"""Pylint plugin for checking in Sphinx, Google, or Numpy style docstrings """ from __future__ import print_function, division, absolute_import import astroid from pylint.interfaces import IAstroidChecker from pylint.checkers import BaseChecker from pylint.checkers.utils import node_frame_class import pylint.extensions._check_docs_utils as utils class DocstringChecker(BaseChecker): """Checker for 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. Constructor parameters can be documented in either the class docstring or ``__init__`` docstring, but not both. * 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. * Check that all explicity raised exceptions in a function are documented in the function docstring. Caught exceptions are ignored. 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 = 'docstring_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.'), 'W9005': ('"%s" has constructor parameters documented in class and __init__', 'multiple-constructor-doc', 'Please remove parameter declarations in the class or constructor.'), 'W9006': ('"%s" not documented as being raised', 'missing-raises-doc', 'Please document exceptions for all raised exception types.'), 'W9007': ('Missing return type documentation', 'missing-returns-doc', 'Please add documentation about what this method returns.'), } 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.' }), ('accept-no-raise-doc', {'default': True, 'type' : 'yn', 'metavar' : '', 'help': 'Whether to accept totally missing raises' 'documentation in a docstring of a function that' 'raises an exception.' }), ('accept-no-return-doc', {'default': True, 'type' : 'yn', 'metavar' : '', 'help': 'Whether to accept totally missing return' 'documentation in a docstring of a function that' 'returns a statement.' }), ) priority = -2 constructor_names = {"__init__", "__new__"} not_needed_param_in_docstring = {'self', 'cls'} 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` """ node_allow_no_param = None node_doc = utils.docstringify(node.doc) if node.name in self.constructor_names: class_node = node_frame_class(node) if class_node is not None: class_doc = utils.docstringify(class_node.doc) self.check_single_constructor_params(class_doc, node_doc, class_node) # __init__ or class docstrings can have no parameters documented # as long as the other documents them. node_allow_no_param = class_doc.has_params() or None class_allow_no_param = node_doc.has_params() or None self.check_arguments_in_docstring( class_doc, node.args, class_node, class_allow_no_param) self.check_arguments_in_docstring( node_doc, node.args, node, node_allow_no_param) def visit_raise(self, node): func_node = node.frame() if not isinstance(func_node, astroid.FunctionDef): return expected_excs = utils.possible_exc_types(node) if not expected_excs: return doc = utils.docstringify(func_node.doc) if not doc.is_valid(): if doc.doc: self._handle_no_raise_doc(expected_excs, func_node) return found_excs = doc.exceptions() missing_excs = expected_excs - found_excs self._add_raise_message(missing_excs, func_node) def visit_return(self, node): if node.value is None: return func_node = node.frame() if not isinstance(func_node, astroid.FunctionDef): return doc = utils.docstringify(func_node.doc) if not doc.is_valid() and self.config.accept_no_return_doc: return if not doc.has_returns(): self.add_message( 'missing-returns-doc', node=func_node ) def check_arguments_in_docstring(self, doc, arguments_node, warning_node, accept_no_param_doc=None): """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` :param accept_no_param_doc: Whether or not to allow no parameters to be documented. If None then this value is read from the configuration. :type accept_no_param_doc: bool or None """ # Tolerate missing param or type declarations if there is a link to # another method carrying the same name. if not doc.doc: return if accept_no_param_doc is None: accept_no_param_doc = self.config.accept_no_param_doc tolerate_missing_params = doc.params_documented_elsewhere() # Collect the function arguments. expected_argument_names = set(arg.name for arg in arguments_node.args) expected_argument_names.update(arg.name for arg in arguments_node.kwonlyargs) 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 = doc.match_param_docs() # Tolerate no parameter documentation at all. if (not params_with_doc and not params_with_type and 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 = ( (expected_argument_names ^ found_argument_names) - not_needed_names) else: missing_or_differing_argument_names = ( (found_argument_names - 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 check_single_constructor_params(self, class_doc, init_doc, class_node): if class_doc.has_params() and init_doc.has_params(): self.add_message( 'multiple-constructor-doc', args=(class_node.name,), node=class_node) def _handle_no_raise_doc(self, excs, node): if self.config.accept_no_raise_doc: return self._add_raise_message(excs, node) def _add_raise_message(self, missing_excs, node): """ Adds a message on :param:`node` for the missing exception type. :param missing_excs: A list of missing exception types. :type missing_excs: list :param node: The node show the message on. """ if not missing_excs: return self.add_message( 'missing-raises-doc', args=(', '.join(sorted(missing_excs)),), node=node) 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(DocstringChecker(linter))