"""Pylint plugin for parameter documentation checking in Sphinx, Google or Numpy style docstrings """ from __future__ import print_function, division, absolute_import import re from pylint.interfaces import IAstroidChecker from pylint.checkers import BaseChecker from pylint.checkers.utils import node_frame_class def space_indentation(s): """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(' ')) class ParamDocChecker(BaseChecker): """Checker for parameter documentation in Sphinx, Google or Numpy style docstrings * Check that all function, method and constructor parameters are mentioned in the params and types part of the docstring. By convention, constructor parameters are documented in the class docstring. * Check that there are no naming inconsistencies between the signature and the documentation, i.e. also report documented parameters that are missing in the signature. This is important to find cases where parameters are renamed only in the code, not in the documentation. Activate this checker by adding the line:: load-plugins=pylint.extensions.check_docs to the ``MASTER`` section of your ``.pylintrc``. :param linter: linter object :type linter: :class:`pylint.lint.PyLinter` """ __implements__ = IAstroidChecker name = 'param_checks' msgs = { 'W9003': ('"%s" missing or differing in parameter documentation', 'missing-param-doc', 'Please add parameter declarations for all parameters.'), 'W9004': ('"%s" missing or differing in parameter type documentation', 'missing-type-doc', 'Please add parameter type declarations for all parameters.'), } options = (('accept-no-param-doc', {'default': True, 'type' : 'yn', 'metavar' : '', 'help': 'Whether to accept totally missing parameter ' 'documentation in a docstring of a function that has ' 'parameters' }), ) priority = -2 def __init__(self, linter=None): BaseChecker.__init__(self, linter) constructor_names = set(["__init__", "__new__"]) def visit_functiondef(self, node): """Called for function and method definitions (def). :param node: Node for a function or method definition in the AST :type node: :class:`astroid.scoped_nodes.Function` """ if node.name in self.constructor_names: class_node = node_frame_class(node) if class_node is not None: self.check_arguments_in_docstring( class_node.doc, node.args, class_node) return self.check_arguments_in_docstring(node.doc, node.args, node) re_for_parameters_see = re.compile(r""" For\s+the\s+(other)?\s*parameters\s*,\s+see """, re.X | re.S) re_sphinx_param_in_docstring = re.compile(r""" :param # Sphinx keyword \s+ # whitespace (?: # optional type declaration (\w+) \s+ )? (\w+) # Parameter name \s* # whitespace : # final colon """, re.X | re.S) re_sphinx_type_in_docstring = re.compile(r""" :type # Sphinx keyword \s+ # whitespace (\w+) # Parameter name \s* # whitespace : # final colon """, re.X | re.S) re_google_param_section = re.compile(r""" ^([ ]*) Args \s*: \s*?$ # Google parameter header ( .* ) # section """, re.X | re.S | re.M) re_google_param_line = re.compile(r""" \s* (\w+) # identifier \s* ( [(] .*? [)] )? \s* : # optional type declaration \s* ( \w+ )? # beginning of optional description """, re.X) re_numpy_param_section = re.compile(r""" ^([ ]*) Parameters \s*?$ # Numpy parameters header \s* [-=]+ \s*?$ # underline ( .* ) # section """, re.X | re.S | re.M) re_numpy_param_line = re.compile(r""" \s* (\w+) # identifier \s* : \s* ( \w+ )? # optional type declaration """, re.X) not_needed_param_in_docstring = set(['self', 'cls']) def check_arguments_in_docstring(self, doc, arguments_node, warning_node): """Check that all parameters in a function, method or class constructor on the one hand and the parameters mentioned in the parameter documentation (e.g. the Sphinx tags 'param' and 'type') on the other hand are consistent with each other. * Undocumented parameters except 'self' are noticed. * Undocumented parameter types except for 'self' and the ``*`` and ``**`` parameters are noticed. * Parameters mentioned in the parameter documentation that don't or no longer exist in the function parameter list are noticed. * If the text "For the parameters, see" or "For the other parameters, see" (ignoring additional whitespace) is mentioned in the docstring, missing parameter documentation is tolerated. * If there's no Sphinx style, Google style or NumPy style parameter documentation at all, i.e. ``:param`` is never mentioned etc., the checker assumes that the parameters are documented in another format and the absence is tolerated. :param doc: Docstring for the function, method or class. :type doc: str :param arguments_node: Arguments node for the function, method or class constructor. :type arguments_node: :class:`astroid.scoped_nodes.Arguments` :param warning_node: The node to assign the warnings to :type warning_node: :class:`astroid.scoped_nodes.Node` """ # Tolerate missing param or type declarations if there is a link to # another method carrying the same name. if doc is None: return doc = doc.expandtabs() tolerate_missing_params = self.re_for_parameters_see.search(doc) is not None # Collect the function arguments. expected_argument_names = [arg.name for arg in arguments_node.args] not_needed_type_in_docstring = ( self.not_needed_param_in_docstring.copy()) if arguments_node.vararg is not None: expected_argument_names.append(arguments_node.vararg) not_needed_type_in_docstring.add(arguments_node.vararg) if arguments_node.kwarg is not None: expected_argument_names.append(arguments_node.kwarg) not_needed_type_in_docstring.add(arguments_node.kwarg) params_with_doc, params_with_type = self.match_param_docs(doc) # Tolerate no parameter documentation at all. if (not params_with_doc and not params_with_type and self.config.accept_no_param_doc): tolerate_missing_params = True def _compare_args(found_argument_names, message_id, not_needed_names): """Compare the found argument names with the expected ones and generate a message if there are inconsistencies. :param list found_argument_names: argument names found in the docstring :param str message_id: pylint message id :param not_needed_names: names that may be omitted :type not_needed_names: set of str """ if not tolerate_missing_params: missing_or_differing_argument_names = ( (set(expected_argument_names) ^ set(found_argument_names)) - not_needed_names) else: missing_or_differing_argument_names = ( (set(found_argument_names) - set(expected_argument_names)) - not_needed_names) if missing_or_differing_argument_names: self.add_message( message_id, args=(', '.join( sorted(missing_or_differing_argument_names)),), node=warning_node) _compare_args(params_with_doc, 'missing-param-doc', self.not_needed_param_in_docstring) _compare_args(params_with_type, 'missing-type-doc', not_needed_type_in_docstring) def match_param_docs(self, doc): """Match parameter documentation in docstrings written in Sphinx, Google or NumPy style :param str doc: docstring :return: tuple of lists of str: params_with_doc, params_with_type """ params_with_doc = [] params_with_type = [] if self.re_sphinx_param_in_docstring.search(doc) is not None: # Sphinx param declarations for match in re.finditer(self.re_sphinx_param_in_docstring, doc): name = match.group(2) params_with_doc.append(name) if match.group(1) is not None: params_with_type.append(name) # Sphinx type declarations params_with_type += re.findall( self.re_sphinx_type_in_docstring, doc) else: match = self.re_google_param_section.search(doc) if match is not None: is_google = True re_line = self.re_google_param_line else: match = self.re_numpy_param_section.search(doc) if match is not None: is_google = False re_line = self.re_numpy_param_line else: # some other documentation style return [], [] min_indentation = len(match.group(1)) if is_google: min_indentation += 1 prev_param_name = None is_first = True for line in 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: # Lines with more than minimum indentation must contain a # description. if (not params_with_doc or params_with_doc[-1] != prev_param_name): assert prev_param_name is not None params_with_doc.append(prev_param_name) else: # Lines with minimum indentation must contain the beginning # of a new parameter documentation. match = re_line.match(line) if match is None: break prev_param_name = match.group(1) if match.group(2) is not None: params_with_type.append(prev_param_name) if is_google and match.group(3) is not None: params_with_doc.append(prev_param_name) return params_with_doc, params_with_type def register(linter): """Required method to auto register this checker. :param linter: Main interface object for Pylint plugins :type linter: Pylint object """ linter.register_checker(ParamDocChecker(linter))