Mini Shell
# Licensed under the GPL: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
# For details: https://github.com/PyCQA/pylint/blob/main/LICENSE
# Copyright (c) https://github.com/PyCQA/pylint/blob/main/CONTRIBUTORS.txt
"""Utility methods for docstring checking."""
from __future__ import annotations
import re
import astroid
from astroid import nodes
from astroid.util import UninferableBase
from pylint.checkers import utils
def space_indentation(s: str) -> int:
"""The number of leading spaces in a string.
:param str s: input string
:rtype: int
:return: number of leading spaces
"""
return len(s) - len(s.lstrip(" "))
def get_setters_property_name(node: nodes.FunctionDef) -> str | None:
"""Get the name of the property that the given node is a setter for.
:param node: The node to get the property name for.
:type node: str
:rtype: str or None
:returns: The name of the property that the node is a setter for,
or None if one could not be found.
"""
decorators = node.decorators.nodes if node.decorators else []
for decorator in decorators:
if (
isinstance(decorator, nodes.Attribute)
and decorator.attrname == "setter"
and isinstance(decorator.expr, nodes.Name)
):
return decorator.expr.name # type: ignore[no-any-return]
return None
def get_setters_property(node: nodes.FunctionDef) -> nodes.FunctionDef | None:
"""Get the property node for the given setter node.
:param node: The node to get the property for.
:type node: nodes.FunctionDef
:rtype: nodes.FunctionDef or None
:returns: The node relating to the property of the given setter node,
or None if one could not be found.
"""
property_ = None
property_name = get_setters_property_name(node)
class_node = utils.node_frame_class(node)
if property_name and class_node:
class_attrs: list[nodes.FunctionDef] = class_node.getattr(node.name)
for attr in class_attrs:
if utils.decorated_with_property(attr):
property_ = attr
break
return property_
def returns_something(return_node: nodes.Return) -> bool:
"""Check if a return node returns a value other than None.
:param return_node: The return node to check.
:type return_node: astroid.Return
:rtype: bool
:return: True if the return node returns a value other than None,
False otherwise.
"""
returns = return_node.value
if returns is None:
return False
return not (isinstance(returns, nodes.Const) and returns.value is None)
def _get_raise_target(node: nodes.NodeNG) -> nodes.NodeNG | UninferableBase | None:
if isinstance(node.exc, nodes.Call):
func = node.exc.func
if isinstance(func, (nodes.Name, nodes.Attribute)):
return utils.safe_infer(func)
return None
def _split_multiple_exc_types(target: str) -> list[str]:
delimiters = r"(\s*,(?:\s*or\s)?\s*|\s+or\s+)"
return re.split(delimiters, target)
def possible_exc_types(node: nodes.NodeNG) -> set[nodes.ClassDef]:
"""Gets all the possible raised exception types for the given raise node.
.. note::
Caught exception types are ignored.
:param node: The raise node to find exception types for.
:returns: A list of exception types possibly raised by :param:`node`.
"""
exceptions = []
if isinstance(node.exc, nodes.Name):
inferred = utils.safe_infer(node.exc)
if inferred:
exceptions = [inferred]
elif node.exc is None:
handler = node.parent
while handler and not isinstance(handler, nodes.ExceptHandler):
handler = handler.parent
if handler and handler.type:
try:
for exception in astroid.unpack_infer(handler.type):
if not isinstance(exception, UninferableBase):
exceptions.append(exception)
except astroid.InferenceError:
pass
else:
target = _get_raise_target(node)
if isinstance(target, nodes.ClassDef):
exceptions = [target]
elif isinstance(target, nodes.FunctionDef):
for ret in target.nodes_of_class(nodes.Return):
if ret.value is None:
continue
if ret.frame(future=True) != target:
# return from inner function - ignore it
continue
val = utils.safe_infer(ret.value)
if val and utils.inherit_from_std_ex(val):
if isinstance(val, nodes.ClassDef):
exceptions.append(val)
elif isinstance(val, astroid.Instance):
exceptions.append(val.getattr("__class__")[0])
try:
return {
exc
for exc in exceptions
if not utils.node_ignores_exception(node, exc.name)
}
except astroid.InferenceError:
return set()
def docstringify(
docstring: nodes.Const | None, default_type: str = "default"
) -> Docstring:
best_match = (0, DOCSTRING_TYPES.get(default_type, Docstring)(docstring))
for docstring_type in (
SphinxDocstring,
EpytextDocstring,
GoogleDocstring,
NumpyDocstring,
):
instance = docstring_type(docstring)
matching_sections = instance.matching_sections()
if matching_sections > best_match[0]:
best_match = (matching_sections, instance)
return best_match[1]
class Docstring:
re_for_parameters_see = re.compile(
r"""
For\s+the\s+(other)?\s*parameters\s*,\s+see
""",
re.X | re.S,
)
supports_yields: bool = False
"""True if the docstring supports a "yield" section.
False if the docstring uses the returns section to document generators.
"""
# These methods are designed to be overridden
def __init__(self, doc: nodes.Const | None) -> None:
docstring: str = doc.value if doc else ""
self.doc = docstring.expandtabs()
def __repr__(self) -> str:
return f"<{self.__class__.__name__}:'''{self.doc}'''>"
def matching_sections(self) -> int:
"""Returns the number of matching docstring sections."""
return 0
def exceptions(self) -> set[str]:
return set()
def has_params(self) -> bool:
return False
def has_returns(self) -> bool:
return False
def has_rtype(self) -> bool:
return False
def has_property_returns(self) -> bool:
return False
def has_property_type(self) -> bool:
return False
def has_yields(self) -> bool:
return False
def has_yields_type(self) -> bool:
return False
def match_param_docs(self) -> tuple[set[str], set[str]]:
return set(), set()
def params_documented_elsewhere(self) -> bool:
return self.re_for_parameters_see.search(self.doc) is not None
class SphinxDocstring(Docstring):
re_type = r"""
[~!.]? # Optional link style prefix
\w(?:\w|\.[^\.])* # Valid python name
"""
re_simple_container_type = rf"""
{re_type} # a container type
[\(\[] [^\n\s]+ [\)\]] # with the contents of the container
"""
re_multiple_simple_type = r"""
(?:{container_type}|{type})
(?:(?:\s+(?:of|or)\s+|\s*,\s*|\s+\|\s+)(?:{container_type}|{type}))*
""".format(
type=re_type, container_type=re_simple_container_type
)
re_xref = rf"""
(?::\w+:)? # optional tag
`{re_type}` # what to reference
"""
re_param_raw = rf"""
: # initial colon
(?: # Sphinx keywords
param|parameter|
arg|argument|
key|keyword
)
\s+ # whitespace
(?: # optional type declaration
({re_type}|{re_simple_container_type})
\s+
)?
((\\\*{{0,2}}\w+)|(\w+)) # Parameter name with potential asterisks
\s* # whitespace
: # final colon
"""
re_param_in_docstring = re.compile(re_param_raw, re.X | re.S)
re_type_raw = rf"""
:type # Sphinx keyword
\s+ # whitespace
({re_multiple_simple_type}) # Parameter name
\s* # whitespace
: # final colon
"""
re_type_in_docstring = re.compile(re_type_raw, re.X | re.S)
re_property_type_raw = rf"""
:type: # Sphinx keyword
\s+ # whitespace
{re_multiple_simple_type} # type declaration
"""
re_property_type_in_docstring = re.compile(re_property_type_raw, re.X | re.S)
re_raise_raw = rf"""
: # initial colon
(?: # Sphinx keyword
raises?|
except|exception
)
\s+ # whitespace
({re_multiple_simple_type}) # exception type
\s* # whitespace
: # final colon
"""
re_raise_in_docstring = re.compile(re_raise_raw, re.X | re.S)
re_rtype_in_docstring = re.compile(r":rtype:")
re_returns_in_docstring = re.compile(r":returns?:")
supports_yields = False
def matching_sections(self) -> int:
"""Returns the number of matching docstring sections."""
return sum(
bool(i)
for i in (
self.re_param_in_docstring.search(self.doc),
self.re_raise_in_docstring.search(self.doc),
self.re_rtype_in_docstring.search(self.doc),
self.re_returns_in_docstring.search(self.doc),
self.re_property_type_in_docstring.search(self.doc),
)
)
def exceptions(self) -> set[str]:
types: set[str] = set()
for match in re.finditer(self.re_raise_in_docstring, self.doc):
raise_type = match.group(1)
types.update(_split_multiple_exc_types(raise_type))
return types
def has_params(self) -> bool:
if not self.doc:
return False
return self.re_param_in_docstring.search(self.doc) is not None
def has_returns(self) -> bool:
if not self.doc:
return False
return bool(self.re_returns_in_docstring.search(self.doc))
def has_rtype(self) -> bool:
if not self.doc:
return False
return bool(self.re_rtype_in_docstring.search(self.doc))
def has_property_returns(self) -> bool:
if not self.doc:
return False
# The summary line is the return doc,
# so the first line must not be a known directive.
return not self.doc.lstrip().startswith(":")
def has_property_type(self) -> bool:
if not self.doc:
return False
return bool(self.re_property_type_in_docstring.search(self.doc))
def match_param_docs(self) -> tuple[set[str], set[str]]:
params_with_doc = set()
params_with_type = set()
for match in re.finditer(self.re_param_in_docstring, self.doc):
name = match.group(2)
# Remove escape characters necessary for asterisks
name = name.replace("\\", "")
params_with_doc.add(name)
param_type = match.group(1)
if param_type is not None:
params_with_type.add(name)
params_with_type.update(re.findall(self.re_type_in_docstring, self.doc))
return params_with_doc, params_with_type
class EpytextDocstring(SphinxDocstring):
"""Epytext is similar to Sphinx.
See the docs:
http://epydoc.sourceforge.net/epytext.html
http://epydoc.sourceforge.net/fields.html#fields
It's used in PyCharm:
https://www.jetbrains.com/help/pycharm/2016.1/creating-documentation-comments.html#d848203e314
https://www.jetbrains.com/help/pycharm/2016.1/using-docstrings-to-specify-types.html
"""
re_param_in_docstring = re.compile(
SphinxDocstring.re_param_raw.replace(":", "@", 1), re.X | re.S
)
re_type_in_docstring = re.compile(
SphinxDocstring.re_type_raw.replace(":", "@", 1), re.X | re.S
)
re_property_type_in_docstring = re.compile(
SphinxDocstring.re_property_type_raw.replace(":", "@", 1), re.X | re.S
)
re_raise_in_docstring = re.compile(
SphinxDocstring.re_raise_raw.replace(":", "@", 1), re.X | re.S
)
re_rtype_in_docstring = re.compile(
r"""
@ # initial "at" symbol
(?: # Epytext keyword
rtype|returntype
)
: # final colon
""",
re.X | re.S,
)
re_returns_in_docstring = re.compile(r"@returns?:")
def has_property_returns(self) -> bool:
if not self.doc:
return False
# If this is a property docstring, the summary is the return doc.
if self.has_property_type():
# The summary line is the return doc,
# so the first line must not be a known directive.
return not self.doc.lstrip().startswith("@")
return False
class GoogleDocstring(Docstring):
re_type = SphinxDocstring.re_type
re_xref = SphinxDocstring.re_xref
re_container_type = rf"""
(?:{re_type}|{re_xref}) # a container type
[\(\[] [^\n]+ [\)\]] # with the contents of the container
"""
re_multiple_type = r"""
(?:{container_type}|{type}|{xref})
(?:(?:\s+(?:of|or)\s+|\s*,\s*|\s+\|\s+)(?:{container_type}|{type}|{xref}))*
""".format(
type=re_type, xref=re_xref, container_type=re_container_type
)
_re_section_template = r"""
^([ ]*) {0} \s*: \s*$ # Google parameter header
( .* ) # section
"""
re_param_section = re.compile(
_re_section_template.format(r"(?:Args|Arguments|Parameters)"),
re.X | re.S | re.M,
)
re_keyword_param_section = re.compile(
_re_section_template.format(r"Keyword\s(?:Args|Arguments|Parameters)"),
re.X | re.S | re.M,
)
re_param_line = re.compile(
rf"""
\s* ((?:\\?\*{{0,2}})?[\w\\]+) # identifier potentially with asterisks or escaped `\`
\s* ( [(]
{re_multiple_type}
(?:,\s+optional)?
[)] )? \s* : # optional type declaration
\s* (.*) # beginning of optional description
""",
re.X | re.S | re.M,
)
re_raise_section = re.compile(
_re_section_template.format(r"Raises"), re.X | re.S | re.M
)
re_raise_line = re.compile(
rf"""
\s* ({re_multiple_type}) \s* : # identifier
\s* (.*) # beginning of optional description
""",
re.X | re.S | re.M,
)
re_returns_section = re.compile(
_re_section_template.format(r"Returns?"), re.X | re.S | re.M
)
re_returns_line = re.compile(
rf"""
\s* ({re_multiple_type}:)? # identifier
\s* (.*) # beginning of description
""",
re.X | re.S | re.M,
)
re_property_returns_line = re.compile(
rf"""
^{re_multiple_type}: # identifier
\s* (.*) # Summary line / description
""",
re.X | re.S | re.M,
)
re_yields_section = re.compile(
_re_section_template.format(r"Yields?"), re.X | re.S | re.M
)
re_yields_line = re_returns_line
supports_yields = True
def matching_sections(self) -> int:
"""Returns the number of matching docstring sections."""
return sum(
bool(i)
for i in (
self.re_param_section.search(self.doc),
self.re_raise_section.search(self.doc),
self.re_returns_section.search(self.doc),
self.re_yields_section.search(self.doc),
self.re_property_returns_line.search(self._first_line()),
)
)
def has_params(self) -> bool:
if not self.doc:
return False
return self.re_param_section.search(self.doc) is not None
def has_returns(self) -> bool:
if not self.doc:
return False
entries = self._parse_section(self.re_returns_section)
for entry in entries:
match = self.re_returns_line.match(entry)
if not match:
continue
return_desc = match.group(2)
if return_desc:
return True
return False
def has_rtype(self) -> bool:
if not self.doc:
return False
entries = self._parse_section(self.re_returns_section)
for entry in entries:
match = self.re_returns_line.match(entry)
if not match:
continue
return_type = match.group(1)
if return_type:
return True
return False
def has_property_returns(self) -> bool:
# The summary line is the return doc,
# so the first line must not be a known directive.
first_line = self._first_line()
return not bool(
self.re_param_section.search(first_line)
or self.re_raise_section.search(first_line)
or self.re_returns_section.search(first_line)
or self.re_yields_section.search(first_line)
)
def has_property_type(self) -> bool:
if not self.doc:
return False
return bool(self.re_property_returns_line.match(self._first_line()))
def has_yields(self) -> bool:
if not self.doc:
return False
entries = self._parse_section(self.re_yields_section)
for entry in entries:
match = self.re_yields_line.match(entry)
if not match:
continue
yield_desc = match.group(2)
if yield_desc:
return True
return False
def has_yields_type(self) -> bool:
if not self.doc:
return False
entries = self._parse_section(self.re_yields_section)
for entry in entries:
match = self.re_yields_line.match(entry)
if not match:
continue
yield_type = match.group(1)
if yield_type:
return True
return False
def exceptions(self) -> set[str]:
types: set[str] = set()
entries = self._parse_section(self.re_raise_section)
for entry in entries:
match = self.re_raise_line.match(entry)
if not match:
continue
exc_type = match.group(1)
exc_desc = match.group(2)
if exc_desc:
types.update(_split_multiple_exc_types(exc_type))
return types
def match_param_docs(self) -> tuple[set[str], set[str]]:
params_with_doc: set[str] = set()
params_with_type: set[str] = set()
entries = self._parse_section(self.re_param_section)
entries.extend(self._parse_section(self.re_keyword_param_section))
for entry in entries:
match = self.re_param_line.match(entry)
if not match:
continue
param_name = match.group(1)
# Remove escape characters necessary for asterisks
param_name = param_name.replace("\\", "")
param_type = match.group(2)
param_desc = match.group(3)
if param_type:
params_with_type.add(param_name)
if param_desc:
params_with_doc.add(param_name)
return params_with_doc, params_with_type
def _first_line(self) -> str:
return self.doc.lstrip().split("\n", 1)[0]
@staticmethod
def min_section_indent(section_match: re.Match[str]) -> int:
return len(section_match.group(1)) + 1
@staticmethod
def _is_section_header(_: str) -> bool:
# Google parsing does not need to detect section headers,
# because it works off of indentation level only
return False
def _parse_section(self, section_re: re.Pattern[str]) -> list[str]:
section_match = section_re.search(self.doc)
if section_match is None:
return []
min_indentation = self.min_section_indent(section_match)
entries: list[str] = []
entry: list[str] = []
is_first = True
for line in section_match.group(2).splitlines():
if not line.strip():
continue
indentation = space_indentation(line)
if indentation < min_indentation:
break
# The first line after the header defines the minimum
# indentation.
if is_first:
min_indentation = indentation
is_first = False
if indentation == min_indentation:
if self._is_section_header(line):
break
# Lines with minimum indentation must contain the beginning
# of a new parameter documentation.
if entry:
entries.append("\n".join(entry))
entry = []
entry.append(line)
if entry:
entries.append("\n".join(entry))
return entries
class NumpyDocstring(GoogleDocstring):
_re_section_template = r"""
^([ ]*) {0} \s*?$ # Numpy parameters header
\s* [-=]+ \s*?$ # underline
( .* ) # section
"""
re_param_section = re.compile(
_re_section_template.format(r"(?:Args|Arguments|Parameters)"),
re.X | re.S | re.M,
)
re_default_value = r"""((['"]\w+\s*['"])|(\d+)|(True)|(False)|(None))"""
re_param_line = re.compile(
rf"""
\s* (?P<param_name>\*{{0,2}}\w+)(\s?(:|\n)) # identifier with potential asterisks
\s*
(?P<param_type>
(
({GoogleDocstring.re_multiple_type}) # default type declaration
(,\s+optional)? # optional 'optional' indication
)?
(
{{({re_default_value},?\s*)+}} # set of default values
)?
(?:$|\n)
)?
(
\s* (?P<param_desc>.*) # optional description
)?
""",
re.X | re.S,
)
re_raise_section = re.compile(
_re_section_template.format(r"Raises"), re.X | re.S | re.M
)
re_raise_line = re.compile(
rf"""
\s* ({GoogleDocstring.re_type})$ # type declaration
\s* (.*) # optional description
""",
re.X | re.S | re.M,
)
re_returns_section = re.compile(
_re_section_template.format(r"Returns?"), re.X | re.S | re.M
)
re_returns_line = re.compile(
rf"""
\s* (?:\w+\s+:\s+)? # optional name
({GoogleDocstring.re_multiple_type})$ # type declaration
\s* (.*) # optional description
""",
re.X | re.S | re.M,
)
re_yields_section = re.compile(
_re_section_template.format(r"Yields?"), re.X | re.S | re.M
)
re_yields_line = re_returns_line
supports_yields = True
def match_param_docs(self) -> tuple[set[str], set[str]]:
"""Matches parameter documentation section to parameter documentation rules."""
params_with_doc = set()
params_with_type = set()
entries = self._parse_section(self.re_param_section)
entries.extend(self._parse_section(self.re_keyword_param_section))
for entry in entries:
match = self.re_param_line.match(entry)
if not match:
continue
# check if parameter has description only
re_only_desc = re.match(r"\s*(\*{0,2}\w+)\s*:?\n\s*\w*$", entry)
if re_only_desc:
param_name = match.group("param_name")
param_desc = match.group("param_type")
param_type = None
else:
param_name = match.group("param_name")
param_type = match.group("param_type")
param_desc = match.group("param_desc")
# The re_param_line pattern needs to match multi-line which removes the ability
# to match a single line description like 'arg : a number type.'
# We are not trying to determine whether 'a number type' is correct typing
# but we do accept it as typing as it is in the place where typing
# should be
if param_type is None and re.match(r"\s*(\*{0,2}\w+)\s*:.+$", entry):
param_type = param_desc
# If the description is "" but we have a type description
# we consider the description to be the type
if not param_desc and param_type:
param_desc = param_type
if param_type:
params_with_type.add(param_name)
if param_desc:
params_with_doc.add(param_name)
return params_with_doc, params_with_type
@staticmethod
def min_section_indent(section_match: re.Match[str]) -> int:
return len(section_match.group(1))
@staticmethod
def _is_section_header(line: str) -> bool:
return bool(re.match(r"\s*-+$", line))
DOCSTRING_TYPES = {
"sphinx": SphinxDocstring,
"epytext": EpytextDocstring,
"google": GoogleDocstring,
"numpy": NumpyDocstring,
"default": Docstring,
}
"""A map of the name of the docstring type to its class.
:type: dict(str, type)
"""
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