_match(self):
return self.re.match
def mayReturnEmpty(self):
return self.re_match("") is not None
def _generateDefaultName(self):
return "Re:({})".format(repr(self.pattern).replace("\\\\", "\\"))
def parseImpl(self, instring, loc, doActions=True):
result = self.re_match(instring, loc)
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
ret = ParseResults(result.group())
d = result.groupdict()
if d:
for k, v in d.items():
ret[k] = v
return loc, ret
def parseImplAsGroupList(self, instring, loc, doActions=True):
result = self.re_match(instring, loc)
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
ret = result.groups()
return loc, ret
def parseImplAsMatch(self, instring, loc, doActions=True):
result = self.re_match(instring, loc)
if not result:
raise ParseException(instring, loc, self.errmsg, self)
loc = result.end()
ret = result
return loc, ret
def sub(self, repl: str) -> ParserElement:
r"""
Return :class:`Regex` with an attached parse action to transform the parsed
result as if called using `re.sub(expr, repl, string) <https://docs.python.org/3/library/re.html#re.sub>`_.
Example::
make_html = Regex(r"(\w+):(.*?):").sub(r"<\1>\2</\1>")
print(make_html.transform_string("h1:main title:"))
# prints "<h1>main title</h1>"
"""
if self.asGroupList:
raise TypeError("cannot use sub() with Regex(asGroupList=True)")
if self.asMatch and callable(repl):
raise TypeError("cannot use sub() with a callable with Regex(asMatch=True)")
if self.asMatch:
def pa(tokens):
return tokens[0].expand(repl)
else:
def pa(tokens):
return self.re.sub(repl, tokens[0])
return self.add_parse_action(pa)
class MatchFirst(ParseExpression):
"""Requires that at least one :class:`ParseExpression` is found. If
more than one expression matches, the first one listed is the one that will
match. May be constructed using the ``'|'`` operator.
Example::
# construct MatchFirst using '|' operator
# watch the order of expressions to match
number = Word(nums) | Combine(Word(nums) + '.' + Word(nums))
print(number.search_string("123 3.1416 789")) # Fail! -> [['123'], ['3'], ['1416'], ['789']]
# put more selective expression first
number = Combine(Word(nums) + '.' + Word(nums)) | Word(nums)
print(number.search_string("123 3.1416 789")) # Better -> [['123'], ['3.1416'], ['789']]
"""
def __init__(self, exprs: typing.Iterable[ParserElement], savelist: bool = False):
super().__init__(exprs, savelist)
if self.exprs:
self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
self.skipWhitespace = all(e.skipWhitespace for e in self.exprs)
else:
self.mayReturnEmpty = True
def streamline(self) -> ParserElement:
if self.streamlined:
return self
super().streamline()
if self.exprs:
self.saveAsList = any(e.saveAsList for e in self.exprs)
self.mayReturnEmpty = any(e.mayReturnEmpty for e in self.exprs)
self.skipWhitespace = all(
e.skipWhitespace and not isinstance(e, White) for e in self.exprs
)
else:
self.saveAsList = False
self.mayReturnEmpty = True
return self
def parseImpl(self, instring, loc, doActions=True):
maxExcLoc = -1
maxException = None
for e in self.exprs:
try:
return e._parse(
instring,
loc,
doActions,
)
except ParseFatalException as pfe:
pfe.__traceback__ = None
pfe.parserElement = e
raise
except ParseException as err:
if err.loc > maxExcLoc:
maxException = err
maxExcLoc = err.loc
except IndexError:
if len(instring) > maxExcLoc:
maxException = ParseException(
instring, len(instring), e.errmsg, self
)
maxExcLoc = len(instring)
if maxException is not None:
maxException.msg = self.errmsg
raise maxException
else:
raise ParseException(
instring, loc, "no defined alternatives to match", self
)
def __ior__(self, other):
if isinstance(other, str_type):
other = self._literalStringClass(other)
return self.append(other) # MatchFirst([self, other])
def _generateDefaultName(self):
return "{" + " | ".join(str(e) for e in self.exprs) + "}"
def _setResultsName(self, name, listAllMatches=False):
if (
__diag__.warn_multiple_tokens_in_named_alternation
and Diagnostics.warn_multiple_tokens_in_named_alternation
not in self.suppress_warnings_
):
if any(
isinstance(e, And)
and Diagnostics.warn_multiple_tokens_in_named_alternation
not in e.suppress_warnings_
for e in self.exprs
):
warnings.warn(
"{}: setting results name {!r} on {} expression "
"will return a list of all parsed tokens in an And alternative, "
"in prior versions only the first token was returned; enclose "
"contained argument in Group".format(
"warn_multiple_tokens_in_named_alternation",
name,
type(self).__name__,
),
stacklevel=3,
)
return super()._setResultsName(name, listAllMatches)
def _escape_regex_range_chars(s: str) -> str:
# escape these chars: ^-[]
for c in r"\^-[]":
s = s.replace(c, _bslash + c)
s = s.replace("\n", r"\n")
s = s.replace("\t", r"\t")
return str(s)
The provided code snippet includes necessary dependencies for implementing the `one_of` function. Write a Python function `def one_of( strs: Union[typing.Iterable[str], str], caseless: bool = False, use_regex: bool = True, as_keyword: bool = False, *, useRegex: bool = True, asKeyword: bool = False, ) -> ParserElement` to solve the following problem:
Helper to quickly define a set of alternative :class:`Literal` s, and makes sure to do longest-first testing when there is a conflict, regardless of the input order, but returns a :class:`MatchFirst` for best performance. Parameters: - ``strs`` - a string of space-delimited literals, or a collection of string literals - ``caseless`` - treat all literals as caseless - (default= ``False``) - ``use_regex`` - as an optimization, will generate a :class:`Regex` object; otherwise, will generate a :class:`MatchFirst` object (if ``caseless=True`` or ``asKeyword=True``, or if creating a :class:`Regex` raises an exception) - (default= ``True``) - ``as_keyword`` - enforce :class:`Keyword`-style matching on the generated expressions - (default= ``False``) - ``asKeyword`` and ``useRegex`` are retained for pre-PEP8 compatibility, but will be removed in a future release Example:: comp_oper = one_of("< = > <= >= !=") var = Word(alphas) number = Word(nums) term = var | number comparison_expr = term + comp_oper + term print(comparison_expr.search_string("B = 12 AA=23 B<=AA AA>12")) prints:: [['B', '=', '12'], ['AA', '=', '23'], ['B', '<=', 'AA'], ['AA', '>', '12']]
Here is the function:
def one_of(
strs: Union[typing.Iterable[str], str],
caseless: bool = False,
use_regex: bool = True,
as_keyword: bool = False,
*,
useRegex: bool = True,
asKeyword: bool = False,
) -> ParserElement:
"""Helper to quickly define a set of alternative :class:`Literal` s,
and makes sure to do longest-first testing when there is a conflict,
regardless of the input order, but returns
a :class:`MatchFirst` for best performance.
Parameters:
- ``strs`` - a string of space-delimited literals, or a collection of
string literals
- ``caseless`` - treat all literals as caseless - (default= ``False``)
- ``use_regex`` - as an optimization, will
generate a :class:`Regex` object; otherwise, will generate
a :class:`MatchFirst` object (if ``caseless=True`` or ``asKeyword=True``, or if
creating a :class:`Regex` raises an exception) - (default= ``True``)
- ``as_keyword`` - enforce :class:`Keyword`-style matching on the
generated expressions - (default= ``False``)
- ``asKeyword`` and ``useRegex`` are retained for pre-PEP8 compatibility,
but will be removed in a future release
Example::
comp_oper = one_of("< = > <= >= !=")
var = Word(alphas)
number = Word(nums)
term = var | number
comparison_expr = term + comp_oper + term
print(comparison_expr.search_string("B = 12 AA=23 B<=AA AA>12"))
prints::
[['B', '=', '12'], ['AA', '=', '23'], ['B', '<=', 'AA'], ['AA', '>', '12']]
"""
asKeyword = asKeyword or as_keyword
useRegex = useRegex and use_regex
if (
isinstance(caseless, str_type)
and __diag__.warn_on_multiple_string_args_to_oneof
):
warnings.warn(
"More than one string argument passed to one_of, pass"
" choices as a list or space-delimited string",
stacklevel=2,
)
if caseless:
isequal = lambda a, b: a.upper() == b.upper()
masks = lambda a, b: b.upper().startswith(a.upper())
parseElementClass = CaselessKeyword if asKeyword else CaselessLiteral
else:
isequal = lambda a, b: a == b
masks = lambda a, b: b.startswith(a)
parseElementClass = Keyword if asKeyword else Literal
symbols: List[str] = []
if isinstance(strs, str_type):
symbols = strs.split()
elif isinstance(strs, Iterable):
symbols = list(strs)
else:
raise TypeError("Invalid argument to one_of, expected string or iterable")
if not symbols:
return NoMatch()
# reorder given symbols to take care to avoid masking longer choices with shorter ones
# (but only if the given symbols are not just single characters)
if any(len(sym) > 1 for sym in symbols):
i = 0
while i < len(symbols) - 1:
cur = symbols[i]
for j, other in enumerate(symbols[i + 1 :]):
if isequal(other, cur):
del symbols[i + j + 1]
break
elif masks(cur, other):
del symbols[i + j + 1]
symbols.insert(i, other)
break
else:
i += 1
if useRegex:
re_flags: int = re.IGNORECASE if caseless else 0
try:
if all(len(sym) == 1 for sym in symbols):
# symbols are just single characters, create range regex pattern
patt = "[{}]".format(
"".join(_escape_regex_range_chars(sym) for sym in symbols)
)
else:
patt = "|".join(re.escape(sym) for sym in symbols)
# wrap with \b word break markers if defining as keywords
if asKeyword:
patt = r"\b(?:{})\b".format(patt)
ret = Regex(patt, flags=re_flags).set_name(" | ".join(symbols))
if caseless:
# add parse action to return symbols as specified, not in random
# casing as found in input string
symbol_map = {sym.lower(): sym for sym in symbols}
ret.add_parse_action(lambda s, l, t: symbol_map[t[0].lower()])
return ret
except re.error:
warnings.warn(
"Exception creating Regex for one_of, building MatchFirst", stacklevel=2
)
# last resort, just use MatchFirst
return MatchFirst(parseElementClass(sym) for sym in symbols).set_name(
" | ".join(symbols)
) | Helper to quickly define a set of alternative :class:`Literal` s, and makes sure to do longest-first testing when there is a conflict, regardless of the input order, but returns a :class:`MatchFirst` for best performance. Parameters: - ``strs`` - a string of space-delimited literals, or a collection of string literals - ``caseless`` - treat all literals as caseless - (default= ``False``) - ``use_regex`` - as an optimization, will generate a :class:`Regex` object; otherwise, will generate a :class:`MatchFirst` object (if ``caseless=True`` or ``asKeyword=True``, or if creating a :class:`Regex` raises an exception) - (default= ``True``) - ``as_keyword`` - enforce :class:`Keyword`-style matching on the generated expressions - (default= ``False``) - ``asKeyword`` and ``useRegex`` are retained for pre-PEP8 compatibility, but will be removed in a future release Example:: comp_oper = one_of("< = > <= >= !=") var = Word(alphas) number = Word(nums) term = var | number comparison_expr = term + comp_oper + term print(comparison_expr.search_string("B = 12 AA=23 B<=AA AA>12")) prints:: [['B', '=', '12'], ['AA', '=', '23'], ['B', '<=', 'AA'], ['AA', '>', '12']] |
173,731 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
class OneOrMore(_MultipleMatch):
"""
Repetition of one or more of the given expression.
Parameters:
- expr - expression that must match one or more times
- stop_on - (default= ``None``) - expression for a terminating sentinel
(only required if the sentinel would ordinarily match the repetition
expression)
Example::
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).set_parse_action(' '.join))
text = "shape: SQUARE posn: upper left color: BLACK"
attr_expr[1, ...].parse_string(text).pprint() # Fail! read 'color' as data instead of next label -> [['shape', 'SQUARE color']]
# use stop_on attribute for OneOrMore to avoid reading label string as part of the data
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))
OneOrMore(attr_expr).parse_string(text).pprint() # Better -> [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'BLACK']]
# could also be written as
(attr_expr * (1,)).parse_string(text).pprint()
"""
def _generateDefaultName(self):
return "{" + str(self.expr) + "}..."
class Group(TokenConverter):
"""Converter to return the matched tokens as a list - useful for
returning tokens of :class:`ZeroOrMore` and :class:`OneOrMore` expressions.
The optional ``aslist`` argument when set to True will return the
parsed tokens as a Python list instead of a pyparsing ParseResults.
Example::
ident = Word(alphas)
num = Word(nums)
term = ident | num
func = ident + Opt(delimited_list(term))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', 'a', 'b', '100']
func = ident + Group(Opt(delimited_list(term)))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', ['a', 'b', '100']]
"""
def __init__(self, expr: ParserElement, aslist: bool = False):
super().__init__(expr)
self.saveAsList = True
self._asPythonList = aslist
def postParse(self, instring, loc, tokenlist):
if self._asPythonList:
return ParseResults.List(
tokenlist.asList()
if isinstance(tokenlist, ParseResults)
else list(tokenlist)
)
else:
return [tokenlist]
class Dict(TokenConverter):
"""Converter to return a repetitive expression as a list, but also
as a dictionary. Each element can also be referenced using the first
token in the expression as its key. Useful for tabular report
scraping when the first column can be used as a item key.
The optional ``asdict`` argument when set to True will return the
parsed tokens as a Python dict instead of a pyparsing ParseResults.
Example::
data_word = Word(alphas)
label = data_word + FollowedBy(':')
text = "shape: SQUARE posn: upper left color: light blue texture: burlap"
attr_expr = (label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))
# print attributes as plain groups
print(attr_expr[1, ...].parse_string(text).dump())
# instead of OneOrMore(expr), parse using Dict(Group(expr)[1, ...]) - Dict will auto-assign names
result = Dict(Group(attr_expr)[1, ...]).parse_string(text)
print(result.dump())
# access named fields as dict entries, or output as dict
print(result['shape'])
print(result.as_dict())
prints::
['shape', 'SQUARE', 'posn', 'upper left', 'color', 'light blue', 'texture', 'burlap']
[['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']]
- color: 'light blue'
- posn: 'upper left'
- shape: 'SQUARE'
- texture: 'burlap'
SQUARE
{'color': 'light blue', 'posn': 'upper left', 'texture': 'burlap', 'shape': 'SQUARE'}
See more examples at :class:`ParseResults` of accessing fields by results name.
"""
def __init__(self, expr: ParserElement, asdict: bool = False):
super().__init__(expr)
self.saveAsList = True
self._asPythonDict = asdict
def postParse(self, instring, loc, tokenlist):
for i, tok in enumerate(tokenlist):
if len(tok) == 0:
continue
ikey = tok[0]
if isinstance(ikey, int):
ikey = str(ikey).strip()
if len(tok) == 1:
tokenlist[ikey] = _ParseResultsWithOffset("", i)
elif len(tok) == 2 and not isinstance(tok[1], ParseResults):
tokenlist[ikey] = _ParseResultsWithOffset(tok[1], i)
else:
try:
dictvalue = tok.copy() # ParseResults(i)
except Exception:
exc = TypeError(
"could not extract dict values from parsed results"
" - Dict expression must contain Grouped expressions"
)
raise exc from None
del dictvalue[0]
if len(dictvalue) != 1 or (
isinstance(dictvalue, ParseResults) and dictvalue.haskeys()
):
tokenlist[ikey] = _ParseResultsWithOffset(dictvalue, i)
else:
tokenlist[ikey] = _ParseResultsWithOffset(dictvalue[0], i)
if self._asPythonDict:
return [tokenlist.as_dict()] if self.resultsName else tokenlist.as_dict()
else:
return [tokenlist] if self.resultsName else tokenlist
The provided code snippet includes necessary dependencies for implementing the `dict_of` function. Write a Python function `def dict_of(key: ParserElement, value: ParserElement) -> ParserElement` to solve the following problem:
Helper to easily and clearly define a dictionary by specifying the respective patterns for the key and value. Takes care of defining the :class:`Dict`, :class:`ZeroOrMore`, and :class:`Group` tokens in the proper order. The key pattern can include delimiting markers or punctuation, as long as they are suppressed, thereby leaving the significant key text. The value pattern can include named results, so that the :class:`Dict` results can include named token fields. Example:: text = "shape: SQUARE posn: upper left color: light blue texture: burlap" attr_expr = (label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join)) print(attr_expr[1, ...].parse_string(text).dump()) attr_label = label attr_value = Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join) # similar to Dict, but simpler call format result = dict_of(attr_label, attr_value).parse_string(text) print(result.dump()) print(result['shape']) print(result.shape) # object attribute access works too print(result.as_dict()) prints:: [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']] - color: 'light blue' - posn: 'upper left' - shape: 'SQUARE' - texture: 'burlap' SQUARE SQUARE {'color': 'light blue', 'shape': 'SQUARE', 'posn': 'upper left', 'texture': 'burlap'}
Here is the function:
def dict_of(key: ParserElement, value: ParserElement) -> ParserElement:
"""Helper to easily and clearly define a dictionary by specifying
the respective patterns for the key and value. Takes care of
defining the :class:`Dict`, :class:`ZeroOrMore`, and
:class:`Group` tokens in the proper order. The key pattern
can include delimiting markers or punctuation, as long as they are
suppressed, thereby leaving the significant key text. The value
pattern can include named results, so that the :class:`Dict` results
can include named token fields.
Example::
text = "shape: SQUARE posn: upper left color: light blue texture: burlap"
attr_expr = (label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))
print(attr_expr[1, ...].parse_string(text).dump())
attr_label = label
attr_value = Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join)
# similar to Dict, but simpler call format
result = dict_of(attr_label, attr_value).parse_string(text)
print(result.dump())
print(result['shape'])
print(result.shape) # object attribute access works too
print(result.as_dict())
prints::
[['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']]
- color: 'light blue'
- posn: 'upper left'
- shape: 'SQUARE'
- texture: 'burlap'
SQUARE
SQUARE
{'color': 'light blue', 'shape': 'SQUARE', 'posn': 'upper left', 'texture': 'burlap'}
"""
return Dict(OneOrMore(Group(key + value))) | Helper to easily and clearly define a dictionary by specifying the respective patterns for the key and value. Takes care of defining the :class:`Dict`, :class:`ZeroOrMore`, and :class:`Group` tokens in the proper order. The key pattern can include delimiting markers or punctuation, as long as they are suppressed, thereby leaving the significant key text. The value pattern can include named results, so that the :class:`Dict` results can include named token fields. Example:: text = "shape: SQUARE posn: upper left color: light blue texture: burlap" attr_expr = (label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join)) print(attr_expr[1, ...].parse_string(text).dump()) attr_label = label attr_value = Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join) # similar to Dict, but simpler call format result = dict_of(attr_label, attr_value).parse_string(text) print(result.dump()) print(result['shape']) print(result.shape) # object attribute access works too print(result.as_dict()) prints:: [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'light blue'], ['texture', 'burlap']] - color: 'light blue' - posn: 'upper left' - shape: 'SQUARE' - texture: 'burlap' SQUARE SQUARE {'color': 'light blue', 'shape': 'SQUARE', 'posn': 'upper left', 'texture': 'burlap'} |
173,732 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
import copy
class Diagnostics(Enum):
"""
Diagnostic configuration (all default to disabled)
- ``warn_multiple_tokens_in_named_alternation`` - flag to enable warnings when a results
name is defined on a :class:`MatchFirst` or :class:`Or` expression with one or more :class:`And` subexpressions
- ``warn_ungrouped_named_tokens_in_collection`` - flag to enable warnings when a results
name is defined on a containing expression with ungrouped subexpressions that also
have results names
- ``warn_name_set_on_empty_Forward`` - flag to enable warnings when a :class:`Forward` is defined
with a results name, but has no contents defined
- ``warn_on_parse_using_empty_Forward`` - flag to enable warnings when a :class:`Forward` is
defined in a grammar but has never had an expression attached to it
- ``warn_on_assignment_to_Forward`` - flag to enable warnings when a :class:`Forward` is defined
but is overwritten by assigning using ``'='`` instead of ``'<<='`` or ``'<<'``
- ``warn_on_multiple_string_args_to_oneof`` - flag to enable warnings when :class:`one_of` is
incorrectly called with multiple str arguments
- ``enable_debug_on_named_expressions`` - flag to auto-enable debug on all subsequent
calls to :class:`ParserElement.set_name`
Diagnostics are enabled/disabled by calling :class:`enable_diag` and :class:`disable_diag`.
All warnings can be enabled by calling :class:`enable_all_warnings`.
"""
warn_multiple_tokens_in_named_alternation = 0
warn_ungrouped_named_tokens_in_collection = 1
warn_name_set_on_empty_Forward = 2
warn_on_parse_using_empty_Forward = 3
warn_on_assignment_to_Forward = 4
warn_on_multiple_string_args_to_oneof = 5
warn_on_match_first_with_lshift_operator = 6
enable_debug_on_named_expressions = 7
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class Empty(Token):
"""
An empty token, will always match.
"""
def __init__(self):
super().__init__()
self.mayReturnEmpty = True
self.mayIndexError = False
ParserElement._literalStringClass = Literal
The provided code snippet includes necessary dependencies for implementing the `original_text_for` function. Write a Python function `def original_text_for( expr: ParserElement, as_string: bool = True, *, asString: bool = True ) -> ParserElement` to solve the following problem:
Helper to return the original, untokenized text for a given expression. Useful to restore the parsed fields of an HTML start tag into the raw tag text itself, or to revert separate tokens with intervening whitespace back to the original matching input text. By default, returns astring containing the original parsed text. If the optional ``as_string`` argument is passed as ``False``, then the return value is a :class:`ParseResults` containing any results names that were originally matched, and a single token containing the original matched text from the input string. So if the expression passed to :class:`original_text_for` contains expressions with defined results names, you must set ``as_string`` to ``False`` if you want to preserve those results name values. The ``asString`` pre-PEP8 argument is retained for compatibility, but will be removed in a future release. Example:: src = "this is test <b> bold <i>text</i> </b> normal text " for tag in ("b", "i"): opener, closer = make_html_tags(tag) patt = original_text_for(opener + SkipTo(closer) + closer) print(patt.search_string(src)[0]) prints:: ['<b> bold <i>text</i> </b>'] ['<i>text</i>']
Here is the function:
def original_text_for(
expr: ParserElement, as_string: bool = True, *, asString: bool = True
) -> ParserElement:
"""Helper to return the original, untokenized text for a given
expression. Useful to restore the parsed fields of an HTML start
tag into the raw tag text itself, or to revert separate tokens with
intervening whitespace back to the original matching input text. By
default, returns astring containing the original parsed text.
If the optional ``as_string`` argument is passed as
``False``, then the return value is
a :class:`ParseResults` containing any results names that
were originally matched, and a single token containing the original
matched text from the input string. So if the expression passed to
:class:`original_text_for` contains expressions with defined
results names, you must set ``as_string`` to ``False`` if you
want to preserve those results name values.
The ``asString`` pre-PEP8 argument is retained for compatibility,
but will be removed in a future release.
Example::
src = "this is test <b> bold <i>text</i> </b> normal text "
for tag in ("b", "i"):
opener, closer = make_html_tags(tag)
patt = original_text_for(opener + SkipTo(closer) + closer)
print(patt.search_string(src)[0])
prints::
['<b> bold <i>text</i> </b>']
['<i>text</i>']
"""
asString = asString and as_string
locMarker = Empty().set_parse_action(lambda s, loc, t: loc)
endlocMarker = locMarker.copy()
endlocMarker.callPreparse = False
matchExpr = locMarker("_original_start") + expr + endlocMarker("_original_end")
if asString:
extractText = lambda s, l, t: s[t._original_start : t._original_end]
else:
def extractText(s, l, t):
t[:] = [s[t.pop("_original_start") : t.pop("_original_end")]]
matchExpr.set_parse_action(extractText)
matchExpr.ignoreExprs = expr.ignoreExprs
matchExpr.suppress_warning(Diagnostics.warn_ungrouped_named_tokens_in_collection)
return matchExpr | Helper to return the original, untokenized text for a given expression. Useful to restore the parsed fields of an HTML start tag into the raw tag text itself, or to revert separate tokens with intervening whitespace back to the original matching input text. By default, returns astring containing the original parsed text. If the optional ``as_string`` argument is passed as ``False``, then the return value is a :class:`ParseResults` containing any results names that were originally matched, and a single token containing the original matched text from the input string. So if the expression passed to :class:`original_text_for` contains expressions with defined results names, you must set ``as_string`` to ``False`` if you want to preserve those results name values. The ``asString`` pre-PEP8 argument is retained for compatibility, but will be removed in a future release. Example:: src = "this is test <b> bold <i>text</i> </b> normal text " for tag in ("b", "i"): opener, closer = make_html_tags(tag) patt = original_text_for(opener + SkipTo(closer) + closer) print(patt.search_string(src)[0]) prints:: ['<b> bold <i>text</i> </b>'] ['<i>text</i>'] |
173,733 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
class TokenConverter(ParseElementEnhance):
"""
Abstract subclass of :class:`ParseExpression`, for converting parsed results.
"""
def __init__(self, expr: Union[ParserElement, str], savelist=False):
super().__init__(expr) # , savelist)
self.saveAsList = False
The provided code snippet includes necessary dependencies for implementing the `ungroup` function. Write a Python function `def ungroup(expr: ParserElement) -> ParserElement` to solve the following problem:
Helper to undo pyparsing's default grouping of And expressions, even if all but one are non-empty.
Here is the function:
def ungroup(expr: ParserElement) -> ParserElement:
"""Helper to undo pyparsing's default grouping of And expressions,
even if all but one are non-empty.
"""
return TokenConverter(expr).add_parse_action(lambda t: t[0]) | Helper to undo pyparsing's default grouping of And expressions, even if all but one are non-empty. |
173,734 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
import copy
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class Empty(Token):
"""
An empty token, will always match.
"""
def __init__(self):
super().__init__()
self.mayReturnEmpty = True
self.mayIndexError = False
ParserElement._literalStringClass = Literal
class Group(TokenConverter):
"""Converter to return the matched tokens as a list - useful for
returning tokens of :class:`ZeroOrMore` and :class:`OneOrMore` expressions.
The optional ``aslist`` argument when set to True will return the
parsed tokens as a Python list instead of a pyparsing ParseResults.
Example::
ident = Word(alphas)
num = Word(nums)
term = ident | num
func = ident + Opt(delimited_list(term))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', 'a', 'b', '100']
func = ident + Group(Opt(delimited_list(term)))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', ['a', 'b', '100']]
"""
def __init__(self, expr: ParserElement, aslist: bool = False):
super().__init__(expr)
self.saveAsList = True
self._asPythonList = aslist
def postParse(self, instring, loc, tokenlist):
if self._asPythonList:
return ParseResults.List(
tokenlist.asList()
if isinstance(tokenlist, ParseResults)
else list(tokenlist)
)
else:
return [tokenlist]
The provided code snippet includes necessary dependencies for implementing the `locatedExpr` function. Write a Python function `def locatedExpr(expr: ParserElement) -> ParserElement` to solve the following problem:
(DEPRECATED - future code should use the Located class) Helper to decorate a returned token with its starting and ending locations in the input string. This helper adds the following results names: - ``locn_start`` - location where matched expression begins - ``locn_end`` - location where matched expression ends - ``value`` - the actual parsed results Be careful if the input text contains ``<TAB>`` characters, you may want to call :class:`ParserElement.parseWithTabs` Example:: wd = Word(alphas) for match in locatedExpr(wd).searchString("ljsdf123lksdjjf123lkkjj1222"): print(match) prints:: [[0, 'ljsdf', 5]] [[8, 'lksdjjf', 15]] [[18, 'lkkjj', 23]]
Here is the function:
def locatedExpr(expr: ParserElement) -> ParserElement:
"""
(DEPRECATED - future code should use the Located class)
Helper to decorate a returned token with its starting and ending
locations in the input string.
This helper adds the following results names:
- ``locn_start`` - location where matched expression begins
- ``locn_end`` - location where matched expression ends
- ``value`` - the actual parsed results
Be careful if the input text contains ``<TAB>`` characters, you
may want to call :class:`ParserElement.parseWithTabs`
Example::
wd = Word(alphas)
for match in locatedExpr(wd).searchString("ljsdf123lksdjjf123lkkjj1222"):
print(match)
prints::
[[0, 'ljsdf', 5]]
[[8, 'lksdjjf', 15]]
[[18, 'lkkjj', 23]]
"""
locator = Empty().set_parse_action(lambda ss, ll, tt: ll)
return Group(
locator("locn_start")
+ expr("value")
+ locator.copy().leaveWhitespace()("locn_end")
) | (DEPRECATED - future code should use the Located class) Helper to decorate a returned token with its starting and ending locations in the input string. This helper adds the following results names: - ``locn_start`` - location where matched expression begins - ``locn_end`` - location where matched expression ends - ``value`` - the actual parsed results Be careful if the input text contains ``<TAB>`` characters, you may want to call :class:`ParserElement.parseWithTabs` Example:: wd = Word(alphas) for match in locatedExpr(wd).searchString("ljsdf123lksdjjf123lkkjj1222"): print(match) prints:: [[0, 'ljsdf', 5]] [[8, 'lksdjjf', 15]] [[18, 'lkkjj', 23]] |
173,735 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
import typing
from typing import (
NamedTuple,
Union,
Callable,
Any,
Generator,
Tuple,
List,
TextIO,
Set,
Sequence,
)
import copy
str_type: Tuple[type, ...] = (str, bytes)
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class Literal(Token):
"""
Token to exactly match a specified string.
Example::
Literal('blah').parse_string('blah') # -> ['blah']
Literal('blah').parse_string('blahfooblah') # -> ['blah']
Literal('blah').parse_string('bla') # -> Exception: Expected "blah"
For case-insensitive matching, use :class:`CaselessLiteral`.
For keyword matching (force word break before and after the matched string),
use :class:`Keyword` or :class:`CaselessKeyword`.
"""
def __init__(self, match_string: str = "", *, matchString: str = ""):
super().__init__()
match_string = matchString or match_string
self.match = match_string
self.matchLen = len(match_string)
try:
self.firstMatchChar = match_string[0]
except IndexError:
raise ValueError("null string passed to Literal; use Empty() instead")
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = False
self.mayIndexError = False
# Performance tuning: modify __class__ to select
# a parseImpl optimized for single-character check
if self.matchLen == 1 and type(self) is Literal:
self.__class__ = _SingleCharLiteral
def _generateDefaultName(self):
return repr(self.match)
def parseImpl(self, instring, loc, doActions=True):
if instring[loc] == self.firstMatchChar and instring.startswith(
self.match, loc
):
return loc + self.matchLen, self.match
raise ParseException(instring, loc, self.errmsg, self)
ParserElement._literalStringClass = Literal
class CharsNotIn(Token):
"""Token for matching words composed of characters *not* in a given
set (will include whitespace in matched characters if not listed in
the provided exclusion set - see example). Defined with string
containing all disallowed characters, and an optional minimum,
maximum, and/or exact length. The default value for ``min`` is
1 (a minimum value < 1 is not valid); the default values for
``max`` and ``exact`` are 0, meaning no maximum or exact
length restriction.
Example::
# define a comma-separated-value as anything that is not a ','
csv_value = CharsNotIn(',')
print(delimited_list(csv_value).parse_string("dkls,lsdkjf,s12 34,@!#,213"))
prints::
['dkls', 'lsdkjf', 's12 34', '@!#', '213']
"""
def __init__(
self,
not_chars: str = "",
min: int = 1,
max: int = 0,
exact: int = 0,
*,
notChars: str = "",
):
super().__init__()
self.skipWhitespace = False
self.notChars = not_chars or notChars
self.notCharsSet = set(self.notChars)
if min < 1:
raise ValueError(
"cannot specify a minimum length < 1; use "
"Opt(CharsNotIn()) if zero-length char group is permitted"
)
self.minLen = min
if max > 0:
self.maxLen = max
else:
self.maxLen = _MAX_INT
if exact > 0:
self.maxLen = exact
self.minLen = exact
self.errmsg = "Expected " + self.name
self.mayReturnEmpty = self.minLen == 0
self.mayIndexError = False
def _generateDefaultName(self):
not_chars_str = _collapse_string_to_ranges(self.notChars)
if len(not_chars_str) > 16:
return "!W:({}...)".format(self.notChars[: 16 - 3])
else:
return "!W:({})".format(self.notChars)
def parseImpl(self, instring, loc, doActions=True):
notchars = self.notCharsSet
if instring[loc] in notchars:
raise ParseException(instring, loc, self.errmsg, self)
start = loc
loc += 1
maxlen = min(start + self.maxLen, len(instring))
while loc < maxlen and instring[loc] not in notchars:
loc += 1
if loc - start < self.minLen:
raise ParseException(instring, loc, self.errmsg, self)
return loc, instring[start:loc]
class OneOrMore(_MultipleMatch):
"""
Repetition of one or more of the given expression.
Parameters:
- expr - expression that must match one or more times
- stop_on - (default= ``None``) - expression for a terminating sentinel
(only required if the sentinel would ordinarily match the repetition
expression)
Example::
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).set_parse_action(' '.join))
text = "shape: SQUARE posn: upper left color: BLACK"
attr_expr[1, ...].parse_string(text).pprint() # Fail! read 'color' as data instead of next label -> [['shape', 'SQUARE color']]
# use stop_on attribute for OneOrMore to avoid reading label string as part of the data
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))
OneOrMore(attr_expr).parse_string(text).pprint() # Better -> [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'BLACK']]
# could also be written as
(attr_expr * (1,)).parse_string(text).pprint()
"""
def _generateDefaultName(self):
return "{" + str(self.expr) + "}..."
class ZeroOrMore(_MultipleMatch):
"""
Optional repetition of zero or more of the given expression.
Parameters:
- ``expr`` - expression that must match zero or more times
- ``stop_on`` - expression for a terminating sentinel
(only required if the sentinel would ordinarily match the repetition
expression) - (default= ``None``)
Example: similar to :class:`OneOrMore`
"""
def __init__(
self,
expr: ParserElement,
stop_on: typing.Optional[Union[ParserElement, str]] = None,
*,
stopOn: typing.Optional[Union[ParserElement, str]] = None,
):
super().__init__(expr, stopOn=stopOn or stop_on)
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
try:
return super().parseImpl(instring, loc, doActions)
except (ParseException, IndexError):
return loc, ParseResults([], name=self.resultsName)
def _generateDefaultName(self):
return "[" + str(self.expr) + "]..."
Optional = Opt
class Forward(ParseElementEnhance):
"""
Forward declaration of an expression to be defined later -
used for recursive grammars, such as algebraic infix notation.
When the expression is known, it is assigned to the ``Forward``
variable using the ``'<<'`` operator.
Note: take care when assigning to ``Forward`` not to overlook
precedence of operators.
Specifically, ``'|'`` has a lower precedence than ``'<<'``, so that::
fwd_expr << a | b | c
will actually be evaluated as::
(fwd_expr << a) | b | c
thereby leaving b and c out as parseable alternatives. It is recommended that you
explicitly group the values inserted into the ``Forward``::
fwd_expr << (a | b | c)
Converting to use the ``'<<='`` operator instead will avoid this problem.
See :class:`ParseResults.pprint` for an example of a recursive
parser created using ``Forward``.
"""
def __init__(self, other: typing.Optional[Union[ParserElement, str]] = None):
self.caller_frame = traceback.extract_stack(limit=2)[0]
super().__init__(other, savelist=False)
self.lshift_line = None
def __lshift__(self, other):
if hasattr(self, "caller_frame"):
del self.caller_frame
if isinstance(other, str_type):
other = self._literalStringClass(other)
self.expr = other
self.mayIndexError = self.expr.mayIndexError
self.mayReturnEmpty = self.expr.mayReturnEmpty
self.set_whitespace_chars(
self.expr.whiteChars, copy_defaults=self.expr.copyDefaultWhiteChars
)
self.skipWhitespace = self.expr.skipWhitespace
self.saveAsList = self.expr.saveAsList
self.ignoreExprs.extend(self.expr.ignoreExprs)
self.lshift_line = traceback.extract_stack(limit=2)[-2]
return self
def __ilshift__(self, other):
return self << other
def __or__(self, other):
caller_line = traceback.extract_stack(limit=2)[-2]
if (
__diag__.warn_on_match_first_with_lshift_operator
and caller_line == self.lshift_line
and Diagnostics.warn_on_match_first_with_lshift_operator
not in self.suppress_warnings_
):
warnings.warn(
"using '<<' operator with '|' is probably an error, use '<<='",
stacklevel=2,
)
ret = super().__or__(other)
return ret
def __del__(self):
# see if we are getting dropped because of '=' reassignment of var instead of '<<=' or '<<'
if (
self.expr is None
and __diag__.warn_on_assignment_to_Forward
and Diagnostics.warn_on_assignment_to_Forward not in self.suppress_warnings_
):
warnings.warn_explicit(
"Forward defined here but no expression attached later using '<<=' or '<<'",
UserWarning,
filename=self.caller_frame.filename,
lineno=self.caller_frame.lineno,
)
def parseImpl(self, instring, loc, doActions=True):
if (
self.expr is None
and __diag__.warn_on_parse_using_empty_Forward
and Diagnostics.warn_on_parse_using_empty_Forward
not in self.suppress_warnings_
):
# walk stack until parse_string, scan_string, search_string, or transform_string is found
parse_fns = [
"parse_string",
"scan_string",
"search_string",
"transform_string",
]
tb = traceback.extract_stack(limit=200)
for i, frm in enumerate(reversed(tb), start=1):
if frm.name in parse_fns:
stacklevel = i + 1
break
else:
stacklevel = 2
warnings.warn(
"Forward expression was never assigned a value, will not parse any input",
stacklevel=stacklevel,
)
if not ParserElement._left_recursion_enabled:
return super().parseImpl(instring, loc, doActions)
# ## Bounded Recursion algorithm ##
# Recursion only needs to be processed at ``Forward`` elements, since they are
# the only ones that can actually refer to themselves. The general idea is
# to handle recursion stepwise: We start at no recursion, then recurse once,
# recurse twice, ..., until more recursion offers no benefit (we hit the bound).
#
# The "trick" here is that each ``Forward`` gets evaluated in two contexts
# - to *match* a specific recursion level, and
# - to *search* the bounded recursion level
# and the two run concurrently. The *search* must *match* each recursion level
# to find the best possible match. This is handled by a memo table, which
# provides the previous match to the next level match attempt.
#
# See also "Left Recursion in Parsing Expression Grammars", Medeiros et al.
#
# There is a complication since we not only *parse* but also *transform* via
# actions: We do not want to run the actions too often while expanding. Thus,
# we expand using `doActions=False` and only run `doActions=True` if the next
# recursion level is acceptable.
with ParserElement.recursion_lock:
memo = ParserElement.recursion_memos
try:
# we are parsing at a specific recursion expansion - use it as-is
prev_loc, prev_result = memo[loc, self, doActions]
if isinstance(prev_result, Exception):
raise prev_result
return prev_loc, prev_result.copy()
except KeyError:
act_key = (loc, self, True)
peek_key = (loc, self, False)
# we are searching for the best recursion expansion - keep on improving
# both `doActions` cases must be tracked separately here!
prev_loc, prev_peek = memo[peek_key] = (
loc - 1,
ParseException(
instring, loc, "Forward recursion without base case", self
),
)
if doActions:
memo[act_key] = memo[peek_key]
while True:
try:
new_loc, new_peek = super().parseImpl(instring, loc, False)
except ParseException:
# we failed before getting any match – do not hide the error
if isinstance(prev_peek, Exception):
raise
new_loc, new_peek = prev_loc, prev_peek
# the match did not get better: we are done
if new_loc <= prev_loc:
if doActions:
# replace the match for doActions=False as well,
# in case the action did backtrack
prev_loc, prev_result = memo[peek_key] = memo[act_key]
del memo[peek_key], memo[act_key]
return prev_loc, prev_result.copy()
del memo[peek_key]
return prev_loc, prev_peek.copy()
# the match did get better: see if we can improve further
else:
if doActions:
try:
memo[act_key] = super().parseImpl(instring, loc, True)
except ParseException as e:
memo[peek_key] = memo[act_key] = (new_loc, e)
raise
prev_loc, prev_peek = memo[peek_key] = new_loc, new_peek
def leave_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = False
return self
def ignore_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = True
return self
def streamline(self) -> ParserElement:
if not self.streamlined:
self.streamlined = True
if self.expr is not None:
self.expr.streamline()
return self
def validate(self, validateTrace=None) -> None:
if validateTrace is None:
validateTrace = []
if self not in validateTrace:
tmp = validateTrace[:] + [self]
if self.expr is not None:
self.expr.validate(tmp)
self._checkRecursion([])
def _generateDefaultName(self):
# Avoid infinite recursion by setting a temporary _defaultName
self._defaultName = ": ..."
# Use the string representation of main expression.
retString = "..."
try:
if self.expr is not None:
retString = str(self.expr)[:1000]
else:
retString = "None"
finally:
return self.__class__.__name__ + ": " + retString
def copy(self) -> ParserElement:
if self.expr is not None:
return super().copy()
else:
ret = Forward()
ret <<= self
return ret
def _setResultsName(self, name, list_all_matches=False):
if (
__diag__.warn_name_set_on_empty_Forward
and Diagnostics.warn_name_set_on_empty_Forward
not in self.suppress_warnings_
):
if self.expr is None:
warnings.warn(
"{}: setting results name {!r} on {} expression "
"that has no contained expression".format(
"warn_name_set_on_empty_Forward", name, type(self).__name__
),
stacklevel=3,
)
return super()._setResultsName(name, list_all_matches)
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class Combine(TokenConverter):
"""Converter to concatenate all matching tokens to a single string.
By default, the matching patterns must also be contiguous in the
input string; this can be disabled by specifying
``'adjacent=False'`` in the constructor.
Example::
real = Word(nums) + '.' + Word(nums)
print(real.parse_string('3.1416')) # -> ['3', '.', '1416']
# will also erroneously match the following
print(real.parse_string('3. 1416')) # -> ['3', '.', '1416']
real = Combine(Word(nums) + '.' + Word(nums))
print(real.parse_string('3.1416')) # -> ['3.1416']
# no match when there are internal spaces
print(real.parse_string('3. 1416')) # -> Exception: Expected W:(0123...)
"""
def __init__(
self,
expr: ParserElement,
join_string: str = "",
adjacent: bool = True,
*,
joinString: typing.Optional[str] = None,
):
super().__init__(expr)
joinString = joinString if joinString is not None else join_string
# suppress whitespace-stripping in contained parse expressions, but re-enable it on the Combine itself
if adjacent:
self.leave_whitespace()
self.adjacent = adjacent
self.skipWhitespace = True
self.joinString = joinString
self.callPreparse = True
def ignore(self, other) -> ParserElement:
if self.adjacent:
ParserElement.ignore(self, other)
else:
super().ignore(other)
return self
def postParse(self, instring, loc, tokenlist):
retToks = tokenlist.copy()
del retToks[:]
retToks += ParseResults(
["".join(tokenlist._asStringList(self.joinString))], modal=self.modalResults
)
if self.resultsName and retToks.haskeys():
return [retToks]
else:
return retToks
class Group(TokenConverter):
"""Converter to return the matched tokens as a list - useful for
returning tokens of :class:`ZeroOrMore` and :class:`OneOrMore` expressions.
The optional ``aslist`` argument when set to True will return the
parsed tokens as a Python list instead of a pyparsing ParseResults.
Example::
ident = Word(alphas)
num = Word(nums)
term = ident | num
func = ident + Opt(delimited_list(term))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', 'a', 'b', '100']
func = ident + Group(Opt(delimited_list(term)))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', ['a', 'b', '100']]
"""
def __init__(self, expr: ParserElement, aslist: bool = False):
super().__init__(expr)
self.saveAsList = True
self._asPythonList = aslist
def postParse(self, instring, loc, tokenlist):
if self._asPythonList:
return ParseResults.List(
tokenlist.asList()
if isinstance(tokenlist, ParseResults)
else list(tokenlist)
)
else:
return [tokenlist]
class Suppress(TokenConverter):
"""Converter for ignoring the results of a parsed expression.
Example::
source = "a, b, c,d"
wd = Word(alphas)
wd_list1 = wd + (',' + wd)[...]
print(wd_list1.parse_string(source))
# often, delimiters that are useful during parsing are just in the
# way afterward - use Suppress to keep them out of the parsed output
wd_list2 = wd + (Suppress(',') + wd)[...]
print(wd_list2.parse_string(source))
# Skipped text (using '...') can be suppressed as well
source = "lead in START relevant text END trailing text"
start_marker = Keyword("START")
end_marker = Keyword("END")
find_body = Suppress(...) + start_marker + ... + end_marker
print(find_body.parse_string(source)
prints::
['a', ',', 'b', ',', 'c', ',', 'd']
['a', 'b', 'c', 'd']
['START', 'relevant text ', 'END']
(See also :class:`delimited_list`.)
"""
def __init__(self, expr: Union[ParserElement, str], savelist: bool = False):
if expr is ...:
expr = _PendingSkip(NoMatch())
super().__init__(expr)
def __add__(self, other) -> "ParserElement":
if isinstance(self.expr, _PendingSkip):
return Suppress(SkipTo(other)) + other
else:
return super().__add__(other)
def __sub__(self, other) -> "ParserElement":
if isinstance(self.expr, _PendingSkip):
return Suppress(SkipTo(other)) - other
else:
return super().__sub__(other)
def postParse(self, instring, loc, tokenlist):
return []
def suppress(self) -> ParserElement:
return self
empty = Empty().set_name("empty")
quoted_string = Combine(
Regex(r'"(?:[^"\n\r\\]|(?:"")|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*') + '"'
| Regex(r"'(?:[^'\n\r\\]|(?:'')|(?:\\(?:[^x]|x[0-9a-fA-F]+)))*") + "'"
).set_name("quotedString using single or double quotes")
The provided code snippet includes necessary dependencies for implementing the `nested_expr` function. Write a Python function `def nested_expr( opener: Union[str, ParserElement] = "(", closer: Union[str, ParserElement] = ")", content: typing.Optional[ParserElement] = None, ignore_expr: ParserElement = quoted_string(), *, ignoreExpr: ParserElement = quoted_string(), ) -> ParserElement` to solve the following problem:
Helper method for defining nested lists enclosed in opening and closing delimiters (``"("`` and ``")"`` are the default). Parameters: - ``opener`` - opening character for a nested list (default= ``"("``); can also be a pyparsing expression - ``closer`` - closing character for a nested list (default= ``")"``); can also be a pyparsing expression - ``content`` - expression for items within the nested lists (default= ``None``) - ``ignore_expr`` - expression for ignoring opening and closing delimiters (default= :class:`quoted_string`) - ``ignoreExpr`` - this pre-PEP8 argument is retained for compatibility but will be removed in a future release If an expression is not provided for the content argument, the nested expression will capture all whitespace-delimited content between delimiters as a list of separate values. Use the ``ignore_expr`` argument to define expressions that may contain opening or closing characters that should not be treated as opening or closing characters for nesting, such as quoted_string or a comment expression. Specify multiple expressions using an :class:`Or` or :class:`MatchFirst`. The default is :class:`quoted_string`, but if no expressions are to be ignored, then pass ``None`` for this argument. Example:: data_type = one_of("void int short long char float double") decl_data_type = Combine(data_type + Opt(Word('*'))) ident = Word(alphas+'_', alphanums+'_') number = pyparsing_common.number arg = Group(decl_data_type + ident) LPAR, RPAR = map(Suppress, "()") code_body = nested_expr('{', '}', ignore_expr=(quoted_string | c_style_comment)) c_function = (decl_data_type("type") + ident("name") + LPAR + Opt(delimited_list(arg), [])("args") + RPAR + code_body("body")) c_function.ignore(c_style_comment) source_code = ''' int is_odd(int x) { return (x%2); } int dec_to_hex(char hchar) { if (hchar >= '0' && hchar <= '9') { return (ord(hchar)-ord('0')); } else { return (10+ord(hchar)-ord('A')); } } ''' for func in c_function.search_string(source_code): print("%(name)s (%(type)s) args: %(args)s" % func) prints:: is_odd (int) args: [['int', 'x']] dec_to_hex (int) args: [['char', 'hchar']]
Here is the function:
def nested_expr(
opener: Union[str, ParserElement] = "(",
closer: Union[str, ParserElement] = ")",
content: typing.Optional[ParserElement] = None,
ignore_expr: ParserElement = quoted_string(),
*,
ignoreExpr: ParserElement = quoted_string(),
) -> ParserElement:
"""Helper method for defining nested lists enclosed in opening and
closing delimiters (``"("`` and ``")"`` are the default).
Parameters:
- ``opener`` - opening character for a nested list
(default= ``"("``); can also be a pyparsing expression
- ``closer`` - closing character for a nested list
(default= ``")"``); can also be a pyparsing expression
- ``content`` - expression for items within the nested lists
(default= ``None``)
- ``ignore_expr`` - expression for ignoring opening and closing delimiters
(default= :class:`quoted_string`)
- ``ignoreExpr`` - this pre-PEP8 argument is retained for compatibility
but will be removed in a future release
If an expression is not provided for the content argument, the
nested expression will capture all whitespace-delimited content
between delimiters as a list of separate values.
Use the ``ignore_expr`` argument to define expressions that may
contain opening or closing characters that should not be treated as
opening or closing characters for nesting, such as quoted_string or
a comment expression. Specify multiple expressions using an
:class:`Or` or :class:`MatchFirst`. The default is
:class:`quoted_string`, but if no expressions are to be ignored, then
pass ``None`` for this argument.
Example::
data_type = one_of("void int short long char float double")
decl_data_type = Combine(data_type + Opt(Word('*')))
ident = Word(alphas+'_', alphanums+'_')
number = pyparsing_common.number
arg = Group(decl_data_type + ident)
LPAR, RPAR = map(Suppress, "()")
code_body = nested_expr('{', '}', ignore_expr=(quoted_string | c_style_comment))
c_function = (decl_data_type("type")
+ ident("name")
+ LPAR + Opt(delimited_list(arg), [])("args") + RPAR
+ code_body("body"))
c_function.ignore(c_style_comment)
source_code = '''
int is_odd(int x) {
return (x%2);
}
int dec_to_hex(char hchar) {
if (hchar >= '0' && hchar <= '9') {
return (ord(hchar)-ord('0'));
} else {
return (10+ord(hchar)-ord('A'));
}
}
'''
for func in c_function.search_string(source_code):
print("%(name)s (%(type)s) args: %(args)s" % func)
prints::
is_odd (int) args: [['int', 'x']]
dec_to_hex (int) args: [['char', 'hchar']]
"""
if ignoreExpr != ignore_expr:
ignoreExpr = ignore_expr if ignoreExpr == quoted_string() else ignoreExpr
if opener == closer:
raise ValueError("opening and closing strings cannot be the same")
if content is None:
if isinstance(opener, str_type) and isinstance(closer, str_type):
if len(opener) == 1 and len(closer) == 1:
if ignoreExpr is not None:
content = Combine(
OneOrMore(
~ignoreExpr
+ CharsNotIn(
opener + closer + ParserElement.DEFAULT_WHITE_CHARS,
exact=1,
)
)
).set_parse_action(lambda t: t[0].strip())
else:
content = empty.copy() + CharsNotIn(
opener + closer + ParserElement.DEFAULT_WHITE_CHARS
).set_parse_action(lambda t: t[0].strip())
else:
if ignoreExpr is not None:
content = Combine(
OneOrMore(
~ignoreExpr
+ ~Literal(opener)
+ ~Literal(closer)
+ CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS, exact=1)
)
).set_parse_action(lambda t: t[0].strip())
else:
content = Combine(
OneOrMore(
~Literal(opener)
+ ~Literal(closer)
+ CharsNotIn(ParserElement.DEFAULT_WHITE_CHARS, exact=1)
)
).set_parse_action(lambda t: t[0].strip())
else:
raise ValueError(
"opening and closing arguments must be strings if no content expression is given"
)
ret = Forward()
if ignoreExpr is not None:
ret <<= Group(
Suppress(opener) + ZeroOrMore(ignoreExpr | ret | content) + Suppress(closer)
)
else:
ret <<= Group(Suppress(opener) + ZeroOrMore(ret | content) + Suppress(closer))
ret.set_name("nested %s%s expression" % (opener, closer))
return ret | Helper method for defining nested lists enclosed in opening and closing delimiters (``"("`` and ``")"`` are the default). Parameters: - ``opener`` - opening character for a nested list (default= ``"("``); can also be a pyparsing expression - ``closer`` - closing character for a nested list (default= ``")"``); can also be a pyparsing expression - ``content`` - expression for items within the nested lists (default= ``None``) - ``ignore_expr`` - expression for ignoring opening and closing delimiters (default= :class:`quoted_string`) - ``ignoreExpr`` - this pre-PEP8 argument is retained for compatibility but will be removed in a future release If an expression is not provided for the content argument, the nested expression will capture all whitespace-delimited content between delimiters as a list of separate values. Use the ``ignore_expr`` argument to define expressions that may contain opening or closing characters that should not be treated as opening or closing characters for nesting, such as quoted_string or a comment expression. Specify multiple expressions using an :class:`Or` or :class:`MatchFirst`. The default is :class:`quoted_string`, but if no expressions are to be ignored, then pass ``None`` for this argument. Example:: data_type = one_of("void int short long char float double") decl_data_type = Combine(data_type + Opt(Word('*'))) ident = Word(alphas+'_', alphanums+'_') number = pyparsing_common.number arg = Group(decl_data_type + ident) LPAR, RPAR = map(Suppress, "()") code_body = nested_expr('{', '}', ignore_expr=(quoted_string | c_style_comment)) c_function = (decl_data_type("type") + ident("name") + LPAR + Opt(delimited_list(arg), [])("args") + RPAR + code_body("body")) c_function.ignore(c_style_comment) source_code = ''' int is_odd(int x) { return (x%2); } int dec_to_hex(char hchar) { if (hchar >= '0' && hchar <= '9') { return (ord(hchar)-ord('0')); } else { return (10+ord(hchar)-ord('A')); } } ''' for func in c_function.search_string(source_code): print("%(name)s (%(type)s) args: %(args)s" % func) prints:: is_odd (int) args: [['int', 'x']] dec_to_hex (int) args: [['char', 'hchar']] |
173,736 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
def _makeTags(tagStr, xml, suppress_LT=Suppress("<"), suppress_GT=Suppress(">")):
"""Internal helper to construct opening and closing tag expressions, given a tag name"""
if isinstance(tagStr, str_type):
resname = tagStr
tagStr = Keyword(tagStr, caseless=not xml)
else:
resname = tagStr.name
tagAttrName = Word(alphas, alphanums + "_-:")
if xml:
tagAttrValue = dbl_quoted_string.copy().set_parse_action(remove_quotes)
openTag = (
suppress_LT
+ tagStr("tag")
+ Dict(ZeroOrMore(Group(tagAttrName + Suppress("=") + tagAttrValue)))
+ Opt("/", default=[False])("empty").set_parse_action(
lambda s, l, t: t[0] == "/"
)
+ suppress_GT
)
else:
tagAttrValue = quoted_string.copy().set_parse_action(remove_quotes) | Word(
printables, exclude_chars=">"
)
openTag = (
suppress_LT
+ tagStr("tag")
+ Dict(
ZeroOrMore(
Group(
tagAttrName.set_parse_action(lambda t: t[0].lower())
+ Opt(Suppress("=") + tagAttrValue)
)
)
)
+ Opt("/", default=[False])("empty").set_parse_action(
lambda s, l, t: t[0] == "/"
)
+ suppress_GT
)
closeTag = Combine(Literal("</") + tagStr + ">", adjacent=False)
openTag.set_name("<%s>" % resname)
# add start<tagname> results name in parse action now that ungrouped names are not reported at two levels
openTag.add_parse_action(
lambda t: t.__setitem__(
"start" + "".join(resname.replace(":", " ").title().split()), t.copy()
)
)
closeTag = closeTag(
"end" + "".join(resname.replace(":", " ").title().split())
).set_name("</%s>" % resname)
openTag.tag = resname
closeTag.tag = resname
openTag.tag_body = SkipTo(closeTag())
return openTag, closeTag
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
The provided code snippet includes necessary dependencies for implementing the `make_html_tags` function. Write a Python function `def make_html_tags( tag_str: Union[str, ParserElement] ) -> Tuple[ParserElement, ParserElement]` to solve the following problem:
Helper to construct opening and closing tag expressions for HTML, given a tag name. Matches tags in either upper or lower case, attributes with namespaces and with quoted or unquoted values. Example:: text = '<td>More info at the <a href="https://github.com/pyparsing/pyparsing/wiki">pyparsing</a> wiki page</td>' # make_html_tags returns pyparsing expressions for the opening and # closing tags as a 2-tuple a, a_end = make_html_tags("A") link_expr = a + SkipTo(a_end)("link_text") + a_end for link in link_expr.search_string(text): # attributes in the <A> tag (like "href" shown here) are # also accessible as named results print(link.link_text, '->', link.href) prints:: pyparsing -> https://github.com/pyparsing/pyparsing/wiki
Here is the function:
def make_html_tags(
tag_str: Union[str, ParserElement]
) -> Tuple[ParserElement, ParserElement]:
"""Helper to construct opening and closing tag expressions for HTML,
given a tag name. Matches tags in either upper or lower case,
attributes with namespaces and with quoted or unquoted values.
Example::
text = '<td>More info at the <a href="https://github.com/pyparsing/pyparsing/wiki">pyparsing</a> wiki page</td>'
# make_html_tags returns pyparsing expressions for the opening and
# closing tags as a 2-tuple
a, a_end = make_html_tags("A")
link_expr = a + SkipTo(a_end)("link_text") + a_end
for link in link_expr.search_string(text):
# attributes in the <A> tag (like "href" shown here) are
# also accessible as named results
print(link.link_text, '->', link.href)
prints::
pyparsing -> https://github.com/pyparsing/pyparsing/wiki
"""
return _makeTags(tag_str, False) | Helper to construct opening and closing tag expressions for HTML, given a tag name. Matches tags in either upper or lower case, attributes with namespaces and with quoted or unquoted values. Example:: text = '<td>More info at the <a href="https://github.com/pyparsing/pyparsing/wiki">pyparsing</a> wiki page</td>' # make_html_tags returns pyparsing expressions for the opening and # closing tags as a 2-tuple a, a_end = make_html_tags("A") link_expr = a + SkipTo(a_end)("link_text") + a_end for link in link_expr.search_string(text): # attributes in the <A> tag (like "href" shown here) are # also accessible as named results print(link.link_text, '->', link.href) prints:: pyparsing -> https://github.com/pyparsing/pyparsing/wiki |
173,737 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
def _makeTags(tagStr, xml, suppress_LT=Suppress("<"), suppress_GT=Suppress(">")):
"""Internal helper to construct opening and closing tag expressions, given a tag name"""
if isinstance(tagStr, str_type):
resname = tagStr
tagStr = Keyword(tagStr, caseless=not xml)
else:
resname = tagStr.name
tagAttrName = Word(alphas, alphanums + "_-:")
if xml:
tagAttrValue = dbl_quoted_string.copy().set_parse_action(remove_quotes)
openTag = (
suppress_LT
+ tagStr("tag")
+ Dict(ZeroOrMore(Group(tagAttrName + Suppress("=") + tagAttrValue)))
+ Opt("/", default=[False])("empty").set_parse_action(
lambda s, l, t: t[0] == "/"
)
+ suppress_GT
)
else:
tagAttrValue = quoted_string.copy().set_parse_action(remove_quotes) | Word(
printables, exclude_chars=">"
)
openTag = (
suppress_LT
+ tagStr("tag")
+ Dict(
ZeroOrMore(
Group(
tagAttrName.set_parse_action(lambda t: t[0].lower())
+ Opt(Suppress("=") + tagAttrValue)
)
)
)
+ Opt("/", default=[False])("empty").set_parse_action(
lambda s, l, t: t[0] == "/"
)
+ suppress_GT
)
closeTag = Combine(Literal("</") + tagStr + ">", adjacent=False)
openTag.set_name("<%s>" % resname)
# add start<tagname> results name in parse action now that ungrouped names are not reported at two levels
openTag.add_parse_action(
lambda t: t.__setitem__(
"start" + "".join(resname.replace(":", " ").title().split()), t.copy()
)
)
closeTag = closeTag(
"end" + "".join(resname.replace(":", " ").title().split())
).set_name("</%s>" % resname)
openTag.tag = resname
closeTag.tag = resname
openTag.tag_body = SkipTo(closeTag())
return openTag, closeTag
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
The provided code snippet includes necessary dependencies for implementing the `make_xml_tags` function. Write a Python function `def make_xml_tags( tag_str: Union[str, ParserElement] ) -> Tuple[ParserElement, ParserElement]` to solve the following problem:
Helper to construct opening and closing tag expressions for XML, given a tag name. Matches tags only in the given upper/lower case. Example: similar to :class:`make_html_tags`
Here is the function:
def make_xml_tags(
tag_str: Union[str, ParserElement]
) -> Tuple[ParserElement, ParserElement]:
"""Helper to construct opening and closing tag expressions for XML,
given a tag name. Matches tags only in the given upper/lower case.
Example: similar to :class:`make_html_tags`
"""
return _makeTags(tag_str, True) | Helper to construct opening and closing tag expressions for XML, given a tag name. Matches tags only in the given upper/lower case. Example: similar to :class:`make_html_tags` |
173,738 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
_htmlEntityMap = {k.rstrip(";"): v for k, v in html.entities.html5.items()}
The provided code snippet includes necessary dependencies for implementing the `replace_html_entity` function. Write a Python function `def replace_html_entity(t)` to solve the following problem:
Helper parser action to replace common HTML entities with their special characters
Here is the function:
def replace_html_entity(t):
"""Helper parser action to replace common HTML entities with their special characters"""
return _htmlEntityMap.get(t.entity) | Helper parser action to replace common HTML entities with their special characters |
173,739 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
class OpAssoc(Enum):
LEFT = 1
RIGHT = 2
InfixNotationOperatorSpec = Union[
Tuple[
InfixNotationOperatorArgType,
int,
OpAssoc,
typing.Optional[ParseAction],
],
Tuple[
InfixNotationOperatorArgType,
int,
OpAssoc,
],
]
str_type: Tuple[type, ...] = (str, bytes)
class ParserElement(ABC):
"""Abstract base level parser element class."""
DEFAULT_WHITE_CHARS: str = " \n\t\r"
verbose_stacktrace: bool = False
_literalStringClass: typing.Optional[type] = None
def set_default_whitespace_chars(chars: str) -> None:
r"""
Overrides the default whitespace chars
Example::
# default whitespace chars are space, <TAB> and newline
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def', 'ghi', 'jkl']
# change to just treat newline as significant
ParserElement.set_default_whitespace_chars(" \t")
Word(alphas)[1, ...].parse_string("abc def\nghi jkl") # -> ['abc', 'def']
"""
ParserElement.DEFAULT_WHITE_CHARS = chars
# update whitespace all parse expressions defined in this module
for expr in _builtin_exprs:
if expr.copyDefaultWhiteChars:
expr.whiteChars = set(chars)
def inline_literals_using(cls: type) -> None:
"""
Set class to be used for inclusion of string literals into a parser.
Example::
# default literal class used is Literal
integer = Word(nums)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '/', '12', '/', '31']
# change to Suppress
ParserElement.inline_literals_using(Suppress)
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
date_str.parse_string("1999/12/31") # -> ['1999', '12', '31']
"""
ParserElement._literalStringClass = cls
class DebugActions(NamedTuple):
debug_try: typing.Optional[DebugStartAction]
debug_match: typing.Optional[DebugSuccessAction]
debug_fail: typing.Optional[DebugExceptionAction]
def __init__(self, savelist: bool = False):
self.parseAction: List[ParseAction] = list()
self.failAction: typing.Optional[ParseFailAction] = None
self.customName = None
self._defaultName = None
self.resultsName = None
self.saveAsList = savelist
self.skipWhitespace = True
self.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
self.copyDefaultWhiteChars = True
# used when checking for left-recursion
self.mayReturnEmpty = False
self.keepTabs = False
self.ignoreExprs: List["ParserElement"] = list()
self.debug = False
self.streamlined = False
# optimize exception handling for subclasses that don't advance parse index
self.mayIndexError = True
self.errmsg = ""
# mark results names as modal (report only last) or cumulative (list all)
self.modalResults = True
# custom debug actions
self.debugActions = self.DebugActions(None, None, None)
# avoid redundant calls to preParse
self.callPreparse = True
self.callDuringTry = False
self.suppress_warnings_: List[Diagnostics] = []
def suppress_warning(self, warning_type: Diagnostics) -> "ParserElement":
"""
Suppress warnings emitted for a particular diagnostic on this expression.
Example::
base = pp.Forward()
base.suppress_warning(Diagnostics.warn_on_parse_using_empty_Forward)
# statement would normally raise a warning, but is now suppressed
print(base.parseString("x"))
"""
self.suppress_warnings_.append(warning_type)
return self
def copy(self) -> "ParserElement":
"""
Make a copy of this :class:`ParserElement`. Useful for defining
different parse actions for the same parsing pattern, using copies of
the original parse element.
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
integerK = integer.copy().add_parse_action(lambda toks: toks[0] * 1024) + Suppress("K")
integerM = integer.copy().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
print((integerK | integerM | integer)[1, ...].parse_string("5K 100 640K 256M"))
prints::
[5120, 100, 655360, 268435456]
Equivalent form of ``expr.copy()`` is just ``expr()``::
integerM = integer().add_parse_action(lambda toks: toks[0] * 1024 * 1024) + Suppress("M")
"""
cpy = copy.copy(self)
cpy.parseAction = self.parseAction[:]
cpy.ignoreExprs = self.ignoreExprs[:]
if self.copyDefaultWhiteChars:
cpy.whiteChars = set(ParserElement.DEFAULT_WHITE_CHARS)
return cpy
def set_results_name(
self, name: str, list_all_matches: bool = False, *, listAllMatches: bool = False
) -> "ParserElement":
"""
Define name for referencing matching tokens as a nested attribute
of the returned parse results.
Normally, results names are assigned as you would assign keys in a dict:
any existing value is overwritten by later values. If it is necessary to
keep all values captured for a particular results name, call ``set_results_name``
with ``list_all_matches`` = True.
NOTE: ``set_results_name`` returns a *copy* of the original :class:`ParserElement` object;
this is so that the client can define a basic element, such as an
integer, and reference it in multiple places with different names.
You can also set results names using the abbreviated syntax,
``expr("name")`` in place of ``expr.set_results_name("name")``
- see :class:`__call__`. If ``list_all_matches`` is required, use
``expr("name*")``.
Example::
date_str = (integer.set_results_name("year") + '/'
+ integer.set_results_name("month") + '/'
+ integer.set_results_name("day"))
# equivalent form:
date_str = integer("year") + '/' + integer("month") + '/' + integer("day")
"""
listAllMatches = listAllMatches or list_all_matches
return self._setResultsName(name, listAllMatches)
def _setResultsName(self, name, listAllMatches=False):
if name is None:
return self
newself = self.copy()
if name.endswith("*"):
name = name[:-1]
listAllMatches = True
newself.resultsName = name
newself.modalResults = not listAllMatches
return newself
def set_break(self, break_flag: bool = True) -> "ParserElement":
"""
Method to invoke the Python pdb debugger when this element is
about to be parsed. Set ``break_flag`` to ``True`` to enable, ``False`` to
disable.
"""
if break_flag:
_parseMethod = self._parse
def breaker(instring, loc, doActions=True, callPreParse=True):
import pdb
# this call to pdb.set_trace() is intentional, not a checkin error
pdb.set_trace()
return _parseMethod(instring, loc, doActions, callPreParse)
breaker._originalParseMethod = _parseMethod
self._parse = breaker
else:
if hasattr(self._parse, "_originalParseMethod"):
self._parse = self._parse._originalParseMethod
return self
def set_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Define one or more actions to perform when successfully matching parse element definition.
Parse actions can be called to perform data conversions, do extra validation,
update external data structures, or enhance or replace the parsed tokens.
Each parse action ``fn`` is a callable method with 0-3 arguments, called as
``fn(s, loc, toks)`` , ``fn(loc, toks)`` , ``fn(toks)`` , or just ``fn()`` , where:
- s = the original string being parsed (see note below)
- loc = the location of the matching substring
- toks = a list of the matched tokens, packaged as a :class:`ParseResults` object
The parsed tokens are passed to the parse action as ParseResults. They can be
modified in place using list-style append, extend, and pop operations to update
the parsed list elements; and with dictionary-style item set and del operations
to add, update, or remove any named results. If the tokens are modified in place,
it is not necessary to return them with a return statement.
Parse actions can also completely replace the given tokens, with another ``ParseResults``
object, or with some entirely different object (common for parse actions that perform data
conversions). A convenient way to build a new parse result is to define the values
using a dict, and then create the return value using :class:`ParseResults.from_dict`.
If None is passed as the ``fn`` parse action, all previously added parse actions for this
expression are cleared.
Optional keyword arguments:
- call_during_try = (default= ``False``) indicate if parse action should be run during
lookaheads and alternate testing. For parse actions that have side effects, it is
important to only call the parse action once it is determined that it is being
called as part of a successful parse. For parse actions that perform additional
validation, then call_during_try should be passed as True, so that the validation
code is included in the preliminary "try" parses.
Note: the default parsing behavior is to expand tabs in the input string
before starting the parsing process. See :class:`parse_string` for more
information on parsing strings containing ``<TAB>`` s, and suggested
methods to maintain a consistent view of the parsed string, the parse
location, and line and column positions within the parsed string.
Example::
# parse dates in the form YYYY/MM/DD
# use parse action to convert toks from str to int at parse time
def convert_to_int(toks):
return int(toks[0])
# use a parse action to verify that the date is a valid date
def is_valid_date(instring, loc, toks):
from datetime import date
year, month, day = toks[::2]
try:
date(year, month, day)
except ValueError:
raise ParseException(instring, loc, "invalid date given")
integer = Word(nums)
date_str = integer + '/' + integer + '/' + integer
# add parse actions
integer.set_parse_action(convert_to_int)
date_str.set_parse_action(is_valid_date)
# note that integer fields are now ints, not strings
date_str.run_tests('''
# successful parse - note that integer fields were converted to ints
1999/12/31
# fail - invalid date
1999/13/31
''')
"""
if list(fns) == [None]:
self.parseAction = []
else:
if not all(callable(fn) for fn in fns):
raise TypeError("parse actions must be callable")
self.parseAction = [_trim_arity(fn) for fn in fns]
self.callDuringTry = kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_parse_action(self, *fns: ParseAction, **kwargs) -> "ParserElement":
"""
Add one or more parse actions to expression's list of parse actions. See :class:`set_parse_action`.
See examples in :class:`copy`.
"""
self.parseAction += [_trim_arity(fn) for fn in fns]
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def add_condition(self, *fns: ParseCondition, **kwargs) -> "ParserElement":
"""Add a boolean predicate function to expression's list of parse actions. See
:class:`set_parse_action` for function call signatures. Unlike ``set_parse_action``,
functions passed to ``add_condition`` need to return boolean success/fail of the condition.
Optional keyword arguments:
- message = define a custom message to be used in the raised exception
- fatal = if True, will raise ParseFatalException to stop parsing immediately; otherwise will raise
ParseException
- call_during_try = boolean to indicate if this method should be called during internal tryParse calls,
default=False
Example::
integer = Word(nums).set_parse_action(lambda toks: int(toks[0]))
year_int = integer.copy()
year_int.add_condition(lambda toks: toks[0] >= 2000, message="Only support years 2000 and later")
date_str = year_int + '/' + integer + '/' + integer
result = date_str.parse_string("1999/12/31") # -> Exception: Only support years 2000 and later (at char 0),
(line:1, col:1)
"""
for fn in fns:
self.parseAction.append(
condition_as_parse_action(
fn, message=kwargs.get("message"), fatal=kwargs.get("fatal", False)
)
)
self.callDuringTry = self.callDuringTry or kwargs.get(
"call_during_try", kwargs.get("callDuringTry", False)
)
return self
def set_fail_action(self, fn: ParseFailAction) -> "ParserElement":
"""
Define action to perform if parsing fails at this expression.
Fail acton fn is a callable function that takes the arguments
``fn(s, loc, expr, err)`` where:
- s = string being parsed
- loc = location where expression match was attempted and failed
- expr = the parse expression that failed
- err = the exception thrown
The function returns no value. It may throw :class:`ParseFatalException`
if it is desired to stop parsing immediately."""
self.failAction = fn
return self
def _skipIgnorables(self, instring, loc):
exprsFound = True
while exprsFound:
exprsFound = False
for e in self.ignoreExprs:
try:
while 1:
loc, dummy = e._parse(instring, loc)
exprsFound = True
except ParseException:
pass
return loc
def preParse(self, instring, loc):
if self.ignoreExprs:
loc = self._skipIgnorables(instring, loc)
if self.skipWhitespace:
instrlen = len(instring)
white_chars = self.whiteChars
while loc < instrlen and instring[loc] in white_chars:
loc += 1
return loc
def parseImpl(self, instring, loc, doActions=True):
return loc, []
def postParse(self, instring, loc, tokenlist):
return tokenlist
# @profile
def _parseNoCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
TRY, MATCH, FAIL = 0, 1, 2
debugging = self.debug # and doActions)
len_instring = len(instring)
if debugging or self.failAction:
# print("Match {} at loc {}({}, {})".format(self, loc, lineno(loc, instring), col(loc, instring)))
try:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.debugActions.debug_try:
self.debugActions.debug_try(instring, tokens_start, self, False)
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except Exception as err:
# print("Exception raised:", err)
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
if self.failAction:
self.failAction(instring, tokens_start, self, err)
raise
else:
if callPreParse and self.callPreparse:
pre_loc = self.preParse(instring, loc)
else:
pre_loc = loc
tokens_start = pre_loc
if self.mayIndexError or pre_loc >= len_instring:
try:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
except IndexError:
raise ParseException(instring, len_instring, self.errmsg, self)
else:
loc, tokens = self.parseImpl(instring, pre_loc, doActions)
tokens = self.postParse(instring, loc, tokens)
ret_tokens = ParseResults(
tokens, self.resultsName, asList=self.saveAsList, modal=self.modalResults
)
if self.parseAction and (doActions or self.callDuringTry):
if debugging:
try:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
except Exception as err:
# print "Exception raised in user parse action:", err
if self.debugActions.debug_fail:
self.debugActions.debug_fail(
instring, tokens_start, self, err, False
)
raise
else:
for fn in self.parseAction:
try:
tokens = fn(instring, tokens_start, ret_tokens)
except IndexError as parse_action_exc:
exc = ParseException("exception raised in parse action")
raise exc from parse_action_exc
if tokens is not None and tokens is not ret_tokens:
ret_tokens = ParseResults(
tokens,
self.resultsName,
asList=self.saveAsList
and isinstance(tokens, (ParseResults, list)),
modal=self.modalResults,
)
if debugging:
# print("Matched", self, "->", ret_tokens.as_list())
if self.debugActions.debug_match:
self.debugActions.debug_match(
instring, tokens_start, loc, self, ret_tokens, False
)
return loc, ret_tokens
def try_parse(self, instring: str, loc: int, raise_fatal: bool = False) -> int:
try:
return self._parse(instring, loc, doActions=False)[0]
except ParseFatalException:
if raise_fatal:
raise
raise ParseException(instring, loc, self.errmsg, self)
def can_parse_next(self, instring: str, loc: int) -> bool:
try:
self.try_parse(instring, loc)
except (ParseException, IndexError):
return False
else:
return True
# cache for left-recursion in Forward references
recursion_lock = RLock()
recursion_memos: typing.Dict[
Tuple[int, "Forward", bool], Tuple[int, Union[ParseResults, Exception]]
] = {}
# argument cache for optimizing repeated calls when backtracking through recursive expressions
packrat_cache = (
{}
) # this is set later by enabled_packrat(); this is here so that reset_cache() doesn't fail
packrat_cache_lock = RLock()
packrat_cache_stats = [0, 0]
# this method gets repeatedly called during backtracking with the same arguments -
# we can cache these arguments and save ourselves the trouble of re-parsing the contained expression
def _parseCache(
self, instring, loc, doActions=True, callPreParse=True
) -> Tuple[int, ParseResults]:
HIT, MISS = 0, 1
TRY, MATCH, FAIL = 0, 1, 2
lookup = (self, instring, loc, callPreParse, doActions)
with ParserElement.packrat_cache_lock:
cache = ParserElement.packrat_cache
value = cache.get(lookup)
if value is cache.not_in_cache:
ParserElement.packrat_cache_stats[MISS] += 1
try:
value = self._parseNoCache(instring, loc, doActions, callPreParse)
except ParseBaseException as pe:
# cache a copy of the exception, without the traceback
cache.set(lookup, pe.__class__(*pe.args))
raise
else:
cache.set(lookup, (value[0], value[1].copy(), loc))
return value
else:
ParserElement.packrat_cache_stats[HIT] += 1
if self.debug and self.debugActions.debug_try:
try:
self.debugActions.debug_try(instring, loc, self, cache_hit=True)
except TypeError:
pass
if isinstance(value, Exception):
if self.debug and self.debugActions.debug_fail:
try:
self.debugActions.debug_fail(
instring, loc, self, value, cache_hit=True
)
except TypeError:
pass
raise value
loc_, result, endloc = value[0], value[1].copy(), value[2]
if self.debug and self.debugActions.debug_match:
try:
self.debugActions.debug_match(
instring, loc_, endloc, self, result, cache_hit=True
)
except TypeError:
pass
return loc_, result
_parse = _parseNoCache
def reset_cache() -> None:
ParserElement.packrat_cache.clear()
ParserElement.packrat_cache_stats[:] = [0] * len(
ParserElement.packrat_cache_stats
)
ParserElement.recursion_memos.clear()
_packratEnabled = False
_left_recursion_enabled = False
def disable_memoization() -> None:
"""
Disables active Packrat or Left Recursion parsing and their memoization
This method also works if neither Packrat nor Left Recursion are enabled.
This makes it safe to call before activating Packrat nor Left Recursion
to clear any previous settings.
"""
ParserElement.reset_cache()
ParserElement._left_recursion_enabled = False
ParserElement._packratEnabled = False
ParserElement._parse = ParserElement._parseNoCache
def enable_left_recursion(
cache_size_limit: typing.Optional[int] = None, *, force=False
) -> None:
"""
Enables "bounded recursion" parsing, which allows for both direct and indirect
left-recursion. During parsing, left-recursive :class:`Forward` elements are
repeatedly matched with a fixed recursion depth that is gradually increased
until finding the longest match.
Example::
import pyparsing as pp
pp.ParserElement.enable_left_recursion()
E = pp.Forward("E")
num = pp.Word(pp.nums)
# match `num`, or `num '+' num`, or `num '+' num '+' num`, ...
E <<= E + '+' - num | num
print(E.parse_string("1+2+3"))
Recursion search naturally memoizes matches of ``Forward`` elements and may
thus skip reevaluation of parse actions during backtracking. This may break
programs with parse actions which rely on strict ordering of side-effects.
Parameters:
- cache_size_limit - (default=``None``) - memoize at most this many
``Forward`` elements during matching; if ``None`` (the default),
memoize all ``Forward`` elements.
Bounded Recursion parsing works similar but not identical to Packrat parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._packratEnabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if cache_size_limit is None:
ParserElement.recursion_memos = _UnboundedMemo()
elif cache_size_limit > 0:
ParserElement.recursion_memos = _LRUMemo(capacity=cache_size_limit)
else:
raise NotImplementedError("Memo size of %s" % cache_size_limit)
ParserElement._left_recursion_enabled = True
def enable_packrat(cache_size_limit: int = 128, *, force: bool = False) -> None:
"""
Enables "packrat" parsing, which adds memoizing to the parsing logic.
Repeated parse attempts at the same string location (which happens
often in many complex grammars) can immediately return a cached value,
instead of re-executing parsing/validating code. Memoizing is done of
both valid results and parsing exceptions.
Parameters:
- cache_size_limit - (default= ``128``) - if an integer value is provided
will limit the size of the packrat cache; if None is passed, then
the cache size will be unbounded; if 0 is passed, the cache will
be effectively disabled.
This speedup may break existing programs that use parse actions that
have side-effects. For this reason, packrat parsing is disabled when
you first import pyparsing. To activate the packrat feature, your
program must call the class method :class:`ParserElement.enable_packrat`.
For best results, call ``enable_packrat()`` immediately after
importing pyparsing.
Example::
import pyparsing
pyparsing.ParserElement.enable_packrat()
Packrat parsing works similar but not identical to Bounded Recursion parsing,
thus the two cannot be used together. Use ``force=True`` to disable any
previous, conflicting settings.
"""
if force:
ParserElement.disable_memoization()
elif ParserElement._left_recursion_enabled:
raise RuntimeError("Packrat and Bounded Recursion are not compatible")
if not ParserElement._packratEnabled:
ParserElement._packratEnabled = True
if cache_size_limit is None:
ParserElement.packrat_cache = _UnboundedCache()
else:
ParserElement.packrat_cache = _FifoCache(cache_size_limit)
ParserElement._parse = ParserElement._parseCache
def parse_string(
self, instring: str, parse_all: bool = False, *, parseAll: bool = False
) -> ParseResults:
"""
Parse a string with respect to the parser definition. This function is intended as the primary interface to the
client code.
:param instring: The input string to be parsed.
:param parse_all: If set, the entire input string must match the grammar.
:param parseAll: retained for pre-PEP8 compatibility, will be removed in a future release.
:raises ParseException: Raised if ``parse_all`` is set and the input string does not match the whole grammar.
:returns: the parsed data as a :class:`ParseResults` object, which may be accessed as a `list`, a `dict`, or
an object with attributes if the given parser includes results names.
If the input string is required to match the entire grammar, ``parse_all`` flag must be set to ``True``. This
is also equivalent to ending the grammar with :class:`StringEnd`().
To report proper column numbers, ``parse_string`` operates on a copy of the input string where all tabs are
converted to spaces (8 spaces per tab, as per the default in ``string.expandtabs``). If the input string
contains tabs and the grammar uses parse actions that use the ``loc`` argument to index into the string
being parsed, one can ensure a consistent view of the input string by doing one of the following:
- calling ``parse_with_tabs`` on your grammar before calling ``parse_string`` (see :class:`parse_with_tabs`),
- define your parse action using the full ``(s,loc,toks)`` signature, and reference the input string using the
parse action's ``s`` argument, or
- explicitly expand the tabs in your input string before calling ``parse_string``.
Examples:
By default, partial matches are OK.
>>> res = Word('a').parse_string('aaaaabaaa')
>>> print(res)
['aaaaa']
The parsing behavior varies by the inheriting class of this abstract class. Please refer to the children
directly to see more examples.
It raises an exception if parse_all flag is set and instring does not match the whole grammar.
>>> res = Word('a').parse_string('aaaaabaaa', parse_all=True)
Traceback (most recent call last):
...
pyparsing.ParseException: Expected end of text, found 'b' (at char 5), (line:1, col:6)
"""
parseAll = parse_all or parseAll
ParserElement.reset_cache()
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = instring.expandtabs()
try:
loc, tokens = self._parse(instring, 0)
if parseAll:
loc = self.preParse(instring, loc)
se = Empty() + StringEnd()
se._parse(instring, loc)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clearing out pyparsing internal stack trace
raise exc.with_traceback(None)
else:
return tokens
def scan_string(
self,
instring: str,
max_matches: int = _MAX_INT,
overlap: bool = False,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> Generator[Tuple[ParseResults, int, int], None, None]:
"""
Scan the input string for expression matches. Each match will return the
matching tokens, start location, and end location. May be called with optional
``max_matches`` argument, to clip scanning after 'n' matches are found. If
``overlap`` is specified, then overlapping matches will be reported.
Note that the start and end locations are reported relative to the string
being parsed. See :class:`parse_string` for more information on parsing
strings with embedded tabs.
Example::
source = "sldjf123lsdjjkf345sldkjf879lkjsfd987"
print(source)
for tokens, start, end in Word(alphas).scan_string(source):
print(' '*start + '^'*(end-start))
print(' '*start + tokens[0])
prints::
sldjf123lsdjjkf345sldkjf879lkjsfd987
^^^^^
sldjf
^^^^^^^
lsdjjkf
^^^^^^
sldkjf
^^^^^^
lkjsfd
"""
maxMatches = min(maxMatches, max_matches)
if not self.streamlined:
self.streamline()
for e in self.ignoreExprs:
e.streamline()
if not self.keepTabs:
instring = str(instring).expandtabs()
instrlen = len(instring)
loc = 0
preparseFn = self.preParse
parseFn = self._parse
ParserElement.resetCache()
matches = 0
try:
while loc <= instrlen and matches < maxMatches:
try:
preloc = preparseFn(instring, loc)
nextLoc, tokens = parseFn(instring, preloc, callPreParse=False)
except ParseException:
loc = preloc + 1
else:
if nextLoc > loc:
matches += 1
if debug:
print(
{
"tokens": tokens.asList(),
"start": preloc,
"end": nextLoc,
}
)
yield tokens, preloc, nextLoc
if overlap:
nextloc = preparseFn(instring, loc)
if nextloc > loc:
loc = nextLoc
else:
loc += 1
else:
loc = nextLoc
else:
loc = preloc + 1
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def transform_string(self, instring: str, *, debug: bool = False) -> str:
"""
Extension to :class:`scan_string`, to modify matching text with modified tokens that may
be returned from a parse action. To use ``transform_string``, define a grammar and
attach a parse action to it that modifies the returned token list.
Invoking ``transform_string()`` on a target string will then scan for matches,
and replace the matched text patterns according to the logic in the parse
action. ``transform_string()`` returns the resulting transformed string.
Example::
wd = Word(alphas)
wd.set_parse_action(lambda toks: toks[0].title())
print(wd.transform_string("now is the winter of our discontent made glorious summer by this sun of york."))
prints::
Now Is The Winter Of Our Discontent Made Glorious Summer By This Sun Of York.
"""
out: List[str] = []
lastE = 0
# force preservation of <TAB>s, to minimize unwanted transformation of string, and to
# keep string locs straight between transform_string and scan_string
self.keepTabs = True
try:
for t, s, e in self.scan_string(instring, debug=debug):
out.append(instring[lastE:s])
if t:
if isinstance(t, ParseResults):
out += t.as_list()
elif isinstance(t, Iterable) and not isinstance(t, str_type):
out.extend(t)
else:
out.append(t)
lastE = e
out.append(instring[lastE:])
out = [o for o in out if o]
return "".join([str(s) for s in _flatten(out)])
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def search_string(
self,
instring: str,
max_matches: int = _MAX_INT,
*,
debug: bool = False,
maxMatches: int = _MAX_INT,
) -> ParseResults:
"""
Another extension to :class:`scan_string`, simplifying the access to the tokens found
to match the given parse expression. May be called with optional
``max_matches`` argument, to clip searching after 'n' matches are found.
Example::
# a capitalized word starts with an uppercase letter, followed by zero or more lowercase letters
cap_word = Word(alphas.upper(), alphas.lower())
print(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity"))
# the sum() builtin can be used to merge results into a single ParseResults object
print(sum(cap_word.search_string("More than Iron, more than Lead, more than Gold I need Electricity")))
prints::
[['More'], ['Iron'], ['Lead'], ['Gold'], ['I'], ['Electricity']]
['More', 'Iron', 'Lead', 'Gold', 'I', 'Electricity']
"""
maxMatches = min(maxMatches, max_matches)
try:
return ParseResults(
[t for t, s, e in self.scan_string(instring, maxMatches, debug=debug)]
)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def split(
self,
instring: str,
maxsplit: int = _MAX_INT,
include_separators: bool = False,
*,
includeSeparators=False,
) -> Generator[str, None, None]:
"""
Generator method to split a string using the given expression as a separator.
May be called with optional ``maxsplit`` argument, to limit the number of splits;
and the optional ``include_separators`` argument (default= ``False``), if the separating
matching text should be included in the split results.
Example::
punc = one_of(list(".,;:/-!?"))
print(list(punc.split("This, this?, this sentence, is badly punctuated!")))
prints::
['This', ' this', '', ' this sentence', ' is badly punctuated', '']
"""
includeSeparators = includeSeparators or include_separators
last = 0
for t, s, e in self.scan_string(instring, max_matches=maxsplit):
yield instring[last:s]
if includeSeparators:
yield t[0]
last = e
yield instring[last:]
def __add__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator - returns :class:`And`. Adding strings to a :class:`ParserElement`
converts them to :class:`Literal`s by default.
Example::
greet = Word(alphas) + "," + Word(alphas) + "!"
hello = "Hello, World!"
print(hello, "->", greet.parse_string(hello))
prints::
Hello, World! -> ['Hello', ',', 'World', '!']
``...`` may be used as a parse expression as a short form of :class:`SkipTo`.
Literal('start') + ... + Literal('end')
is equivalent to:
Literal('start') + SkipTo('end')("_skipped*") + Literal('end')
Note that the skipped text is returned with '_skipped' as a results name,
and to support having multiple skips in the same parser, the value returned is
a list of all skipped text.
"""
if other is Ellipsis:
return _PendingSkip(self)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return And([self, other])
def __radd__(self, other) -> "ParserElement":
"""
Implementation of ``+`` operator when left operand is not a :class:`ParserElement`
"""
if other is Ellipsis:
return SkipTo(self)("_skipped*") + self
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other + self
def __sub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator, returns :class:`And` with error stop
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return self + And._ErrorStop() + other
def __rsub__(self, other) -> "ParserElement":
"""
Implementation of ``-`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other - self
def __mul__(self, other) -> "ParserElement":
"""
Implementation of ``*`` operator, allows use of ``expr * 3`` in place of
``expr + expr + expr``. Expressions may also be multiplied by a 2-integer
tuple, similar to ``{min, max}`` multipliers in regular expressions. Tuples
may also include ``None`` as in:
- ``expr*(n, None)`` or ``expr*(n, )`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr*(None, n)`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr*(None, None)`` is equivalent to ``ZeroOrMore(expr)``
- ``expr*(1, None)`` is equivalent to ``OneOrMore(expr)``
Note that ``expr*(None, n)`` does not raise an exception if
more than n exprs exist in the input stream; that is,
``expr*(None, n)`` does not enforce a maximum number of expr
occurrences. If this behavior is desired, then write
``expr*(None, n) + ~expr``
"""
if other is Ellipsis:
other = (0, None)
elif isinstance(other, tuple) and other[:1] == (Ellipsis,):
other = ((0,) + other[1:] + (None,))[:2]
if isinstance(other, int):
minElements, optElements = other, 0
elif isinstance(other, tuple):
other = tuple(o if o is not Ellipsis else None for o in other)
other = (other + (None, None))[:2]
if other[0] is None:
other = (0, other[1])
if isinstance(other[0], int) and other[1] is None:
if other[0] == 0:
return ZeroOrMore(self)
if other[0] == 1:
return OneOrMore(self)
else:
return self * other[0] + ZeroOrMore(self)
elif isinstance(other[0], int) and isinstance(other[1], int):
minElements, optElements = other
optElements -= minElements
else:
raise TypeError(
"cannot multiply ParserElement and ({}) objects".format(
",".join(type(item).__name__ for item in other)
)
)
else:
raise TypeError(
"cannot multiply ParserElement and {} objects".format(
type(other).__name__
)
)
if minElements < 0:
raise ValueError("cannot multiply ParserElement by negative value")
if optElements < 0:
raise ValueError(
"second tuple value must be greater or equal to first tuple value"
)
if minElements == optElements == 0:
return And([])
if optElements:
def makeOptionalList(n):
if n > 1:
return Opt(self + makeOptionalList(n - 1))
else:
return Opt(self)
if minElements:
if minElements == 1:
ret = self + makeOptionalList(optElements)
else:
ret = And([self] * minElements) + makeOptionalList(optElements)
else:
ret = makeOptionalList(optElements)
else:
if minElements == 1:
ret = self
else:
ret = And([self] * minElements)
return ret
def __rmul__(self, other) -> "ParserElement":
return self.__mul__(other)
def __or__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator - returns :class:`MatchFirst`
"""
if other is Ellipsis:
return _PendingSkip(self, must_skip=True)
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return MatchFirst([self, other])
def __ror__(self, other) -> "ParserElement":
"""
Implementation of ``|`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other | self
def __xor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator - returns :class:`Or`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Or([self, other])
def __rxor__(self, other) -> "ParserElement":
"""
Implementation of ``^`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other ^ self
def __and__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator - returns :class:`Each`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return Each([self, other])
def __rand__(self, other) -> "ParserElement":
"""
Implementation of ``&`` operator when left operand is not a :class:`ParserElement`
"""
if isinstance(other, str_type):
other = self._literalStringClass(other)
if not isinstance(other, ParserElement):
raise TypeError(
"Cannot combine element of type {} with ParserElement".format(
type(other).__name__
)
)
return other & self
def __invert__(self) -> "ParserElement":
"""
Implementation of ``~`` operator - returns :class:`NotAny`
"""
return NotAny(self)
# disable __iter__ to override legacy use of sequential access to __getitem__ to
# iterate over a sequence
__iter__ = None
def __getitem__(self, key):
"""
use ``[]`` indexing notation as a short form for expression repetition:
- ``expr[n]`` is equivalent to ``expr*n``
- ``expr[m, n]`` is equivalent to ``expr*(m, n)``
- ``expr[n, ...]`` or ``expr[n,]`` is equivalent
to ``expr*n + ZeroOrMore(expr)``
(read as "at least n instances of ``expr``")
- ``expr[..., n]`` is equivalent to ``expr*(0, n)``
(read as "0 to n instances of ``expr``")
- ``expr[...]`` and ``expr[0, ...]`` are equivalent to ``ZeroOrMore(expr)``
- ``expr[1, ...]`` is equivalent to ``OneOrMore(expr)``
``None`` may be used in place of ``...``.
Note that ``expr[..., n]`` and ``expr[m, n]``do not raise an exception
if more than ``n`` ``expr``s exist in the input stream. If this behavior is
desired, then write ``expr[..., n] + ~expr``.
"""
# convert single arg keys to tuples
try:
if isinstance(key, str_type):
key = (key,)
iter(key)
except TypeError:
key = (key, key)
if len(key) > 2:
raise TypeError(
"only 1 or 2 index arguments supported ({}{})".format(
key[:5], "... [{}]".format(len(key)) if len(key) > 5 else ""
)
)
# clip to 2 elements
ret = self * tuple(key[:2])
return ret
def __call__(self, name: str = None) -> "ParserElement":
"""
Shortcut for :class:`set_results_name`, with ``list_all_matches=False``.
If ``name`` is given with a trailing ``'*'`` character, then ``list_all_matches`` will be
passed as ``True``.
If ``name` is omitted, same as calling :class:`copy`.
Example::
# these are equivalent
userdata = Word(alphas).set_results_name("name") + Word(nums + "-").set_results_name("socsecno")
userdata = Word(alphas)("name") + Word(nums + "-")("socsecno")
"""
if name is not None:
return self._setResultsName(name)
else:
return self.copy()
def suppress(self) -> "ParserElement":
"""
Suppresses the output of this :class:`ParserElement`; useful to keep punctuation from
cluttering up returned output.
"""
return Suppress(self)
def ignore_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Enables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern.
:param recursive: If ``True`` (the default), also enable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = True
return self
def leave_whitespace(self, recursive: bool = True) -> "ParserElement":
"""
Disables the skipping of whitespace before matching the characters in the
:class:`ParserElement`'s defined pattern. This is normally only used internally by
the pyparsing module, but may be needed in some whitespace-sensitive grammars.
:param recursive: If true (the default), also disable whitespace skipping in child elements (if any)
"""
self.skipWhitespace = False
return self
def set_whitespace_chars(
self, chars: Union[Set[str], str], copy_defaults: bool = False
) -> "ParserElement":
"""
Overrides the default whitespace chars
"""
self.skipWhitespace = True
self.whiteChars = set(chars)
self.copyDefaultWhiteChars = copy_defaults
return self
def parse_with_tabs(self) -> "ParserElement":
"""
Overrides default behavior to expand ``<TAB>`` s to spaces before parsing the input string.
Must be called before ``parse_string`` when the input grammar contains elements that
match ``<TAB>`` characters.
"""
self.keepTabs = True
return self
def ignore(self, other: "ParserElement") -> "ParserElement":
"""
Define expression to be ignored (e.g., comments) while doing pattern
matching; may be called repeatedly, to define multiple comment or other
ignorable patterns.
Example::
patt = Word(alphas)[1, ...]
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj']
patt.ignore(c_style_comment)
patt.parse_string('ablaj /* comment */ lskjd')
# -> ['ablaj', 'lskjd']
"""
import typing
if isinstance(other, str_type):
other = Suppress(other)
if isinstance(other, Suppress):
if other not in self.ignoreExprs:
self.ignoreExprs.append(other)
else:
self.ignoreExprs.append(Suppress(other.copy()))
return self
def set_debug_actions(
self,
start_action: DebugStartAction,
success_action: DebugSuccessAction,
exception_action: DebugExceptionAction,
) -> "ParserElement":
"""
Customize display of debugging messages while doing pattern matching:
- ``start_action`` - method to be called when an expression is about to be parsed;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, cache_hit: bool)``
- ``success_action`` - method to be called when an expression has successfully parsed;
should have the signature ``fn(input_string: str, start_location: int, end_location: int, expression: ParserELement, parsed_tokens: ParseResults, cache_hit: bool)``
- ``exception_action`` - method to be called when expression fails to parse;
should have the signature ``fn(input_string: str, location: int, expression: ParserElement, exception: Exception, cache_hit: bool)``
"""
self.debugActions = self.DebugActions(
start_action or _default_start_debug_action,
success_action or _default_success_debug_action,
exception_action or _default_exception_debug_action,
)
self.debug = True
return self
def set_debug(self, flag: bool = True) -> "ParserElement":
"""
Enable display of debugging messages while doing pattern matching.
Set ``flag`` to ``True`` to enable, ``False`` to disable.
Example::
wd = Word(alphas).set_name("alphaword")
integer = Word(nums).set_name("numword")
term = wd | integer
# turn on debugging for wd
wd.set_debug()
term[1, ...].parse_string("abc 123 xyz 890")
prints::
Match alphaword at loc 0(1,1)
Matched alphaword -> ['abc']
Match alphaword at loc 3(1,4)
Exception raised:Expected alphaword (at char 4), (line:1, col:5)
Match alphaword at loc 7(1,8)
Matched alphaword -> ['xyz']
Match alphaword at loc 11(1,12)
Exception raised:Expected alphaword (at char 12), (line:1, col:13)
Match alphaword at loc 15(1,16)
Exception raised:Expected alphaword (at char 15), (line:1, col:16)
The output shown is that produced by the default debug actions - custom debug actions can be
specified using :class:`set_debug_actions`. Prior to attempting
to match the ``wd`` expression, the debugging message ``"Match <exprname> at loc <n>(<line>,<col>)"``
is shown. Then if the parse succeeds, a ``"Matched"`` message is shown, or an ``"Exception raised"``
message is shown. Also note the use of :class:`set_name` to assign a human-readable name to the expression,
which makes debugging and exception messages easier to understand - for instance, the default
name created for the :class:`Word` expression without calling ``set_name`` is ``"W:(A-Za-z)"``.
"""
if flag:
self.set_debug_actions(
_default_start_debug_action,
_default_success_debug_action,
_default_exception_debug_action,
)
else:
self.debug = False
return self
def default_name(self) -> str:
if self._defaultName is None:
self._defaultName = self._generateDefaultName()
return self._defaultName
def _generateDefaultName(self):
"""
Child classes must define this method, which defines how the ``default_name`` is set.
"""
def set_name(self, name: str) -> "ParserElement":
"""
Define name for this expression, makes debugging and exception messages clearer.
Example::
Word(nums).parse_string("ABC") # -> Exception: Expected W:(0-9) (at char 0), (line:1, col:1)
Word(nums).set_name("integer").parse_string("ABC") # -> Exception: Expected integer (at char 0), (line:1, col:1)
"""
self.customName = name
self.errmsg = "Expected " + self.name
if __diag__.enable_debug_on_named_expressions:
self.set_debug()
return self
def name(self) -> str:
# This will use a user-defined name if available, but otherwise defaults back to the auto-generated name
return self.customName if self.customName is not None else self.default_name
def __str__(self) -> str:
return self.name
def __repr__(self) -> str:
return str(self)
def streamline(self) -> "ParserElement":
self.streamlined = True
self._defaultName = None
return self
def recurse(self) -> Sequence["ParserElement"]:
return []
def _checkRecursion(self, parseElementList):
subRecCheckList = parseElementList[:] + [self]
for e in self.recurse():
e._checkRecursion(subRecCheckList)
def validate(self, validateTrace=None) -> None:
"""
Check defined expressions for valid structure, check for infinite recursive definitions.
"""
self._checkRecursion([])
def parse_file(
self,
file_or_filename: Union[str, Path, TextIO],
encoding: str = "utf-8",
parse_all: bool = False,
*,
parseAll: bool = False,
) -> ParseResults:
"""
Execute the parse expression on the given file or filename.
If a filename is specified (instead of a file object),
the entire file is opened, read, and closed before parsing.
"""
parseAll = parseAll or parse_all
try:
file_contents = file_or_filename.read()
except AttributeError:
with open(file_or_filename, "r", encoding=encoding) as f:
file_contents = f.read()
try:
return self.parse_string(file_contents, parseAll)
except ParseBaseException as exc:
if ParserElement.verbose_stacktrace:
raise
else:
# catch and re-raise exception from here, clears out pyparsing internal stack trace
raise exc.with_traceback(None)
def __eq__(self, other):
if self is other:
return True
elif isinstance(other, str_type):
return self.matches(other, parse_all=True)
elif isinstance(other, ParserElement):
return vars(self) == vars(other)
return False
def __hash__(self):
return id(self)
def matches(
self, test_string: str, parse_all: bool = True, *, parseAll: bool = True
) -> bool:
"""
Method for quick testing of a parser against a test string. Good for simple
inline microtests of sub expressions while building up larger parser.
Parameters:
- ``test_string`` - to test against this expression for a match
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
Example::
expr = Word(nums)
assert expr.matches("100")
"""
parseAll = parseAll and parse_all
try:
self.parse_string(str(test_string), parse_all=parseAll)
return True
except ParseBaseException:
return False
def run_tests(
self,
tests: Union[str, List[str]],
parse_all: bool = True,
comment: typing.Optional[Union["ParserElement", str]] = "#",
full_dump: bool = True,
print_results: bool = True,
failure_tests: bool = False,
post_parse: Callable[[str, ParseResults], str] = None,
file: typing.Optional[TextIO] = None,
with_line_numbers: bool = False,
*,
parseAll: bool = True,
fullDump: bool = True,
printResults: bool = True,
failureTests: bool = False,
postParse: Callable[[str, ParseResults], str] = None,
) -> Tuple[bool, List[Tuple[str, Union[ParseResults, Exception]]]]:
"""
Execute the parse expression on a series of test strings, showing each
test, the parsed results or where the parse failed. Quick and easy way to
run a parse expression against a list of sample strings.
Parameters:
- ``tests`` - a list of separate test strings, or a multiline string of test strings
- ``parse_all`` - (default= ``True``) - flag to pass to :class:`parse_string` when running tests
- ``comment`` - (default= ``'#'``) - expression for indicating embedded comments in the test
string; pass None to disable comment filtering
- ``full_dump`` - (default= ``True``) - dump results as list followed by results names in nested outline;
if False, only dump nested list
- ``print_results`` - (default= ``True``) prints test output to stdout
- ``failure_tests`` - (default= ``False``) indicates if these tests are expected to fail parsing
- ``post_parse`` - (default= ``None``) optional callback for successful parse results; called as
`fn(test_string, parse_results)` and returns a string to be added to the test output
- ``file`` - (default= ``None``) optional file-like object to which test output will be written;
if None, will default to ``sys.stdout``
- ``with_line_numbers`` - default= ``False``) show test strings with line and column numbers
Returns: a (success, results) tuple, where success indicates that all tests succeeded
(or failed if ``failure_tests`` is True), and the results contain a list of lines of each
test's output
Example::
number_expr = pyparsing_common.number.copy()
result = number_expr.run_tests('''
# unsigned integer
100
# negative integer
-100
# float with scientific notation
6.02e23
# integer with scientific notation
1e-12
''')
print("Success" if result[0] else "Failed!")
result = number_expr.run_tests('''
# stray character
100Z
# missing leading digit before '.'
-.100
# too many '.'
3.14.159
''', failure_tests=True)
print("Success" if result[0] else "Failed!")
prints::
# unsigned integer
100
[100]
# negative integer
-100
[-100]
# float with scientific notation
6.02e23
[6.02e+23]
# integer with scientific notation
1e-12
[1e-12]
Success
# stray character
100Z
^
FAIL: Expected end of text (at char 3), (line:1, col:4)
# missing leading digit before '.'
-.100
^
FAIL: Expected {real number with scientific notation | real number | signed integer} (at char 0), (line:1, col:1)
# too many '.'
3.14.159
^
FAIL: Expected end of text (at char 4), (line:1, col:5)
Success
Each test string must be on a single line. If you want to test a string that spans multiple
lines, create a test like this::
expr.run_tests(r"this is a test\\n of strings that spans \\n 3 lines")
(Note that this is a raw string literal, you must include the leading ``'r'``.)
"""
from .testing import pyparsing_test
parseAll = parseAll and parse_all
fullDump = fullDump and full_dump
printResults = printResults and print_results
failureTests = failureTests or failure_tests
postParse = postParse or post_parse
if isinstance(tests, str_type):
line_strip = type(tests).strip
tests = [line_strip(test_line) for test_line in tests.rstrip().splitlines()]
if isinstance(comment, str_type):
comment = Literal(comment)
if file is None:
file = sys.stdout
print_ = file.write
result: Union[ParseResults, Exception]
allResults = []
comments = []
success = True
NL = Literal(r"\n").add_parse_action(replace_with("\n")).ignore(quoted_string)
BOM = "\ufeff"
for t in tests:
if comment is not None and comment.matches(t, False) or comments and not t:
comments.append(
pyparsing_test.with_line_numbers(t) if with_line_numbers else t
)
continue
if not t:
continue
out = [
"\n" + "\n".join(comments) if comments else "",
pyparsing_test.with_line_numbers(t) if with_line_numbers else t,
]
comments = []
try:
# convert newline marks to actual newlines, and strip leading BOM if present
t = NL.transform_string(t.lstrip(BOM))
result = self.parse_string(t, parse_all=parseAll)
except ParseBaseException as pe:
fatal = "(FATAL)" if isinstance(pe, ParseFatalException) else ""
out.append(pe.explain())
out.append("FAIL: " + str(pe))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(pe.__traceback__))
success = success and failureTests
result = pe
except Exception as exc:
out.append("FAIL-EXCEPTION: {}: {}".format(type(exc).__name__, exc))
if ParserElement.verbose_stacktrace:
out.extend(traceback.format_tb(exc.__traceback__))
success = success and failureTests
result = exc
else:
success = success and not failureTests
if postParse is not None:
try:
pp_value = postParse(t, result)
if pp_value is not None:
if isinstance(pp_value, ParseResults):
out.append(pp_value.dump())
else:
out.append(str(pp_value))
else:
out.append(result.dump())
except Exception as e:
out.append(result.dump(full=fullDump))
out.append(
"{} failed: {}: {}".format(
postParse.__name__, type(e).__name__, e
)
)
else:
out.append(result.dump(full=fullDump))
out.append("")
if printResults:
print_("\n".join(out))
allResults.append((t, result))
return success, allResults
def create_diagram(
self,
output_html: Union[TextIO, Path, str],
vertical: int = 3,
show_results_names: bool = False,
show_groups: bool = False,
**kwargs,
) -> None:
"""
Create a railroad diagram for the parser.
Parameters:
- output_html (str or file-like object) - output target for generated
diagram HTML
- vertical (int) - threshold for formatting multiple alternatives vertically
instead of horizontally (default=3)
- show_results_names - bool flag whether diagram should show annotations for
defined results names
- show_groups - bool flag whether groups should be highlighted with an unlabeled surrounding box
Additional diagram-formatting keyword arguments can also be included;
see railroad.Diagram class.
"""
try:
from .diagram import to_railroad, railroad_to_html
except ImportError as ie:
raise Exception(
"must ``pip install pyparsing[diagrams]`` to generate parser railroad diagrams"
) from ie
self.streamline()
railroad = to_railroad(
self,
vertical=vertical,
show_results_names=show_results_names,
show_groups=show_groups,
diagram_kwargs=kwargs,
)
if isinstance(output_html, (str, Path)):
with open(output_html, "w", encoding="utf-8") as diag_file:
diag_file.write(railroad_to_html(railroad))
else:
# we were passed a file-like object, just write to it
output_html.write(railroad_to_html(railroad))
setDefaultWhitespaceChars = set_default_whitespace_chars
inlineLiteralsUsing = inline_literals_using
setResultsName = set_results_name
setBreak = set_break
setParseAction = set_parse_action
addParseAction = add_parse_action
addCondition = add_condition
setFailAction = set_fail_action
tryParse = try_parse
canParseNext = can_parse_next
resetCache = reset_cache
enableLeftRecursion = enable_left_recursion
enablePackrat = enable_packrat
parseString = parse_string
scanString = scan_string
searchString = search_string
transformString = transform_string
setWhitespaceChars = set_whitespace_chars
parseWithTabs = parse_with_tabs
setDebugActions = set_debug_actions
setDebug = set_debug
defaultName = default_name
setName = set_name
parseFile = parse_file
runTests = run_tests
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
ParserElement._literalStringClass = Literal
class FollowedBy(ParseElementEnhance):
"""Lookahead matching of the given parse expression.
``FollowedBy`` does *not* advance the parsing position within
the input string, it only verifies that the specified parse
expression matches at the current position. ``FollowedBy``
always returns a null token list. If any results names are defined
in the lookahead expression, those *will* be returned for access by
name.
Example::
# use FollowedBy to match a label only if it is followed by a ':'
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))
attr_expr[1, ...].parse_string("shape: SQUARE color: BLACK posn: upper left").pprint()
prints::
[['shape', 'SQUARE'], ['color', 'BLACK'], ['posn', 'upper left']]
"""
def __init__(self, expr: Union[ParserElement, str]):
super().__init__(expr)
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
# by using self._expr.parse and deleting the contents of the returned ParseResults list
# we keep any named results that were defined in the FollowedBy expression
_, ret = self.expr._parse(instring, loc, doActions=doActions)
del ret[:]
return loc, ret
class OneOrMore(_MultipleMatch):
"""
Repetition of one or more of the given expression.
Parameters:
- expr - expression that must match one or more times
- stop_on - (default= ``None``) - expression for a terminating sentinel
(only required if the sentinel would ordinarily match the repetition
expression)
Example::
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).set_parse_action(' '.join))
text = "shape: SQUARE posn: upper left color: BLACK"
attr_expr[1, ...].parse_string(text).pprint() # Fail! read 'color' as data instead of next label -> [['shape', 'SQUARE color']]
# use stop_on attribute for OneOrMore to avoid reading label string as part of the data
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))
OneOrMore(attr_expr).parse_string(text).pprint() # Better -> [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'BLACK']]
# could also be written as
(attr_expr * (1,)).parse_string(text).pprint()
"""
def _generateDefaultName(self):
return "{" + str(self.expr) + "}..."
class Opt(ParseElementEnhance):
"""
Optional matching of the given expression.
Parameters:
- ``expr`` - expression that must match zero or more times
- ``default`` (optional) - value to be returned if the optional expression is not found.
Example::
# US postal code can be a 5-digit zip, plus optional 4-digit qualifier
zip = Combine(Word(nums, exact=5) + Opt('-' + Word(nums, exact=4)))
zip.run_tests('''
# traditional ZIP code
12345
# ZIP+4 form
12101-0001
# invalid ZIP
98765-
''')
prints::
# traditional ZIP code
12345
['12345']
# ZIP+4 form
12101-0001
['12101-0001']
# invalid ZIP
98765-
^
FAIL: Expected end of text (at char 5), (line:1, col:6)
"""
__optionalNotMatched = _NullToken()
def __init__(
self, expr: Union[ParserElement, str], default: Any = __optionalNotMatched
):
super().__init__(expr, savelist=False)
self.saveAsList = self.expr.saveAsList
self.defaultValue = default
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
self_expr = self.expr
try:
loc, tokens = self_expr._parse(instring, loc, doActions, callPreParse=False)
except (ParseException, IndexError):
default_value = self.defaultValue
if default_value is not self.__optionalNotMatched:
if self_expr.resultsName:
tokens = ParseResults([default_value])
tokens[self_expr.resultsName] = default_value
else:
tokens = [default_value]
else:
tokens = []
return loc, tokens
def _generateDefaultName(self):
inner = str(self.expr)
# strip off redundant inner {}'s
while len(inner) > 1 and inner[0 :: len(inner) - 1] == "{}":
inner = inner[1:-1]
return "[" + inner + "]"
class Forward(ParseElementEnhance):
"""
Forward declaration of an expression to be defined later -
used for recursive grammars, such as algebraic infix notation.
When the expression is known, it is assigned to the ``Forward``
variable using the ``'<<'`` operator.
Note: take care when assigning to ``Forward`` not to overlook
precedence of operators.
Specifically, ``'|'`` has a lower precedence than ``'<<'``, so that::
fwd_expr << a | b | c
will actually be evaluated as::
(fwd_expr << a) | b | c
thereby leaving b and c out as parseable alternatives. It is recommended that you
explicitly group the values inserted into the ``Forward``::
fwd_expr << (a | b | c)
Converting to use the ``'<<='`` operator instead will avoid this problem.
See :class:`ParseResults.pprint` for an example of a recursive
parser created using ``Forward``.
"""
def __init__(self, other: typing.Optional[Union[ParserElement, str]] = None):
self.caller_frame = traceback.extract_stack(limit=2)[0]
super().__init__(other, savelist=False)
self.lshift_line = None
def __lshift__(self, other):
if hasattr(self, "caller_frame"):
del self.caller_frame
if isinstance(other, str_type):
other = self._literalStringClass(other)
self.expr = other
self.mayIndexError = self.expr.mayIndexError
self.mayReturnEmpty = self.expr.mayReturnEmpty
self.set_whitespace_chars(
self.expr.whiteChars, copy_defaults=self.expr.copyDefaultWhiteChars
)
self.skipWhitespace = self.expr.skipWhitespace
self.saveAsList = self.expr.saveAsList
self.ignoreExprs.extend(self.expr.ignoreExprs)
self.lshift_line = traceback.extract_stack(limit=2)[-2]
return self
def __ilshift__(self, other):
return self << other
def __or__(self, other):
caller_line = traceback.extract_stack(limit=2)[-2]
if (
__diag__.warn_on_match_first_with_lshift_operator
and caller_line == self.lshift_line
and Diagnostics.warn_on_match_first_with_lshift_operator
not in self.suppress_warnings_
):
warnings.warn(
"using '<<' operator with '|' is probably an error, use '<<='",
stacklevel=2,
)
ret = super().__or__(other)
return ret
def __del__(self):
# see if we are getting dropped because of '=' reassignment of var instead of '<<=' or '<<'
if (
self.expr is None
and __diag__.warn_on_assignment_to_Forward
and Diagnostics.warn_on_assignment_to_Forward not in self.suppress_warnings_
):
warnings.warn_explicit(
"Forward defined here but no expression attached later using '<<=' or '<<'",
UserWarning,
filename=self.caller_frame.filename,
lineno=self.caller_frame.lineno,
)
def parseImpl(self, instring, loc, doActions=True):
if (
self.expr is None
and __diag__.warn_on_parse_using_empty_Forward
and Diagnostics.warn_on_parse_using_empty_Forward
not in self.suppress_warnings_
):
# walk stack until parse_string, scan_string, search_string, or transform_string is found
parse_fns = [
"parse_string",
"scan_string",
"search_string",
"transform_string",
]
tb = traceback.extract_stack(limit=200)
for i, frm in enumerate(reversed(tb), start=1):
if frm.name in parse_fns:
stacklevel = i + 1
break
else:
stacklevel = 2
warnings.warn(
"Forward expression was never assigned a value, will not parse any input",
stacklevel=stacklevel,
)
if not ParserElement._left_recursion_enabled:
return super().parseImpl(instring, loc, doActions)
# ## Bounded Recursion algorithm ##
# Recursion only needs to be processed at ``Forward`` elements, since they are
# the only ones that can actually refer to themselves. The general idea is
# to handle recursion stepwise: We start at no recursion, then recurse once,
# recurse twice, ..., until more recursion offers no benefit (we hit the bound).
#
# The "trick" here is that each ``Forward`` gets evaluated in two contexts
# - to *match* a specific recursion level, and
# - to *search* the bounded recursion level
# and the two run concurrently. The *search* must *match* each recursion level
# to find the best possible match. This is handled by a memo table, which
# provides the previous match to the next level match attempt.
#
# See also "Left Recursion in Parsing Expression Grammars", Medeiros et al.
#
# There is a complication since we not only *parse* but also *transform* via
# actions: We do not want to run the actions too often while expanding. Thus,
# we expand using `doActions=False` and only run `doActions=True` if the next
# recursion level is acceptable.
with ParserElement.recursion_lock:
memo = ParserElement.recursion_memos
try:
# we are parsing at a specific recursion expansion - use it as-is
prev_loc, prev_result = memo[loc, self, doActions]
if isinstance(prev_result, Exception):
raise prev_result
return prev_loc, prev_result.copy()
except KeyError:
act_key = (loc, self, True)
peek_key = (loc, self, False)
# we are searching for the best recursion expansion - keep on improving
# both `doActions` cases must be tracked separately here!
prev_loc, prev_peek = memo[peek_key] = (
loc - 1,
ParseException(
instring, loc, "Forward recursion without base case", self
),
)
if doActions:
memo[act_key] = memo[peek_key]
while True:
try:
new_loc, new_peek = super().parseImpl(instring, loc, False)
except ParseException:
# we failed before getting any match – do not hide the error
if isinstance(prev_peek, Exception):
raise
new_loc, new_peek = prev_loc, prev_peek
# the match did not get better: we are done
if new_loc <= prev_loc:
if doActions:
# replace the match for doActions=False as well,
# in case the action did backtrack
prev_loc, prev_result = memo[peek_key] = memo[act_key]
del memo[peek_key], memo[act_key]
return prev_loc, prev_result.copy()
del memo[peek_key]
return prev_loc, prev_peek.copy()
# the match did get better: see if we can improve further
else:
if doActions:
try:
memo[act_key] = super().parseImpl(instring, loc, True)
except ParseException as e:
memo[peek_key] = memo[act_key] = (new_loc, e)
raise
prev_loc, prev_peek = memo[peek_key] = new_loc, new_peek
def leave_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = False
return self
def ignore_whitespace(self, recursive: bool = True) -> ParserElement:
self.skipWhitespace = True
return self
def streamline(self) -> ParserElement:
if not self.streamlined:
self.streamlined = True
if self.expr is not None:
self.expr.streamline()
return self
def validate(self, validateTrace=None) -> None:
if validateTrace is None:
validateTrace = []
if self not in validateTrace:
tmp = validateTrace[:] + [self]
if self.expr is not None:
self.expr.validate(tmp)
self._checkRecursion([])
def _generateDefaultName(self):
# Avoid infinite recursion by setting a temporary _defaultName
self._defaultName = ": ..."
# Use the string representation of main expression.
retString = "..."
try:
if self.expr is not None:
retString = str(self.expr)[:1000]
else:
retString = "None"
finally:
return self.__class__.__name__ + ": " + retString
def copy(self) -> ParserElement:
if self.expr is not None:
return super().copy()
else:
ret = Forward()
ret <<= self
return ret
def _setResultsName(self, name, list_all_matches=False):
if (
__diag__.warn_name_set_on_empty_Forward
and Diagnostics.warn_name_set_on_empty_Forward
not in self.suppress_warnings_
):
if self.expr is None:
warnings.warn(
"{}: setting results name {!r} on {} expression "
"that has no contained expression".format(
"warn_name_set_on_empty_Forward", name, type(self).__name__
),
stacklevel=3,
)
return super()._setResultsName(name, list_all_matches)
ignoreWhitespace = ignore_whitespace
leaveWhitespace = leave_whitespace
class Group(TokenConverter):
"""Converter to return the matched tokens as a list - useful for
returning tokens of :class:`ZeroOrMore` and :class:`OneOrMore` expressions.
The optional ``aslist`` argument when set to True will return the
parsed tokens as a Python list instead of a pyparsing ParseResults.
Example::
ident = Word(alphas)
num = Word(nums)
term = ident | num
func = ident + Opt(delimited_list(term))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', 'a', 'b', '100']
func = ident + Group(Opt(delimited_list(term)))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', ['a', 'b', '100']]
"""
def __init__(self, expr: ParserElement, aslist: bool = False):
super().__init__(expr)
self.saveAsList = True
self._asPythonList = aslist
def postParse(self, instring, loc, tokenlist):
if self._asPythonList:
return ParseResults.List(
tokenlist.asList()
if isinstance(tokenlist, ParseResults)
else list(tokenlist)
)
else:
return [tokenlist]
class Suppress(TokenConverter):
"""Converter for ignoring the results of a parsed expression.
Example::
source = "a, b, c,d"
wd = Word(alphas)
wd_list1 = wd + (',' + wd)[...]
print(wd_list1.parse_string(source))
# often, delimiters that are useful during parsing are just in the
# way afterward - use Suppress to keep them out of the parsed output
wd_list2 = wd + (Suppress(',') + wd)[...]
print(wd_list2.parse_string(source))
# Skipped text (using '...') can be suppressed as well
source = "lead in START relevant text END trailing text"
start_marker = Keyword("START")
end_marker = Keyword("END")
find_body = Suppress(...) + start_marker + ... + end_marker
print(find_body.parse_string(source)
prints::
['a', ',', 'b', ',', 'c', ',', 'd']
['a', 'b', 'c', 'd']
['START', 'relevant text ', 'END']
(See also :class:`delimited_list`.)
"""
def __init__(self, expr: Union[ParserElement, str], savelist: bool = False):
if expr is ...:
expr = _PendingSkip(NoMatch())
super().__init__(expr)
def __add__(self, other) -> "ParserElement":
if isinstance(self.expr, _PendingSkip):
return Suppress(SkipTo(other)) + other
else:
return super().__add__(other)
def __sub__(self, other) -> "ParserElement":
if isinstance(self.expr, _PendingSkip):
return Suppress(SkipTo(other)) - other
else:
return super().__sub__(other)
def postParse(self, instring, loc, tokenlist):
return []
def suppress(self) -> ParserElement:
return self
The provided code snippet includes necessary dependencies for implementing the `infix_notation` function. Write a Python function `def infix_notation( base_expr: ParserElement, op_list: List[InfixNotationOperatorSpec], lpar: Union[str, ParserElement] = Suppress("("), rpar: Union[str, ParserElement] = Suppress(")"), ) -> ParserElement` to solve the following problem:
Helper method for constructing grammars of expressions made up of operators working in a precedence hierarchy. Operators may be unary or binary, left- or right-associative. Parse actions can also be attached to operator expressions. The generated parser will also recognize the use of parentheses to override operator precedences (see example below). Note: if you define a deep operator list, you may see performance issues when using infix_notation. See :class:`ParserElement.enable_packrat` for a mechanism to potentially improve your parser performance. Parameters: - ``base_expr`` - expression representing the most basic operand to be used in the expression - ``op_list`` - list of tuples, one for each operator precedence level in the expression grammar; each tuple is of the form ``(op_expr, num_operands, right_left_assoc, (optional)parse_action)``, where: - ``op_expr`` is the pyparsing expression for the operator; may also be a string, which will be converted to a Literal; if ``num_operands`` is 3, ``op_expr`` is a tuple of two expressions, for the two operators separating the 3 terms - ``num_operands`` is the number of terms for this operator (must be 1, 2, or 3) - ``right_left_assoc`` is the indicator whether the operator is right or left associative, using the pyparsing-defined constants ``OpAssoc.RIGHT`` and ``OpAssoc.LEFT``. - ``parse_action`` is the parse action to be associated with expressions matching this operator expression (the parse action tuple member may be omitted); if the parse action is passed a tuple or list of functions, this is equivalent to calling ``set_parse_action(*fn)`` (:class:`ParserElement.set_parse_action`) - ``lpar`` - expression for matching left-parentheses; if passed as a str, then will be parsed as Suppress(lpar). If lpar is passed as an expression (such as ``Literal('(')``), then it will be kept in the parsed results, and grouped with them. (default= ``Suppress('(')``) - ``rpar`` - expression for matching right-parentheses; if passed as a str, then will be parsed as Suppress(rpar). If rpar is passed as an expression (such as ``Literal(')')``), then it will be kept in the parsed results, and grouped with them. (default= ``Suppress(')')``) Example:: # simple example of four-function arithmetic with ints and # variable names integer = pyparsing_common.signed_integer varname = pyparsing_common.identifier arith_expr = infix_notation(integer | varname, [ ('-', 1, OpAssoc.RIGHT), (one_of('* /'), 2, OpAssoc.LEFT), (one_of('+ -'), 2, OpAssoc.LEFT), ]) arith_expr.run_tests(''' 5+3*6 (5+3)*6 -2--11 ''', full_dump=False) prints:: 5+3*6 [[5, '+', [3, '*', 6]]] (5+3)*6 [[[5, '+', 3], '*', 6]] -2--11 [[['-', 2], '-', ['-', 11]]]
Here is the function:
def infix_notation(
base_expr: ParserElement,
op_list: List[InfixNotationOperatorSpec],
lpar: Union[str, ParserElement] = Suppress("("),
rpar: Union[str, ParserElement] = Suppress(")"),
) -> ParserElement:
"""Helper method for constructing grammars of expressions made up of
operators working in a precedence hierarchy. Operators may be unary
or binary, left- or right-associative. Parse actions can also be
attached to operator expressions. The generated parser will also
recognize the use of parentheses to override operator precedences
(see example below).
Note: if you define a deep operator list, you may see performance
issues when using infix_notation. See
:class:`ParserElement.enable_packrat` for a mechanism to potentially
improve your parser performance.
Parameters:
- ``base_expr`` - expression representing the most basic operand to
be used in the expression
- ``op_list`` - list of tuples, one for each operator precedence level
in the expression grammar; each tuple is of the form ``(op_expr,
num_operands, right_left_assoc, (optional)parse_action)``, where:
- ``op_expr`` is the pyparsing expression for the operator; may also
be a string, which will be converted to a Literal; if ``num_operands``
is 3, ``op_expr`` is a tuple of two expressions, for the two
operators separating the 3 terms
- ``num_operands`` is the number of terms for this operator (must be 1,
2, or 3)
- ``right_left_assoc`` is the indicator whether the operator is right
or left associative, using the pyparsing-defined constants
``OpAssoc.RIGHT`` and ``OpAssoc.LEFT``.
- ``parse_action`` is the parse action to be associated with
expressions matching this operator expression (the parse action
tuple member may be omitted); if the parse action is passed
a tuple or list of functions, this is equivalent to calling
``set_parse_action(*fn)``
(:class:`ParserElement.set_parse_action`)
- ``lpar`` - expression for matching left-parentheses; if passed as a
str, then will be parsed as Suppress(lpar). If lpar is passed as
an expression (such as ``Literal('(')``), then it will be kept in
the parsed results, and grouped with them. (default= ``Suppress('(')``)
- ``rpar`` - expression for matching right-parentheses; if passed as a
str, then will be parsed as Suppress(rpar). If rpar is passed as
an expression (such as ``Literal(')')``), then it will be kept in
the parsed results, and grouped with them. (default= ``Suppress(')')``)
Example::
# simple example of four-function arithmetic with ints and
# variable names
integer = pyparsing_common.signed_integer
varname = pyparsing_common.identifier
arith_expr = infix_notation(integer | varname,
[
('-', 1, OpAssoc.RIGHT),
(one_of('* /'), 2, OpAssoc.LEFT),
(one_of('+ -'), 2, OpAssoc.LEFT),
])
arith_expr.run_tests('''
5+3*6
(5+3)*6
-2--11
''', full_dump=False)
prints::
5+3*6
[[5, '+', [3, '*', 6]]]
(5+3)*6
[[[5, '+', 3], '*', 6]]
-2--11
[[['-', 2], '-', ['-', 11]]]
"""
# captive version of FollowedBy that does not do parse actions or capture results names
class _FB(FollowedBy):
def parseImpl(self, instring, loc, doActions=True):
self.expr.try_parse(instring, loc)
return loc, []
_FB.__name__ = "FollowedBy>"
ret = Forward()
if isinstance(lpar, str):
lpar = Suppress(lpar)
if isinstance(rpar, str):
rpar = Suppress(rpar)
# if lpar and rpar are not suppressed, wrap in group
if not (isinstance(rpar, Suppress) and isinstance(rpar, Suppress)):
lastExpr = base_expr | Group(lpar + ret + rpar)
else:
lastExpr = base_expr | (lpar + ret + rpar)
for i, operDef in enumerate(op_list):
opExpr, arity, rightLeftAssoc, pa = (operDef + (None,))[:4]
if isinstance(opExpr, str_type):
opExpr = ParserElement._literalStringClass(opExpr)
if arity == 3:
if not isinstance(opExpr, (tuple, list)) or len(opExpr) != 2:
raise ValueError(
"if numterms=3, opExpr must be a tuple or list of two expressions"
)
opExpr1, opExpr2 = opExpr
term_name = "{}{} term".format(opExpr1, opExpr2)
else:
term_name = "{} term".format(opExpr)
if not 1 <= arity <= 3:
raise ValueError("operator must be unary (1), binary (2), or ternary (3)")
if rightLeftAssoc not in (OpAssoc.LEFT, OpAssoc.RIGHT):
raise ValueError("operator must indicate right or left associativity")
thisExpr: Forward = Forward().set_name(term_name)
if rightLeftAssoc is OpAssoc.LEFT:
if arity == 1:
matchExpr = _FB(lastExpr + opExpr) + Group(lastExpr + opExpr[1, ...])
elif arity == 2:
if opExpr is not None:
matchExpr = _FB(lastExpr + opExpr + lastExpr) + Group(
lastExpr + (opExpr + lastExpr)[1, ...]
)
else:
matchExpr = _FB(lastExpr + lastExpr) + Group(lastExpr[2, ...])
elif arity == 3:
matchExpr = _FB(
lastExpr + opExpr1 + lastExpr + opExpr2 + lastExpr
) + Group(lastExpr + OneOrMore(opExpr1 + lastExpr + opExpr2 + lastExpr))
elif rightLeftAssoc is OpAssoc.RIGHT:
if arity == 1:
# try to avoid LR with this extra test
if not isinstance(opExpr, Opt):
opExpr = Opt(opExpr)
matchExpr = _FB(opExpr.expr + thisExpr) + Group(opExpr + thisExpr)
elif arity == 2:
if opExpr is not None:
matchExpr = _FB(lastExpr + opExpr + thisExpr) + Group(
lastExpr + (opExpr + thisExpr)[1, ...]
)
else:
matchExpr = _FB(lastExpr + thisExpr) + Group(
lastExpr + thisExpr[1, ...]
)
elif arity == 3:
matchExpr = _FB(
lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr
) + Group(lastExpr + opExpr1 + thisExpr + opExpr2 + thisExpr)
if pa:
if isinstance(pa, (tuple, list)):
matchExpr.set_parse_action(*pa)
else:
matchExpr.set_parse_action(pa)
thisExpr <<= (matchExpr | lastExpr).setName(term_name)
lastExpr = thisExpr
ret <<= lastExpr
return ret | Helper method for constructing grammars of expressions made up of operators working in a precedence hierarchy. Operators may be unary or binary, left- or right-associative. Parse actions can also be attached to operator expressions. The generated parser will also recognize the use of parentheses to override operator precedences (see example below). Note: if you define a deep operator list, you may see performance issues when using infix_notation. See :class:`ParserElement.enable_packrat` for a mechanism to potentially improve your parser performance. Parameters: - ``base_expr`` - expression representing the most basic operand to be used in the expression - ``op_list`` - list of tuples, one for each operator precedence level in the expression grammar; each tuple is of the form ``(op_expr, num_operands, right_left_assoc, (optional)parse_action)``, where: - ``op_expr`` is the pyparsing expression for the operator; may also be a string, which will be converted to a Literal; if ``num_operands`` is 3, ``op_expr`` is a tuple of two expressions, for the two operators separating the 3 terms - ``num_operands`` is the number of terms for this operator (must be 1, 2, or 3) - ``right_left_assoc`` is the indicator whether the operator is right or left associative, using the pyparsing-defined constants ``OpAssoc.RIGHT`` and ``OpAssoc.LEFT``. - ``parse_action`` is the parse action to be associated with expressions matching this operator expression (the parse action tuple member may be omitted); if the parse action is passed a tuple or list of functions, this is equivalent to calling ``set_parse_action(*fn)`` (:class:`ParserElement.set_parse_action`) - ``lpar`` - expression for matching left-parentheses; if passed as a str, then will be parsed as Suppress(lpar). If lpar is passed as an expression (such as ``Literal('(')``), then it will be kept in the parsed results, and grouped with them. (default= ``Suppress('(')``) - ``rpar`` - expression for matching right-parentheses; if passed as a str, then will be parsed as Suppress(rpar). If rpar is passed as an expression (such as ``Literal(')')``), then it will be kept in the parsed results, and grouped with them. (default= ``Suppress(')')``) Example:: # simple example of four-function arithmetic with ints and # variable names integer = pyparsing_common.signed_integer varname = pyparsing_common.identifier arith_expr = infix_notation(integer | varname, [ ('-', 1, OpAssoc.RIGHT), (one_of('* /'), 2, OpAssoc.LEFT), (one_of('+ -'), 2, OpAssoc.LEFT), ]) arith_expr.run_tests(''' 5+3*6 (5+3)*6 -2--11 ''', full_dump=False) prints:: 5+3*6 [[5, '+', [3, '*', 6]]] (5+3)*6 [[[5, '+', 3], '*', 6]] -2--11 [[['-', 2], '-', ['-', 11]]] |
173,740 | import html.entities
import re
import typing
from . import __diag__
from .core import *
from .util import _bslash, _flatten, _escape_regex_range_chars
class Empty(Token):
"""
An empty token, will always match.
"""
def __init__(self):
super().__init__()
self.mayReturnEmpty = True
self.mayIndexError = False
class LineEnd(PositionToken):
"""Matches if current position is at the end of a line within the
parse string
"""
def __init__(self):
super().__init__()
self.whiteChars.discard("\n")
self.set_whitespace_chars(self.whiteChars, copy_defaults=False)
self.errmsg = "Expected end of line"
def parseImpl(self, instring, loc, doActions=True):
if loc < len(instring):
if instring[loc] == "\n":
return loc + 1, "\n"
else:
raise ParseException(instring, loc, self.errmsg, self)
elif loc == len(instring):
return loc + 1, []
else:
raise ParseException(instring, loc, self.errmsg, self)
class OneOrMore(_MultipleMatch):
"""
Repetition of one or more of the given expression.
Parameters:
- expr - expression that must match one or more times
- stop_on - (default= ``None``) - expression for a terminating sentinel
(only required if the sentinel would ordinarily match the repetition
expression)
Example::
data_word = Word(alphas)
label = data_word + FollowedBy(':')
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word).set_parse_action(' '.join))
text = "shape: SQUARE posn: upper left color: BLACK"
attr_expr[1, ...].parse_string(text).pprint() # Fail! read 'color' as data instead of next label -> [['shape', 'SQUARE color']]
# use stop_on attribute for OneOrMore to avoid reading label string as part of the data
attr_expr = Group(label + Suppress(':') + OneOrMore(data_word, stop_on=label).set_parse_action(' '.join))
OneOrMore(attr_expr).parse_string(text).pprint() # Better -> [['shape', 'SQUARE'], ['posn', 'upper left'], ['color', 'BLACK']]
# could also be written as
(attr_expr * (1,)).parse_string(text).pprint()
"""
def _generateDefaultName(self):
return "{" + str(self.expr) + "}..."
class Opt(ParseElementEnhance):
"""
Optional matching of the given expression.
Parameters:
- ``expr`` - expression that must match zero or more times
- ``default`` (optional) - value to be returned if the optional expression is not found.
Example::
# US postal code can be a 5-digit zip, plus optional 4-digit qualifier
zip = Combine(Word(nums, exact=5) + Opt('-' + Word(nums, exact=4)))
zip.run_tests('''
# traditional ZIP code
12345
# ZIP+4 form
12101-0001
# invalid ZIP
98765-
''')
prints::
# traditional ZIP code
12345
['12345']
# ZIP+4 form
12101-0001
['12101-0001']
# invalid ZIP
98765-
^
FAIL: Expected end of text (at char 5), (line:1, col:6)
"""
__optionalNotMatched = _NullToken()
def __init__(
self, expr: Union[ParserElement, str], default: Any = __optionalNotMatched
):
super().__init__(expr, savelist=False)
self.saveAsList = self.expr.saveAsList
self.defaultValue = default
self.mayReturnEmpty = True
def parseImpl(self, instring, loc, doActions=True):
self_expr = self.expr
try:
loc, tokens = self_expr._parse(instring, loc, doActions, callPreParse=False)
except (ParseException, IndexError):
default_value = self.defaultValue
if default_value is not self.__optionalNotMatched:
if self_expr.resultsName:
tokens = ParseResults([default_value])
tokens[self_expr.resultsName] = default_value
else:
tokens = [default_value]
else:
tokens = []
return loc, tokens
def _generateDefaultName(self):
inner = str(self.expr)
# strip off redundant inner {}'s
while len(inner) > 1 and inner[0 :: len(inner) - 1] == "{}":
inner = inner[1:-1]
return "[" + inner + "]"
class Group(TokenConverter):
"""Converter to return the matched tokens as a list - useful for
returning tokens of :class:`ZeroOrMore` and :class:`OneOrMore` expressions.
The optional ``aslist`` argument when set to True will return the
parsed tokens as a Python list instead of a pyparsing ParseResults.
Example::
ident = Word(alphas)
num = Word(nums)
term = ident | num
func = ident + Opt(delimited_list(term))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', 'a', 'b', '100']
func = ident + Group(Opt(delimited_list(term)))
print(func.parse_string("fn a, b, 100"))
# -> ['fn', ['a', 'b', '100']]
"""
def __init__(self, expr: ParserElement, aslist: bool = False):
super().__init__(expr)
self.saveAsList = True
self._asPythonList = aslist
def postParse(self, instring, loc, tokenlist):
if self._asPythonList:
return ParseResults.List(
tokenlist.asList()
if isinstance(tokenlist, ParseResults)
else list(tokenlist)
)
else:
return [tokenlist]
_bslash = chr(92)
The provided code snippet includes necessary dependencies for implementing the `indentedBlock` function. Write a Python function `def indentedBlock(blockStatementExpr, indentStack, indent=True, backup_stacks=[])` to solve the following problem:
(DEPRECATED - use IndentedBlock class instead) Helper method for defining space-delimited indentation blocks, such as those used to define block statements in Python source code. Parameters: - ``blockStatementExpr`` - expression defining syntax of statement that is repeated within the indented block - ``indentStack`` - list created by caller to manage indentation stack (multiple ``statementWithIndentedBlock`` expressions within a single grammar should share a common ``indentStack``) - ``indent`` - boolean indicating whether block must be indented beyond the current level; set to ``False`` for block of left-most statements (default= ``True``) A valid block must contain at least one ``blockStatement``. (Note that indentedBlock uses internal parse actions which make it incompatible with packrat parsing.) Example:: data = ''' def A(z): A1 B = 100 G = A2 A2 A3 B def BB(a,b,c): BB1 def BBA(): bba1 bba2 bba3 C D def spam(x,y): def eggs(z): pass ''' indentStack = [1] stmt = Forward() identifier = Word(alphas, alphanums) funcDecl = ("def" + identifier + Group("(" + Opt(delimitedList(identifier)) + ")") + ":") func_body = indentedBlock(stmt, indentStack) funcDef = Group(funcDecl + func_body) rvalue = Forward() funcCall = Group(identifier + "(" + Opt(delimitedList(rvalue)) + ")") rvalue << (funcCall | identifier | Word(nums)) assignment = Group(identifier + "=" + rvalue) stmt << (funcDef | assignment | identifier) module_body = stmt[1, ...] parseTree = module_body.parseString(data) parseTree.pprint() prints:: [['def', 'A', ['(', 'z', ')'], ':', [['A1'], [['B', '=', '100']], [['G', '=', 'A2']], ['A2'], ['A3']]], 'B', ['def', 'BB', ['(', 'a', 'b', 'c', ')'], ':', [['BB1'], [['def', 'BBA', ['(', ')'], ':', [['bba1'], ['bba2'], ['bba3']]]]]], 'C', 'D', ['def', 'spam', ['(', 'x', 'y', ')'], ':', [[['def', 'eggs', ['(', 'z', ')'], ':', [['pass']]]]]]]
Here is the function:
def indentedBlock(blockStatementExpr, indentStack, indent=True, backup_stacks=[]):
"""
(DEPRECATED - use IndentedBlock class instead)
Helper method for defining space-delimited indentation blocks,
such as those used to define block statements in Python source code.
Parameters:
- ``blockStatementExpr`` - expression defining syntax of statement that
is repeated within the indented block
- ``indentStack`` - list created by caller to manage indentation stack
(multiple ``statementWithIndentedBlock`` expressions within a single
grammar should share a common ``indentStack``)
- ``indent`` - boolean indicating whether block must be indented beyond
the current level; set to ``False`` for block of left-most statements
(default= ``True``)
A valid block must contain at least one ``blockStatement``.
(Note that indentedBlock uses internal parse actions which make it
incompatible with packrat parsing.)
Example::
data = '''
def A(z):
A1
B = 100
G = A2
A2
A3
B
def BB(a,b,c):
BB1
def BBA():
bba1
bba2
bba3
C
D
def spam(x,y):
def eggs(z):
pass
'''
indentStack = [1]
stmt = Forward()
identifier = Word(alphas, alphanums)
funcDecl = ("def" + identifier + Group("(" + Opt(delimitedList(identifier)) + ")") + ":")
func_body = indentedBlock(stmt, indentStack)
funcDef = Group(funcDecl + func_body)
rvalue = Forward()
funcCall = Group(identifier + "(" + Opt(delimitedList(rvalue)) + ")")
rvalue << (funcCall | identifier | Word(nums))
assignment = Group(identifier + "=" + rvalue)
stmt << (funcDef | assignment | identifier)
module_body = stmt[1, ...]
parseTree = module_body.parseString(data)
parseTree.pprint()
prints::
[['def',
'A',
['(', 'z', ')'],
':',
[['A1'], [['B', '=', '100']], [['G', '=', 'A2']], ['A2'], ['A3']]],
'B',
['def',
'BB',
['(', 'a', 'b', 'c', ')'],
':',
[['BB1'], [['def', 'BBA', ['(', ')'], ':', [['bba1'], ['bba2'], ['bba3']]]]]],
'C',
'D',
['def',
'spam',
['(', 'x', 'y', ')'],
':',
[[['def', 'eggs', ['(', 'z', ')'], ':', [['pass']]]]]]]
"""
backup_stacks.append(indentStack[:])
def reset_stack():
indentStack[:] = backup_stacks[-1]
def checkPeerIndent(s, l, t):
if l >= len(s):
return
curCol = col(l, s)
if curCol != indentStack[-1]:
if curCol > indentStack[-1]:
raise ParseException(s, l, "illegal nesting")
raise ParseException(s, l, "not a peer entry")
def checkSubIndent(s, l, t):
curCol = col(l, s)
if curCol > indentStack[-1]:
indentStack.append(curCol)
else:
raise ParseException(s, l, "not a subentry")
def checkUnindent(s, l, t):
if l >= len(s):
return
curCol = col(l, s)
if not (indentStack and curCol in indentStack):
raise ParseException(s, l, "not an unindent")
if curCol < indentStack[-1]:
indentStack.pop()
NL = OneOrMore(LineEnd().set_whitespace_chars("\t ").suppress())
INDENT = (Empty() + Empty().set_parse_action(checkSubIndent)).set_name("INDENT")
PEER = Empty().set_parse_action(checkPeerIndent).set_name("")
UNDENT = Empty().set_parse_action(checkUnindent).set_name("UNINDENT")
if indent:
smExpr = Group(
Opt(NL)
+ INDENT
+ OneOrMore(PEER + Group(blockStatementExpr) + Opt(NL))
+ UNDENT
)
else:
smExpr = Group(
Opt(NL)
+ OneOrMore(PEER + Group(blockStatementExpr) + Opt(NL))
+ Opt(UNDENT)
)
# add a parse action to remove backup_stack from list of backups
smExpr.add_parse_action(
lambda: backup_stacks.pop(-1) and None if backup_stacks else None
)
smExpr.set_fail_action(lambda a, b, c, d: reset_stack())
blockStatementExpr.ignore(_bslash + LineEnd())
return smExpr.set_name("indented block") | (DEPRECATED - use IndentedBlock class instead) Helper method for defining space-delimited indentation blocks, such as those used to define block statements in Python source code. Parameters: - ``blockStatementExpr`` - expression defining syntax of statement that is repeated within the indented block - ``indentStack`` - list created by caller to manage indentation stack (multiple ``statementWithIndentedBlock`` expressions within a single grammar should share a common ``indentStack``) - ``indent`` - boolean indicating whether block must be indented beyond the current level; set to ``False`` for block of left-most statements (default= ``True``) A valid block must contain at least one ``blockStatement``. (Note that indentedBlock uses internal parse actions which make it incompatible with packrat parsing.) Example:: data = ''' def A(z): A1 B = 100 G = A2 A2 A3 B def BB(a,b,c): BB1 def BBA(): bba1 bba2 bba3 C D def spam(x,y): def eggs(z): pass ''' indentStack = [1] stmt = Forward() identifier = Word(alphas, alphanums) funcDecl = ("def" + identifier + Group("(" + Opt(delimitedList(identifier)) + ")") + ":") func_body = indentedBlock(stmt, indentStack) funcDef = Group(funcDecl + func_body) rvalue = Forward() funcCall = Group(identifier + "(" + Opt(delimitedList(rvalue)) + ")") rvalue << (funcCall | identifier | Word(nums)) assignment = Group(identifier + "=" + rvalue) stmt << (funcDef | assignment | identifier) module_body = stmt[1, ...] parseTree = module_body.parseString(data) parseTree.pprint() prints:: [['def', 'A', ['(', 'z', ')'], ':', [['A1'], [['B', '=', '100']], [['G', '=', 'A2']], ['A2'], ['A3']]], 'B', ['def', 'BB', ['(', 'a', 'b', 'c', ')'], ':', [['BB1'], [['def', 'BBA', ['(', ')'], ':', [['bba1'], ['bba2'], ['bba3']]]]]], 'C', 'D', ['def', 'spam', ['(', 'x', 'y', ')'], ':', [[['def', 'eggs', ['(', 'z', ')'], ':', [['pass']]]]]]] |
173,778 | import bs4
import collections
import dataclasses
import datetime
import itertools
import json
import logging
import re
import snscrape.base
import typing
import urllib.parse
def _timezone(s):
return pytz.timezone(s) | null |
173,779 | import bs4
import collections
import dataclasses
import datetime
import itertools
import json
import logging
import re
import snscrape.base
import typing
import urllib.parse
def _localised_datetime(tz, *args, **kwargs):
return tz.localize(datetime.datetime(*args, **kwargs)) | null |
173,780 | import bs4
import collections
import dataclasses
import datetime
import itertools
import json
import logging
import re
import snscrape.base
import typing
import urllib.parse
try:
import zoneinfo
except ImportError:
# Python 3.8 support; nowadays, Europe/Moscow is always UTC+3, but it's more complicated before 2014, so need proper zone info
import pytz
else:
def _timezone(s):
return zoneinfo.ZoneInfo(s) | null |
173,781 | import bs4
import collections
import dataclasses
import datetime
import itertools
import json
import logging
import re
import snscrape.base
import typing
import urllib.parse
def _localised_datetime(tz, *args, **kwargs):
return datetime.datetime(*args, tzinfo = tz, **kwargs) | null |
173,782 | import dataclasses
import datetime
import logging
import re
import snscrape.base
import snscrape.version
import string
import time
import typing
The provided code snippet includes necessary dependencies for implementing the `_cmp_id` function. Write a Python function `def _cmp_id(id1, id2)` to solve the following problem:
Compare two Reddit IDs. Returns -1 if id1 is less than id2, 0 if they are equal, and 1 if id1 is greater than id2. id1 and id2 may have prefixes like t1_, but if included, they must be present on both and equal.
Here is the function:
def _cmp_id(id1, id2):
'''Compare two Reddit IDs. Returns -1 if id1 is less than id2, 0 if they are equal, and 1 if id1 is greater than id2.
id1 and id2 may have prefixes like t1_, but if included, they must be present on both and equal.'''
if id1.startswith('t') and '_' in id1:
prefix, id1 = id1.split('_', 1)
if not id2.startswith(f'{prefix}_'):
raise ValueError('id2 must have the same prefix as id1')
_, id2 = id2.split('_', 1)
if id1.strip(string.ascii_lowercase + string.digits) != '':
raise ValueError('invalid characters in id1')
if id2.strip(string.ascii_lowercase + string.digits) != '':
raise ValueError('invalid characters in id2')
if len(id1) < len(id2):
return -1
if len(id1) > len(id2):
return 1
if id1 < id2:
return -1
if id1 > id2:
return 1
return 0 | Compare two Reddit IDs. Returns -1 if id1 is less than id2, 0 if they are equal, and 1 if id1 is greater than id2. id1 and id2 may have prefixes like t1_, but if included, they must be present on both and equal. |
173,783 | import argparse
import collections
import contextlib
import dataclasses
import datetime
import importlib.metadata
import inspect
import logging
import os
import requests
import sys
import tempfile
logger = logging
def _dump_stack_and_locals(trace, exc = None):
with tempfile.NamedTemporaryFile('w', prefix = 'snscrape_locals_', delete = False) as fp:
if exc is not None:
fp.write('Exception:\n')
fp.write(f' {type(exc).__module__}.{type(exc).__name__}: {exc!s}\n')
fp.write(f' args: {exc.args!r}\n')
fp.write('\n')
fp.write('Stack:\n')
for frameRecord in trace:
fp.write(f' File "{frameRecord.filename}", line {frameRecord.lineno}, in {frameRecord.function}\n')
if frameRecord.code_context is not None:
for line in frameRecord.code_context:
fp.write(f' {line.strip()}\n')
fp.write('\n')
modules = [inspect.getmodule(frameRecord[0]) for frameRecord in trace]
for i, (module, frameRecord) in enumerate(zip(modules, trace)):
if module is None:
# Module-less frame, e.g. dataclass.__init__
for j in reversed(range(i)):
if modules[j] is not None:
break
else:
# No previous module scope
continue
module = modules[j]
if not module.__name__.startswith('snscrape.') and module.__name__ != 'snscrape':
continue
locals_ = frameRecord[0].f_locals
fp.write(f'Locals from file "{frameRecord.filename}", line {frameRecord.lineno}, in {frameRecord.function}:\n')
for variableName in locals_:
variable = locals_[variableName]
varRepr = _repr(variableName, variable)
fp.write(f' {variableName} {type(variable)} = ')
fp.write(varRepr.replace('\n', '\n '))
fp.write('\n')
fp.write('\n')
if 'self' in locals_ and hasattr(locals_['self'], '__dict__'):
fp.write('Object dict:\n')
fp.write(repr(locals_['self'].__dict__))
fp.write('\n\n')
name = fp.name
return name
def _dump_locals_on_exception():
try:
yield
except Exception as e:
trace = inspect.trace()
if len(trace) >= 2:
name = _dump_stack_and_locals(trace[1:], exc = e)
logger.fatal(f'Dumped stack and locals to {name}', extra = {'_snscrapeSuppressDumpLocals': True})
raise | null |
173,784 | import argparse
import collections
import contextlib
import dataclasses
import datetime
import importlib.metadata
import inspect
import logging
import os
import requests
import sys
import tempfile
def parse_datetime_arg(arg):
for format in ('%Y-%m-%d %H:%M:%S %z', '%Y-%m-%d %H:%M:%S', '%Y-%m-%d %z', '%Y-%m-%d'):
try:
d = datetime.datetime.strptime(arg, format)
except ValueError:
continue
else:
if d.tzinfo is None:
return d.replace(tzinfo = datetime.timezone.utc)
return d
# Try treating it as a unix timestamp
try:
d = datetime.datetime.fromtimestamp(int(arg), datetime.timezone.utc)
except ValueError:
pass
else:
return d
raise argparse.ArgumentTypeError(f'Cannot parse {arg!r} into a datetime object')
def parse_format(arg):
# Replace '{' by '{0.' to use properties of the item, but keep '{{' intact
parts = arg.split('{')
out = ''
it = iter(zip(parts, parts[1:]))
for part, nextPart in it:
out += part
if nextPart == '': # Double brace
out += '{{'
next(it)
else: # Single brace
out += '{0.'
out += parts[-1]
return out
class CitationAction(argparse.Action):
def __init__(self, option_strings, dest = argparse.SUPPRESS, *args, default = argparse.SUPPRESS, **kwargs):
super().__init__(option_strings, dest, *args, **kwargs)
def __call__(self, parser, namespace, values, optionString):
try:
m = importlib.metadata.metadata('snscrape')
except importlib.metadata.PackageNotFoundError:
print('Error: could not find snscrape installation. --citation does not work without the package being installed.', file = sys.stderr)
parser.exit(1)
print(f'Author: {m["author"]}')
print(f'Title: {m["name"]}: {m["summary"]}')
print(f'URL: {m["home-page"]}')
print(f'Version: {m["version"]}')
print(f'Date: 2018‒{m["version"].split(".", 3)[3][:4]}')
if '.dev' in m['version']:
print()
print('WARNING! You are running a development version. The date range may be incorrect. Please adjust the upper end of the range to the year of the commit.')
parser.exit()
def parse_args():
import snscrape.base
import snscrape.modules
import snscrape.version
parser = argparse.ArgumentParser(formatter_class = argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('--version', action = 'version', version = f'snscrape {snscrape.version.__version__}')
parser.add_argument('--citation', action = CitationAction, nargs = 0, help = 'Display recommended citation information and exit')
parser.add_argument('-v', '--verbose', '--verbosity', dest = 'verbosity', action = 'count', default = 0, help = 'Increase output verbosity')
parser.add_argument('--dump-locals', dest = 'dumpLocals', action = 'store_true', default = False, help = 'Dump local variables on serious log messages (warnings or higher)')
parser.add_argument('--retry', '--retries', dest = 'retries', type = int, default = 3, metavar = 'N',
help = 'When the connection fails or the server returns an unexpected response, retry up to N times with an exponential backoff')
parser.add_argument('-n', '--max-results', dest = 'maxResults', type = lambda x: int(x) if int(x) >= 0 else parser.error('--max-results N must be zero or positive'), metavar = 'N', help = 'Only return the first N results')
group = parser.add_mutually_exclusive_group(required = False)
group.add_argument('-f', '--format', dest = 'format', type = parse_format, default = None, help = 'Output format')
group.add_argument('--jsonl', dest = 'jsonl', action = 'store_true', default = False, help = 'Output JSONL')
parser.add_argument('--with-entity', dest = 'withEntity', action = 'store_true', default = False, help = 'Include the entity (e.g. user, channel) as the first output item')
parser.add_argument('--since', type = parse_datetime_arg, metavar = 'DATETIME', help = 'Only return results newer than DATETIME')
parser.add_argument('--progress', action = 'store_true', default = False, help = 'Report progress on stderr')
subparsers = parser.add_subparsers(dest = 'scraper', metavar = 'SCRAPER', title = 'scrapers', required = True)
classes = snscrape.base.Scraper.__subclasses__()
scrapers = {}
for cls in classes:
if cls.name is not None:
scrapers[cls.name] = cls
classes.extend(cls.__subclasses__())
for scraper, cls in sorted(scrapers.items()):
subparser = subparsers.add_parser(cls.name, help = '', formatter_class = argparse.ArgumentDefaultsHelpFormatter)
cls._cli_setup_parser(subparser)
subparser.set_defaults(cls = cls)
args = parser.parse_args()
if not args.withEntity and args.maxResults == 0:
parser.error('--max-results 0 is only valid when used with --with-entity')
return args | null |
173,785 | import argparse
import collections
import contextlib
import dataclasses
import datetime
import importlib.metadata
import inspect
import logging
import os
import requests
import sys
import tempfile
logger = logging
class Logger(logging.Logger):
def _log_with_stack(self, level, *args, **kwargs):
def warning(self, *args, **kwargs):
def error(self, *args, **kwargs):
def critical(self, *args, **kwargs):
def log(self, level, *args, **kwargs):
def setup_logging():
logging.setLoggerClass(Logger)
global logger
logger = logging.getLogger(__name__) | null |
173,786 | import argparse
import collections
import contextlib
import dataclasses
import datetime
import importlib.metadata
import inspect
import logging
import os
import requests
import sys
import tempfile
dumpLocals = False
def configure_logging(verbosity, dumpLocals_):
global dumpLocals
dumpLocals = dumpLocals_
rootLogger = logging.getLogger()
# Set level
if verbosity > 0:
level = logging.INFO if verbosity == 1 else logging.DEBUG
rootLogger.setLevel(level)
for handler in rootLogger.handlers:
handler.setLevel(level)
# Create formatter
formatter = logging.Formatter('{asctime}.{msecs:03.0f} {levelname} {name} {message}', datefmt = '%Y-%m-%d %H:%M:%S', style = '{')
# Remove existing handlers
for handler in rootLogger.handlers:
rootLogger.removeHandler(handler)
# Add stream handler
handler = logging.StreamHandler()
handler.setFormatter(formatter)
rootLogger.addHandler(handler) | null |
173,787 | import abc
import copy
import dataclasses
import datetime
import functools
import json
import logging
import requests
import requests.adapters
import urllib3.connection
import time
import warnings
class DeprecatedFeatureWarning(FutureWarning):
__getattr__, __dir__ = _module_deprecation_helper(__all__, Entity = Item)
def _module_deprecation_helper(all, **names):
def __getattr__(name):
if name in names:
warnings.warn(f'{name} is deprecated, use {names[name].__name__} instead', DeprecatedFeatureWarning, stacklevel = 2)
return names[name]
raise AttributeError(f'module {__name__!r} has no attribute {name!r}')
def __dir__():
return sorted(all + list(names.keys()))
return __getattr__, __dir__ | null |
173,788 | import abc
import copy
import dataclasses
import datetime
import functools
import json
import logging
import requests
import requests.adapters
import urllib3.connection
import time
import warnings
The provided code snippet includes necessary dependencies for implementing the `_json_serialise_datetime` function. Write a Python function `def _json_serialise_datetime(obj)` to solve the following problem:
A JSON serialiser that converts datetime.datetime and datetime.date objects to ISO-8601 strings.
Here is the function:
def _json_serialise_datetime(obj):
'''A JSON serialiser that converts datetime.datetime and datetime.date objects to ISO-8601 strings.'''
if isinstance(obj, (datetime.datetime, datetime.date)):
return obj.isoformat()
raise TypeError(f'Object of type {type(obj)} is not JSON serializable') | A JSON serialiser that converts datetime.datetime and datetime.date objects to ISO-8601 strings. |
173,789 | import abc
import copy
import dataclasses
import datetime
import functools
import json
import logging
import requests
import requests.adapters
import urllib3.connection
import time
import warnings
class _DeprecatedProperty:
def __init__(self, name, repl, replStr):
self.name = name
self.repl = repl
self.replStr = replStr
def __get__(self, obj, objType):
if obj is None: # if the access is through the class using _DeprecatedProperty rather than an instance of the class:
return self
warnings.warn(f'{self.name} is deprecated, use {self.replStr} instead', DeprecatedFeatureWarning, stacklevel = 2)
return self.repl(obj)
class _JSONDataclass:
'''A base class for dataclasses for conversion to JSON'''
def json(self):
'''Convert the object to a JSON string'''
with warnings.catch_warnings():
warnings.filterwarnings(action = 'ignore', category = DeprecatedFeatureWarning)
out = _json_dataclass_to_dict(self)
for key, value in list(out.items()): # Modifying the dict below, so make a copy first
if isinstance(value, IntWithGranularity):
out[key] = int(value)
assert f'{key}.granularity' not in out, f'Granularity collision on {key}.granularity'
out[f'{key}.granularity'] = value.granularity
return json.dumps(out, default = _json_serialise_datetime)
def _json_dataclass_to_dict(obj):
if isinstance(obj, _JSONDataclass) or dataclasses.is_dataclass(obj):
out = {}
out['_type'] = f'{type(obj).__module__}.{type(obj).__name__}'
for field in dataclasses.fields(obj):
assert field.name != '_type'
if field.name.startswith('_'):
continue
out[field.name] = _json_dataclass_to_dict(getattr(obj, field.name))
# Add properties
for k in dir(obj):
if isinstance(getattr(type(obj), k, None), (property, _DeprecatedProperty)):
assert k != '_type'
if k.startswith('_'):
continue
out[k] = _json_dataclass_to_dict(getattr(obj, k))
return out
elif isinstance(obj, (tuple, list)):
return type(obj)(_json_dataclass_to_dict(x) for x in obj)
elif isinstance(obj, dict):
return {_json_dataclass_to_dict(k): _json_dataclass_to_dict(v) for k, v in obj.items()}
elif isinstance(obj, set):
return {_json_dataclass_to_dict(v) for v in obj}
else:
return copy.deepcopy(obj) | null |
173,790 | import abc
import copy
import dataclasses
import datetime
import functools
import json
import logging
import requests
import requests.adapters
import urllib3.connection
import time
import warnings
def nonempty_string(name):
def f(s):
s = s.strip()
if s:
return s
raise ValueError('must not be an empty string')
f.__name__ = name
return f | null |
173,791 | class Indent:
def __init__(self, instance, line):
self.instance = instance
self.line = line
def __enter__(self):
self.instance._indent += 1
def __exit__(self, type_, value, traceback):
self.instance._indent -= 1
self.instance._indent_last_line = self.line
The provided code snippet includes necessary dependencies for implementing the `indent` function. Write a Python function `def indent(func)` to solve the following problem:
Decorator for allowing to use method as normal method or with context manager for auto-indenting code blocks.
Here is the function:
def indent(func):
"""
Decorator for allowing to use method as normal method or with
context manager for auto-indenting code blocks.
"""
def wrapper(self, line, *args, optimize=True, **kwds):
last_line = self._indent_last_line
line = func(self, line, *args, **kwds)
# When two blocks have the same condition (such as value has to be dict),
# do the check only once and keep it under one block.
if optimize and last_line == line:
self._code.pop()
self._indent_last_line = line
return Indent(self, line)
return wrapper | Decorator for allowing to use method as normal method or with context manager for auto-indenting code blocks. |
173,792 | from collections import OrderedDict
import re
from .exceptions import JsonSchemaValueException, JsonSchemaDefinitionException
from .indent import indent
from .ref_resolver import RefResolver
def enforce_list(variable):
if isinstance(variable, list):
return variable
return [variable] | null |
173,793 | from collections import OrderedDict
import re
from .exceptions import JsonSchemaValueException, JsonSchemaDefinitionException
from .indent import indent
from .ref_resolver import RefResolver
def repr_regex(regex):
all_flags = ("A", "I", "DEBUG", "L", "M", "S", "X")
flags = " | ".join(f"re.{f}" for f in all_flags if regex.flags & getattr(re, f))
flags = ", " + flags if flags else ""
return "re.compile({!r}{})".format(regex.pattern, flags)
def serialize_regexes(patterns_dict):
# Unfortunately using `pprint.pformat` is causing errors
# specially with big regexes
regex_patterns = (
repr(k) + ": " + repr_regex(v)
for k, v in patterns_dict.items()
)
return '{\n ' + ",\n ".join(regex_patterns) + "\n}" | null |
173,794 | import contextlib
import json
import re
from urllib import parse as urlparse
from urllib.parse import unquote
from urllib.request import urlopen
from .exceptions import JsonSchemaDefinitionException
The provided code snippet includes necessary dependencies for implementing the `get_id` function. Write a Python function `def get_id(schema)` to solve the following problem:
Originally ID was `id` and since v7 it's `$id`.
Here is the function:
def get_id(schema):
"""
Originally ID was `id` and since v7 it's `$id`.
"""
return schema.get('$id', schema.get('id', '')) | Originally ID was `id` and since v7 it's `$id`. |
173,795 | import contextlib
import json
import re
from urllib import parse as urlparse
from urllib.parse import unquote
from urllib.request import urlopen
from .exceptions import JsonSchemaDefinitionException
class JsonSchemaDefinitionException(JsonSchemaException):
"""
Exception raised by generator of validation function.
"""
The provided code snippet includes necessary dependencies for implementing the `resolve_path` function. Write a Python function `def resolve_path(schema, fragment)` to solve the following problem:
Return definition from path. Path is unescaped according https://tools.ietf.org/html/rfc6901
Here is the function:
def resolve_path(schema, fragment):
"""
Return definition from path.
Path is unescaped according https://tools.ietf.org/html/rfc6901
"""
fragment = fragment.lstrip('/')
parts = unquote(fragment).split('/') if fragment else []
for part in parts:
part = part.replace('~1', '/').replace('~0', '~')
if isinstance(schema, list):
schema = schema[int(part)]
elif part in schema:
schema = schema[part]
else:
raise JsonSchemaDefinitionException('Unresolvable ref: {}'.format(part))
return schema | Return definition from path. Path is unescaped according https://tools.ietf.org/html/rfc6901 |
173,796 | import contextlib
import json
import re
from urllib import parse as urlparse
from urllib.parse import unquote
from urllib.request import urlopen
from .exceptions import JsonSchemaDefinitionException
def normalize(uri):
return urlparse.urlsplit(uri).geturl() | null |
173,797 | import contextlib
import json
import re
from urllib import parse as urlparse
from urllib.parse import unquote
from urllib.request import urlopen
from .exceptions import JsonSchemaDefinitionException
class JsonSchemaDefinitionException(JsonSchemaException):
"""
Exception raised by generator of validation function.
"""
The provided code snippet includes necessary dependencies for implementing the `resolve_remote` function. Write a Python function `def resolve_remote(uri, handlers)` to solve the following problem:
Resolve a remote ``uri``. .. note:: urllib library is used to fetch requests from the remote ``uri`` if handlers does notdefine otherwise.
Here is the function:
def resolve_remote(uri, handlers):
"""
Resolve a remote ``uri``.
.. note::
urllib library is used to fetch requests from the remote ``uri``
if handlers does notdefine otherwise.
"""
scheme = urlparse.urlsplit(uri).scheme
if scheme in handlers:
result = handlers[scheme](uri)
else:
req = urlopen(uri)
encoding = req.info().get_content_charset() or 'utf-8'
try:
result = json.loads(req.read().decode(encoding),)
except ValueError as exc:
raise JsonSchemaDefinitionException('{} failed to decode: {}'.format(uri, exc))
return result | Resolve a remote ``uri``. .. note:: urllib library is used to fetch requests from the remote ``uri`` if handlers does notdefine otherwise. |
173,798 | import re
from .parser import _next_significant, _to_token_iterator
def parse_b(tokens, a):
token = _next_significant(tokens)
if token is None:
return (a, 0)
elif token == '+':
return parse_signless_b(tokens, a, 1)
elif token == '-':
return parse_signless_b(tokens, a, -1)
elif (token.type == 'number' and token.is_integer and
token.representation[0] in '-+'):
return parse_end(tokens, a, token.int_value)
def parse_signless_b(tokens, a, b_sign):
token = _next_significant(tokens)
if (token.type == 'number' and token.is_integer and
not token.representation[0] in '-+'):
return parse_end(tokens, a, b_sign * token.int_value)
def parse_end(tokens, a, b):
if _next_significant(tokens) is None:
return (a, b)
N_DASH_DIGITS_RE = re.compile('^n(-[0-9]+)$')
def _to_token_iterator(input, skip_comments=False):
"""Iterate component values out of string or component values iterable.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments: If the input is a string, ignore all CSS comments.
:returns: An iterator yielding :term:`component values`.
"""
# Accept ASCII-only byte strings on Python 2, with implicit conversion.
if isinstance(input, str):
input = parse_component_value_list(input, skip_comments)
return iter(input)
def _next_significant(tokens):
"""Return the next significant (neither whitespace or comment) token.
:type tokens: :term:`iterator`
:param tokens: An iterator yielding :term:`component values`.
:returns: A :term:`component value`, or :obj:`None`.
"""
for token in tokens:
if token.type not in ('whitespace', 'comment'):
return token
The provided code snippet includes necessary dependencies for implementing the `parse_nth` function. Write a Python function `def parse_nth(input)` to solve the following problem:
Parse `<An+B> <https://drafts.csswg.org/css-syntax-3/#anb>`_, as found in `:nth-child() <https://drafts.csswg.org/selectors/#nth-child-pseudo>`_ and related Selector pseudo-classes. Although tinycss2 does not include a full Selector parser, this bit of syntax is included as it is particularly tricky to define on top of a CSS tokenizer. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :returns: A ``(a, b)`` tuple of integers, or :obj:`None` if the input is invalid.
Here is the function:
def parse_nth(input):
"""Parse `<An+B> <https://drafts.csswg.org/css-syntax-3/#anb>`_,
as found in `:nth-child()
<https://drafts.csswg.org/selectors/#nth-child-pseudo>`_
and related Selector pseudo-classes.
Although tinycss2 does not include a full Selector parser,
this bit of syntax is included as it is particularly tricky to define
on top of a CSS tokenizer.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:returns:
A ``(a, b)`` tuple of integers, or :obj:`None` if the input is invalid.
"""
tokens = _to_token_iterator(input, skip_comments=True)
token = _next_significant(tokens)
if token is None:
return
token_type = token.type
if token_type == 'number' and token.is_integer:
return parse_end(tokens, 0, token.int_value)
elif token_type == 'dimension' and token.is_integer:
unit = token.lower_unit
if unit == 'n':
return parse_b(tokens, token.int_value)
elif unit == 'n-':
return parse_signless_b(tokens, token.int_value, -1)
else:
match = N_DASH_DIGITS_RE.match(unit)
if match:
return parse_end(tokens, token.int_value, int(match.group(1)))
elif token_type == 'ident':
ident = token.lower_value
if ident == 'even':
return parse_end(tokens, 2, 0)
elif ident == 'odd':
return parse_end(tokens, 2, 1)
elif ident == 'n':
return parse_b(tokens, 1)
elif ident == '-n':
return parse_b(tokens, -1)
elif ident == 'n-':
return parse_signless_b(tokens, 1, -1)
elif ident == '-n-':
return parse_signless_b(tokens, -1, -1)
elif ident[0] == '-':
match = N_DASH_DIGITS_RE.match(ident[1:])
if match:
return parse_end(tokens, -1, int(match.group(1)))
else:
match = N_DASH_DIGITS_RE.match(ident)
if match:
return parse_end(tokens, 1, int(match.group(1)))
elif token == '+':
token = next(tokens) # Whitespace after an initial '+' is invalid.
if token.type == 'ident':
ident = token.lower_value
if ident == 'n':
return parse_b(tokens, 1)
elif ident == 'n-':
return parse_signless_b(tokens, 1, -1)
else:
match = N_DASH_DIGITS_RE.match(ident)
if match:
return parse_end(tokens, 1, int(match.group(1))) | Parse `<An+B> <https://drafts.csswg.org/css-syntax-3/#anb>`_, as found in `:nth-child() <https://drafts.csswg.org/selectors/#nth-child-pseudo>`_ and related Selector pseudo-classes. Although tinycss2 does not include a full Selector parser, this bit of syntax is included as it is particularly tricky to define on top of a CSS tokenizer. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :returns: A ``(a, b)`` tuple of integers, or :obj:`None` if the input is invalid. |
173,799 | from .ast import AtRule, Declaration, ParseError, QualifiedRule
from .tokenizer import parse_component_value_list
def _to_token_iterator(input, skip_comments=False):
"""Iterate component values out of string or component values iterable.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments: If the input is a string, ignore all CSS comments.
:returns: An iterator yielding :term:`component values`.
"""
# Accept ASCII-only byte strings on Python 2, with implicit conversion.
if isinstance(input, str):
input = parse_component_value_list(input, skip_comments)
return iter(input)
def _next_significant(tokens):
"""Return the next significant (neither whitespace or comment) token.
:type tokens: :term:`iterator`
:param tokens: An iterator yielding :term:`component values`.
:returns: A :term:`component value`, or :obj:`None`.
"""
for token in tokens:
if token.type not in ('whitespace', 'comment'):
return token
def _parse_declaration(first_token, tokens):
"""Parse a declaration.
Consume :obj:`tokens` until the end of the declaration or the first error.
:type first_token: :term:`component value`
:param first_token: The first component value of the rule.
:type tokens: :term:`iterator`
:param tokens: An iterator yielding :term:`component values`.
:returns:
A :class:`~tinycss2.ast.Declaration`
or :class:`~tinycss2.ast.ParseError`.
"""
name = first_token
if name.type != 'ident':
return ParseError(name.source_line, name.source_column, 'invalid',
'Expected <ident> for declaration name, got %s.'
% name.type)
colon = _next_significant(tokens)
if colon is None:
return ParseError(name.source_line, name.source_column, 'invalid',
"Expected ':' after declaration name, got EOF")
elif colon != ':':
return ParseError(colon.source_line, colon.source_column, 'invalid',
"Expected ':' after declaration name, got %s."
% colon.type)
value = []
state = 'value'
for i, token in enumerate(tokens):
if state == 'value' and token == '!':
state = 'bang'
bang_position = i
elif state == 'bang' and token.type == 'ident' \
and token.lower_value == 'important':
state = 'important'
elif token.type not in ('whitespace', 'comment'):
state = 'value'
value.append(token)
if state == 'important':
del value[bang_position:]
return Declaration(name.source_line, name.source_column, name.value,
name.lower_value, value, state == 'important')
class ParseError(Node):
"""A syntax error of some sort. May occur anywhere in the tree.
Syntax errors are not fatal in the parser
to allow for different error handling behaviors.
For example, an error in a Selector list makes the whole rule invalid,
but an error in a Media Query list only replaces one comma-separated query
with ``not all``.
.. autoattribute:: type
.. attribute:: kind
Machine-readable string indicating the type of error.
Example: ``'bad-url'``.
.. attribute:: message
Human-readable explanation of the error, as a string.
Could be translated, expanded to include details, etc.
"""
__slots__ = ['kind', 'message']
type = 'error'
repr_format = '<{self.__class__.__name__} {self.kind}>'
def __init__(self, line, column, kind, message):
Node.__init__(self, line, column)
self.kind = kind
self.message = message
def _serialize_to(self, write):
if self.kind == 'bad-string':
write('"[bad string]\n')
elif self.kind == 'bad-url':
write('url([bad url])')
elif self.kind in ')]}':
write(self.kind)
elif self.kind in ('eof-in-string', 'eof-in-url'):
pass
else: # pragma: no cover
raise TypeError('Can not serialize %r' % self)
The provided code snippet includes necessary dependencies for implementing the `parse_one_declaration` function. Write a Python function `def parse_one_declaration(input, skip_comments=False)` to solve the following problem:
Parse a single :diagram:`declaration`. This is used e.g. for a declaration in an `@supports <https://drafts.csswg.org/css-conditional/#at-supports>`_ test. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: If the input is a string, ignore all CSS comments. :returns: A :class:`~tinycss2.ast.Declaration` or :class:`~tinycss2.ast.ParseError`. Any whitespace or comment before the ``:`` colon is dropped.
Here is the function:
def parse_one_declaration(input, skip_comments=False):
"""Parse a single :diagram:`declaration`.
This is used e.g. for a declaration in an `@supports
<https://drafts.csswg.org/css-conditional/#at-supports>`_ test.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments: If the input is a string, ignore all CSS comments.
:returns:
A :class:`~tinycss2.ast.Declaration`
or :class:`~tinycss2.ast.ParseError`.
Any whitespace or comment before the ``:`` colon is dropped.
"""
tokens = _to_token_iterator(input, skip_comments)
first_token = _next_significant(tokens)
if first_token is None:
return ParseError(1, 1, 'empty', 'Input is empty')
return _parse_declaration(first_token, tokens) | Parse a single :diagram:`declaration`. This is used e.g. for a declaration in an `@supports <https://drafts.csswg.org/css-conditional/#at-supports>`_ test. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: If the input is a string, ignore all CSS comments. :returns: A :class:`~tinycss2.ast.Declaration` or :class:`~tinycss2.ast.ParseError`. Any whitespace or comment before the ``:`` colon is dropped. |
173,800 | from .ast import AtRule, Declaration, ParseError, QualifiedRule
from .tokenizer import parse_component_value_list
def _to_token_iterator(input, skip_comments=False):
"""Iterate component values out of string or component values iterable.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments: If the input is a string, ignore all CSS comments.
:returns: An iterator yielding :term:`component values`.
"""
# Accept ASCII-only byte strings on Python 2, with implicit conversion.
if isinstance(input, str):
input = parse_component_value_list(input, skip_comments)
return iter(input)
def _consume_declaration_in_list(first_token, tokens):
"""Like :func:`_parse_declaration`, but stop at the first ``;``."""
other_declaration_tokens = []
for token in tokens:
if token == ';':
break
other_declaration_tokens.append(token)
return _parse_declaration(first_token, iter(other_declaration_tokens))
def _consume_at_rule(at_keyword, tokens):
"""Parse an at-rule.
Consume just enough of :obj:`tokens` for this rule.
:type at_keyword: :class:`AtKeywordToken`
:param at_keyword: The at-rule keyword token starting this rule.
:type tokens: :term:`iterator`
:param tokens: An iterator yielding :term:`component values`.
:returns:
A :class:`~tinycss2.ast.QualifiedRule`,
or :class:`~tinycss2.ast.ParseError`.
"""
prelude = []
content = None
for token in tokens:
if token.type == '{} block':
content = token.content
break
elif token == ';':
break
prelude.append(token)
return AtRule(at_keyword.source_line, at_keyword.source_column,
at_keyword.value, at_keyword.lower_value, prelude, content)
The provided code snippet includes necessary dependencies for implementing the `parse_declaration_list` function. Write a Python function `def parse_declaration_list(input, skip_comments=False, skip_whitespace=False)` to solve the following problem:
Parse a :diagram:`declaration list` (which may also contain at-rules). This is used e.g. for the :attr:`~tinycss2.ast.QualifiedRule.content` of a style rule or ``@page`` rule, or for the ``style`` attribute of an HTML element. In contexts that don’t expect any at-rule, all :class:`~tinycss2.ast.AtRule` objects should simply be rejected as invalid. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: Ignore CSS comments at the top-level of the list. If the input is a string, ignore all comments. :type skip_whitespace: :obj:`bool` :param skip_whitespace: Ignore whitespace at the top-level of the list. Whitespace is still preserved in the :attr:`~tinycss2.ast.Declaration.value` of declarations and the :attr:`~tinycss2.ast.AtRule.prelude` and :attr:`~tinycss2.ast.AtRule.content` of at-rules. :returns: A list of :class:`~tinycss2.ast.Declaration`, :class:`~tinycss2.ast.AtRule`, :class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false), :class:`~tinycss2.ast.WhitespaceToken` (if ``skip_whitespace`` is false), and :class:`~tinycss2.ast.ParseError` objects
Here is the function:
def parse_declaration_list(input, skip_comments=False, skip_whitespace=False):
"""Parse a :diagram:`declaration list` (which may also contain at-rules).
This is used e.g. for the :attr:`~tinycss2.ast.QualifiedRule.content`
of a style rule or ``@page`` rule,
or for the ``style`` attribute of an HTML element.
In contexts that don’t expect any at-rule,
all :class:`~tinycss2.ast.AtRule` objects
should simply be rejected as invalid.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments:
Ignore CSS comments at the top-level of the list.
If the input is a string, ignore all comments.
:type skip_whitespace: :obj:`bool`
:param skip_whitespace:
Ignore whitespace at the top-level of the list.
Whitespace is still preserved
in the :attr:`~tinycss2.ast.Declaration.value` of declarations
and the :attr:`~tinycss2.ast.AtRule.prelude`
and :attr:`~tinycss2.ast.AtRule.content` of at-rules.
:returns:
A list of
:class:`~tinycss2.ast.Declaration`,
:class:`~tinycss2.ast.AtRule`,
:class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false),
:class:`~tinycss2.ast.WhitespaceToken`
(if ``skip_whitespace`` is false),
and :class:`~tinycss2.ast.ParseError` objects
"""
tokens = _to_token_iterator(input, skip_comments)
result = []
for token in tokens:
if token.type == 'whitespace':
if not skip_whitespace:
result.append(token)
elif token.type == 'comment':
if not skip_comments:
result.append(token)
elif token.type == 'at-keyword':
result.append(_consume_at_rule(token, tokens))
elif token != ';':
result.append(_consume_declaration_in_list(token, tokens))
return result | Parse a :diagram:`declaration list` (which may also contain at-rules). This is used e.g. for the :attr:`~tinycss2.ast.QualifiedRule.content` of a style rule or ``@page`` rule, or for the ``style`` attribute of an HTML element. In contexts that don’t expect any at-rule, all :class:`~tinycss2.ast.AtRule` objects should simply be rejected as invalid. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: Ignore CSS comments at the top-level of the list. If the input is a string, ignore all comments. :type skip_whitespace: :obj:`bool` :param skip_whitespace: Ignore whitespace at the top-level of the list. Whitespace is still preserved in the :attr:`~tinycss2.ast.Declaration.value` of declarations and the :attr:`~tinycss2.ast.AtRule.prelude` and :attr:`~tinycss2.ast.AtRule.content` of at-rules. :returns: A list of :class:`~tinycss2.ast.Declaration`, :class:`~tinycss2.ast.AtRule`, :class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false), :class:`~tinycss2.ast.WhitespaceToken` (if ``skip_whitespace`` is false), and :class:`~tinycss2.ast.ParseError` objects |
173,801 | from .ast import AtRule, Declaration, ParseError, QualifiedRule
from .tokenizer import parse_component_value_list
def _to_token_iterator(input, skip_comments=False):
"""Iterate component values out of string or component values iterable.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments: If the input is a string, ignore all CSS comments.
:returns: An iterator yielding :term:`component values`.
"""
# Accept ASCII-only byte strings on Python 2, with implicit conversion.
if isinstance(input, str):
input = parse_component_value_list(input, skip_comments)
return iter(input)
def _next_significant(tokens):
"""Return the next significant (neither whitespace or comment) token.
:type tokens: :term:`iterator`
:param tokens: An iterator yielding :term:`component values`.
:returns: A :term:`component value`, or :obj:`None`.
"""
for token in tokens:
if token.type not in ('whitespace', 'comment'):
return token
def _consume_rule(first_token, tokens):
"""Parse a qualified rule or at-rule.
Consume just enough of :obj:`tokens` for this rule.
:type first_token: :term:`component value`
:param first_token: The first component value of the rule.
:type tokens: :term:`iterator`
:param tokens: An iterator yielding :term:`component values`.
:returns:
A :class:`~tinycss2.ast.QualifiedRule`,
:class:`~tinycss2.ast.AtRule`,
or :class:`~tinycss2.ast.ParseError`.
"""
if first_token.type == 'at-keyword':
return _consume_at_rule(first_token, tokens)
if first_token.type == '{} block':
prelude = []
block = first_token
else:
prelude = [first_token]
for token in tokens:
if token.type == '{} block':
block = token
break
prelude.append(token)
else:
return ParseError(
prelude[-1].source_line, prelude[-1].source_column, 'invalid',
'EOF reached before {} block for a qualified rule.')
return QualifiedRule(first_token.source_line, first_token.source_column,
prelude, block.content)
class ParseError(Node):
"""A syntax error of some sort. May occur anywhere in the tree.
Syntax errors are not fatal in the parser
to allow for different error handling behaviors.
For example, an error in a Selector list makes the whole rule invalid,
but an error in a Media Query list only replaces one comma-separated query
with ``not all``.
.. autoattribute:: type
.. attribute:: kind
Machine-readable string indicating the type of error.
Example: ``'bad-url'``.
.. attribute:: message
Human-readable explanation of the error, as a string.
Could be translated, expanded to include details, etc.
"""
__slots__ = ['kind', 'message']
type = 'error'
repr_format = '<{self.__class__.__name__} {self.kind}>'
def __init__(self, line, column, kind, message):
Node.__init__(self, line, column)
self.kind = kind
self.message = message
def _serialize_to(self, write):
if self.kind == 'bad-string':
write('"[bad string]\n')
elif self.kind == 'bad-url':
write('url([bad url])')
elif self.kind in ')]}':
write(self.kind)
elif self.kind in ('eof-in-string', 'eof-in-url'):
pass
else: # pragma: no cover
raise TypeError('Can not serialize %r' % self)
The provided code snippet includes necessary dependencies for implementing the `parse_one_rule` function. Write a Python function `def parse_one_rule(input, skip_comments=False)` to solve the following problem:
Parse a single :diagram:`qualified rule` or :diagram:`at-rule`. This would be used e.g. by `insertRule() <https://drafts.csswg.org/cssom/#dom-cssstylesheet-insertrule>`_ in an implementation of CSSOM. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: If the input is a string, ignore all CSS comments. :returns: A :class:`~tinycss2.ast.QualifiedRule`, :class:`~tinycss2.ast.AtRule`, or :class:`~tinycss2.ast.ParseError` objects. Any whitespace or comment before or after the rule is dropped.
Here is the function:
def parse_one_rule(input, skip_comments=False):
"""Parse a single :diagram:`qualified rule` or :diagram:`at-rule`.
This would be used e.g. by `insertRule()
<https://drafts.csswg.org/cssom/#dom-cssstylesheet-insertrule>`_
in an implementation of CSSOM.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments:
If the input is a string, ignore all CSS comments.
:returns:
A :class:`~tinycss2.ast.QualifiedRule`,
:class:`~tinycss2.ast.AtRule`,
or :class:`~tinycss2.ast.ParseError` objects.
Any whitespace or comment before or after the rule is dropped.
"""
tokens = _to_token_iterator(input, skip_comments)
first = _next_significant(tokens)
if first is None:
return ParseError(1, 1, 'empty', 'Input is empty')
rule = _consume_rule(first, tokens)
next = _next_significant(tokens)
if next is not None:
return ParseError(
next.source_line, next.source_column, 'extra-input',
'Expected a single rule, got %s after the first rule.' % next.type)
return rule | Parse a single :diagram:`qualified rule` or :diagram:`at-rule`. This would be used e.g. by `insertRule() <https://drafts.csswg.org/cssom/#dom-cssstylesheet-insertrule>`_ in an implementation of CSSOM. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: If the input is a string, ignore all CSS comments. :returns: A :class:`~tinycss2.ast.QualifiedRule`, :class:`~tinycss2.ast.AtRule`, or :class:`~tinycss2.ast.ParseError` objects. Any whitespace or comment before or after the rule is dropped. |
173,802 | from .ast import AtRule, Declaration, ParseError, QualifiedRule
from .tokenizer import parse_component_value_list
def _to_token_iterator(input, skip_comments=False):
"""Iterate component values out of string or component values iterable.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments: If the input is a string, ignore all CSS comments.
:returns: An iterator yielding :term:`component values`.
"""
# Accept ASCII-only byte strings on Python 2, with implicit conversion.
if isinstance(input, str):
input = parse_component_value_list(input, skip_comments)
return iter(input)
def _consume_rule(first_token, tokens):
"""Parse a qualified rule or at-rule.
Consume just enough of :obj:`tokens` for this rule.
:type first_token: :term:`component value`
:param first_token: The first component value of the rule.
:type tokens: :term:`iterator`
:param tokens: An iterator yielding :term:`component values`.
:returns:
A :class:`~tinycss2.ast.QualifiedRule`,
:class:`~tinycss2.ast.AtRule`,
or :class:`~tinycss2.ast.ParseError`.
"""
if first_token.type == 'at-keyword':
return _consume_at_rule(first_token, tokens)
if first_token.type == '{} block':
prelude = []
block = first_token
else:
prelude = [first_token]
for token in tokens:
if token.type == '{} block':
block = token
break
prelude.append(token)
else:
return ParseError(
prelude[-1].source_line, prelude[-1].source_column, 'invalid',
'EOF reached before {} block for a qualified rule.')
return QualifiedRule(first_token.source_line, first_token.source_column,
prelude, block.content)
The provided code snippet includes necessary dependencies for implementing the `parse_rule_list` function. Write a Python function `def parse_rule_list(input, skip_comments=False, skip_whitespace=False)` to solve the following problem:
Parse a non-top-level :diagram:`rule list`. This is used for parsing the :attr:`~tinycss2.ast.AtRule.content` of nested rules like ``@media``. This differs from :func:`parse_stylesheet` in that top-level ``<!--`` and ``-->`` tokens are not ignored. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: Ignore CSS comments at the top-level of the list. If the input is a string, ignore all comments. :type skip_whitespace: :obj:`bool` :param skip_whitespace: Ignore whitespace at the top-level of the list. Whitespace is still preserved in the :attr:`~tinycss2.ast.QualifiedRule.prelude` and the :attr:`~tinycss2.ast.QualifiedRule.content` of rules. :returns: A list of :class:`~tinycss2.ast.QualifiedRule`, :class:`~tinycss2.ast.AtRule`, :class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false), :class:`~tinycss2.ast.WhitespaceToken` (if ``skip_whitespace`` is false), and :class:`~tinycss2.ast.ParseError` objects.
Here is the function:
def parse_rule_list(input, skip_comments=False, skip_whitespace=False):
"""Parse a non-top-level :diagram:`rule list`.
This is used for parsing the :attr:`~tinycss2.ast.AtRule.content`
of nested rules like ``@media``.
This differs from :func:`parse_stylesheet` in that
top-level ``<!--`` and ``-->`` tokens are not ignored.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments:
Ignore CSS comments at the top-level of the list.
If the input is a string, ignore all comments.
:type skip_whitespace: :obj:`bool`
:param skip_whitespace:
Ignore whitespace at the top-level of the list.
Whitespace is still preserved
in the :attr:`~tinycss2.ast.QualifiedRule.prelude`
and the :attr:`~tinycss2.ast.QualifiedRule.content` of rules.
:returns:
A list of
:class:`~tinycss2.ast.QualifiedRule`,
:class:`~tinycss2.ast.AtRule`,
:class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false),
:class:`~tinycss2.ast.WhitespaceToken`
(if ``skip_whitespace`` is false),
and :class:`~tinycss2.ast.ParseError` objects.
"""
tokens = _to_token_iterator(input, skip_comments)
result = []
for token in tokens:
if token.type == 'whitespace':
if not skip_whitespace:
result.append(token)
elif token.type == 'comment':
if not skip_comments:
result.append(token)
else:
result.append(_consume_rule(token, tokens))
return result | Parse a non-top-level :diagram:`rule list`. This is used for parsing the :attr:`~tinycss2.ast.AtRule.content` of nested rules like ``@media``. This differs from :func:`parse_stylesheet` in that top-level ``<!--`` and ``-->`` tokens are not ignored. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :type skip_comments: :obj:`bool` :param skip_comments: Ignore CSS comments at the top-level of the list. If the input is a string, ignore all comments. :type skip_whitespace: :obj:`bool` :param skip_whitespace: Ignore whitespace at the top-level of the list. Whitespace is still preserved in the :attr:`~tinycss2.ast.QualifiedRule.prelude` and the :attr:`~tinycss2.ast.QualifiedRule.content` of rules. :returns: A list of :class:`~tinycss2.ast.QualifiedRule`, :class:`~tinycss2.ast.AtRule`, :class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false), :class:`~tinycss2.ast.WhitespaceToken` (if ``skip_whitespace`` is false), and :class:`~tinycss2.ast.ParseError` objects. |
173,803 | from webencodings import UTF8, decode, lookup
from .parser import parse_stylesheet
def decode_stylesheet_bytes(css_bytes, protocol_encoding=None,
environment_encoding=None):
"""Determine the character encoding of a CSS stylesheet and decode it.
This is based on the presence of a :abbr:`BOM (Byte Order Mark)`,
a ``@charset`` rule, and encoding meta-information.
:type css_bytes: :obj:`bytes`
:param css_bytes: A CSS byte string.
:type protocol_encoding: :obj:`str`
:param protocol_encoding:
The encoding label, if any, defined by HTTP or equivalent protocol.
(e.g. via the ``charset`` parameter of the ``Content-Type`` header.)
:type environment_encoding: :class:`webencodings.Encoding`
:param environment_encoding:
The `environment encoding
<https://www.w3.org/TR/css-syntax/#environment-encoding>`_, if any.
:returns:
A 2-tuple of a decoded Unicode string and the
:class:`webencodings.Encoding` object that was used.
"""
# https://drafts.csswg.org/css-syntax/#the-input-byte-stream
if protocol_encoding:
fallback = lookup(protocol_encoding)
if fallback:
return decode(css_bytes, fallback)
if css_bytes.startswith(b'@charset "'):
# 10 is len(b'@charset "')
# 100 is arbitrary so that no encoding label is more than 100-10 bytes.
end_quote = css_bytes.find(b'"', 10, 100)
if end_quote != -1 and css_bytes.startswith(b'";', end_quote):
fallback = lookup(css_bytes[10:end_quote].decode('latin1'))
if fallback:
if fallback.name in ('utf-16be', 'utf-16le'):
return decode(css_bytes, UTF8)
return decode(css_bytes, fallback)
if environment_encoding:
return decode(css_bytes, environment_encoding)
return decode(css_bytes, UTF8)
def parse_stylesheet(input, skip_comments=False, skip_whitespace=False):
"""Parse :diagram:`stylesheet` from text.
This is used e.g. for a ``<style>`` HTML element.
This differs from :func:`parse_rule_list` in that
top-level ``<!--`` and ``-->`` tokens are ignored.
This is a legacy quirk for the ``<style>`` HTML element.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments:
Ignore CSS comments at the top-level of the stylesheet.
If the input is a string, ignore all comments.
:type skip_whitespace: :obj:`bool`
:param skip_whitespace:
Ignore whitespace at the top-level of the stylesheet.
Whitespace is still preserved
in the :attr:`~tinycss2.ast.QualifiedRule.prelude`
and the :attr:`~tinycss2.ast.QualifiedRule.content` of rules.
:returns:
A list of
:class:`~tinycss2.ast.QualifiedRule`,
:class:`~tinycss2.ast.AtRule`,
:class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false),
:class:`~tinycss2.ast.WhitespaceToken`
(if ``skip_whitespace`` is false),
and :class:`~tinycss2.ast.ParseError` objects.
"""
tokens = _to_token_iterator(input, skip_comments)
result = []
for token in tokens:
if token.type == 'whitespace':
if not skip_whitespace:
result.append(token)
elif token.type == 'comment':
if not skip_comments:
result.append(token)
elif token not in ('<!--', '-->'):
result.append(_consume_rule(token, tokens))
return result
The provided code snippet includes necessary dependencies for implementing the `parse_stylesheet_bytes` function. Write a Python function `def parse_stylesheet_bytes(css_bytes, protocol_encoding=None, environment_encoding=None, skip_comments=False, skip_whitespace=False)` to solve the following problem:
Parse :diagram:`stylesheet` from bytes, determining the character encoding as web browsers do. This is used when reading a file or fetching a URL. The character encoding is determined from the initial bytes (a :abbr:`BOM (Byte Order Mark)` or a ``@charset`` rule) as well as the parameters. The ultimate fallback is UTF-8. :type css_bytes: :obj:`bytes` :param css_bytes: A CSS byte string. :type protocol_encoding: :obj:`str` :param protocol_encoding: The encoding label, if any, defined by HTTP or equivalent protocol. (e.g. via the ``charset`` parameter of the ``Content-Type`` header.) :type environment_encoding: :class:`webencodings.Encoding` :param environment_encoding: The `environment encoding`_, if any. :type skip_comments: :obj:`bool` :param skip_comments: Ignore CSS comments at the top-level of the stylesheet. If the input is a string, ignore all comments. :type skip_whitespace: :obj:`bool` :param skip_whitespace: Ignore whitespace at the top-level of the stylesheet. Whitespace is still preserved in the :attr:`~tinycss2.ast.QualifiedRule.prelude` and the :attr:`~tinycss2.ast.QualifiedRule.content` of rules. :returns: A ``(rules, encoding)`` tuple. * ``rules`` is a list of :class:`~tinycss2.ast.QualifiedRule`, :class:`~tinycss2.ast.AtRule`, :class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false), :class:`~tinycss2.ast.WhitespaceToken` (if ``skip_whitespace`` is false), and :class:`~tinycss2.ast.ParseError` objects. * ``encoding`` is the :class:`webencodings.Encoding` object that was used. If ``rules`` contains an ``@import`` rule, this is the `environment encoding`_ for the imported stylesheet. .. _environment encoding: https://www.w3.org/TR/css-syntax/#environment-encoding .. code-block:: python response = urlopen('http://example.net/foo.css') rules, encoding = parse_stylesheet_bytes( css_bytes=response.read(), # Python 3.x protocol_encoding=response.info().get_content_type().get_param('charset'), # Python 2.x protocol_encoding=response.info().gettype().getparam('charset'), ) for rule in rules: ...
Here is the function:
def parse_stylesheet_bytes(css_bytes, protocol_encoding=None,
environment_encoding=None,
skip_comments=False, skip_whitespace=False):
"""Parse :diagram:`stylesheet` from bytes,
determining the character encoding as web browsers do.
This is used when reading a file or fetching a URL.
The character encoding is determined from the initial bytes
(a :abbr:`BOM (Byte Order Mark)` or a ``@charset`` rule)
as well as the parameters. The ultimate fallback is UTF-8.
:type css_bytes: :obj:`bytes`
:param css_bytes: A CSS byte string.
:type protocol_encoding: :obj:`str`
:param protocol_encoding:
The encoding label, if any, defined by HTTP or equivalent protocol.
(e.g. via the ``charset`` parameter of the ``Content-Type`` header.)
:type environment_encoding: :class:`webencodings.Encoding`
:param environment_encoding:
The `environment encoding`_, if any.
:type skip_comments: :obj:`bool`
:param skip_comments:
Ignore CSS comments at the top-level of the stylesheet.
If the input is a string, ignore all comments.
:type skip_whitespace: :obj:`bool`
:param skip_whitespace:
Ignore whitespace at the top-level of the stylesheet.
Whitespace is still preserved
in the :attr:`~tinycss2.ast.QualifiedRule.prelude`
and the :attr:`~tinycss2.ast.QualifiedRule.content` of rules.
:returns:
A ``(rules, encoding)`` tuple.
* ``rules`` is a list of
:class:`~tinycss2.ast.QualifiedRule`,
:class:`~tinycss2.ast.AtRule`,
:class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false),
:class:`~tinycss2.ast.WhitespaceToken`
(if ``skip_whitespace`` is false),
and :class:`~tinycss2.ast.ParseError` objects.
* ``encoding`` is the :class:`webencodings.Encoding` object
that was used.
If ``rules`` contains an ``@import`` rule, this is
the `environment encoding`_ for the imported stylesheet.
.. _environment encoding:
https://www.w3.org/TR/css-syntax/#environment-encoding
.. code-block:: python
response = urlopen('http://example.net/foo.css')
rules, encoding = parse_stylesheet_bytes(
css_bytes=response.read(),
# Python 3.x
protocol_encoding=response.info().get_content_type().get_param('charset'),
# Python 2.x
protocol_encoding=response.info().gettype().getparam('charset'),
)
for rule in rules:
...
"""
css_unicode, encoding = decode_stylesheet_bytes(
css_bytes, protocol_encoding, environment_encoding)
stylesheet = parse_stylesheet(css_unicode, skip_comments, skip_whitespace)
return stylesheet, encoding | Parse :diagram:`stylesheet` from bytes, determining the character encoding as web browsers do. This is used when reading a file or fetching a URL. The character encoding is determined from the initial bytes (a :abbr:`BOM (Byte Order Mark)` or a ``@charset`` rule) as well as the parameters. The ultimate fallback is UTF-8. :type css_bytes: :obj:`bytes` :param css_bytes: A CSS byte string. :type protocol_encoding: :obj:`str` :param protocol_encoding: The encoding label, if any, defined by HTTP or equivalent protocol. (e.g. via the ``charset`` parameter of the ``Content-Type`` header.) :type environment_encoding: :class:`webencodings.Encoding` :param environment_encoding: The `environment encoding`_, if any. :type skip_comments: :obj:`bool` :param skip_comments: Ignore CSS comments at the top-level of the stylesheet. If the input is a string, ignore all comments. :type skip_whitespace: :obj:`bool` :param skip_whitespace: Ignore whitespace at the top-level of the stylesheet. Whitespace is still preserved in the :attr:`~tinycss2.ast.QualifiedRule.prelude` and the :attr:`~tinycss2.ast.QualifiedRule.content` of rules. :returns: A ``(rules, encoding)`` tuple. * ``rules`` is a list of :class:`~tinycss2.ast.QualifiedRule`, :class:`~tinycss2.ast.AtRule`, :class:`~tinycss2.ast.Comment` (if ``skip_comments`` is false), :class:`~tinycss2.ast.WhitespaceToken` (if ``skip_whitespace`` is false), and :class:`~tinycss2.ast.ParseError` objects. * ``encoding`` is the :class:`webencodings.Encoding` object that was used. If ``rules`` contains an ``@import`` rule, this is the `environment encoding`_ for the imported stylesheet. .. _environment encoding: https://www.w3.org/TR/css-syntax/#environment-encoding .. code-block:: python response = urlopen('http://example.net/foo.css') rules, encoding = parse_stylesheet_bytes( css_bytes=response.read(), # Python 3.x protocol_encoding=response.info().get_content_type().get_param('charset'), # Python 2.x protocol_encoding=response.info().gettype().getparam('charset'), ) for rule in rules: ... |
173,804 | import collections
import re
from colorsys import hls_to_rgb
from .parser import parse_one_component_value
class RGBA(collections.namedtuple('RGBA', ['red', 'green', 'blue', 'alpha'])):
"""An RGBA color.
A tuple of four floats in the 0..1 range: ``(red, green, blue, alpha)``.
.. attribute:: red
Convenience access to the red channel. Same as ``rgba[0]``.
.. attribute:: green
Convenience access to the green channel. Same as ``rgba[1]``.
.. attribute:: blue
Convenience access to the blue channel. Same as ``rgba[2]``.
.. attribute:: alpha
Convenience access to the alpha channel. Same as ``rgba[3]``.
"""
def _parse_alpha(args):
"""Parse a list of one alpha value.
If args is a list of a single INTEGER or NUMBER token,
return its value clipped to the 0..1 range. Otherwise, return None.
"""
if len(args) == 1 and args[0].type == 'number':
return min(1, max(0, args[0].value))
def _parse_rgb(args, alpha):
"""Parse a list of RGB channels.
If args is a list of 3 INTEGER tokens or 3 PERCENTAGE tokens, return RGB
values as a tuple of 3 floats in 0..1. Otherwise, return None.
"""
types = [arg.type for arg in args]
if (types == ['number', 'number', 'number'] and
all(a.is_integer for a in args)):
r, g, b = [arg.int_value / 255 for arg in args[:3]]
return RGBA(r, g, b, alpha)
elif types == ['percentage', 'percentage', 'percentage']:
r, g, b = [arg.value / 100 for arg in args[:3]]
return RGBA(r, g, b, alpha)
def _parse_hsl(args, alpha):
"""Parse a list of HSL channels.
If args is a list of 1 INTEGER token and 2 PERCENTAGE tokens, return RGB
values as a tuple of 3 floats in 0..1. Otherwise, return None.
"""
types = [arg.type for arg in args]
if types == ['number', 'percentage', 'percentage'] and args[0].is_integer:
r, g, b = hls_to_rgb(
args[0].int_value / 360, args[2].value / 100, args[1].value / 100)
return RGBA(r, g, b, alpha)
def _parse_comma_separated(tokens):
"""Parse a list of tokens (typically the content of a function token)
as arguments made of a single token each, separated by mandatory commas,
with optional white space around each argument.
return the argument list without commas or white space;
or None if the function token content do not match the description above.
"""
tokens = [token for token in tokens
if token.type not in ('whitespace', 'comment')]
if not tokens:
return []
if len(tokens) % 2 == 1 and all(token == ',' for token in tokens[1::2]):
return tokens[::2]
_HASH_REGEXPS = (
(2, re.compile('^{}$'.format(4 * '([\\da-f])'), re.I).match),
(1, re.compile('^{}$'.format(4 * '([\\da-f]{2})'), re.I).match),
(2, re.compile('^{}$'.format(3 * '([\\da-f])'), re.I).match),
(1, re.compile('^{}$'.format(3 * '([\\da-f]{2})'), re.I).match),
)
_COLOR_KEYWORDS = _SPECIAL_COLOR_KEYWORDS.copy()
_COLOR_KEYWORDS.update(
# 255 maps to 1, 0 to 0, the rest is linear.
(keyword, RGBA(r / 255., g / 255., b / 255., 1.))
for keyword, (r, g, b) in _BASIC_COLOR_KEYWORDS + _EXTENDED_COLOR_KEYWORDS)
def parse_one_component_value(input, skip_comments=False):
"""Parse a single :diagram:`component value`.
This is used e.g. for an attribute value
referred to by ``attr(foo length)``.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:type skip_comments: :obj:`bool`
:param skip_comments: If the input is a string, ignore all CSS comments.
:returns:
A :term:`component value` (that is neither whitespace or comment),
or a :class:`~tinycss2.ast.ParseError`.
"""
tokens = _to_token_iterator(input, skip_comments)
first = _next_significant(tokens)
second = _next_significant(tokens)
if first is None:
return ParseError(1, 1, 'empty', 'Input is empty')
if second is not None:
return ParseError(
second.source_line, second.source_column, 'extra-input',
'Got more than one token')
else:
return first
The provided code snippet includes necessary dependencies for implementing the `parse_color` function. Write a Python function `def parse_color(input)` to solve the following problem:
Parse a color value as defined in `CSS Color Level 3 <https://www.w3.org/TR/css-color-3/>`_. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :returns: * :obj:`None` if the input is not a valid color value. (No exception is raised.) * The string ``'currentColor'`` for the ``currentColor`` keyword * Or a :class:`RGBA` object for every other values (including keywords, HSL and HSLA.) The alpha channel is clipped to [0, 1] but red, green, or blue can be out of range (eg. ``rgb(-10%, 120%, 0%)`` is represented as ``(-0.1, 1.2, 0, 1)``.)
Here is the function:
def parse_color(input):
"""Parse a color value as defined in `CSS Color Level 3
<https://www.w3.org/TR/css-color-3/>`_.
:type input: :obj:`str` or :term:`iterable`
:param input: A string or an iterable of :term:`component values`.
:returns:
* :obj:`None` if the input is not a valid color value.
(No exception is raised.)
* The string ``'currentColor'`` for the ``currentColor`` keyword
* Or a :class:`RGBA` object for every other values
(including keywords, HSL and HSLA.)
The alpha channel is clipped to [0, 1]
but red, green, or blue can be out of range
(eg. ``rgb(-10%, 120%, 0%)`` is represented as
``(-0.1, 1.2, 0, 1)``.)
"""
if isinstance(input, str):
token = parse_one_component_value(input, skip_comments=True)
else:
token = input
if token.type == 'ident':
return _COLOR_KEYWORDS.get(token.lower_value)
elif token.type == 'hash':
for multiplier, regexp in _HASH_REGEXPS:
match = regexp(token.value)
if match:
channels = [
int(group * multiplier, 16) / 255
for group in match.groups()]
if len(channels) == 3:
channels.append(1.)
return RGBA(*channels)
elif token.type == 'function':
args = _parse_comma_separated(token.arguments)
if args:
name = token.lower_name
if name == 'rgb':
return _parse_rgb(args, alpha=1.)
elif name == 'rgba':
alpha = _parse_alpha(args[3:])
if alpha is not None:
return _parse_rgb(args[:3], alpha)
elif name == 'hsl':
return _parse_hsl(args, alpha=1.)
elif name == 'hsla':
alpha = _parse_alpha(args[3:])
if alpha is not None:
return _parse_hsl(args[:3], alpha) | Parse a color value as defined in `CSS Color Level 3 <https://www.w3.org/TR/css-color-3/>`_. :type input: :obj:`str` or :term:`iterable` :param input: A string or an iterable of :term:`component values`. :returns: * :obj:`None` if the input is not a valid color value. (No exception is raised.) * The string ``'currentColor'`` for the ``currentColor`` keyword * Or a :class:`RGBA` object for every other values (including keywords, HSL and HSLA.) The alpha channel is clipped to [0, 1] but red, green, or blue can be out of range (eg. ``rgb(-10%, 120%, 0%)`` is represented as ``(-0.1, 1.2, 0, 1)``.) |
173,805 | def _serialize_to(nodes, write):
"""Serialize an iterable of nodes to CSS syntax.
White chunks as a string by calling the provided :obj:`write` callback.
"""
bad_pairs = BAD_PAIRS
previous_type = None
for node in nodes:
serialization_type = (node.type if node.type != 'literal'
else node.value)
if (previous_type, serialization_type) in bad_pairs:
write('/**/')
elif previous_type == '\\' and not (
serialization_type == 'whitespace' and
node.value.startswith('\n')):
write('\n')
node._serialize_to(write)
if serialization_type == 'declaration':
write(';')
previous_type = serialization_type
The provided code snippet includes necessary dependencies for implementing the `serialize` function. Write a Python function `def serialize(nodes)` to solve the following problem:
Serialize nodes to CSS syntax. This should be used for :term:`component values` instead of just :meth:`tinycss2.ast.Node.serialize` on each node as it takes care of corner cases such as ``;`` between declarations, and consecutive identifiers that would otherwise parse back as the same token. :type nodes: :term:`iterable` :param nodes: An iterable of :class:`tinycss2.ast.Node` objects. :returns: A :obj:`string <str>` representing the nodes.
Here is the function:
def serialize(nodes):
"""Serialize nodes to CSS syntax.
This should be used for :term:`component values`
instead of just :meth:`tinycss2.ast.Node.serialize` on each node
as it takes care of corner cases such as ``;`` between declarations,
and consecutive identifiers
that would otherwise parse back as the same token.
:type nodes: :term:`iterable`
:param nodes: An iterable of :class:`tinycss2.ast.Node` objects.
:returns: A :obj:`string <str>` representing the nodes.
"""
chunks = []
_serialize_to(nodes, chunks.append)
return ''.join(chunks) | Serialize nodes to CSS syntax. This should be used for :term:`component values` instead of just :meth:`tinycss2.ast.Node.serialize` on each node as it takes care of corner cases such as ``;`` between declarations, and consecutive identifiers that would otherwise parse back as the same token. :type nodes: :term:`iterable` :param nodes: An iterable of :class:`tinycss2.ast.Node` objects. :returns: A :obj:`string <str>` representing the nodes. |
173,806 | def serialize_name(value):
return ''.join(
c if c in ('abcdefghijklmnopqrstuvwxyz-_0123456789'
'ABCDEFGHIJKLMNOPQRSTUVWXYZ') or ord(c) > 0x7F else
r'\A ' if c == '\n' else
r'\D ' if c == '\r' else
r'\C ' if c == '\f' else
'\\' + c
for c in value
)
The provided code snippet includes necessary dependencies for implementing the `serialize_identifier` function. Write a Python function `def serialize_identifier(value)` to solve the following problem:
Serialize any string as a CSS identifier :type value: :obj:`str` :param value: A string representing a CSS value. :returns: A :obj:`string <str>` that would parse as an :class:`tinycss2.ast.IdentToken` whose :attr:`tinycss2.ast.IdentToken.value` attribute equals the passed ``value`` argument.
Here is the function:
def serialize_identifier(value):
"""Serialize any string as a CSS identifier
:type value: :obj:`str`
:param value: A string representing a CSS value.
:returns:
A :obj:`string <str>` that would parse as an
:class:`tinycss2.ast.IdentToken` whose
:attr:`tinycss2.ast.IdentToken.value` attribute equals the passed
``value`` argument.
"""
if value == '-':
return r'\-'
if value[:2] == '--':
return '--' + serialize_name(value[2:])
if value[0] == '-':
result = '-'
value = value[1:]
else:
result = ''
c = value[0]
result += (
c if c in ('abcdefghijklmnopqrstuvwxyz_'
'ABCDEFGHIJKLMNOPQRSTUVWXYZ') or ord(c) > 0x7F else
r'\A ' if c == '\n' else
r'\D ' if c == '\r' else
r'\C ' if c == '\f' else
'\\%X ' % ord(c) if c in '0123456789' else
'\\' + c
)
result += serialize_name(value[1:])
return result | Serialize any string as a CSS identifier :type value: :obj:`str` :param value: A string representing a CSS value. :returns: A :obj:`string <str>` that would parse as an :class:`tinycss2.ast.IdentToken` whose :attr:`tinycss2.ast.IdentToken.value` attribute equals the passed ``value`` argument. |
173,808 | from base64 import b64encode
from errno import EOPNOTSUPP, EINVAL, EAGAIN
import functools
from io import BytesIO
import logging
import os
from os import SEEK_CUR
import socket
import struct
import sys
def set_default_proxy(proxy_type=None, addr=None, port=None, rdns=True,
username=None, password=None):
def setdefaultproxy(*args, **kwargs):
if "proxytype" in kwargs:
kwargs["proxy_type"] = kwargs.pop("proxytype")
return set_default_proxy(*args, **kwargs) | null |
173,811 | from base64 import b64encode
from errno import EOPNOTSUPP, EINVAL, EAGAIN
import functools
from io import BytesIO
import logging
import os
from os import SEEK_CUR
import socket
import struct
import sys
class ProxyError(IOError):
"""Socket_err contains original socket.error exception."""
def __init__(self, msg, socket_err=None):
self.msg = msg
self.socket_err = socket_err
if socket_err:
self.msg += ": {}".format(socket_err)
def __str__(self):
return self.msg
class socksocket(_BaseSocket):
"""socksocket([family[, type[, proto]]]) -> socket object
Open a SOCKS enabled socket. The parameters are the same as
those of the standard socket init. In order for SOCKS to work,
you must specify family=AF_INET and proto=0.
The "type" argument must be either SOCK_STREAM or SOCK_DGRAM.
"""
default_proxy = None
def __init__(self, family=socket.AF_INET, type=socket.SOCK_STREAM,
proto=0, *args, **kwargs):
if type not in (socket.SOCK_STREAM, socket.SOCK_DGRAM):
msg = "Socket type must be stream or datagram, not {!r}"
raise ValueError(msg.format(type))
super(socksocket, self).__init__(family, type, proto, *args, **kwargs)
self._proxyconn = None # TCP connection to keep UDP relay alive
if self.default_proxy:
self.proxy = self.default_proxy
else:
self.proxy = (None, None, None, None, None, None)
self.proxy_sockname = None
self.proxy_peername = None
self._timeout = None
def _readall(self, file, count):
"""Receive EXACTLY the number of bytes requested from the file object.
Blocks until the required number of bytes have been received."""
data = b""
while len(data) < count:
d = file.read(count - len(data))
if not d:
raise GeneralProxyError("Connection closed unexpectedly")
data += d
return data
def settimeout(self, timeout):
self._timeout = timeout
try:
# test if we're connected, if so apply timeout
peer = self.get_proxy_peername()
super(socksocket, self).settimeout(self._timeout)
except socket.error:
pass
def gettimeout(self):
return self._timeout
def setblocking(self, v):
if v:
self.settimeout(None)
else:
self.settimeout(0.0)
def set_proxy(self, proxy_type=None, addr=None, port=None, rdns=True,
username=None, password=None):
""" Sets the proxy to be used.
proxy_type - The type of the proxy to be used. Three types
are supported: PROXY_TYPE_SOCKS4 (including socks4a),
PROXY_TYPE_SOCKS5 and PROXY_TYPE_HTTP
addr - The address of the server (IP or DNS).
port - The port of the server. Defaults to 1080 for SOCKS
servers and 8080 for HTTP proxy servers.
rdns - Should DNS queries be performed on the remote side
(rather than the local side). The default is True.
Note: This has no effect with SOCKS4 servers.
username - Username to authenticate with to the server.
The default is no authentication.
password - Password to authenticate with to the server.
Only relevant when username is also provided."""
self.proxy = (proxy_type, addr, port, rdns,
username.encode() if username else None,
password.encode() if password else None)
def setproxy(self, *args, **kwargs):
if "proxytype" in kwargs:
kwargs["proxy_type"] = kwargs.pop("proxytype")
return self.set_proxy(*args, **kwargs)
def bind(self, *pos, **kw):
"""Implements proxy connection for UDP sockets.
Happens during the bind() phase."""
(proxy_type, proxy_addr, proxy_port, rdns, username,
password) = self.proxy
if not proxy_type or self.type != socket.SOCK_DGRAM:
return _orig_socket.bind(self, *pos, **kw)
if self._proxyconn:
raise socket.error(EINVAL, "Socket already bound to an address")
if proxy_type != SOCKS5:
msg = "UDP only supported by SOCKS5 proxy type"
raise socket.error(EOPNOTSUPP, msg)
super(socksocket, self).bind(*pos, **kw)
# Need to specify actual local port because
# some relays drop packets if a port of zero is specified.
# Avoid specifying host address in case of NAT though.
_, port = self.getsockname()
dst = ("0", port)
self._proxyconn = _orig_socket()
proxy = self._proxy_addr()
self._proxyconn.connect(proxy)
UDP_ASSOCIATE = b"\x03"
_, relay = self._SOCKS5_request(self._proxyconn, UDP_ASSOCIATE, dst)
# The relay is most likely on the same host as the SOCKS proxy,
# but some proxies return a private IP address (10.x.y.z)
host, _ = proxy
_, port = relay
super(socksocket, self).connect((host, port))
super(socksocket, self).settimeout(self._timeout)
self.proxy_sockname = ("0.0.0.0", 0) # Unknown
def sendto(self, bytes, *args, **kwargs):
if self.type != socket.SOCK_DGRAM:
return super(socksocket, self).sendto(bytes, *args, **kwargs)
if not self._proxyconn:
self.bind(("", 0))
address = args[-1]
flags = args[:-1]
header = BytesIO()
RSV = b"\x00\x00"
header.write(RSV)
STANDALONE = b"\x00"
header.write(STANDALONE)
self._write_SOCKS5_address(address, header)
sent = super(socksocket, self).send(header.getvalue() + bytes, *flags,
**kwargs)
return sent - header.tell()
def send(self, bytes, flags=0, **kwargs):
if self.type == socket.SOCK_DGRAM:
return self.sendto(bytes, flags, self.proxy_peername, **kwargs)
else:
return super(socksocket, self).send(bytes, flags, **kwargs)
def recvfrom(self, bufsize, flags=0):
if self.type != socket.SOCK_DGRAM:
return super(socksocket, self).recvfrom(bufsize, flags)
if not self._proxyconn:
self.bind(("", 0))
buf = BytesIO(super(socksocket, self).recv(bufsize + 1024, flags))
buf.seek(2, SEEK_CUR)
frag = buf.read(1)
if ord(frag):
raise NotImplementedError("Received UDP packet fragment")
fromhost, fromport = self._read_SOCKS5_address(buf)
if self.proxy_peername:
peerhost, peerport = self.proxy_peername
if fromhost != peerhost or peerport not in (0, fromport):
raise socket.error(EAGAIN, "Packet filtered")
return (buf.read(bufsize), (fromhost, fromport))
def recv(self, *pos, **kw):
bytes, _ = self.recvfrom(*pos, **kw)
return bytes
def close(self):
if self._proxyconn:
self._proxyconn.close()
return super(socksocket, self).close()
def get_proxy_sockname(self):
"""Returns the bound IP address and port number at the proxy."""
return self.proxy_sockname
getproxysockname = get_proxy_sockname
def get_proxy_peername(self):
"""
Returns the IP and port number of the proxy.
"""
return self.getpeername()
getproxypeername = get_proxy_peername
def get_peername(self):
"""Returns the IP address and port number of the destination machine.
Note: get_proxy_peername returns the proxy."""
return self.proxy_peername
getpeername = get_peername
def _negotiate_SOCKS5(self, *dest_addr):
"""Negotiates a stream connection through a SOCKS5 server."""
CONNECT = b"\x01"
self.proxy_peername, self.proxy_sockname = self._SOCKS5_request(
self, CONNECT, dest_addr)
def _SOCKS5_request(self, conn, cmd, dst):
"""
Send SOCKS5 request with given command (CMD field) and
address (DST field). Returns resolved DST address that was used.
"""
proxy_type, addr, port, rdns, username, password = self.proxy
writer = conn.makefile("wb")
reader = conn.makefile("rb", 0) # buffering=0 renamed in Python 3
try:
# First we'll send the authentication packages we support.
if username and password:
# The username/password details were supplied to the
# set_proxy method so we support the USERNAME/PASSWORD
# authentication (in addition to the standard none).
writer.write(b"\x05\x02\x00\x02")
else:
# No username/password were entered, therefore we
# only support connections with no authentication.
writer.write(b"\x05\x01\x00")
# We'll receive the server's response to determine which
# method was selected
writer.flush()
chosen_auth = self._readall(reader, 2)
if chosen_auth[0:1] != b"\x05":
# Note: string[i:i+1] is used because indexing of a bytestring
# via bytestring[i] yields an integer in Python 3
raise GeneralProxyError(
"SOCKS5 proxy server sent invalid data")
# Check the chosen authentication method
if chosen_auth[1:2] == b"\x02":
# Okay, we need to perform a basic username/password
# authentication.
if not (username and password):
# Although we said we don't support authentication, the
# server may still request basic username/password
# authentication
raise SOCKS5AuthError("No username/password supplied. "
"Server requested username/password"
" authentication")
writer.write(b"\x01" + chr(len(username)).encode()
+ username
+ chr(len(password)).encode()
+ password)
writer.flush()
auth_status = self._readall(reader, 2)
if auth_status[0:1] != b"\x01":
# Bad response
raise GeneralProxyError(
"SOCKS5 proxy server sent invalid data")
if auth_status[1:2] != b"\x00":
# Authentication failed
raise SOCKS5AuthError("SOCKS5 authentication failed")
# Otherwise, authentication succeeded
# No authentication is required if 0x00
elif chosen_auth[1:2] != b"\x00":
# Reaching here is always bad
if chosen_auth[1:2] == b"\xFF":
raise SOCKS5AuthError(
"All offered SOCKS5 authentication methods were"
" rejected")
else:
raise GeneralProxyError(
"SOCKS5 proxy server sent invalid data")
# Now we can request the actual connection
writer.write(b"\x05" + cmd + b"\x00")
resolved = self._write_SOCKS5_address(dst, writer)
writer.flush()
# Get the response
resp = self._readall(reader, 3)
if resp[0:1] != b"\x05":
raise GeneralProxyError(
"SOCKS5 proxy server sent invalid data")
status = ord(resp[1:2])
if status != 0x00:
# Connection failed: server returned an error
error = SOCKS5_ERRORS.get(status, "Unknown error")
raise SOCKS5Error("{:#04x}: {}".format(status, error))
# Get the bound address/port
bnd = self._read_SOCKS5_address(reader)
super(socksocket, self).settimeout(self._timeout)
return (resolved, bnd)
finally:
reader.close()
writer.close()
def _write_SOCKS5_address(self, addr, file):
"""
Return the host and port packed for the SOCKS5 protocol,
and the resolved address as a tuple object.
"""
host, port = addr
proxy_type, _, _, rdns, username, password = self.proxy
family_to_byte = {socket.AF_INET: b"\x01", socket.AF_INET6: b"\x04"}
# If the given destination address is an IP address, we'll
# use the IP address request even if remote resolving was specified.
# Detect whether the address is IPv4/6 directly.
for family in (socket.AF_INET, socket.AF_INET6):
try:
addr_bytes = socket.inet_pton(family, host)
file.write(family_to_byte[family] + addr_bytes)
host = socket.inet_ntop(family, addr_bytes)
file.write(struct.pack(">H", port))
return host, port
except socket.error:
continue
# Well it's not an IP number, so it's probably a DNS name.
if rdns:
# Resolve remotely
host_bytes = host.encode("idna")
file.write(b"\x03" + chr(len(host_bytes)).encode() + host_bytes)
else:
# Resolve locally
addresses = socket.getaddrinfo(host, port, socket.AF_UNSPEC,
socket.SOCK_STREAM,
socket.IPPROTO_TCP,
socket.AI_ADDRCONFIG)
# We can't really work out what IP is reachable, so just pick the
# first.
target_addr = addresses[0]
family = target_addr[0]
host = target_addr[4][0]
addr_bytes = socket.inet_pton(family, host)
file.write(family_to_byte[family] + addr_bytes)
host = socket.inet_ntop(family, addr_bytes)
file.write(struct.pack(">H", port))
return host, port
def _read_SOCKS5_address(self, file):
atyp = self._readall(file, 1)
if atyp == b"\x01":
addr = socket.inet_ntoa(self._readall(file, 4))
elif atyp == b"\x03":
length = self._readall(file, 1)
addr = self._readall(file, ord(length))
elif atyp == b"\x04":
addr = socket.inet_ntop(socket.AF_INET6, self._readall(file, 16))
else:
raise GeneralProxyError("SOCKS5 proxy server sent invalid data")
port = struct.unpack(">H", self._readall(file, 2))[0]
return addr, port
def _negotiate_SOCKS4(self, dest_addr, dest_port):
"""Negotiates a connection through a SOCKS4 server."""
proxy_type, addr, port, rdns, username, password = self.proxy
writer = self.makefile("wb")
reader = self.makefile("rb", 0) # buffering=0 renamed in Python 3
try:
# Check if the destination address provided is an IP address
remote_resolve = False
try:
addr_bytes = socket.inet_aton(dest_addr)
except socket.error:
# It's a DNS name. Check where it should be resolved.
if rdns:
addr_bytes = b"\x00\x00\x00\x01"
remote_resolve = True
else:
addr_bytes = socket.inet_aton(
socket.gethostbyname(dest_addr))
# Construct the request packet
writer.write(struct.pack(">BBH", 0x04, 0x01, dest_port))
writer.write(addr_bytes)
# The username parameter is considered userid for SOCKS4
if username:
writer.write(username)
writer.write(b"\x00")
# DNS name if remote resolving is required
# NOTE: This is actually an extension to the SOCKS4 protocol
# called SOCKS4A and may not be supported in all cases.
if remote_resolve:
writer.write(dest_addr.encode("idna") + b"\x00")
writer.flush()
# Get the response from the server
resp = self._readall(reader, 8)
if resp[0:1] != b"\x00":
# Bad data
raise GeneralProxyError(
"SOCKS4 proxy server sent invalid data")
status = ord(resp[1:2])
if status != 0x5A:
# Connection failed: server returned an error
error = SOCKS4_ERRORS.get(status, "Unknown error")
raise SOCKS4Error("{:#04x}: {}".format(status, error))
# Get the bound address/port
self.proxy_sockname = (socket.inet_ntoa(resp[4:]),
struct.unpack(">H", resp[2:4])[0])
if remote_resolve:
self.proxy_peername = socket.inet_ntoa(addr_bytes), dest_port
else:
self.proxy_peername = dest_addr, dest_port
finally:
reader.close()
writer.close()
def _negotiate_HTTP(self, dest_addr, dest_port):
"""Negotiates a connection through an HTTP server.
NOTE: This currently only supports HTTP CONNECT-style proxies."""
proxy_type, addr, port, rdns, username, password = self.proxy
# If we need to resolve locally, we do this now
addr = dest_addr if rdns else socket.gethostbyname(dest_addr)
http_headers = [
(b"CONNECT " + addr.encode("idna") + b":"
+ str(dest_port).encode() + b" HTTP/1.1"),
b"Host: " + dest_addr.encode("idna")
]
if username and password:
http_headers.append(b"Proxy-Authorization: basic "
+ b64encode(username + b":" + password))
http_headers.append(b"\r\n")
self.sendall(b"\r\n".join(http_headers))
# We just need the first line to check if the connection was successful
fobj = self.makefile()
status_line = fobj.readline()
fobj.close()
if not status_line:
raise GeneralProxyError("Connection closed unexpectedly")
try:
proto, status_code, status_msg = status_line.split(" ", 2)
except ValueError:
raise GeneralProxyError("HTTP proxy server sent invalid response")
if not proto.startswith("HTTP/"):
raise GeneralProxyError(
"Proxy server does not appear to be an HTTP proxy")
try:
status_code = int(status_code)
except ValueError:
raise HTTPError(
"HTTP proxy server did not return a valid HTTP status")
if status_code != 200:
error = "{}: {}".format(status_code, status_msg)
if status_code in (400, 403, 405):
# It's likely that the HTTP proxy server does not support the
# CONNECT tunneling method
error += ("\n[*] Note: The HTTP proxy server may not be"
" supported by PySocks (must be a CONNECT tunnel"
" proxy)")
raise HTTPError(error)
self.proxy_sockname = (b"0.0.0.0", 0)
self.proxy_peername = addr, dest_port
_proxy_negotiators = {
SOCKS4: _negotiate_SOCKS4,
SOCKS5: _negotiate_SOCKS5,
HTTP: _negotiate_HTTP
}
def connect(self, dest_pair, catch_errors=None):
"""
Connects to the specified destination through a proxy.
Uses the same API as socket's connect().
To select the proxy server, use set_proxy().
dest_pair - 2-tuple of (IP/hostname, port).
"""
if len(dest_pair) != 2 or dest_pair[0].startswith("["):
# Probably IPv6, not supported -- raise an error, and hope
# Happy Eyeballs (RFC6555) makes sure at least the IPv4
# connection works...
raise socket.error("PySocks doesn't support IPv6: %s"
% str(dest_pair))
dest_addr, dest_port = dest_pair
if self.type == socket.SOCK_DGRAM:
if not self._proxyconn:
self.bind(("", 0))
dest_addr = socket.gethostbyname(dest_addr)
# If the host address is INADDR_ANY or similar, reset the peer
# address so that packets are received from any peer
if dest_addr == "0.0.0.0" and not dest_port:
self.proxy_peername = None
else:
self.proxy_peername = (dest_addr, dest_port)
return
(proxy_type, proxy_addr, proxy_port, rdns, username,
password) = self.proxy
# Do a minimal input check first
if (not isinstance(dest_pair, (list, tuple))
or len(dest_pair) != 2
or not dest_addr
or not isinstance(dest_port, int)):
# Inputs failed, raise an error
raise GeneralProxyError(
"Invalid destination-connection (host, port) pair")
# We set the timeout here so that we don't hang in connection or during
# negotiation.
super(socksocket, self).settimeout(self._timeout)
if proxy_type is None:
# Treat like regular socket object
self.proxy_peername = dest_pair
super(socksocket, self).settimeout(self._timeout)
super(socksocket, self).connect((dest_addr, dest_port))
return
proxy_addr = self._proxy_addr()
try:
# Initial connection to proxy server.
super(socksocket, self).connect(proxy_addr)
except socket.error as error:
# Error while connecting to proxy
self.close()
if not catch_errors:
proxy_addr, proxy_port = proxy_addr
proxy_server = "{}:{}".format(proxy_addr, proxy_port)
printable_type = PRINTABLE_PROXY_TYPES[proxy_type]
msg = "Error connecting to {} proxy {}".format(printable_type,
proxy_server)
log.debug("%s due to: %s", msg, error)
raise ProxyConnectionError(msg, error)
else:
raise error
else:
# Connected to proxy server, now negotiate
try:
# Calls negotiate_{SOCKS4, SOCKS5, HTTP}
negotiate = self._proxy_negotiators[proxy_type]
negotiate(self, dest_addr, dest_port)
except socket.error as error:
if not catch_errors:
# Wrap socket errors
self.close()
raise GeneralProxyError("Socket error", error)
else:
raise error
except ProxyError:
# Protocol error while negotiating with proxy
self.close()
raise
def connect_ex(self, dest_pair):
""" https://docs.python.org/3/library/socket.html#socket.socket.connect_ex
Like connect(address), but return an error indicator instead of raising an exception for errors returned by the C-level connect() call (other problems, such as "host not found" can still raise exceptions).
"""
try:
self.connect(dest_pair, catch_errors=True)
return 0
except OSError as e:
# If the error is numeric (socket errors are numeric), then return number as
# connect_ex expects. Otherwise raise the error again (socket timeout for example)
if e.errno:
return e.errno
else:
raise
def _proxy_addr(self):
"""
Return proxy address to connect to as tuple object
"""
(proxy_type, proxy_addr, proxy_port, rdns, username,
password) = self.proxy
proxy_port = proxy_port or DEFAULT_PORTS.get(proxy_type)
if not proxy_port:
raise GeneralProxyError("Invalid proxy type")
return proxy_addr, proxy_port
The provided code snippet includes necessary dependencies for implementing the `create_connection` function. Write a Python function `def create_connection(dest_pair, timeout=None, source_address=None, proxy_type=None, proxy_addr=None, proxy_port=None, proxy_rdns=True, proxy_username=None, proxy_password=None, socket_options=None)` to solve the following problem:
create_connection(dest_pair, *[, timeout], **proxy_args) -> socket object Like socket.create_connection(), but connects to proxy before returning the socket object. dest_pair - 2-tuple of (IP/hostname, port). **proxy_args - Same args passed to socksocket.set_proxy() if present. timeout - Optional socket timeout value, in seconds. source_address - tuple (host, port) for the socket to bind to as its source address before connecting (only for compatibility)
Here is the function:
def create_connection(dest_pair,
timeout=None, source_address=None,
proxy_type=None, proxy_addr=None,
proxy_port=None, proxy_rdns=True,
proxy_username=None, proxy_password=None,
socket_options=None):
"""create_connection(dest_pair, *[, timeout], **proxy_args) -> socket object
Like socket.create_connection(), but connects to proxy
before returning the socket object.
dest_pair - 2-tuple of (IP/hostname, port).
**proxy_args - Same args passed to socksocket.set_proxy() if present.
timeout - Optional socket timeout value, in seconds.
source_address - tuple (host, port) for the socket to bind to as its source
address before connecting (only for compatibility)
"""
# Remove IPv6 brackets on the remote address and proxy address.
remote_host, remote_port = dest_pair
if remote_host.startswith("["):
remote_host = remote_host.strip("[]")
if proxy_addr and proxy_addr.startswith("["):
proxy_addr = proxy_addr.strip("[]")
err = None
# Allow the SOCKS proxy to be on IPv4 or IPv6 addresses.
for r in socket.getaddrinfo(proxy_addr, proxy_port, 0, socket.SOCK_STREAM):
family, socket_type, proto, canonname, sa = r
sock = None
try:
sock = socksocket(family, socket_type, proto)
if socket_options:
for opt in socket_options:
sock.setsockopt(*opt)
if isinstance(timeout, (int, float)):
sock.settimeout(timeout)
if proxy_type:
sock.set_proxy(proxy_type, proxy_addr, proxy_port, proxy_rdns,
proxy_username, proxy_password)
if source_address:
sock.bind(source_address)
sock.connect((remote_host, remote_port))
return sock
except (socket.error, ProxyError) as e:
err = e
if sock:
sock.close()
sock = None
if err:
raise err
raise socket.error("gai returned empty list.") | create_connection(dest_pair, *[, timeout], **proxy_args) -> socket object Like socket.create_connection(), but connects to proxy before returning the socket object. dest_pair - 2-tuple of (IP/hostname, port). **proxy_args - Same args passed to socksocket.set_proxy() if present. timeout - Optional socket timeout value, in seconds. source_address - tuple (host, port) for the socket to bind to as its source address before connecting (only for compatibility) |
173,813 | import json
import pathlib
import platform
import click
from jsonschema import ValidationError
from rich.console import Console
from rich.json import JSON
from rich.markup import escape
from rich.padding import Padding
from rich.style import Style
from jupyter_events.schema import EventSchema, EventSchemaFileAbsent, EventSchemaLoadingError
class RC:
"""Return code enum."""
OK = 0
INVALID = 1
UNPARSEABLE = 2
NOT_FOUND = 3
class EMOJI:
"""Terminal emoji enum"""
X = "XX" if WIN else "\u274c"
OK = "OK" if WIN else "\u2714"
console = Console()
error_console = Console(stderr=True)
class EventSchemaLoadingError(Exception):
"""An error for an event schema loading error."""
pass
class EventSchemaFileAbsent(Exception): # noqa
"""An error for an absent event schema file."""
pass
class EventSchema:
"""A validated schema that can be used.
On instantiation, validate the schema against
Jupyter Event's metaschema.
Parameters
----------
schema: dict or str
JSON schema to validate against Jupyter Events.
validator_class: jsonschema.validators
The validator class from jsonschema used to validate instances
of this event schema. The schema itself will be validated
against Jupyter Event's metaschema to ensure that
any schema registered here follows the expected form
of Jupyter Events.
resolver:
RefResolver for nested JSON schema references.
"""
def __init__(
self,
schema: SchemaType,
validator_class: Type[Validator] = validators.Draft7Validator, # type:ignore[assignment]
format_checker: FormatChecker = draft7_format_checker,
resolver: Optional[RefResolver] = None,
):
"""Initialize an event schema."""
_schema = self._load_schema(schema)
# Validate the schema against Jupyter Events metaschema.
validate_schema(_schema)
# Create a validator for this schema
self._validator = validator_class(_schema, resolver=resolver, format_checker=format_checker)
self._schema = _schema
def __repr__(self):
"""A string repr for an event schema."""
return json.dumps(self._schema, indent=2)
def _ensure_yaml_loaded(schema: SchemaType, was_str: bool = False) -> None:
"""Ensures schema was correctly loaded into a dictionary. Raises
EventSchemaLoadingError otherwise."""
if isinstance(schema, dict):
return
error_msg = "Could not deserialize schema into a dictionary."
def intended_as_path(schema: str) -> bool:
path = Path(schema)
return path.match("*.yml") or path.match("*.yaml") or path.match("*.json")
# detect whether the user specified a string but intended a PurePath to
# generate a more helpful error message
if was_str and intended_as_path(schema): # type:ignore[arg-type]
error_msg += " Paths to schema files must be explicitly wrapped in a Pathlib object."
else:
error_msg += " Double check the schema and ensure it is in the proper form."
raise EventSchemaLoadingError(error_msg)
def _load_schema(schema: SchemaType) -> dict:
"""Load a JSON schema from different sources/data types.
`schema` could be a dictionary or serialized string representing the
schema itself or a Pathlib object representing a schema file on disk.
Returns a dictionary with schema data.
"""
# if schema is already a dictionary, return it
if isinstance(schema, dict):
return schema
# if schema is PurePath, ensure file exists at path and then load from file
if isinstance(schema, PurePath):
if not Path(schema).exists():
msg = f'Schema file not present at path "{schema}".'
raise EventSchemaFileAbsent(msg)
loaded_schema = yaml.load(schema)
EventSchema._ensure_yaml_loaded(loaded_schema)
return loaded_schema
# finally, if schema is string, attempt to deserialize and return the output
if isinstance(schema, str):
# note the diff b/w load v.s. loads
loaded_schema = yaml.loads(schema)
EventSchema._ensure_yaml_loaded(loaded_schema, was_str=True)
return loaded_schema
msg = f"Expected a dictionary, string, or PurePath, but instead received {schema.__class__.__name__}."
raise EventSchemaUnrecognized(msg)
def id(self) -> str:
"""Schema $id field."""
return self._schema["$id"]
def version(self) -> int:
"""Schema's version."""
return self._schema["version"]
def validate(self, data: dict) -> None:
"""Validate an incoming instance of this event schema."""
self._validator.validate(data)
The provided code snippet includes necessary dependencies for implementing the `validate` function. Write a Python function `def validate(ctx: click.Context, schema: str) -> int` to solve the following problem:
Validate a SCHEMA against Jupyter Event's meta schema. SCHEMA can be a JSON/YAML string or filepath to a schema.
Here is the function:
def validate(ctx: click.Context, schema: str) -> int:
"""Validate a SCHEMA against Jupyter Event's meta schema.
SCHEMA can be a JSON/YAML string or filepath to a schema.
"""
console.rule("Validating the following schema", style=Style(color="blue"))
_schema = None
try:
# attempt to read schema as a serialized string
_schema = EventSchema._load_schema(schema)
except EventSchemaLoadingError:
# pass here to avoid printing traceback of this exception if next block
# excepts
pass
# if not a serialized schema string, try to interpret it as a path to schema file
if _schema is None:
schema_path = pathlib.Path(schema)
try:
_schema = EventSchema._load_schema(schema_path)
except (EventSchemaLoadingError, EventSchemaFileAbsent) as e:
# no need for full tracestack for user error exceptions. just print
# the error message and return
error_console.print(f"[bold red]ERROR[/]: {e}")
return ctx.exit(RC.UNPARSEABLE)
# Print what was found.
schema_json = JSON(json.dumps(_schema))
console.print(Padding(schema_json, (1, 0, 1, 4)))
# Now validate this schema against the meta-schema.
try:
EventSchema(_schema)
console.rule("Results", style=Style(color="green"))
out = Padding(f"[green]{EMOJI.OK}[white] Nice work! This schema is valid.", (1, 0, 1, 0))
console.print(out)
return ctx.exit(RC.OK)
except ValidationError as err:
error_console.rule("Results", style=Style(color="red"))
error_console.print(f"[red]{EMOJI.X} [white]The schema failed to validate.")
error_console.print("\nWe found the following error with your schema:")
out = escape(str(err)) # type:ignore
error_console.print(Padding(out, (1, 0, 1, 4)))
return ctx.exit(RC.INVALID) | Validate a SCHEMA against Jupyter Event's meta schema. SCHEMA can be a JSON/YAML string or filepath to a schema. |
173,814 | from pathlib import Path
from yaml import dump as ydump
from yaml import load as yload
def loads(stream):
"""Load yaml from a stream."""
return yload(stream, Loader=SafeLoader)
class Path(PurePath):
def __new__(cls: Type[_P], *args: Union[str, _PathLike], **kwargs: Any) -> _P: ...
def __enter__(self: _P) -> _P: ...
def __exit__(
self, exc_type: Optional[Type[BaseException]], exc_value: Optional[BaseException], traceback: Optional[TracebackType]
) -> Optional[bool]: ...
def cwd(cls: Type[_P]) -> _P: ...
def stat(self) -> os.stat_result: ...
def chmod(self, mode: int) -> None: ...
def exists(self) -> bool: ...
def glob(self: _P, pattern: str) -> Generator[_P, None, None]: ...
def group(self) -> str: ...
def is_dir(self) -> bool: ...
def is_file(self) -> bool: ...
if sys.version_info >= (3, 7):
def is_mount(self) -> bool: ...
def is_symlink(self) -> bool: ...
def is_socket(self) -> bool: ...
def is_fifo(self) -> bool: ...
def is_block_device(self) -> bool: ...
def is_char_device(self) -> bool: ...
def iterdir(self: _P) -> Generator[_P, None, None]: ...
def lchmod(self, mode: int) -> None: ...
def lstat(self) -> os.stat_result: ...
def mkdir(self, mode: int = ..., parents: bool = ..., exist_ok: bool = ...) -> None: ...
# Adapted from builtins.open
# Text mode: always returns a TextIOWrapper
def open(
self,
mode: OpenTextMode = ...,
buffering: int = ...,
encoding: Optional[str] = ...,
errors: Optional[str] = ...,
newline: Optional[str] = ...,
) -> TextIOWrapper: ...
# Unbuffered binary mode: returns a FileIO
def open(
self, mode: OpenBinaryMode, buffering: Literal[0], encoding: None = ..., errors: None = ..., newline: None = ...
) -> FileIO: ...
# Buffering is on: return BufferedRandom, BufferedReader, or BufferedWriter
def open(
self,
mode: OpenBinaryModeUpdating,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedRandom: ...
def open(
self,
mode: OpenBinaryModeWriting,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedWriter: ...
def open(
self,
mode: OpenBinaryModeReading,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedReader: ...
# Buffering cannot be determined: fall back to BinaryIO
def open(
self, mode: OpenBinaryMode, buffering: int, encoding: None = ..., errors: None = ..., newline: None = ...
) -> BinaryIO: ...
# Fallback if mode is not specified
def open(
self,
mode: str,
buffering: int = ...,
encoding: Optional[str] = ...,
errors: Optional[str] = ...,
newline: Optional[str] = ...,
) -> IO[Any]: ...
def owner(self) -> str: ...
if sys.version_info >= (3, 9):
def readlink(self: _P) -> _P: ...
if sys.version_info >= (3, 8):
def rename(self: _P, target: Union[str, PurePath]) -> _P: ...
def replace(self: _P, target: Union[str, PurePath]) -> _P: ...
else:
def rename(self, target: Union[str, PurePath]) -> None: ...
def replace(self, target: Union[str, PurePath]) -> None: ...
def resolve(self: _P, strict: bool = ...) -> _P: ...
def rglob(self: _P, pattern: str) -> Generator[_P, None, None]: ...
def rmdir(self) -> None: ...
def symlink_to(self, target: Union[str, Path], target_is_directory: bool = ...) -> None: ...
def touch(self, mode: int = ..., exist_ok: bool = ...) -> None: ...
if sys.version_info >= (3, 8):
def unlink(self, missing_ok: bool = ...) -> None: ...
else:
def unlink(self) -> None: ...
def home(cls: Type[_P]) -> _P: ...
def absolute(self: _P) -> _P: ...
def expanduser(self: _P) -> _P: ...
def read_bytes(self) -> bytes: ...
def read_text(self, encoding: Optional[str] = ..., errors: Optional[str] = ...) -> str: ...
def samefile(self, other_path: Union[str, bytes, int, Path]) -> bool: ...
def write_bytes(self, data: bytes) -> int: ...
def write_text(self, data: str, encoding: Optional[str] = ..., errors: Optional[str] = ...) -> int: ...
if sys.version_info >= (3, 8):
def link_to(self, target: Union[str, bytes, os.PathLike[str]]) -> None: ...
The provided code snippet includes necessary dependencies for implementing the `load` function. Write a Python function `def load(fpath)` to solve the following problem:
Load yaml from a file.
Here is the function:
def load(fpath):
"""Load yaml from a file."""
# coerce PurePath into Path, then read its contents
data = Path(str(fpath)).read_text(encoding="utf-8")
return loads(data) | Load yaml from a file. |
173,815 | from pathlib import Path
from yaml import dump as ydump
from yaml import load as yload
def dumps(stream):
"""Parse the first YAML document in a stream as an object."""
return ydump(stream, Dumper=SafeDumper)
class Path(PurePath):
def __new__(cls: Type[_P], *args: Union[str, _PathLike], **kwargs: Any) -> _P: ...
def __enter__(self: _P) -> _P: ...
def __exit__(
self, exc_type: Optional[Type[BaseException]], exc_value: Optional[BaseException], traceback: Optional[TracebackType]
) -> Optional[bool]: ...
def cwd(cls: Type[_P]) -> _P: ...
def stat(self) -> os.stat_result: ...
def chmod(self, mode: int) -> None: ...
def exists(self) -> bool: ...
def glob(self: _P, pattern: str) -> Generator[_P, None, None]: ...
def group(self) -> str: ...
def is_dir(self) -> bool: ...
def is_file(self) -> bool: ...
if sys.version_info >= (3, 7):
def is_mount(self) -> bool: ...
def is_symlink(self) -> bool: ...
def is_socket(self) -> bool: ...
def is_fifo(self) -> bool: ...
def is_block_device(self) -> bool: ...
def is_char_device(self) -> bool: ...
def iterdir(self: _P) -> Generator[_P, None, None]: ...
def lchmod(self, mode: int) -> None: ...
def lstat(self) -> os.stat_result: ...
def mkdir(self, mode: int = ..., parents: bool = ..., exist_ok: bool = ...) -> None: ...
# Adapted from builtins.open
# Text mode: always returns a TextIOWrapper
def open(
self,
mode: OpenTextMode = ...,
buffering: int = ...,
encoding: Optional[str] = ...,
errors: Optional[str] = ...,
newline: Optional[str] = ...,
) -> TextIOWrapper: ...
# Unbuffered binary mode: returns a FileIO
def open(
self, mode: OpenBinaryMode, buffering: Literal[0], encoding: None = ..., errors: None = ..., newline: None = ...
) -> FileIO: ...
# Buffering is on: return BufferedRandom, BufferedReader, or BufferedWriter
def open(
self,
mode: OpenBinaryModeUpdating,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedRandom: ...
def open(
self,
mode: OpenBinaryModeWriting,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedWriter: ...
def open(
self,
mode: OpenBinaryModeReading,
buffering: Literal[-1, 1] = ...,
encoding: None = ...,
errors: None = ...,
newline: None = ...,
) -> BufferedReader: ...
# Buffering cannot be determined: fall back to BinaryIO
def open(
self, mode: OpenBinaryMode, buffering: int, encoding: None = ..., errors: None = ..., newline: None = ...
) -> BinaryIO: ...
# Fallback if mode is not specified
def open(
self,
mode: str,
buffering: int = ...,
encoding: Optional[str] = ...,
errors: Optional[str] = ...,
newline: Optional[str] = ...,
) -> IO[Any]: ...
def owner(self) -> str: ...
if sys.version_info >= (3, 9):
def readlink(self: _P) -> _P: ...
if sys.version_info >= (3, 8):
def rename(self: _P, target: Union[str, PurePath]) -> _P: ...
def replace(self: _P, target: Union[str, PurePath]) -> _P: ...
else:
def rename(self, target: Union[str, PurePath]) -> None: ...
def replace(self, target: Union[str, PurePath]) -> None: ...
def resolve(self: _P, strict: bool = ...) -> _P: ...
def rglob(self: _P, pattern: str) -> Generator[_P, None, None]: ...
def rmdir(self) -> None: ...
def symlink_to(self, target: Union[str, Path], target_is_directory: bool = ...) -> None: ...
def touch(self, mode: int = ..., exist_ok: bool = ...) -> None: ...
if sys.version_info >= (3, 8):
def unlink(self, missing_ok: bool = ...) -> None: ...
else:
def unlink(self) -> None: ...
def home(cls: Type[_P]) -> _P: ...
def absolute(self: _P) -> _P: ...
def expanduser(self: _P) -> _P: ...
def read_bytes(self) -> bytes: ...
def read_text(self, encoding: Optional[str] = ..., errors: Optional[str] = ...) -> str: ...
def samefile(self, other_path: Union[str, bytes, int, Path]) -> bool: ...
def write_bytes(self, data: bytes) -> int: ...
def write_text(self, data: str, encoding: Optional[str] = ..., errors: Optional[str] = ...) -> int: ...
if sys.version_info >= (3, 8):
def link_to(self, target: Union[str, bytes, os.PathLike[str]]) -> None: ...
The provided code snippet includes necessary dependencies for implementing the `dump` function. Write a Python function `def dump(data, outpath)` to solve the following problem:
Parse the a YAML document in a file as an object.
Here is the function:
def dump(data, outpath):
"""Parse the a YAML document in a file as an object."""
Path(outpath).write_text(dumps(data), encoding="utf-8") | Parse the a YAML document in a file as an object. |
173,816 | import pathlib
import jsonschema
from jsonschema import Draft7Validator, RefResolver, ValidationError
from . import yaml
JUPYTER_EVENTS_SCHEMA_VALIDATOR = Draft7Validator(
schema=EVENT_METASCHEMA,
resolver=METASCHEMA_RESOLVER,
format_checker=draft7_format_checker,
)
The provided code snippet includes necessary dependencies for implementing the `validate_schema` function. Write a Python function `def validate_schema(schema: dict) -> None` to solve the following problem:
Validate a schema dict.
Here is the function:
def validate_schema(schema: dict) -> None:
"""Validate a schema dict."""
try:
# Validate the schema against Jupyter Events metaschema.
JUPYTER_EVENTS_SCHEMA_VALIDATOR.validate(schema)
except ValidationError as err:
reserved_property_msg = " does not match '^(?!__.*)'"
if reserved_property_msg in str(err):
idx = str(err).find(reserved_property_msg)
bad_property = str(err)[:idx].strip()
msg = (
f"{bad_property} is an invalid property name because it "
"starts with `__`. Properties starting with 'dunder' "
"are reserved as special meta-fields for Jupyter Events to use."
)
raise ValidationError(msg) from err
raise err | Validate a schema dict. |
173,817 | from __future__ import unicode_literals
import os.path as op
from .compat import text_type
from .util import preprocess_paths
from platform import version
import pythoncom
import pywintypes
from win32com.shell import shell, shellcon
from .IFileOperationProgressSink import CreateSink
def preprocess_paths(paths):
if not isinstance(paths, list):
paths = [paths]
# Convert items such as pathlib paths to strings
paths = [
path.__fspath__() if hasattr(path, "__fspath__") else path for path in paths
]
return paths
def version() -> str: ...
def CreateSink():
return pythoncom.WrapObject(
FileOperationProgressSink(), shell.IID_IFileOperationProgressSink
)
def send2trash(paths):
paths = preprocess_paths(paths)
# convert data type
paths = [
text_type(path, "mbcs") if not isinstance(path, text_type) else path
for path in paths
]
# convert to full paths
paths = [op.abspath(path) if not op.isabs(path) else path for path in paths]
# remove the leading \\?\ if present
paths = [path[4:] if path.startswith("\\\\?\\") else path for path in paths]
# Need to initialize the com before using
pythoncom.CoInitialize()
# create instance of file operation object
fileop = pythoncom.CoCreateInstance(
shell.CLSID_FileOperation, None, pythoncom.CLSCTX_ALL, shell.IID_IFileOperation,
)
# default flags to use
flags = (
shellcon.FOF_NOCONFIRMATION
| shellcon.FOF_NOERRORUI
| shellcon.FOF_SILENT
| shellcon.FOFX_EARLYFAILURE
)
# determine rest of the flags based on OS version
# use newer recommended flags if available
if int(version().split(".", 1)[0]) >= 8:
flags |= (
0x20000000 # FOFX_ADDUNDORECORD win 8+
| 0x00080000 # FOFX_RECYCLEONDELETE win 8+
)
else:
flags |= shellcon.FOF_ALLOWUNDO
# set the flags
fileop.SetOperationFlags(flags)
# actually try to perform the operation, this section may throw a
# pywintypes.com_error which does not seem to create as nice of an
# error as OSError so wrapping with try to convert
sink = CreateSink()
try:
for path in paths:
item = shell.SHCreateItemFromParsingName(path, None, shell.IID_IShellItem)
fileop.DeleteItem(item, sink)
result = fileop.PerformOperations()
aborted = fileop.GetAnyOperationsAborted()
# if non-zero result or aborted throw an exception
if result or aborted:
raise OSError(None, None, paths, result)
except pywintypes.com_error as error:
# convert to standard OS error, allows other code to get a
# normal errno
raise OSError(None, error.strerror, path, error.hresult)
finally:
# Need to make sure we call this once fore every init
pythoncom.CoUninitialize() | null |
173,818 | from Foundation import NSFileManager, NSURL
from .compat import text_type
from .util import preprocess_paths
def check_op_result(op_result):
# First value will be false on failure
if not op_result[0]:
# Error is in third value, localized failure reason matchs ctypes version
raise OSError(op_result[2].localizedFailureReason())
def preprocess_paths(paths):
if not isinstance(paths, list):
paths = [paths]
# Convert items such as pathlib paths to strings
paths = [
path.__fspath__() if hasattr(path, "__fspath__") else path for path in paths
]
return paths
def send2trash(paths):
paths = preprocess_paths(paths)
paths = [
path.decode("utf-8") if not isinstance(path, text_type) else path
for path in paths
]
for path in paths:
file_url = NSURL.fileURLWithPath_(path)
fm = NSFileManager.defaultManager()
op_result = fm.trashItemAtURL_resultingItemURL_error_(file_url, None, None)
check_op_result(op_result) | null |
173,819 | from __future__ import unicode_literals
from ctypes import cdll, byref, Structure, c_char, c_char_p
from ctypes.util import find_library
from .compat import binary_type
from .util import preprocess_paths
FSPathMakeRefWithOptions = CoreServices.FSPathMakeRefWithOptions
FSMoveObjectToTrashSync = CoreServices.FSMoveObjectToTrashSync
kFSPathMakeRefDoNotFollowLeafSymlink = 0x01
kFSFileOperationDefaultOptions = 0
class FSRef(Structure):
_fields_ = [("hidden", c_char * 80)]
def check_op_result(op_result):
if op_result:
msg = GetMacOSStatusCommentString(op_result).decode("utf-8")
raise OSError(msg)
def preprocess_paths(paths):
if not isinstance(paths, list):
paths = [paths]
# Convert items such as pathlib paths to strings
paths = [
path.__fspath__() if hasattr(path, "__fspath__") else path for path in paths
]
return paths
def send2trash(paths):
paths = preprocess_paths(paths)
paths = [
path.encode("utf-8") if not isinstance(path, binary_type) else path
for path in paths
]
for path in paths:
fp = FSRef()
opts = kFSPathMakeRefDoNotFollowLeafSymlink
op_result = FSPathMakeRefWithOptions(path, opts, byref(fp), None)
check_op_result(op_result)
opts = kFSFileOperationDefaultOptions
op_result = FSMoveObjectToTrashSync(byref(fp), None, opts)
check_op_result(op_result) | null |
173,820 | from __future__ import unicode_literals
import os.path as op
from .compat import text_type
from .util import preprocess_paths
from ctypes import (
windll,
Structure,
byref,
c_uint,
create_unicode_buffer,
addressof,
GetLastError,
FormatError,
)
from ctypes.wintypes import HWND, UINT, LPCWSTR, BOOL
SHFileOperationW = shell32.SHFileOperationW
class SHFILEOPSTRUCTW(Structure):
FO_DELETE = 3
FOF_SILENT = 4
FOF_NOCONFIRMATION = 16
FOF_ALLOWUNDO = 64
FOF_NOERRORUI = 1024
def get_short_path_name(long_name):
def preprocess_paths(paths):
def send2trash(paths):
paths = preprocess_paths(paths)
# convert data type
paths = [
text_type(path, "mbcs") if not isinstance(path, text_type) else path
for path in paths
]
# convert to full paths
paths = [op.abspath(path) if not op.isabs(path) else path for path in paths]
# get short path to handle path length issues
paths = [get_short_path_name(path) for path in paths]
fileop = SHFILEOPSTRUCTW()
fileop.hwnd = 0
fileop.wFunc = FO_DELETE
# FIX: https://github.com/hsoft/send2trash/issues/17
# Starting in python 3.6.3 it is no longer possible to use:
# LPCWSTR(path + '\0') directly as embedded null characters are no longer
# allowed in strings
# Workaround
# - create buffer of c_wchar[] (LPCWSTR is based on this type)
# - buffer is two c_wchar characters longer (double null terminator)
# - cast the address of the buffer to a LPCWSTR
# NOTE: based on how python allocates memory for these types they should
# always be zero, if this is ever not true we can go back to explicitly
# setting the last two characters to null using buffer[index] = '\0'.
# Additional note on another issue here, unicode_buffer expects length in
# bytes essentially, so having multi-byte characters causes issues if just
# passing pythons string length. Instead of dealing with this difference we
# just create a buffer then a new one with an extra null. Since the non-length
# specified version apparently stops after the first null, join with a space first.
buffer = create_unicode_buffer(" ".join(paths))
# convert to a single string of null terminated paths
path_string = "\0".join(paths)
buffer = create_unicode_buffer(path_string, len(buffer) + 1)
fileop.pFrom = LPCWSTR(addressof(buffer))
fileop.pTo = None
fileop.fFlags = FOF_ALLOWUNDO | FOF_NOCONFIRMATION | FOF_NOERRORUI | FOF_SILENT
fileop.fAnyOperationsAborted = 0
fileop.hNameMappings = 0
fileop.lpszProgressTitle = None
result = SHFileOperationW(byref(fileop))
if result:
raise WindowsError(result, FormatError(result), paths) | null |
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