fname stringlengths 63 176 | rel_fname stringclasses 706 values | line int64 -1 4.5k | name stringlengths 1 81 | kind stringclasses 2 values | category stringclasses 2 values | info stringlengths 0 77.9k ⌀ |
|---|---|---|---|---|---|---|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/__init__.py | pylint/checkers/classes/__init__.py | 13 | ClassChecker | ref | function | linter.register_checker(ClassChecker(linter))
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/__init__.py | pylint/checkers/classes/__init__.py | 14 | register_checker | ref | function | linter.register_checker(SpecialMethodsChecker(linter))
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/__init__.py | pylint/checkers/classes/__init__.py | 14 | SpecialMethodsChecker | ref | function | linter.register_checker(SpecialMethodsChecker(linter))
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 94 | infer | ref | function | nodes.Name: lambda a, b: set(a.infer()) == set(b.infer()),
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 94 | infer | ref | function | nodes.Name: lambda a, b: set(a.infer()) == set(b.infer()),
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 108 | _signature_from_call | def | function | def _signature_from_call(call):
kws = {}
args = []
starred_kws = []
starred_args = []
for keyword in call.keywords or []:
arg, value = keyword.arg, keyword.value
if arg is None and isinstance(value, nodes.Name):
# Starred node and we are interested only in names,
# otherwise some transformation might occur for the parameter.
starred_kws.append(value.name)
elif isinstance(value, nodes.Name):
kws[arg] = value.name
else:
kws[arg] = None
for arg in call.args:
if isinstance(arg, nodes.Starred) and isinstance(arg.value, nodes.Name):
# Positional variadic and a name, otherwise some transformation
# might have occurred.
starred_args.append(arg.value.name)
elif isinstance(arg, nodes.Name):
args.append(arg.name)
else:
args.append(None)
return _CallSignature(args, kws, starred_args, starred_kws)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 134 | _CallSignature | ref | function | return _CallSignature(args, kws, starred_args, starred_kws)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 137 | _signature_from_arguments | def | function | def _signature_from_arguments(arguments):
kwarg = arguments.kwarg
vararg = arguments.vararg
args = [
arg.name
for arg in chain(arguments.posonlyargs, arguments.args)
if arg.name != "self"
]
kwonlyargs = [arg.name for arg in arguments.kwonlyargs]
return _ParameterSignature(args, kwonlyargs, vararg, kwarg)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 146 | _ParameterSignature | ref | function | return _ParameterSignature(args, kwonlyargs, vararg, kwarg)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 149 | _definition_equivalent_to_call | def | function | def _definition_equivalent_to_call(definition, call):
"""Check if a definition signature is equivalent to a call."""
if definition.kwargs:
if definition.kwargs not in call.starred_kws:
return _False
elif call.starred_kws:
return _False
if definition.varargs:
if definition.varargs not in call.starred_args:
return _False
elif call.starred_args:
return _False
if any(kw not in call.kws for kw in definition.kwonlyargs):
return _False
if definition.args != call.args:
return _False
# No extra kwargs in call.
return all(kw in call.args or kw in definition.kwonlyargs for kw in call.kws)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 173 | _positional_parameters | def | function | def _positional_parameters(method):
positional = method.args.args
if method.is_bound() and method.type in {"classmethod", "method"}:
positional = positional[1:]
return positional
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 175 | is_bound | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 180 | _DefaultMissing | def | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 184 | _DefaultMissing | ref | function | _DEFAULT_MISSING = _DefaultMissing()
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 187 | _has_different_parameters_default_value | def | function | def _has_different_parameters_default_value(original, overridden):
"""Check if original and overridden methods arguments have different default values.
Return _True if one of the overridden arguments has a default
value different from the default value of the original argument
If one of the method doesn't have argument (.args is None)
return _False
"""
if original.args is None or overridden.args is None:
return _False
for param in chain(original.args, original.kwonlyargs):
try:
original_default = original.default_value(param.name)
except astroid.exceptions.NoDefault:
original_default = _DEFAULT_MISSING
try:
overridden_default = overridden.default_value(param.name)
if original_default is _DEFAULT_MISSING:
# Only the original has a default.
return _True
except astroid.exceptions.NoDefault:
if original_default is _DEFAULT_MISSING:
# Both have a default, no difference
continue
# Only the override has a default.
return _True
original_type = type(original_default)
if not isinstance(overridden_default, original_type):
# Two args with same name but different types
return _True
is_same_fn = ASTROID_TYPE_COMPARATORS.get(original_type)
if is_same_fn is None:
# If the default value comparison is unhandled, assume the value is different
return _True
if not is_same_fn(original_default, overridden_default):
# Two args with same type but different values
return _True
return _False
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 200 | default_value | ref | function | original_default = original.default_value(param.name)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 204 | default_value | ref | function | overridden_default = overridden.default_value(param.name)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 223 | is_same_fn | ref | function | if not is_same_fn(original_default, overridden_default):
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 229 | _has_different_parameters | def | function | def _has_different_parameters(
original: List[nodes.AssignName],
overridden: List[nodes.AssignName],
dummy_parameter_regex: Pattern,
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 243 | match | ref | function | if any(dummy_parameter_regex.match(name) for name in names):
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 254 | _different_parameters | def | function | def _different_parameters(
original: nodes.FunctionDef,
overridden: nodes.FunctionDef,
dummy_parameter_regex: Pattern,
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 271 | _positional_parameters | ref | function | original_parameters = _positional_parameters(original)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 272 | _positional_parameters | ref | function | overridden_parameters = _positional_parameters(overridden)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 293 | _has_different_parameters | ref | function | different_positional = _has_different_parameters(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 296 | _has_different_parameters | ref | function | different_kwonly = _has_different_parameters(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 332 | _is_invalid_base_class | def | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 333 | is_builtin_object | ref | function | return cls.name in INVALID_BASE_CLASSES and is_builtin_object(cls)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 336 | _has_data_descriptor | def | function | def _has_data_descriptor(cls, attr):
attributes = cls.getattr(attr)
for attribute in attributes:
try:
for inferred in attribute.infer():
if isinstance(inferred, astroid.Instance):
try:
inferred.getattr("__get__")
inferred.getattr("__set__")
except astroid.NotFoundError:
continue
else:
return _True
except astroid.InferenceError:
# Can't infer, avoid emitting a false positive in this case.
return _True
return _False
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 340 | infer | ref | function | for inferred in attribute.infer():
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 355 | _called_in_methods | def | function | def _called_in_methods(func, klass, methods):
"""Check if the func was called in any of the given methods,
belonging to the *klass*. Returns _True if so, _False otherwise.
"""
if not isinstance(func, nodes.FunctionDef):
return _False
for method in methods:
try:
inferred = klass.getattr(method)
except astroid.NotFoundError:
continue
for infer_method in inferred:
for call in infer_method.nodes_of_class(nodes.Call):
try:
bound = next(call.func.infer())
except (astroid.InferenceError, StopIteration):
continue
if not isinstance(bound, astroid.BoundMethod):
continue
func_obj = bound._proxied
if isinstance(func_obj, astroid.UnboundMethod):
func_obj = func_obj._proxied
if func_obj.name == func.name:
return _True
return _False
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 367 | nodes_of_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 369 | infer | ref | function | bound = next(call.func.infer())
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 382 | _is_attribute_property | def | function | def _is_attribute_property(name, klass):
"""Check if the given attribute *name* is a property in the given *klass*.
It will look for `property` calls or for functions
with the given name, decorated by `property` or `property`
subclasses.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
attributes = klass.getattr(name)
except astroid.NotFoundError:
return _False
property_name = "builtins.property"
for attr in attributes:
if attr is astroid.Uninferable:
continue
try:
inferred = next(attr.infer())
except astroid.InferenceError:
continue
if isinstance(inferred, nodes.FunctionDef) and decorated_with_property(
inferred
):
return _True
if inferred.pytype() != property_name:
continue
cls = node_frame_class(inferred)
if cls == klass.declared_metaclass():
continue
return _True
return _False
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 401 | infer | ref | function | inferred = next(attr.infer())
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 404 | decorated_with_property | ref | function | if isinstance(inferred, nodes.FunctionDef) and decorated_with_property(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 408 | pytype | ref | function | if inferred.pytype() != property_name:
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 411 | node_frame_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 412 | declared_metaclass | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 418 | _has_bare_super_call | def | function | def _has_bare_super_call(fundef_node):
for call in fundef_node.nodes_of_class(nodes.Call):
func = call.func
if isinstance(func, nodes.Name) and func.name == "super" and not call.args:
return _True
return _False
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 419 | nodes_of_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 426 | _has_same_layout_slots | def | function | def _has_same_layout_slots(slots, assigned_value):
inferred = next(assigned_value.infer())
if isinstance(inferred, nodes.ClassDef):
other_slots = inferred.slots()
if all(
first_slot and second_slot and first_slot.value == second_slot.value
for (first_slot, second_slot) in zip_longest(slots, other_slots)
):
return _True
return _False
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 427 | infer | ref | function | inferred = next(assigned_value.infer())
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 429 | slots | ref | function | other_slots = inferred.slots()
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 667 | _scope_default | def | function | def _scope_default():
return collections.defaultdict(list)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 671 | ScopeAccessMap | def | class | __init__ set_accessed accessed |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 677 | set_accessed | def | function | def set_accessed(self, node):
"""Set the given node as accessed."""
frame = node_frame_class(node)
if frame is None:
# The node does not live in a class.
return
self._scopes[frame][node.attrname].append(node)
def accessed(self, scope):
"""Get the accessed variables for the given scope."""
return self._scopes.get(scope, {})
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 680 | node_frame_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 686 | accessed | def | function | def accessed(self, scope):
"""Get the accessed variables for the given scope."""
return self._scopes.get(scope, {})
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 691 | ClassChecker | def | class | __init__ open _dummy_rgx _ignore_mixin visit_classdef _check_consistent_mro _check_proper_bases _check_typing_final leave_classdef _check_unused_private_functions _check_unused_private_variables _check_unused_private_attributes _check_attribute_defined_outside_init visit_functiondef _check_useless_super_delegation _check_property_with_parameters _check_invalid_overridden_method _check_slots _check_redefined_slots _check_slots_elt leave_functiondef visit_attribute visit_assignattr _check_invalid_class_object _check_in_slots visit_assign _check_classmethod_declaration _check_protected_attribute_access _is_called_inside_special_method _is_type_self_call _is_classmethod _is_inferred_instance _is_class_attribute visit_name _check_accessed_members _check_first_arg_for_type _check_first_arg_config _check_bases_classes _check_init _check_signature _uses_mandatory_method_param _is_mandatory_method_param |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 771 | ScopeAccessMap | ref | function | self._accessed = ScopeAccessMap()
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 776 | get_global_option | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 777 | get_global_option | ref | function | py_version = get_global_option(self, "py-version")
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 781 | _dummy_rgx | def | function | def _dummy_rgx(self):
return get_global_option(self, "dummy-variables-rgx", default=None)
@astroid.decorators.cachedproperty
def _ignore_mixin(self):
return get_global_option(self, "ignore-mixin-members", default=_True)
@check_messages(
"abstract-method",
"no-init",
"invalid-slots",
"single-string-used-for-slots",
"invalid-slots-object",
"class-variable-slots-conflict",
"inherit-non-class",
"useless-object-inheritance",
"inconsistent-mro",
"duplicate-bases",
"redefined-slots-in-subclass",
)
def visit_classdef(self, node: nodes.ClassDef) -> None:
"""Init visit variable _accessed."""
self._check_bases_classes(node)
# if not an exception or a metaclass
if node.type == "class" and has_known_bases(node):
try:
node.local_attr("__init__")
except astroid.NotFoundError:
self.add_message("no-init", args=node, node=node)
self._check_slots(node)
self._check_proper_bases(node)
self._check_typing_final(node)
self._check_consistent_mro(node)
def _check_consistent_mro(self, node):
"""Detect that a class has a consistent mro or duplicate bases."""
try:
node.mro()
except astroid.InconsistentMroError:
self.add_message("inconsistent-mro", args=node.name, node=node)
except astroid.DuplicateBasesError:
self.add_message("duplicate-bases", args=node.name, node=node)
except NotImplementedError:
# Old style class, there's no mro so don't do anything.
pass
def _check_proper_bases(self, node):
"""Detect that a class inherits something which is not
a class or a type.
"""
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, astroid.Instance) and ancestor.is_subtype_of(
"builtins.type"
):
continue
if not isinstance(ancestor, nodes.ClassDef) or _is_invalid_base_class(
ancestor
):
self.add_message("inherit-non-class", args=base.as_string(), node=node)
if ancestor.name == object.__name__:
self.add_message(
"useless-object-inheritance", args=node.name, node=node
)
def _check_typing_final(self, node: nodes.ClassDef) -> None:
"""Detect that a class does not subclass a class decorated with `typing.final`."""
if not self._py38_plus:
return
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, nodes.ClassDef) and (
decorated_with(ancestor, ["typing.final"])
or uninferable_final_decorators(ancestor.decorators)
):
self.add_message(
"subclassed-final-class",
args=(node.name, ancestor.name),
node=node,
)
@check_messages("unused-private-member", "attribute-defined-outside-init")
def leave_classdef(self, node: nodes.ClassDef) -> None:
"""Close a class node:
check that instance attributes are defined in __init__ and check
access to existent members
"""
self._check_unused_private_functions(node)
self._check_unused_private_variables(node)
self._check_unused_private_attributes(node)
self._check_attribute_defined_outside_init(node)
def _check_unused_private_functions(self, node: nodes.ClassDef) -> None:
for function_def in node.nodes_of_class(nodes.FunctionDef):
if not is_attr_private(function_def.name):
continue
parent_scope = function_def.parent.scope()
if isinstance(parent_scope, nodes.FunctionDef):
# Handle nested functions
if function_def.name in (
n.name for n in parent_scope.nodes_of_class(nodes.Name)
):
continue
for attribute in node.nodes_of_class(nodes.Attribute):
if (
attribute.attrname != function_def.name
or attribute.scope() == function_def # We ignore recursive calls
):
continue
if isinstance(attribute.expr, nodes.Name) and attribute.expr.name in (
"self",
"cls",
node.name,
):
# self.__attrname
# cls.__attrname
# node_name.__attrname
break
if isinstance(attribute.expr, nodes.Call):
# type(self).__attrname
inferred = safe_infer(attribute.expr)
if (
isinstance(inferred, nodes.ClassDef)
and inferred.name == node.name
):
break
else:
name_stack = []
curr = parent_scope
# Generate proper names for nested functions
while curr != node:
name_stack.append(curr.name)
curr = curr.parent.scope()
outer_level_names = f"{'.'.join(reversed(name_stack))}"
function_repr = f"{outer_level_names}.{function_def.name}({function_def.args.as_string()})"
self.add_message(
"unused-private-member",
node=function_def,
args=(node.name, function_repr.lstrip(".")),
)
def _check_unused_private_variables(self, node: nodes.ClassDef) -> None:
"""Check if private variables are never used within a class."""
for assign_name in node.nodes_of_class(nodes.AssignName):
if isinstance(assign_name.parent, nodes.Arguments):
continue # Ignore function arguments
if not is_attr_private(assign_name.name):
continue
for child in node.nodes_of_class((nodes.Name, nodes.Attribute)):
if isinstance(child, nodes.Name) and child.name == assign_name.name:
break
if isinstance(child, nodes.Attribute):
if not isinstance(child.expr, nodes.Name):
break
if child.attrname == assign_name.name and child.expr.name in (
"self",
"cls",
node.name,
):
break
else:
args = (node.name, assign_name.name)
self.add_message("unused-private-member", node=assign_name, args=args)
def _check_unused_private_attributes(self, node: nodes.ClassDef) -> None:
for assign_attr in node.nodes_of_class(nodes.AssignAttr):
if not is_attr_private(assign_attr.attrname) or not isinstance(
assign_attr.expr, nodes.Name
):
continue
# Logic for checking false positive when using __new__,
# Get the returned object names of the __new__ magic function
# Then check if the attribute was consumed in other instance methods
acceptable_obj_names: List[str] = ["self"]
scope = assign_attr.scope()
if isinstance(scope, nodes.FunctionDef) and scope.name == "__new__":
acceptable_obj_names.extend(
[
return_node.value.name
for return_node in scope.nodes_of_class(nodes.Return)
if isinstance(return_node.value, nodes.Name)
]
)
for attribute in node.nodes_of_class(nodes.Attribute):
if attribute.attrname != assign_attr.attrname:
continue
if self._is_type_self_call(attribute.expr):
continue
if assign_attr.expr.name in {
"cls",
node.name,
} and attribute.expr.name in {"cls", "self", node.name}:
# If assigned to cls or class name, can be accessed by cls/self/class name
break
if (
assign_attr.expr.name in acceptable_obj_names
and attribute.expr.name == "self"
):
# If assigned to self.attrib, can only be accessed by self
# Or if __new__ was used, the returned object names are acceptable
break
if assign_attr.expr.name == attribute.expr.name == node.name:
# Recognise attributes which are accessed via the class name
break
else:
args = (node.name, assign_attr.attrname)
self.add_message("unused-private-member", node=assign_attr, args=args)
def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
# check access to existent members on non metaclass classes
if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
# We are in a mixin class. No need to try to figure out if
# something is missing, since it is most likely that it will
# miss.
return
accessed = self._accessed.accessed(cnode)
if cnode.type != "metaclass":
self._check_accessed_members(cnode, accessed)
# checks attributes are defined in an allowed method such as __init__
if not self.linter.is_message_enabled("attribute-defined-outside-init"):
return
defining_methods = self.config.defining_attr_methods
current_module = cnode.root()
for attr, nodes_lst in cnode.instance_attrs.items():
# Exclude `__dict__` as it is already defined.
if attr == "__dict__":
continue
# Skip nodes which are not in the current module and it may screw up
# the output, while it's not worth it
nodes_lst = [
n
for n in nodes_lst
if not isinstance(
n.statement(future=_True), (nodes.Delete, nodes.AugAssign)
)
and n.root() is current_module
]
if not nodes_lst:
continue # error detected by typechecking
# Check if any method attr is defined in is a defining method
# or if we have the attribute defined in a setter.
frames = (node.frame(future=_True) for node in nodes_lst)
if any(
frame.name in defining_methods or is_property_setter(frame)
for frame in frames
):
continue
# check attribute is defined in a parent's __init__
for parent in cnode.instance_attr_ancestors(attr):
attr_defined = _False
# check if any parent method attr is defined in is a defining method
for node in parent.instance_attrs[attr]:
if node.frame(future=_True).name in defining_methods:
attr_defined = _True
if attr_defined:
# we're done :)
break
else:
# check attribute is defined as a class attribute
try:
cnode.local_attr(attr)
except astroid.NotFoundError:
for node in nodes_lst:
if node.frame(future=_True).name not in defining_methods:
# If the attribute was set by a call in any
# of the defining methods, then don't emit
# the warning.
if _called_in_methods(
node.frame(future=_True), cnode, defining_methods
):
continue
self.add_message(
"attribute-defined-outside-init", args=attr, node=node
)
def visit_functiondef(self, node: nodes.FunctionDef) -> None:
"""Check method arguments, overriding."""
# ignore actual functions
if not node.is_method():
return
self._check_useless_super_delegation(node)
self._check_property_with_parameters(node)
# 'is_method()' is called and makes sure that this is a 'nodes.ClassDef'
klass = node.parent.frame(future=_True) # type: nodes.ClassDef
self._meth_could_be_func = _True
# check first argument is self if this is actually a method
self._check_first_arg_for_type(node, klass.type == "metaclass")
if node.name == "__init__":
self._check_init(node, klass)
return
# check signature if the method overloads inherited method
for overridden in klass.local_attr_ancestors(node.name):
# get astroid for the searched method
try:
parent_function = overridden[node.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if not isinstance(parent_function, nodes.FunctionDef):
continue
self._check_signature(node, parent_function, "overridden", klass)
self._check_invalid_overridden_method(node, parent_function)
break
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, nodes.Attribute) and decorator.attrname in {
"getter",
"setter",
"deleter",
}:
# attribute affectation will call this method, not hiding it
return
if isinstance(decorator, nodes.Name):
if decorator.name == "property":
# attribute affectation will either call a setter or raise
# an attribute error, anyway not hiding the function
return
# Infer the decorator and see if it returns something useful
inferred = safe_infer(decorator)
if not inferred:
return
if isinstance(inferred, nodes.FunctionDef):
# Okay, it's a decorator, let's see what it can infer.
try:
inferred = next(inferred.infer_call_result(inferred))
except astroid.InferenceError:
return
try:
if (
isinstance(inferred, (astroid.Instance, nodes.ClassDef))
and inferred.getattr("__get__")
and inferred.getattr("__set__")
):
return
except astroid.AttributeInferenceError:
pass
# check if the method is hidden by an attribute
try:
overridden = klass.instance_attr(node.name)[0]
overridden_frame = overridden.frame(future=_True)
if (
isinstance(overridden_frame, nodes.FunctionDef)
and overridden_frame.type == "method"
):
overridden_frame = overridden_frame.parent.frame(future=_True)
if not (
isinstance(overridden_frame, nodes.ClassDef)
and klass.is_subtype_of(overridden_frame.qname())
):
return
# If a subclass defined the method then it's not our fault.
for ancestor in klass.ancestors():
if node.name in ancestor.instance_attrs and is_attr_private(node.name):
return
for obj in ancestor.lookup(node.name)[1]:
if isinstance(obj, nodes.FunctionDef):
return
args = (overridden.root().name, overridden.fromlineno)
self.add_message("method-hidden", args=args, node=node)
except astroid.NotFoundError:
pass
visit_asyncfunctiondef = visit_functiondef
def _check_useless_super_delegation(self, function):
"""Check if the given function node is an useless method override.
We consider it *useless* if it uses the super() builtin, but having
nothing additional whatsoever than not implementing the method at all.
If the method uses super() to delegate an operation to the rest of the MRO,
and if the method called is the same as the current one, the arguments
passed to super() are the same as the parameters that were passed to
this method, then the method could be removed altogether, by letting
other implementation to take precedence.
"""
if (
not function.is_method()
# With decorators is a change of use
or function.decorators
):
return
body = function.body
if len(body) != 1:
# Multiple statements, which means this overridden method
# could do multiple things we are not aware of.
return
statement = body[0]
if not isinstance(statement, (nodes.Expr, nodes.Return)):
# Doing something else than what we are interested into.
return
call = statement.value
if (
not isinstance(call, nodes.Call)
# Not a super() attribute access.
or not isinstance(call.func, nodes.Attribute)
):
return
# Should be a super call.
try:
super_call = next(call.func.expr.infer())
except astroid.InferenceError:
return
else:
if not isinstance(super_call, astroid.objects.Super):
return
# The name should be the same.
if call.func.attrname != function.name:
return
# Should be a super call with the MRO pointer being the
# current class and the type being the current instance.
current_scope = function.parent.scope()
if (
super_call.mro_pointer != current_scope
or not isinstance(super_call.type, astroid.Instance)
or super_call.type.name != current_scope.name
):
return
# Check values of default args
klass = function.parent.frame(future=_True)
meth_node = None
for overridden in klass.local_attr_ancestors(function.name):
# get astroid for the searched method
try:
meth_node = overridden[function.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if (
not isinstance(meth_node, nodes.FunctionDef)
# If the method have an ancestor which is not a
# function then it is legitimate to redefine it
or _has_different_parameters_default_value(
meth_node.args, function.args
)
):
return
break
# Detect if the parameters are the same as the call's arguments.
params = _signature_from_arguments(function.args)
args = _signature_from_call(call)
if meth_node is not None:
def form_annotations(arguments):
annotations = chain(
(arguments.posonlyargs_annotations or []), arguments.annotations
)
return [ann.as_string() for ann in annotations if ann is not None]
called_annotations = form_annotations(function.args)
overridden_annotations = form_annotations(meth_node.args)
if called_annotations and overridden_annotations:
if called_annotations != overridden_annotations:
return
if _definition_equivalent_to_call(params, args):
self.add_message(
"useless-super-delegation", node=function, args=(function.name,)
)
def _check_property_with_parameters(self, node):
if (
node.args.args
and len(node.args.args) > 1
and decorated_with_property(node)
and not is_property_setter(node)
):
self.add_message("property-with-parameters", node=node)
def _check_invalid_overridden_method(self, function_node, parent_function_node):
parent_is_property = decorated_with_property(
parent_function_node
) or is_property_setter_or_deleter(parent_function_node)
current_is_property = decorated_with_property(
function_node
) or is_property_setter_or_deleter(function_node)
if parent_is_property and not current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "property", function_node.type),
node=function_node,
)
elif not parent_is_property and current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "method", "property"),
node=function_node,
)
parent_is_async = isinstance(parent_function_node, nodes.AsyncFunctionDef)
current_is_async = isinstance(function_node, nodes.AsyncFunctionDef)
if parent_is_async and not current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "async", "non-async"),
node=function_node,
)
elif not parent_is_async and current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "non-async", "async"),
node=function_node,
)
if (
decorated_with(parent_function_node, ["typing.final"])
or uninferable_final_decorators(parent_function_node.decorators)
) and self._py38_plus:
self.add_message(
"overridden-final-method",
args=(function_node.name, parent_function_node.parent.frame().name),
node=function_node,
)
def _check_slots(self, node: nodes.ClassDef) -> None:
if "__slots__" not in node.locals:
return
for slots in node.igetattr("__slots__"):
# check if __slots__ is a valid type
if slots is astroid.Uninferable:
continue
if not is_iterable(slots) and not is_comprehension(slots):
self.add_message("invalid-slots", node=node)
continue
if isinstance(slots, nodes.Const):
# a string, ignore the following checks
self.add_message("single-string-used-for-slots", node=node)
continue
if not hasattr(slots, "itered"):
# we can't obtain the values, maybe a .deque?
continue
if isinstance(slots, nodes.Dict):
values = [item[0] for item in slots.items]
else:
values = slots.itered()
if values is astroid.Uninferable:
return
for elt in values:
try:
self._check_slots_elt(elt, node)
except astroid.InferenceError:
continue
self._check_redefined_slots(node, slots, values)
def _check_redefined_slots(
self,
node: nodes.ClassDef,
slots_node: nodes.NodeNG,
slots_list: List[nodes.NodeNG],
) -> None:
"""Check if `node` redefines a slot which is defined in an ancestor class."""
slots_names: List[str] = []
for slot in slots_list:
if isinstance(slot, nodes.Const):
slots_names.append(slot.value)
else:
inferred_slot = safe_infer(slot)
if inferred_slot:
slots_names.append(inferred_slot.value)
# Slots of all parent classes
ancestors_slots_names = {
slot.value
for ancestor in node.local_attr_ancestors("__slots__")
for slot in ancestor.slots() or []
}
# Slots which are common to `node` and its parent classes
redefined_slots = ancestors_slots_names.intersection(slots_names)
if redefined_slots:
self.add_message(
"redefined-slots-in-subclass",
args=([name for name in slots_names if name in redefined_slots],),
node=slots_node,
)
def _check_slots_elt(self, elt, node):
for inferred in elt.infer():
if inferred is astroid.Uninferable:
continue
if not isinstance(inferred, nodes.Const) or not isinstance(
inferred.value, str
):
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
continue
if not inferred.value:
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
# Check if we have a conflict with a class variable.
class_variable = node.locals.get(inferred.value)
if class_variable:
# Skip annotated assignments which don't conflict at all with slots.
if len(class_variable) == 1:
parent = class_variable[0].parent
if isinstance(parent, nodes.AnnAssign) and parent.value is None:
return
self.add_message(
"class-variable-slots-conflict", args=(inferred.value,), node=elt
)
def leave_functiondef(self, node: nodes.FunctionDef) -> None:
"""On method node, check if this method couldn't be a function.
ignore class, static and abstract methods, initializer,
methods overridden from a parent class.
"""
if node.is_method():
if node.args.args is not None:
self._first_attrs.pop()
if not self.linter.is_message_enabled("no-self-use"):
return
class_node = node.parent.frame(future=_True)
if (
self._meth_could_be_func
and node.type == "method"
and node.name not in PYMETHODS
and not (
node.is_abstract()
or overrides_a_method(class_node, node.name)
or decorated_with_property(node)
or _has_bare_super_call(node)
or is_protocol_class(class_node)
or is_overload_stub(node)
)
):
self.add_message("no-self-use", node=node)
leave_asyncfunctiondef = leave_functiondef
def visit_attribute(self, node: nodes.Attribute) -> None:
"""Check if the getattr is an access to a class member
if so, register it. Also check for access to protected
class member from outside its class (but ignore __special__
methods)
"""
# Check self
if self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
return
if not self.linter.is_message_enabled("protected-access"):
return
self._check_protected_attribute_access(node)
@check_messages("assigning-non-slot", "invalid-class-object")
def visit_assignattr(self, node: nodes.AssignAttr) -> None:
if isinstance(
node.assign_type(), nodes.AugAssign
) and self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
self._check_in_slots(node)
self._check_invalid_class_object(node)
def _check_invalid_class_object(self, node: nodes.AssignAttr) -> None:
if not node.attrname == "__class__":
return
inferred = safe_infer(node.parent.value)
if isinstance(inferred, nodes.ClassDef) or inferred is astroid.Uninferable:
# If is uninferrable, we allow it to prevent false positives
return
self.add_message("invalid-class-object", node=node)
def _check_in_slots(self, node):
"""Check that the given AssignAttr node
is defined in the class slots.
"""
inferred = safe_infer(node.expr)
if not isinstance(inferred, astroid.Instance):
return
klass = inferred._proxied
if not has_known_bases(klass):
return
if "__slots__" not in klass.locals or not klass.newstyle:
return
# If `__setattr__` is defined on the class, then we can't reason about
# what will happen when assigning to an attribute.
if any(
base.locals.get("__setattr__")
for base in klass.mro()
if base.qname() != "builtins.object"
):
return
# If 'typing.Generic' is a base of bases of klass, the cached version
# of 'slots()' might have been evaluated incorrectly, thus deleted cache entry.
if any(base.qname() == "typing.Generic" for base in klass.mro()):
cache = getattr(klass, "__cache", None)
if cache and cache.get(klass.slots) is not None:
del cache[klass.slots]
slots = klass.slots()
if slots is None:
return
# If any ancestor doesn't use slots, the slots
# defined for this class are superfluous.
if any(
"__slots__" not in ancestor.locals and ancestor.name != "object"
for ancestor in klass.ancestors()
):
return
if not any(slot.value == node.attrname for slot in slots):
# If we have a '__dict__' in slots, then
# assigning any name is valid.
if not any(slot.value == "__dict__" for slot in slots):
if _is_attribute_property(node.attrname, klass):
# Properties circumvent the slots mechanism,
# so we should not emit a warning for them.
return
if node.attrname in klass.locals:
for local_name in klass.locals.get(node.attrname):
statement = local_name.statement(future=_True)
if (
isinstance(statement, nodes.AnnAssign)
and not statement.value
):
return
if _has_data_descriptor(klass, node.attrname):
# Descriptors circumvent the slots mechanism as well.
return
if node.attrname == "__class__" and _has_same_layout_slots(
slots, node.parent.value
):
return
self.add_message("assigning-non-slot", args=(node.attrname,), node=node)
@check_messages(
"protected-access", "no-classmethod-decorator", "no-staticmethod-decorator"
)
def visit_assign(self, assign_node: nodes.Assign) -> None:
self._check_classmethod_declaration(assign_node)
node = assign_node.targets[0]
if not isinstance(node, nodes.AssignAttr):
return
if self._uses_mandatory_method_param(node):
return
self._check_protected_attribute_access(node)
def _check_classmethod_declaration(self, node):
"""Checks for uses of classmethod() or staticmethod().
When a @classmethod or @staticmethod decorator should be used instead.
A message will be emitted only if the assignment is at a class scope
and only if the classmethod's argument belongs to the class where it
is defined.
`node` is an assign node.
"""
if not isinstance(node.value, nodes.Call):
return
# check the function called is "classmethod" or "staticmethod"
func = node.value.func
if not isinstance(func, nodes.Name) or func.name not in (
"classmethod",
"staticmethod",
):
return
msg = (
"no-classmethod-decorator"
if func.name == "classmethod"
else "no-staticmethod-decorator"
)
# assignment must be at a class scope
parent_class = node.scope()
if not isinstance(parent_class, nodes.ClassDef):
return
# Check if the arg passed to classmethod is a class member
classmeth_arg = node.value.args[0]
if not isinstance(classmeth_arg, nodes.Name):
return
method_name = classmeth_arg.name
if any(method_name == member.name for member in parent_class.mymethods()):
self.add_message(msg, node=node.targets[0])
def _check_protected_attribute_access(self, node: nodes.Attribute):
"""Given an attribute access node (set or get), check if attribute
access is legitimate. Call _check_first_attr with node before calling
this method. Valid cases are:
* self._attr in a method or cls._attr in a classmethod. Checked by
_check_first_attr.
* Klass._attr inside "Klass" class.
* Klass2._attr inside "Klass" class when Klass2 is a base class of
Klass.
"""
attrname = node.attrname
if (
is_attr_protected(attrname)
and attrname not in self.config.exclude_protected
):
klass = node_frame_class(node)
# In classes, check we are not getting a parent method
# through the class object or through super
callee = node.expr.as_string()
# Typing annotations in function definitions can include protected members
if utils.is_node_in_type_annotation_context(node):
return
# We are not in a class, no remaining valid case
if klass is None:
self.add_message("protected-access", node=node, args=attrname)
return
# If the expression begins with a call to super, that's ok.
if (
isinstance(node.expr, nodes.Call)
and isinstance(node.expr.func, nodes.Name)
and node.expr.func.name == "super"
):
return
# If the expression begins with a call to type(self), that's ok.
if self._is_type_self_call(node.expr):
return
# Check if we are inside the scope of a class or nested inner class
inside_klass = _True
outer_klass = klass
parents_callee = callee.split(".")
parents_callee.reverse()
for callee in parents_callee:
if not outer_klass or callee != outer_klass.name:
inside_klass = _False
break
# Move up one level within the nested classes
outer_klass = get_outer_class(outer_klass)
# We are in a class, one remaining valid cases, Klass._attr inside
# Klass
if not (inside_klass or callee in klass.basenames):
# Detect property assignments in the body of the class.
# This is acceptable:
#
# class A:
# b = property(lambda: self._b)
stmt = node.parent.statement(future=_True)
if (
isinstance(stmt, nodes.Assign)
and len(stmt.targets) == 1
and isinstance(stmt.targets[0], nodes.AssignName)
):
name = stmt.targets[0].name
if _is_attribute_property(name, klass):
return
if (
self._is_classmethod(node.frame(future=_True))
and self._is_inferred_instance(node.expr, klass)
and self._is_class_attribute(attrname, klass)
):
return
licit_protected_member = not attrname.startswith("__")
if (
not self.config.check_protected_access_in_special_methods
and licit_protected_member
and self._is_called_inside_special_method(node)
):
return
self.add_message("protected-access", node=node, args=attrname)
@staticmethod
def _is_called_inside_special_method(node: nodes.NodeNG) -> bool:
"""Returns true if the node is located inside a special (aka dunder) method."""
frame_name = node.frame(future=_True).name
return frame_name and frame_name in PYMETHODS
def _is_type_self_call(self, expr: nodes.NodeNG) -> bool:
return (
isinstance(expr, nodes.Call)
and isinstance(expr.func, nodes.Name)
and expr.func.name == "type"
and len(expr.args) == 1
and self._is_mandatory_method_param(expr.args[0])
)
@staticmethod
def _is_classmethod(func):
"""Check if the given *func* node is a class method."""
return isinstance(func, nodes.FunctionDef) and (
func.type == "classmethod" or func.name == "__class_getitem__"
)
@staticmethod
def _is_inferred_instance(expr, klass):
"""Check if the inferred value of the given *expr* is an instance of *klass*."""
inferred = safe_infer(expr)
if not isinstance(inferred, astroid.Instance):
return _False
return inferred._proxied is klass
@staticmethod
def _is_class_attribute(name, klass):
"""Check if the given attribute *name* is a class or instance member of the given *klass*.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
klass.getattr(name)
return _True
except astroid.NotFoundError:
pass
try:
klass.instance_attr(name)
return _True
except astroid.NotFoundError:
return _False
def visit_name(self, node: nodes.Name) -> None:
"""Check if the name handle an access to a class member
if so, register it
"""
if self._first_attrs and (
node.name == self._first_attrs[-1] or not self._first_attrs[-1]
):
self._meth_could_be_func = _False
def _check_accessed_members(self, node, accessed):
"""Check that accessed members are defined."""
excs = ("AttributeError", "Exception", "BaseException")
for attr, nodes_lst in accessed.items():
try:
# is it a class attribute ?
node.local_attr(attr)
# yes, stop here
continue
except astroid.NotFoundError:
pass
# is it an instance attribute of a parent class ?
try:
next(node.instance_attr_ancestors(attr))
# yes, stop here
continue
except StopIteration:
pass
# is it an instance attribute ?
try:
defstmts = node.instance_attr(attr)
except astroid.NotFoundError:
pass
else:
# filter out augment assignment nodes
defstmts = [stmt for stmt in defstmts if stmt not in nodes_lst]
if not defstmts:
# only augment assignment for this node, no-member should be
# triggered by the typecheck checker
continue
# filter defstmts to only pick the first one when there are
# several assignments in the same scope
scope = defstmts[0].scope()
defstmts = [
stmt
for i, stmt in enumerate(defstmts)
if i == 0 or stmt.scope() is not scope
]
# if there are still more than one, don't attempt to be smarter
# than we can be
if len(defstmts) == 1:
defstmt = defstmts[0]
# check that if the node is accessed in the same method as
# it's defined, it's accessed after the initial assignment
frame = defstmt.frame(future=_True)
lno = defstmt.fromlineno
for _node in nodes_lst:
if (
_node.frame(future=_True) is frame
and _node.fromlineno < lno
and not astroid.are_exclusive(
_node.statement(future=_True), defstmt, excs
)
):
self.add_message(
"access-member-before-definition",
node=_node,
args=(attr, lno),
)
def _check_first_arg_for_type(self, node, metaclass=0):
"""Check the name of first argument, expect:.
* 'self' for a regular method
* 'cls' for a class method or a metaclass regular method (actually
valid-classmethod-first-arg value)
* 'mcs' for a metaclass class method (actually
valid-metaclass-classmethod-first-arg)
* not one of the above for a static method
"""
# don't care about functions with unknown argument (builtins)
if node.args.args is None:
return
if node.args.posonlyargs:
first_arg = node.args.posonlyargs[0].name
elif node.args.args:
first_arg = node.argnames()[0]
else:
first_arg = None
self._first_attrs.append(first_arg)
first = self._first_attrs[-1]
# static method
if node.type == "staticmethod":
if (
first_arg == "self"
or first_arg in self.config.valid_classmethod_first_arg
or first_arg in self.config.valid_metaclass_classmethod_first_arg
):
self.add_message("bad-staticmethod-argument", args=first, node=node)
return
self._first_attrs[-1] = None
# class / regular method with no args
elif not node.args.args and not node.args.posonlyargs:
self.add_message("no-method-argument", node=node)
# metaclass
elif metaclass:
# metaclass __new__ or classmethod
if node.type == "classmethod":
self._check_first_arg_config(
first,
self.config.valid_metaclass_classmethod_first_arg,
node,
"bad-mcs-classmethod-argument",
node.name,
)
# metaclass regular method
else:
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-mcs-method-argument",
node.name,
)
# regular class with class method
elif node.type == "classmethod" or node.name == "__class_getitem__":
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-classmethod-argument",
node.name,
)
# regular class with regular method without self as argument
elif first != "self":
self.add_message("no-self-argument", node=node)
def _check_first_arg_config(self, first, config, node, message, method_name):
if first not in config:
if len(config) == 1:
valid = repr(config[0])
else:
valid = ", ".join(repr(v) for v in config[:-1])
valid = f"{valid} or {config[-1]!r}"
self.add_message(message, args=(method_name, valid), node=node)
def _check_bases_classes(self, node):
"""Check that the given class node implements abstract methods from
base classes
"""
def is_abstract(method):
return method.is_abstract(pass_is_abstract=_False)
# check if this class abstract
if class_is_abstract(node):
return
methods = sorted(
unimplemented_abstract_methods(node, is_abstract).items(),
key=lambda item: item[0],
)
for name, method in methods:
owner = method.parent.frame(future=_True)
if owner is node:
continue
# owner is not this class, it must be a parent class
# check that the ancestor's method is not abstract
if name in node.locals:
# it is redefined as an attribute or with a descriptor
continue
self.add_message("abstract-method", node=node, args=(name, owner.name))
def _check_init(self, node: nodes.FunctionDef, klass_node: nodes.ClassDef) -> None:
"""Check that the __init__ method call super or ancestors'__init__
method (unless it is used for type hinting with `typing.overload`)
"""
if not self.linter.is_message_enabled(
"super-init-not-called"
) and not self.linter.is_message_enabled("non-parent-init-called"):
return
to_call = _ancestors_to_call(klass_node)
not_called_yet = dict(to_call)
parents_with_called_inits: Set[bases.UnboundMethod] = set()
for stmt in node.nodes_of_class(nodes.Call):
expr = stmt.func
if not isinstance(expr, nodes.Attribute) or expr.attrname != "__init__":
continue
# skip the test if using super
if (
isinstance(expr.expr, nodes.Call)
and isinstance(expr.expr.func, nodes.Name)
and expr.expr.func.name == "super"
):
return
try:
for klass in expr.expr.infer():
if klass is astroid.Uninferable:
continue
# The inferred klass can be super(), which was
# assigned to a variable and the `__init__`
# was called later.
#
# base = super()
# base.__init__(...)
if (
isinstance(klass, astroid.Instance)
and isinstance(klass._proxied, nodes.ClassDef)
and is_builtin_object(klass._proxied)
and klass._proxied.name == "super"
):
return
if isinstance(klass, astroid.objects.Super):
return
try:
method = not_called_yet.pop(klass)
# Record that the class' init has been called
parents_with_called_inits.add(node_frame_class(method))
except KeyError:
if klass not in to_call:
self.add_message(
"non-parent-init-called", node=expr, args=klass.name
)
except astroid.InferenceError:
continue
for klass, method in not_called_yet.items():
# Check if the init of the class that defines this init has already
# been called.
if node_frame_class(method) in parents_with_called_inits:
return
# Return if klass is protocol
if klass.qname() in utils.TYPING_PROTOCOLS:
return
# Return if any of the klass' first-order bases is protocol
for base in klass.bases:
# We don't need to catch InferenceError here as _ancestors_to_call
# already does this for us.
for inf_base in base.infer():
if inf_base.qname() in utils.TYPING_PROTOCOLS:
return
if decorated_with(node, ["typing.overload"]):
continue
cls = node_frame_class(method)
if klass.name == "object" or (cls and cls.name == "object"):
continue
self.add_message(
"super-init-not-called",
args=klass.name,
node=node,
confidence=INFERENCE,
)
def _check_signature(self, method1, refmethod, class_type, cls):
"""Check that the signature of the two given methods match."""
if not (
isinstance(method1, nodes.FunctionDef)
and isinstance(refmethod, nodes.FunctionDef)
):
self.add_message(
"method-check-failed", args=(method1, refmethod), node=method1
)
return
instance = cls.instantiate_class()
method1 = astroid.scoped_nodes.function_to_method(method1, instance)
refmethod = astroid.scoped_nodes.function_to_method(refmethod, instance)
# Don't care about functions with unknown argument (builtins).
if method1.args.args is None or refmethod.args.args is None:
return
# Ignore private to class methods.
if is_attr_private(method1.name):
return
# Ignore setters, they have an implicit extra argument,
# which shouldn't be taken in consideration.
if is_property_setter(method1):
return
arg_differ_output = _different_parameters(
refmethod, method1, dummy_parameter_regex=self._dummy_rgx
)
if len(arg_differ_output) > 0:
for msg in arg_differ_output:
if "Number" in msg:
total_args_method1 = len(method1.args.args)
if method1.args.vararg:
total_args_method1 += 1
if method1.args.kwarg:
total_args_method1 += 1
if method1.args.kwonlyargs:
total_args_method1 += len(method1.args.kwonlyargs)
total_args_refmethod = len(refmethod.args.args)
if refmethod.args.vararg:
total_args_refmethod += 1
if refmethod.args.kwarg:
total_args_refmethod += 1
if refmethod.args.kwonlyargs:
total_args_refmethod += len(refmethod.args.kwonlyargs)
error_type = "arguments-differ"
msg_args = (
msg
+ f"was {total_args_refmethod} in '{refmethod.parent.frame().name}.{refmethod.name}' and "
f"is now {total_args_method1} in",
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
elif "renamed" in msg:
error_type = "arguments-renamed"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
else:
error_type = "arguments-differ"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
self.add_message(error_type, args=msg_args, node=method1)
elif (
len(method1.args.defaults) < len(refmethod.args.defaults)
and not method1.args.vararg
):
self.add_message(
"signature-differs", args=(class_type, method1.name), node=method1
)
def _uses_mandatory_method_param(self, node):
"""Check that attribute lookup name use first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
return self._is_mandatory_method_param(node.expr)
def _is_mandatory_method_param(self, node: nodes.NodeNG) -> bool:
"""Check if nodes.Name corresponds to first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
if self._first_attrs:
first_attr = self._first_attrs[-1]
else:
# It's possible the function was already unregistered.
closest_func = utils.get_node_first_ancestor_of_type(
node, nodes.FunctionDef
)
if closest_func is None:
return _False
if not closest_func.args.args:
return _False
first_attr = closest_func.args.args[0].name
return isinstance(node, nodes.Name) and node.name == first_attr
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 782 | get_global_option | ref | function | return get_global_option(self, "dummy-variables-rgx", default=None)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 785 | _ignore_mixin | def | function | def _ignore_mixin(self):
return get_global_option(self, "ignore-mixin-members", default=_True)
@check_messages(
"abstract-method",
"no-init",
"invalid-slots",
"single-string-used-for-slots",
"invalid-slots-object",
"class-variable-slots-conflict",
"inherit-non-class",
"useless-object-inheritance",
"inconsistent-mro",
"duplicate-bases",
"redefined-slots-in-subclass",
)
def visit_classdef(self, node: nodes.ClassDef) -> None:
"""Init visit variable _accessed."""
self._check_bases_classes(node)
# if not an exception or a metaclass
if node.type == "class" and has_known_bases(node):
try:
node.local_attr("__init__")
except astroid.NotFoundError:
self.add_message("no-init", args=node, node=node)
self._check_slots(node)
self._check_proper_bases(node)
self._check_typing_final(node)
self._check_consistent_mro(node)
def _check_consistent_mro(self, node):
"""Detect that a class has a consistent mro or duplicate bases."""
try:
node.mro()
except astroid.InconsistentMroError:
self.add_message("inconsistent-mro", args=node.name, node=node)
except astroid.DuplicateBasesError:
self.add_message("duplicate-bases", args=node.name, node=node)
except NotImplementedError:
# Old style class, there's no mro so don't do anything.
pass
def _check_proper_bases(self, node):
"""Detect that a class inherits something which is not
a class or a type.
"""
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, astroid.Instance) and ancestor.is_subtype_of(
"builtins.type"
):
continue
if not isinstance(ancestor, nodes.ClassDef) or _is_invalid_base_class(
ancestor
):
self.add_message("inherit-non-class", args=base.as_string(), node=node)
if ancestor.name == object.__name__:
self.add_message(
"useless-object-inheritance", args=node.name, node=node
)
def _check_typing_final(self, node: nodes.ClassDef) -> None:
"""Detect that a class does not subclass a class decorated with `typing.final`."""
if not self._py38_plus:
return
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, nodes.ClassDef) and (
decorated_with(ancestor, ["typing.final"])
or uninferable_final_decorators(ancestor.decorators)
):
self.add_message(
"subclassed-final-class",
args=(node.name, ancestor.name),
node=node,
)
@check_messages("unused-private-member", "attribute-defined-outside-init")
def leave_classdef(self, node: nodes.ClassDef) -> None:
"""Close a class node:
check that instance attributes are defined in __init__ and check
access to existent members
"""
self._check_unused_private_functions(node)
self._check_unused_private_variables(node)
self._check_unused_private_attributes(node)
self._check_attribute_defined_outside_init(node)
def _check_unused_private_functions(self, node: nodes.ClassDef) -> None:
for function_def in node.nodes_of_class(nodes.FunctionDef):
if not is_attr_private(function_def.name):
continue
parent_scope = function_def.parent.scope()
if isinstance(parent_scope, nodes.FunctionDef):
# Handle nested functions
if function_def.name in (
n.name for n in parent_scope.nodes_of_class(nodes.Name)
):
continue
for attribute in node.nodes_of_class(nodes.Attribute):
if (
attribute.attrname != function_def.name
or attribute.scope() == function_def # We ignore recursive calls
):
continue
if isinstance(attribute.expr, nodes.Name) and attribute.expr.name in (
"self",
"cls",
node.name,
):
# self.__attrname
# cls.__attrname
# node_name.__attrname
break
if isinstance(attribute.expr, nodes.Call):
# type(self).__attrname
inferred = safe_infer(attribute.expr)
if (
isinstance(inferred, nodes.ClassDef)
and inferred.name == node.name
):
break
else:
name_stack = []
curr = parent_scope
# Generate proper names for nested functions
while curr != node:
name_stack.append(curr.name)
curr = curr.parent.scope()
outer_level_names = f"{'.'.join(reversed(name_stack))}"
function_repr = f"{outer_level_names}.{function_def.name}({function_def.args.as_string()})"
self.add_message(
"unused-private-member",
node=function_def,
args=(node.name, function_repr.lstrip(".")),
)
def _check_unused_private_variables(self, node: nodes.ClassDef) -> None:
"""Check if private variables are never used within a class."""
for assign_name in node.nodes_of_class(nodes.AssignName):
if isinstance(assign_name.parent, nodes.Arguments):
continue # Ignore function arguments
if not is_attr_private(assign_name.name):
continue
for child in node.nodes_of_class((nodes.Name, nodes.Attribute)):
if isinstance(child, nodes.Name) and child.name == assign_name.name:
break
if isinstance(child, nodes.Attribute):
if not isinstance(child.expr, nodes.Name):
break
if child.attrname == assign_name.name and child.expr.name in (
"self",
"cls",
node.name,
):
break
else:
args = (node.name, assign_name.name)
self.add_message("unused-private-member", node=assign_name, args=args)
def _check_unused_private_attributes(self, node: nodes.ClassDef) -> None:
for assign_attr in node.nodes_of_class(nodes.AssignAttr):
if not is_attr_private(assign_attr.attrname) or not isinstance(
assign_attr.expr, nodes.Name
):
continue
# Logic for checking false positive when using __new__,
# Get the returned object names of the __new__ magic function
# Then check if the attribute was consumed in other instance methods
acceptable_obj_names: List[str] = ["self"]
scope = assign_attr.scope()
if isinstance(scope, nodes.FunctionDef) and scope.name == "__new__":
acceptable_obj_names.extend(
[
return_node.value.name
for return_node in scope.nodes_of_class(nodes.Return)
if isinstance(return_node.value, nodes.Name)
]
)
for attribute in node.nodes_of_class(nodes.Attribute):
if attribute.attrname != assign_attr.attrname:
continue
if self._is_type_self_call(attribute.expr):
continue
if assign_attr.expr.name in {
"cls",
node.name,
} and attribute.expr.name in {"cls", "self", node.name}:
# If assigned to cls or class name, can be accessed by cls/self/class name
break
if (
assign_attr.expr.name in acceptable_obj_names
and attribute.expr.name == "self"
):
# If assigned to self.attrib, can only be accessed by self
# Or if __new__ was used, the returned object names are acceptable
break
if assign_attr.expr.name == attribute.expr.name == node.name:
# Recognise attributes which are accessed via the class name
break
else:
args = (node.name, assign_attr.attrname)
self.add_message("unused-private-member", node=assign_attr, args=args)
def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
# check access to existent members on non metaclass classes
if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
# We are in a mixin class. No need to try to figure out if
# something is missing, since it is most likely that it will
# miss.
return
accessed = self._accessed.accessed(cnode)
if cnode.type != "metaclass":
self._check_accessed_members(cnode, accessed)
# checks attributes are defined in an allowed method such as __init__
if not self.linter.is_message_enabled("attribute-defined-outside-init"):
return
defining_methods = self.config.defining_attr_methods
current_module = cnode.root()
for attr, nodes_lst in cnode.instance_attrs.items():
# Exclude `__dict__` as it is already defined.
if attr == "__dict__":
continue
# Skip nodes which are not in the current module and it may screw up
# the output, while it's not worth it
nodes_lst = [
n
for n in nodes_lst
if not isinstance(
n.statement(future=_True), (nodes.Delete, nodes.AugAssign)
)
and n.root() is current_module
]
if not nodes_lst:
continue # error detected by typechecking
# Check if any method attr is defined in is a defining method
# or if we have the attribute defined in a setter.
frames = (node.frame(future=_True) for node in nodes_lst)
if any(
frame.name in defining_methods or is_property_setter(frame)
for frame in frames
):
continue
# check attribute is defined in a parent's __init__
for parent in cnode.instance_attr_ancestors(attr):
attr_defined = _False
# check if any parent method attr is defined in is a defining method
for node in parent.instance_attrs[attr]:
if node.frame(future=_True).name in defining_methods:
attr_defined = _True
if attr_defined:
# we're done :)
break
else:
# check attribute is defined as a class attribute
try:
cnode.local_attr(attr)
except astroid.NotFoundError:
for node in nodes_lst:
if node.frame(future=_True).name not in defining_methods:
# If the attribute was set by a call in any
# of the defining methods, then don't emit
# the warning.
if _called_in_methods(
node.frame(future=_True), cnode, defining_methods
):
continue
self.add_message(
"attribute-defined-outside-init", args=attr, node=node
)
def visit_functiondef(self, node: nodes.FunctionDef) -> None:
"""Check method arguments, overriding."""
# ignore actual functions
if not node.is_method():
return
self._check_useless_super_delegation(node)
self._check_property_with_parameters(node)
# 'is_method()' is called and makes sure that this is a 'nodes.ClassDef'
klass = node.parent.frame(future=_True) # type: nodes.ClassDef
self._meth_could_be_func = _True
# check first argument is self if this is actually a method
self._check_first_arg_for_type(node, klass.type == "metaclass")
if node.name == "__init__":
self._check_init(node, klass)
return
# check signature if the method overloads inherited method
for overridden in klass.local_attr_ancestors(node.name):
# get astroid for the searched method
try:
parent_function = overridden[node.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if not isinstance(parent_function, nodes.FunctionDef):
continue
self._check_signature(node, parent_function, "overridden", klass)
self._check_invalid_overridden_method(node, parent_function)
break
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, nodes.Attribute) and decorator.attrname in {
"getter",
"setter",
"deleter",
}:
# attribute affectation will call this method, not hiding it
return
if isinstance(decorator, nodes.Name):
if decorator.name == "property":
# attribute affectation will either call a setter or raise
# an attribute error, anyway not hiding the function
return
# Infer the decorator and see if it returns something useful
inferred = safe_infer(decorator)
if not inferred:
return
if isinstance(inferred, nodes.FunctionDef):
# Okay, it's a decorator, let's see what it can infer.
try:
inferred = next(inferred.infer_call_result(inferred))
except astroid.InferenceError:
return
try:
if (
isinstance(inferred, (astroid.Instance, nodes.ClassDef))
and inferred.getattr("__get__")
and inferred.getattr("__set__")
):
return
except astroid.AttributeInferenceError:
pass
# check if the method is hidden by an attribute
try:
overridden = klass.instance_attr(node.name)[0]
overridden_frame = overridden.frame(future=_True)
if (
isinstance(overridden_frame, nodes.FunctionDef)
and overridden_frame.type == "method"
):
overridden_frame = overridden_frame.parent.frame(future=_True)
if not (
isinstance(overridden_frame, nodes.ClassDef)
and klass.is_subtype_of(overridden_frame.qname())
):
return
# If a subclass defined the method then it's not our fault.
for ancestor in klass.ancestors():
if node.name in ancestor.instance_attrs and is_attr_private(node.name):
return
for obj in ancestor.lookup(node.name)[1]:
if isinstance(obj, nodes.FunctionDef):
return
args = (overridden.root().name, overridden.fromlineno)
self.add_message("method-hidden", args=args, node=node)
except astroid.NotFoundError:
pass
visit_asyncfunctiondef = visit_functiondef
def _check_useless_super_delegation(self, function):
"""Check if the given function node is an useless method override.
We consider it *useless* if it uses the super() builtin, but having
nothing additional whatsoever than not implementing the method at all.
If the method uses super() to delegate an operation to the rest of the MRO,
and if the method called is the same as the current one, the arguments
passed to super() are the same as the parameters that were passed to
this method, then the method could be removed altogether, by letting
other implementation to take precedence.
"""
if (
not function.is_method()
# With decorators is a change of use
or function.decorators
):
return
body = function.body
if len(body) != 1:
# Multiple statements, which means this overridden method
# could do multiple things we are not aware of.
return
statement = body[0]
if not isinstance(statement, (nodes.Expr, nodes.Return)):
# Doing something else than what we are interested into.
return
call = statement.value
if (
not isinstance(call, nodes.Call)
# Not a super() attribute access.
or not isinstance(call.func, nodes.Attribute)
):
return
# Should be a super call.
try:
super_call = next(call.func.expr.infer())
except astroid.InferenceError:
return
else:
if not isinstance(super_call, astroid.objects.Super):
return
# The name should be the same.
if call.func.attrname != function.name:
return
# Should be a super call with the MRO pointer being the
# current class and the type being the current instance.
current_scope = function.parent.scope()
if (
super_call.mro_pointer != current_scope
or not isinstance(super_call.type, astroid.Instance)
or super_call.type.name != current_scope.name
):
return
# Check values of default args
klass = function.parent.frame(future=_True)
meth_node = None
for overridden in klass.local_attr_ancestors(function.name):
# get astroid for the searched method
try:
meth_node = overridden[function.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if (
not isinstance(meth_node, nodes.FunctionDef)
# If the method have an ancestor which is not a
# function then it is legitimate to redefine it
or _has_different_parameters_default_value(
meth_node.args, function.args
)
):
return
break
# Detect if the parameters are the same as the call's arguments.
params = _signature_from_arguments(function.args)
args = _signature_from_call(call)
if meth_node is not None:
def form_annotations(arguments):
annotations = chain(
(arguments.posonlyargs_annotations or []), arguments.annotations
)
return [ann.as_string() for ann in annotations if ann is not None]
called_annotations = form_annotations(function.args)
overridden_annotations = form_annotations(meth_node.args)
if called_annotations and overridden_annotations:
if called_annotations != overridden_annotations:
return
if _definition_equivalent_to_call(params, args):
self.add_message(
"useless-super-delegation", node=function, args=(function.name,)
)
def _check_property_with_parameters(self, node):
if (
node.args.args
and len(node.args.args) > 1
and decorated_with_property(node)
and not is_property_setter(node)
):
self.add_message("property-with-parameters", node=node)
def _check_invalid_overridden_method(self, function_node, parent_function_node):
parent_is_property = decorated_with_property(
parent_function_node
) or is_property_setter_or_deleter(parent_function_node)
current_is_property = decorated_with_property(
function_node
) or is_property_setter_or_deleter(function_node)
if parent_is_property and not current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "property", function_node.type),
node=function_node,
)
elif not parent_is_property and current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "method", "property"),
node=function_node,
)
parent_is_async = isinstance(parent_function_node, nodes.AsyncFunctionDef)
current_is_async = isinstance(function_node, nodes.AsyncFunctionDef)
if parent_is_async and not current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "async", "non-async"),
node=function_node,
)
elif not parent_is_async and current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "non-async", "async"),
node=function_node,
)
if (
decorated_with(parent_function_node, ["typing.final"])
or uninferable_final_decorators(parent_function_node.decorators)
) and self._py38_plus:
self.add_message(
"overridden-final-method",
args=(function_node.name, parent_function_node.parent.frame().name),
node=function_node,
)
def _check_slots(self, node: nodes.ClassDef) -> None:
if "__slots__" not in node.locals:
return
for slots in node.igetattr("__slots__"):
# check if __slots__ is a valid type
if slots is astroid.Uninferable:
continue
if not is_iterable(slots) and not is_comprehension(slots):
self.add_message("invalid-slots", node=node)
continue
if isinstance(slots, nodes.Const):
# a string, ignore the following checks
self.add_message("single-string-used-for-slots", node=node)
continue
if not hasattr(slots, "itered"):
# we can't obtain the values, maybe a .deque?
continue
if isinstance(slots, nodes.Dict):
values = [item[0] for item in slots.items]
else:
values = slots.itered()
if values is astroid.Uninferable:
return
for elt in values:
try:
self._check_slots_elt(elt, node)
except astroid.InferenceError:
continue
self._check_redefined_slots(node, slots, values)
def _check_redefined_slots(
self,
node: nodes.ClassDef,
slots_node: nodes.NodeNG,
slots_list: List[nodes.NodeNG],
) -> None:
"""Check if `node` redefines a slot which is defined in an ancestor class."""
slots_names: List[str] = []
for slot in slots_list:
if isinstance(slot, nodes.Const):
slots_names.append(slot.value)
else:
inferred_slot = safe_infer(slot)
if inferred_slot:
slots_names.append(inferred_slot.value)
# Slots of all parent classes
ancestors_slots_names = {
slot.value
for ancestor in node.local_attr_ancestors("__slots__")
for slot in ancestor.slots() or []
}
# Slots which are common to `node` and its parent classes
redefined_slots = ancestors_slots_names.intersection(slots_names)
if redefined_slots:
self.add_message(
"redefined-slots-in-subclass",
args=([name for name in slots_names if name in redefined_slots],),
node=slots_node,
)
def _check_slots_elt(self, elt, node):
for inferred in elt.infer():
if inferred is astroid.Uninferable:
continue
if not isinstance(inferred, nodes.Const) or not isinstance(
inferred.value, str
):
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
continue
if not inferred.value:
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
# Check if we have a conflict with a class variable.
class_variable = node.locals.get(inferred.value)
if class_variable:
# Skip annotated assignments which don't conflict at all with slots.
if len(class_variable) == 1:
parent = class_variable[0].parent
if isinstance(parent, nodes.AnnAssign) and parent.value is None:
return
self.add_message(
"class-variable-slots-conflict", args=(inferred.value,), node=elt
)
def leave_functiondef(self, node: nodes.FunctionDef) -> None:
"""On method node, check if this method couldn't be a function.
ignore class, static and abstract methods, initializer,
methods overridden from a parent class.
"""
if node.is_method():
if node.args.args is not None:
self._first_attrs.pop()
if not self.linter.is_message_enabled("no-self-use"):
return
class_node = node.parent.frame(future=_True)
if (
self._meth_could_be_func
and node.type == "method"
and node.name not in PYMETHODS
and not (
node.is_abstract()
or overrides_a_method(class_node, node.name)
or decorated_with_property(node)
or _has_bare_super_call(node)
or is_protocol_class(class_node)
or is_overload_stub(node)
)
):
self.add_message("no-self-use", node=node)
leave_asyncfunctiondef = leave_functiondef
def visit_attribute(self, node: nodes.Attribute) -> None:
"""Check if the getattr is an access to a class member
if so, register it. Also check for access to protected
class member from outside its class (but ignore __special__
methods)
"""
# Check self
if self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
return
if not self.linter.is_message_enabled("protected-access"):
return
self._check_protected_attribute_access(node)
@check_messages("assigning-non-slot", "invalid-class-object")
def visit_assignattr(self, node: nodes.AssignAttr) -> None:
if isinstance(
node.assign_type(), nodes.AugAssign
) and self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
self._check_in_slots(node)
self._check_invalid_class_object(node)
def _check_invalid_class_object(self, node: nodes.AssignAttr) -> None:
if not node.attrname == "__class__":
return
inferred = safe_infer(node.parent.value)
if isinstance(inferred, nodes.ClassDef) or inferred is astroid.Uninferable:
# If is uninferrable, we allow it to prevent false positives
return
self.add_message("invalid-class-object", node=node)
def _check_in_slots(self, node):
"""Check that the given AssignAttr node
is defined in the class slots.
"""
inferred = safe_infer(node.expr)
if not isinstance(inferred, astroid.Instance):
return
klass = inferred._proxied
if not has_known_bases(klass):
return
if "__slots__" not in klass.locals or not klass.newstyle:
return
# If `__setattr__` is defined on the class, then we can't reason about
# what will happen when assigning to an attribute.
if any(
base.locals.get("__setattr__")
for base in klass.mro()
if base.qname() != "builtins.object"
):
return
# If 'typing.Generic' is a base of bases of klass, the cached version
# of 'slots()' might have been evaluated incorrectly, thus deleted cache entry.
if any(base.qname() == "typing.Generic" for base in klass.mro()):
cache = getattr(klass, "__cache", None)
if cache and cache.get(klass.slots) is not None:
del cache[klass.slots]
slots = klass.slots()
if slots is None:
return
# If any ancestor doesn't use slots, the slots
# defined for this class are superfluous.
if any(
"__slots__" not in ancestor.locals and ancestor.name != "object"
for ancestor in klass.ancestors()
):
return
if not any(slot.value == node.attrname for slot in slots):
# If we have a '__dict__' in slots, then
# assigning any name is valid.
if not any(slot.value == "__dict__" for slot in slots):
if _is_attribute_property(node.attrname, klass):
# Properties circumvent the slots mechanism,
# so we should not emit a warning for them.
return
if node.attrname in klass.locals:
for local_name in klass.locals.get(node.attrname):
statement = local_name.statement(future=_True)
if (
isinstance(statement, nodes.AnnAssign)
and not statement.value
):
return
if _has_data_descriptor(klass, node.attrname):
# Descriptors circumvent the slots mechanism as well.
return
if node.attrname == "__class__" and _has_same_layout_slots(
slots, node.parent.value
):
return
self.add_message("assigning-non-slot", args=(node.attrname,), node=node)
@check_messages(
"protected-access", "no-classmethod-decorator", "no-staticmethod-decorator"
)
def visit_assign(self, assign_node: nodes.Assign) -> None:
self._check_classmethod_declaration(assign_node)
node = assign_node.targets[0]
if not isinstance(node, nodes.AssignAttr):
return
if self._uses_mandatory_method_param(node):
return
self._check_protected_attribute_access(node)
def _check_classmethod_declaration(self, node):
"""Checks for uses of classmethod() or staticmethod().
When a @classmethod or @staticmethod decorator should be used instead.
A message will be emitted only if the assignment is at a class scope
and only if the classmethod's argument belongs to the class where it
is defined.
`node` is an assign node.
"""
if not isinstance(node.value, nodes.Call):
return
# check the function called is "classmethod" or "staticmethod"
func = node.value.func
if not isinstance(func, nodes.Name) or func.name not in (
"classmethod",
"staticmethod",
):
return
msg = (
"no-classmethod-decorator"
if func.name == "classmethod"
else "no-staticmethod-decorator"
)
# assignment must be at a class scope
parent_class = node.scope()
if not isinstance(parent_class, nodes.ClassDef):
return
# Check if the arg passed to classmethod is a class member
classmeth_arg = node.value.args[0]
if not isinstance(classmeth_arg, nodes.Name):
return
method_name = classmeth_arg.name
if any(method_name == member.name for member in parent_class.mymethods()):
self.add_message(msg, node=node.targets[0])
def _check_protected_attribute_access(self, node: nodes.Attribute):
"""Given an attribute access node (set or get), check if attribute
access is legitimate. Call _check_first_attr with node before calling
this method. Valid cases are:
* self._attr in a method or cls._attr in a classmethod. Checked by
_check_first_attr.
* Klass._attr inside "Klass" class.
* Klass2._attr inside "Klass" class when Klass2 is a base class of
Klass.
"""
attrname = node.attrname
if (
is_attr_protected(attrname)
and attrname not in self.config.exclude_protected
):
klass = node_frame_class(node)
# In classes, check we are not getting a parent method
# through the class object or through super
callee = node.expr.as_string()
# Typing annotations in function definitions can include protected members
if utils.is_node_in_type_annotation_context(node):
return
# We are not in a class, no remaining valid case
if klass is None:
self.add_message("protected-access", node=node, args=attrname)
return
# If the expression begins with a call to super, that's ok.
if (
isinstance(node.expr, nodes.Call)
and isinstance(node.expr.func, nodes.Name)
and node.expr.func.name == "super"
):
return
# If the expression begins with a call to type(self), that's ok.
if self._is_type_self_call(node.expr):
return
# Check if we are inside the scope of a class or nested inner class
inside_klass = _True
outer_klass = klass
parents_callee = callee.split(".")
parents_callee.reverse()
for callee in parents_callee:
if not outer_klass or callee != outer_klass.name:
inside_klass = _False
break
# Move up one level within the nested classes
outer_klass = get_outer_class(outer_klass)
# We are in a class, one remaining valid cases, Klass._attr inside
# Klass
if not (inside_klass or callee in klass.basenames):
# Detect property assignments in the body of the class.
# This is acceptable:
#
# class A:
# b = property(lambda: self._b)
stmt = node.parent.statement(future=_True)
if (
isinstance(stmt, nodes.Assign)
and len(stmt.targets) == 1
and isinstance(stmt.targets[0], nodes.AssignName)
):
name = stmt.targets[0].name
if _is_attribute_property(name, klass):
return
if (
self._is_classmethod(node.frame(future=_True))
and self._is_inferred_instance(node.expr, klass)
and self._is_class_attribute(attrname, klass)
):
return
licit_protected_member = not attrname.startswith("__")
if (
not self.config.check_protected_access_in_special_methods
and licit_protected_member
and self._is_called_inside_special_method(node)
):
return
self.add_message("protected-access", node=node, args=attrname)
@staticmethod
def _is_called_inside_special_method(node: nodes.NodeNG) -> bool:
"""Returns true if the node is located inside a special (aka dunder) method."""
frame_name = node.frame(future=_True).name
return frame_name and frame_name in PYMETHODS
def _is_type_self_call(self, expr: nodes.NodeNG) -> bool:
return (
isinstance(expr, nodes.Call)
and isinstance(expr.func, nodes.Name)
and expr.func.name == "type"
and len(expr.args) == 1
and self._is_mandatory_method_param(expr.args[0])
)
@staticmethod
def _is_classmethod(func):
"""Check if the given *func* node is a class method."""
return isinstance(func, nodes.FunctionDef) and (
func.type == "classmethod" or func.name == "__class_getitem__"
)
@staticmethod
def _is_inferred_instance(expr, klass):
"""Check if the inferred value of the given *expr* is an instance of *klass*."""
inferred = safe_infer(expr)
if not isinstance(inferred, astroid.Instance):
return _False
return inferred._proxied is klass
@staticmethod
def _is_class_attribute(name, klass):
"""Check if the given attribute *name* is a class or instance member of the given *klass*.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
klass.getattr(name)
return _True
except astroid.NotFoundError:
pass
try:
klass.instance_attr(name)
return _True
except astroid.NotFoundError:
return _False
def visit_name(self, node: nodes.Name) -> None:
"""Check if the name handle an access to a class member
if so, register it
"""
if self._first_attrs and (
node.name == self._first_attrs[-1] or not self._first_attrs[-1]
):
self._meth_could_be_func = _False
def _check_accessed_members(self, node, accessed):
"""Check that accessed members are defined."""
excs = ("AttributeError", "Exception", "BaseException")
for attr, nodes_lst in accessed.items():
try:
# is it a class attribute ?
node.local_attr(attr)
# yes, stop here
continue
except astroid.NotFoundError:
pass
# is it an instance attribute of a parent class ?
try:
next(node.instance_attr_ancestors(attr))
# yes, stop here
continue
except StopIteration:
pass
# is it an instance attribute ?
try:
defstmts = node.instance_attr(attr)
except astroid.NotFoundError:
pass
else:
# filter out augment assignment nodes
defstmts = [stmt for stmt in defstmts if stmt not in nodes_lst]
if not defstmts:
# only augment assignment for this node, no-member should be
# triggered by the typecheck checker
continue
# filter defstmts to only pick the first one when there are
# several assignments in the same scope
scope = defstmts[0].scope()
defstmts = [
stmt
for i, stmt in enumerate(defstmts)
if i == 0 or stmt.scope() is not scope
]
# if there are still more than one, don't attempt to be smarter
# than we can be
if len(defstmts) == 1:
defstmt = defstmts[0]
# check that if the node is accessed in the same method as
# it's defined, it's accessed after the initial assignment
frame = defstmt.frame(future=_True)
lno = defstmt.fromlineno
for _node in nodes_lst:
if (
_node.frame(future=_True) is frame
and _node.fromlineno < lno
and not astroid.are_exclusive(
_node.statement(future=_True), defstmt, excs
)
):
self.add_message(
"access-member-before-definition",
node=_node,
args=(attr, lno),
)
def _check_first_arg_for_type(self, node, metaclass=0):
"""Check the name of first argument, expect:.
* 'self' for a regular method
* 'cls' for a class method or a metaclass regular method (actually
valid-classmethod-first-arg value)
* 'mcs' for a metaclass class method (actually
valid-metaclass-classmethod-first-arg)
* not one of the above for a static method
"""
# don't care about functions with unknown argument (builtins)
if node.args.args is None:
return
if node.args.posonlyargs:
first_arg = node.args.posonlyargs[0].name
elif node.args.args:
first_arg = node.argnames()[0]
else:
first_arg = None
self._first_attrs.append(first_arg)
first = self._first_attrs[-1]
# static method
if node.type == "staticmethod":
if (
first_arg == "self"
or first_arg in self.config.valid_classmethod_first_arg
or first_arg in self.config.valid_metaclass_classmethod_first_arg
):
self.add_message("bad-staticmethod-argument", args=first, node=node)
return
self._first_attrs[-1] = None
# class / regular method with no args
elif not node.args.args and not node.args.posonlyargs:
self.add_message("no-method-argument", node=node)
# metaclass
elif metaclass:
# metaclass __new__ or classmethod
if node.type == "classmethod":
self._check_first_arg_config(
first,
self.config.valid_metaclass_classmethod_first_arg,
node,
"bad-mcs-classmethod-argument",
node.name,
)
# metaclass regular method
else:
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-mcs-method-argument",
node.name,
)
# regular class with class method
elif node.type == "classmethod" or node.name == "__class_getitem__":
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-classmethod-argument",
node.name,
)
# regular class with regular method without self as argument
elif first != "self":
self.add_message("no-self-argument", node=node)
def _check_first_arg_config(self, first, config, node, message, method_name):
if first not in config:
if len(config) == 1:
valid = repr(config[0])
else:
valid = ", ".join(repr(v) for v in config[:-1])
valid = f"{valid} or {config[-1]!r}"
self.add_message(message, args=(method_name, valid), node=node)
def _check_bases_classes(self, node):
"""Check that the given class node implements abstract methods from
base classes
"""
def is_abstract(method):
return method.is_abstract(pass_is_abstract=_False)
# check if this class abstract
if class_is_abstract(node):
return
methods = sorted(
unimplemented_abstract_methods(node, is_abstract).items(),
key=lambda item: item[0],
)
for name, method in methods:
owner = method.parent.frame(future=_True)
if owner is node:
continue
# owner is not this class, it must be a parent class
# check that the ancestor's method is not abstract
if name in node.locals:
# it is redefined as an attribute or with a descriptor
continue
self.add_message("abstract-method", node=node, args=(name, owner.name))
def _check_init(self, node: nodes.FunctionDef, klass_node: nodes.ClassDef) -> None:
"""Check that the __init__ method call super or ancestors'__init__
method (unless it is used for type hinting with `typing.overload`)
"""
if not self.linter.is_message_enabled(
"super-init-not-called"
) and not self.linter.is_message_enabled("non-parent-init-called"):
return
to_call = _ancestors_to_call(klass_node)
not_called_yet = dict(to_call)
parents_with_called_inits: Set[bases.UnboundMethod] = set()
for stmt in node.nodes_of_class(nodes.Call):
expr = stmt.func
if not isinstance(expr, nodes.Attribute) or expr.attrname != "__init__":
continue
# skip the test if using super
if (
isinstance(expr.expr, nodes.Call)
and isinstance(expr.expr.func, nodes.Name)
and expr.expr.func.name == "super"
):
return
try:
for klass in expr.expr.infer():
if klass is astroid.Uninferable:
continue
# The inferred klass can be super(), which was
# assigned to a variable and the `__init__`
# was called later.
#
# base = super()
# base.__init__(...)
if (
isinstance(klass, astroid.Instance)
and isinstance(klass._proxied, nodes.ClassDef)
and is_builtin_object(klass._proxied)
and klass._proxied.name == "super"
):
return
if isinstance(klass, astroid.objects.Super):
return
try:
method = not_called_yet.pop(klass)
# Record that the class' init has been called
parents_with_called_inits.add(node_frame_class(method))
except KeyError:
if klass not in to_call:
self.add_message(
"non-parent-init-called", node=expr, args=klass.name
)
except astroid.InferenceError:
continue
for klass, method in not_called_yet.items():
# Check if the init of the class that defines this init has already
# been called.
if node_frame_class(method) in parents_with_called_inits:
return
# Return if klass is protocol
if klass.qname() in utils.TYPING_PROTOCOLS:
return
# Return if any of the klass' first-order bases is protocol
for base in klass.bases:
# We don't need to catch InferenceError here as _ancestors_to_call
# already does this for us.
for inf_base in base.infer():
if inf_base.qname() in utils.TYPING_PROTOCOLS:
return
if decorated_with(node, ["typing.overload"]):
continue
cls = node_frame_class(method)
if klass.name == "object" or (cls and cls.name == "object"):
continue
self.add_message(
"super-init-not-called",
args=klass.name,
node=node,
confidence=INFERENCE,
)
def _check_signature(self, method1, refmethod, class_type, cls):
"""Check that the signature of the two given methods match."""
if not (
isinstance(method1, nodes.FunctionDef)
and isinstance(refmethod, nodes.FunctionDef)
):
self.add_message(
"method-check-failed", args=(method1, refmethod), node=method1
)
return
instance = cls.instantiate_class()
method1 = astroid.scoped_nodes.function_to_method(method1, instance)
refmethod = astroid.scoped_nodes.function_to_method(refmethod, instance)
# Don't care about functions with unknown argument (builtins).
if method1.args.args is None or refmethod.args.args is None:
return
# Ignore private to class methods.
if is_attr_private(method1.name):
return
# Ignore setters, they have an implicit extra argument,
# which shouldn't be taken in consideration.
if is_property_setter(method1):
return
arg_differ_output = _different_parameters(
refmethod, method1, dummy_parameter_regex=self._dummy_rgx
)
if len(arg_differ_output) > 0:
for msg in arg_differ_output:
if "Number" in msg:
total_args_method1 = len(method1.args.args)
if method1.args.vararg:
total_args_method1 += 1
if method1.args.kwarg:
total_args_method1 += 1
if method1.args.kwonlyargs:
total_args_method1 += len(method1.args.kwonlyargs)
total_args_refmethod = len(refmethod.args.args)
if refmethod.args.vararg:
total_args_refmethod += 1
if refmethod.args.kwarg:
total_args_refmethod += 1
if refmethod.args.kwonlyargs:
total_args_refmethod += len(refmethod.args.kwonlyargs)
error_type = "arguments-differ"
msg_args = (
msg
+ f"was {total_args_refmethod} in '{refmethod.parent.frame().name}.{refmethod.name}' and "
f"is now {total_args_method1} in",
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
elif "renamed" in msg:
error_type = "arguments-renamed"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
else:
error_type = "arguments-differ"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
self.add_message(error_type, args=msg_args, node=method1)
elif (
len(method1.args.defaults) < len(refmethod.args.defaults)
and not method1.args.vararg
):
self.add_message(
"signature-differs", args=(class_type, method1.name), node=method1
)
def _uses_mandatory_method_param(self, node):
"""Check that attribute lookup name use first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
return self._is_mandatory_method_param(node.expr)
def _is_mandatory_method_param(self, node: nodes.NodeNG) -> bool:
"""Check if nodes.Name corresponds to first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
if self._first_attrs:
first_attr = self._first_attrs[-1]
else:
# It's possible the function was already unregistered.
closest_func = utils.get_node_first_ancestor_of_type(
node, nodes.FunctionDef
)
if closest_func is None:
return _False
if not closest_func.args.args:
return _False
first_attr = closest_func.args.args[0].name
return isinstance(node, nodes.Name) and node.name == first_attr
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 786 | get_global_option | ref | function | return get_global_option(self, "ignore-mixin-members", default=True)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 788 | check_messages | ref | function | @check_messages(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 801 | visit_classdef | def | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 803 | _check_bases_classes | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 805 | has_known_bases | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 807 | local_attr | ref | function | node.local_attr("__init__")
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 809 | add_message | ref | function | self.add_message("no-init", args=node, node=node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 810 | _check_slots | ref | function | self._check_slots(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 811 | _check_proper_bases | ref | function | self._check_proper_bases(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 812 | _check_typing_final | ref | function | self._check_typing_final(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 813 | _check_consistent_mro | ref | function | self._check_consistent_mro(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 815 | _check_consistent_mro | def | function | def _check_consistent_mro(self, node):
"""Detect that a class has a consistent mro or duplicate bases."""
try:
node.mro()
except astroid.InconsistentMroError:
self.add_message("inconsistent-mro", args=node.name, node=node)
except astroid.DuplicateBasesError:
self.add_message("duplicate-bases", args=node.name, node=node)
except NotImplementedError:
# Old style class, there's no mro so don't do anything.
pass
def _check_proper_bases(self, node):
"""Detect that a class inherits something which is not
a class or a type.
"""
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, astroid.Instance) and ancestor.is_subtype_of(
"builtins.type"
):
continue
if not isinstance(ancestor, nodes.ClassDef) or _is_invalid_base_class(
ancestor
):
self.add_message("inherit-non-class", args=base.as_string(), node=node)
if ancestor.name == object.__name__:
self.add_message(
"useless-object-inheritance", args=node.name, node=node
)
def _check_typing_final(self, node: nodes.ClassDef) -> None:
"""Detect that a class does not subclass a class decorated with `typing.final`."""
if not self._py38_plus:
return
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, nodes.ClassDef) and (
decorated_with(ancestor, ["typing.final"])
or uninferable_final_decorators(ancestor.decorators)
):
self.add_message(
"subclassed-final-class",
args=(node.name, ancestor.name),
node=node,
)
@check_messages("unused-private-member", "attribute-defined-outside-init")
def leave_classdef(self, node: nodes.ClassDef) -> None:
"""Close a class node:
check that instance attributes are defined in __init__ and check
access to existent members
"""
self._check_unused_private_functions(node)
self._check_unused_private_variables(node)
self._check_unused_private_attributes(node)
self._check_attribute_defined_outside_init(node)
def _check_unused_private_functions(self, node: nodes.ClassDef) -> None:
for function_def in node.nodes_of_class(nodes.FunctionDef):
if not is_attr_private(function_def.name):
continue
parent_scope = function_def.parent.scope()
if isinstance(parent_scope, nodes.FunctionDef):
# Handle nested functions
if function_def.name in (
n.name for n in parent_scope.nodes_of_class(nodes.Name)
):
continue
for attribute in node.nodes_of_class(nodes.Attribute):
if (
attribute.attrname != function_def.name
or attribute.scope() == function_def # We ignore recursive calls
):
continue
if isinstance(attribute.expr, nodes.Name) and attribute.expr.name in (
"self",
"cls",
node.name,
):
# self.__attrname
# cls.__attrname
# node_name.__attrname
break
if isinstance(attribute.expr, nodes.Call):
# type(self).__attrname
inferred = safe_infer(attribute.expr)
if (
isinstance(inferred, nodes.ClassDef)
and inferred.name == node.name
):
break
else:
name_stack = []
curr = parent_scope
# Generate proper names for nested functions
while curr != node:
name_stack.append(curr.name)
curr = curr.parent.scope()
outer_level_names = f"{'.'.join(reversed(name_stack))}"
function_repr = f"{outer_level_names}.{function_def.name}({function_def.args.as_string()})"
self.add_message(
"unused-private-member",
node=function_def,
args=(node.name, function_repr.lstrip(".")),
)
def _check_unused_private_variables(self, node: nodes.ClassDef) -> None:
"""Check if private variables are never used within a class."""
for assign_name in node.nodes_of_class(nodes.AssignName):
if isinstance(assign_name.parent, nodes.Arguments):
continue # Ignore function arguments
if not is_attr_private(assign_name.name):
continue
for child in node.nodes_of_class((nodes.Name, nodes.Attribute)):
if isinstance(child, nodes.Name) and child.name == assign_name.name:
break
if isinstance(child, nodes.Attribute):
if not isinstance(child.expr, nodes.Name):
break
if child.attrname == assign_name.name and child.expr.name in (
"self",
"cls",
node.name,
):
break
else:
args = (node.name, assign_name.name)
self.add_message("unused-private-member", node=assign_name, args=args)
def _check_unused_private_attributes(self, node: nodes.ClassDef) -> None:
for assign_attr in node.nodes_of_class(nodes.AssignAttr):
if not is_attr_private(assign_attr.attrname) or not isinstance(
assign_attr.expr, nodes.Name
):
continue
# Logic for checking false positive when using __new__,
# Get the returned object names of the __new__ magic function
# Then check if the attribute was consumed in other instance methods
acceptable_obj_names: List[str] = ["self"]
scope = assign_attr.scope()
if isinstance(scope, nodes.FunctionDef) and scope.name == "__new__":
acceptable_obj_names.extend(
[
return_node.value.name
for return_node in scope.nodes_of_class(nodes.Return)
if isinstance(return_node.value, nodes.Name)
]
)
for attribute in node.nodes_of_class(nodes.Attribute):
if attribute.attrname != assign_attr.attrname:
continue
if self._is_type_self_call(attribute.expr):
continue
if assign_attr.expr.name in {
"cls",
node.name,
} and attribute.expr.name in {"cls", "self", node.name}:
# If assigned to cls or class name, can be accessed by cls/self/class name
break
if (
assign_attr.expr.name in acceptable_obj_names
and attribute.expr.name == "self"
):
# If assigned to self.attrib, can only be accessed by self
# Or if __new__ was used, the returned object names are acceptable
break
if assign_attr.expr.name == attribute.expr.name == node.name:
# Recognise attributes which are accessed via the class name
break
else:
args = (node.name, assign_attr.attrname)
self.add_message("unused-private-member", node=assign_attr, args=args)
def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
# check access to existent members on non metaclass classes
if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
# We are in a mixin class. No need to try to figure out if
# something is missing, since it is most likely that it will
# miss.
return
accessed = self._accessed.accessed(cnode)
if cnode.type != "metaclass":
self._check_accessed_members(cnode, accessed)
# checks attributes are defined in an allowed method such as __init__
if not self.linter.is_message_enabled("attribute-defined-outside-init"):
return
defining_methods = self.config.defining_attr_methods
current_module = cnode.root()
for attr, nodes_lst in cnode.instance_attrs.items():
# Exclude `__dict__` as it is already defined.
if attr == "__dict__":
continue
# Skip nodes which are not in the current module and it may screw up
# the output, while it's not worth it
nodes_lst = [
n
for n in nodes_lst
if not isinstance(
n.statement(future=_True), (nodes.Delete, nodes.AugAssign)
)
and n.root() is current_module
]
if not nodes_lst:
continue # error detected by typechecking
# Check if any method attr is defined in is a defining method
# or if we have the attribute defined in a setter.
frames = (node.frame(future=_True) for node in nodes_lst)
if any(
frame.name in defining_methods or is_property_setter(frame)
for frame in frames
):
continue
# check attribute is defined in a parent's __init__
for parent in cnode.instance_attr_ancestors(attr):
attr_defined = _False
# check if any parent method attr is defined in is a defining method
for node in parent.instance_attrs[attr]:
if node.frame(future=_True).name in defining_methods:
attr_defined = _True
if attr_defined:
# we're done :)
break
else:
# check attribute is defined as a class attribute
try:
cnode.local_attr(attr)
except astroid.NotFoundError:
for node in nodes_lst:
if node.frame(future=_True).name not in defining_methods:
# If the attribute was set by a call in any
# of the defining methods, then don't emit
# the warning.
if _called_in_methods(
node.frame(future=_True), cnode, defining_methods
):
continue
self.add_message(
"attribute-defined-outside-init", args=attr, node=node
)
def visit_functiondef(self, node: nodes.FunctionDef) -> None:
"""Check method arguments, overriding."""
# ignore actual functions
if not node.is_method():
return
self._check_useless_super_delegation(node)
self._check_property_with_parameters(node)
# 'is_method()' is called and makes sure that this is a 'nodes.ClassDef'
klass = node.parent.frame(future=_True) # type: nodes.ClassDef
self._meth_could_be_func = _True
# check first argument is self if this is actually a method
self._check_first_arg_for_type(node, klass.type == "metaclass")
if node.name == "__init__":
self._check_init(node, klass)
return
# check signature if the method overloads inherited method
for overridden in klass.local_attr_ancestors(node.name):
# get astroid for the searched method
try:
parent_function = overridden[node.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if not isinstance(parent_function, nodes.FunctionDef):
continue
self._check_signature(node, parent_function, "overridden", klass)
self._check_invalid_overridden_method(node, parent_function)
break
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, nodes.Attribute) and decorator.attrname in {
"getter",
"setter",
"deleter",
}:
# attribute affectation will call this method, not hiding it
return
if isinstance(decorator, nodes.Name):
if decorator.name == "property":
# attribute affectation will either call a setter or raise
# an attribute error, anyway not hiding the function
return
# Infer the decorator and see if it returns something useful
inferred = safe_infer(decorator)
if not inferred:
return
if isinstance(inferred, nodes.FunctionDef):
# Okay, it's a decorator, let's see what it can infer.
try:
inferred = next(inferred.infer_call_result(inferred))
except astroid.InferenceError:
return
try:
if (
isinstance(inferred, (astroid.Instance, nodes.ClassDef))
and inferred.getattr("__get__")
and inferred.getattr("__set__")
):
return
except astroid.AttributeInferenceError:
pass
# check if the method is hidden by an attribute
try:
overridden = klass.instance_attr(node.name)[0]
overridden_frame = overridden.frame(future=_True)
if (
isinstance(overridden_frame, nodes.FunctionDef)
and overridden_frame.type == "method"
):
overridden_frame = overridden_frame.parent.frame(future=_True)
if not (
isinstance(overridden_frame, nodes.ClassDef)
and klass.is_subtype_of(overridden_frame.qname())
):
return
# If a subclass defined the method then it's not our fault.
for ancestor in klass.ancestors():
if node.name in ancestor.instance_attrs and is_attr_private(node.name):
return
for obj in ancestor.lookup(node.name)[1]:
if isinstance(obj, nodes.FunctionDef):
return
args = (overridden.root().name, overridden.fromlineno)
self.add_message("method-hidden", args=args, node=node)
except astroid.NotFoundError:
pass
visit_asyncfunctiondef = visit_functiondef
def _check_useless_super_delegation(self, function):
"""Check if the given function node is an useless method override.
We consider it *useless* if it uses the super() builtin, but having
nothing additional whatsoever than not implementing the method at all.
If the method uses super() to delegate an operation to the rest of the MRO,
and if the method called is the same as the current one, the arguments
passed to super() are the same as the parameters that were passed to
this method, then the method could be removed altogether, by letting
other implementation to take precedence.
"""
if (
not function.is_method()
# With decorators is a change of use
or function.decorators
):
return
body = function.body
if len(body) != 1:
# Multiple statements, which means this overridden method
# could do multiple things we are not aware of.
return
statement = body[0]
if not isinstance(statement, (nodes.Expr, nodes.Return)):
# Doing something else than what we are interested into.
return
call = statement.value
if (
not isinstance(call, nodes.Call)
# Not a super() attribute access.
or not isinstance(call.func, nodes.Attribute)
):
return
# Should be a super call.
try:
super_call = next(call.func.expr.infer())
except astroid.InferenceError:
return
else:
if not isinstance(super_call, astroid.objects.Super):
return
# The name should be the same.
if call.func.attrname != function.name:
return
# Should be a super call with the MRO pointer being the
# current class and the type being the current instance.
current_scope = function.parent.scope()
if (
super_call.mro_pointer != current_scope
or not isinstance(super_call.type, astroid.Instance)
or super_call.type.name != current_scope.name
):
return
# Check values of default args
klass = function.parent.frame(future=_True)
meth_node = None
for overridden in klass.local_attr_ancestors(function.name):
# get astroid for the searched method
try:
meth_node = overridden[function.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if (
not isinstance(meth_node, nodes.FunctionDef)
# If the method have an ancestor which is not a
# function then it is legitimate to redefine it
or _has_different_parameters_default_value(
meth_node.args, function.args
)
):
return
break
# Detect if the parameters are the same as the call's arguments.
params = _signature_from_arguments(function.args)
args = _signature_from_call(call)
if meth_node is not None:
def form_annotations(arguments):
annotations = chain(
(arguments.posonlyargs_annotations or []), arguments.annotations
)
return [ann.as_string() for ann in annotations if ann is not None]
called_annotations = form_annotations(function.args)
overridden_annotations = form_annotations(meth_node.args)
if called_annotations and overridden_annotations:
if called_annotations != overridden_annotations:
return
if _definition_equivalent_to_call(params, args):
self.add_message(
"useless-super-delegation", node=function, args=(function.name,)
)
def _check_property_with_parameters(self, node):
if (
node.args.args
and len(node.args.args) > 1
and decorated_with_property(node)
and not is_property_setter(node)
):
self.add_message("property-with-parameters", node=node)
def _check_invalid_overridden_method(self, function_node, parent_function_node):
parent_is_property = decorated_with_property(
parent_function_node
) or is_property_setter_or_deleter(parent_function_node)
current_is_property = decorated_with_property(
function_node
) or is_property_setter_or_deleter(function_node)
if parent_is_property and not current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "property", function_node.type),
node=function_node,
)
elif not parent_is_property and current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "method", "property"),
node=function_node,
)
parent_is_async = isinstance(parent_function_node, nodes.AsyncFunctionDef)
current_is_async = isinstance(function_node, nodes.AsyncFunctionDef)
if parent_is_async and not current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "async", "non-async"),
node=function_node,
)
elif not parent_is_async and current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "non-async", "async"),
node=function_node,
)
if (
decorated_with(parent_function_node, ["typing.final"])
or uninferable_final_decorators(parent_function_node.decorators)
) and self._py38_plus:
self.add_message(
"overridden-final-method",
args=(function_node.name, parent_function_node.parent.frame().name),
node=function_node,
)
def _check_slots(self, node: nodes.ClassDef) -> None:
if "__slots__" not in node.locals:
return
for slots in node.igetattr("__slots__"):
# check if __slots__ is a valid type
if slots is astroid.Uninferable:
continue
if not is_iterable(slots) and not is_comprehension(slots):
self.add_message("invalid-slots", node=node)
continue
if isinstance(slots, nodes.Const):
# a string, ignore the following checks
self.add_message("single-string-used-for-slots", node=node)
continue
if not hasattr(slots, "itered"):
# we can't obtain the values, maybe a .deque?
continue
if isinstance(slots, nodes.Dict):
values = [item[0] for item in slots.items]
else:
values = slots.itered()
if values is astroid.Uninferable:
return
for elt in values:
try:
self._check_slots_elt(elt, node)
except astroid.InferenceError:
continue
self._check_redefined_slots(node, slots, values)
def _check_redefined_slots(
self,
node: nodes.ClassDef,
slots_node: nodes.NodeNG,
slots_list: List[nodes.NodeNG],
) -> None:
"""Check if `node` redefines a slot which is defined in an ancestor class."""
slots_names: List[str] = []
for slot in slots_list:
if isinstance(slot, nodes.Const):
slots_names.append(slot.value)
else:
inferred_slot = safe_infer(slot)
if inferred_slot:
slots_names.append(inferred_slot.value)
# Slots of all parent classes
ancestors_slots_names = {
slot.value
for ancestor in node.local_attr_ancestors("__slots__")
for slot in ancestor.slots() or []
}
# Slots which are common to `node` and its parent classes
redefined_slots = ancestors_slots_names.intersection(slots_names)
if redefined_slots:
self.add_message(
"redefined-slots-in-subclass",
args=([name for name in slots_names if name in redefined_slots],),
node=slots_node,
)
def _check_slots_elt(self, elt, node):
for inferred in elt.infer():
if inferred is astroid.Uninferable:
continue
if not isinstance(inferred, nodes.Const) or not isinstance(
inferred.value, str
):
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
continue
if not inferred.value:
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
# Check if we have a conflict with a class variable.
class_variable = node.locals.get(inferred.value)
if class_variable:
# Skip annotated assignments which don't conflict at all with slots.
if len(class_variable) == 1:
parent = class_variable[0].parent
if isinstance(parent, nodes.AnnAssign) and parent.value is None:
return
self.add_message(
"class-variable-slots-conflict", args=(inferred.value,), node=elt
)
def leave_functiondef(self, node: nodes.FunctionDef) -> None:
"""On method node, check if this method couldn't be a function.
ignore class, static and abstract methods, initializer,
methods overridden from a parent class.
"""
if node.is_method():
if node.args.args is not None:
self._first_attrs.pop()
if not self.linter.is_message_enabled("no-self-use"):
return
class_node = node.parent.frame(future=_True)
if (
self._meth_could_be_func
and node.type == "method"
and node.name not in PYMETHODS
and not (
node.is_abstract()
or overrides_a_method(class_node, node.name)
or decorated_with_property(node)
or _has_bare_super_call(node)
or is_protocol_class(class_node)
or is_overload_stub(node)
)
):
self.add_message("no-self-use", node=node)
leave_asyncfunctiondef = leave_functiondef
def visit_attribute(self, node: nodes.Attribute) -> None:
"""Check if the getattr is an access to a class member
if so, register it. Also check for access to protected
class member from outside its class (but ignore __special__
methods)
"""
# Check self
if self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
return
if not self.linter.is_message_enabled("protected-access"):
return
self._check_protected_attribute_access(node)
@check_messages("assigning-non-slot", "invalid-class-object")
def visit_assignattr(self, node: nodes.AssignAttr) -> None:
if isinstance(
node.assign_type(), nodes.AugAssign
) and self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
self._check_in_slots(node)
self._check_invalid_class_object(node)
def _check_invalid_class_object(self, node: nodes.AssignAttr) -> None:
if not node.attrname == "__class__":
return
inferred = safe_infer(node.parent.value)
if isinstance(inferred, nodes.ClassDef) or inferred is astroid.Uninferable:
# If is uninferrable, we allow it to prevent false positives
return
self.add_message("invalid-class-object", node=node)
def _check_in_slots(self, node):
"""Check that the given AssignAttr node
is defined in the class slots.
"""
inferred = safe_infer(node.expr)
if not isinstance(inferred, astroid.Instance):
return
klass = inferred._proxied
if not has_known_bases(klass):
return
if "__slots__" not in klass.locals or not klass.newstyle:
return
# If `__setattr__` is defined on the class, then we can't reason about
# what will happen when assigning to an attribute.
if any(
base.locals.get("__setattr__")
for base in klass.mro()
if base.qname() != "builtins.object"
):
return
# If 'typing.Generic' is a base of bases of klass, the cached version
# of 'slots()' might have been evaluated incorrectly, thus deleted cache entry.
if any(base.qname() == "typing.Generic" for base in klass.mro()):
cache = getattr(klass, "__cache", None)
if cache and cache.get(klass.slots) is not None:
del cache[klass.slots]
slots = klass.slots()
if slots is None:
return
# If any ancestor doesn't use slots, the slots
# defined for this class are superfluous.
if any(
"__slots__" not in ancestor.locals and ancestor.name != "object"
for ancestor in klass.ancestors()
):
return
if not any(slot.value == node.attrname for slot in slots):
# If we have a '__dict__' in slots, then
# assigning any name is valid.
if not any(slot.value == "__dict__" for slot in slots):
if _is_attribute_property(node.attrname, klass):
# Properties circumvent the slots mechanism,
# so we should not emit a warning for them.
return
if node.attrname in klass.locals:
for local_name in klass.locals.get(node.attrname):
statement = local_name.statement(future=_True)
if (
isinstance(statement, nodes.AnnAssign)
and not statement.value
):
return
if _has_data_descriptor(klass, node.attrname):
# Descriptors circumvent the slots mechanism as well.
return
if node.attrname == "__class__" and _has_same_layout_slots(
slots, node.parent.value
):
return
self.add_message("assigning-non-slot", args=(node.attrname,), node=node)
@check_messages(
"protected-access", "no-classmethod-decorator", "no-staticmethod-decorator"
)
def visit_assign(self, assign_node: nodes.Assign) -> None:
self._check_classmethod_declaration(assign_node)
node = assign_node.targets[0]
if not isinstance(node, nodes.AssignAttr):
return
if self._uses_mandatory_method_param(node):
return
self._check_protected_attribute_access(node)
def _check_classmethod_declaration(self, node):
"""Checks for uses of classmethod() or staticmethod().
When a @classmethod or @staticmethod decorator should be used instead.
A message will be emitted only if the assignment is at a class scope
and only if the classmethod's argument belongs to the class where it
is defined.
`node` is an assign node.
"""
if not isinstance(node.value, nodes.Call):
return
# check the function called is "classmethod" or "staticmethod"
func = node.value.func
if not isinstance(func, nodes.Name) or func.name not in (
"classmethod",
"staticmethod",
):
return
msg = (
"no-classmethod-decorator"
if func.name == "classmethod"
else "no-staticmethod-decorator"
)
# assignment must be at a class scope
parent_class = node.scope()
if not isinstance(parent_class, nodes.ClassDef):
return
# Check if the arg passed to classmethod is a class member
classmeth_arg = node.value.args[0]
if not isinstance(classmeth_arg, nodes.Name):
return
method_name = classmeth_arg.name
if any(method_name == member.name for member in parent_class.mymethods()):
self.add_message(msg, node=node.targets[0])
def _check_protected_attribute_access(self, node: nodes.Attribute):
"""Given an attribute access node (set or get), check if attribute
access is legitimate. Call _check_first_attr with node before calling
this method. Valid cases are:
* self._attr in a method or cls._attr in a classmethod. Checked by
_check_first_attr.
* Klass._attr inside "Klass" class.
* Klass2._attr inside "Klass" class when Klass2 is a base class of
Klass.
"""
attrname = node.attrname
if (
is_attr_protected(attrname)
and attrname not in self.config.exclude_protected
):
klass = node_frame_class(node)
# In classes, check we are not getting a parent method
# through the class object or through super
callee = node.expr.as_string()
# Typing annotations in function definitions can include protected members
if utils.is_node_in_type_annotation_context(node):
return
# We are not in a class, no remaining valid case
if klass is None:
self.add_message("protected-access", node=node, args=attrname)
return
# If the expression begins with a call to super, that's ok.
if (
isinstance(node.expr, nodes.Call)
and isinstance(node.expr.func, nodes.Name)
and node.expr.func.name == "super"
):
return
# If the expression begins with a call to type(self), that's ok.
if self._is_type_self_call(node.expr):
return
# Check if we are inside the scope of a class or nested inner class
inside_klass = _True
outer_klass = klass
parents_callee = callee.split(".")
parents_callee.reverse()
for callee in parents_callee:
if not outer_klass or callee != outer_klass.name:
inside_klass = _False
break
# Move up one level within the nested classes
outer_klass = get_outer_class(outer_klass)
# We are in a class, one remaining valid cases, Klass._attr inside
# Klass
if not (inside_klass or callee in klass.basenames):
# Detect property assignments in the body of the class.
# This is acceptable:
#
# class A:
# b = property(lambda: self._b)
stmt = node.parent.statement(future=_True)
if (
isinstance(stmt, nodes.Assign)
and len(stmt.targets) == 1
and isinstance(stmt.targets[0], nodes.AssignName)
):
name = stmt.targets[0].name
if _is_attribute_property(name, klass):
return
if (
self._is_classmethod(node.frame(future=_True))
and self._is_inferred_instance(node.expr, klass)
and self._is_class_attribute(attrname, klass)
):
return
licit_protected_member = not attrname.startswith("__")
if (
not self.config.check_protected_access_in_special_methods
and licit_protected_member
and self._is_called_inside_special_method(node)
):
return
self.add_message("protected-access", node=node, args=attrname)
@staticmethod
def _is_called_inside_special_method(node: nodes.NodeNG) -> bool:
"""Returns true if the node is located inside a special (aka dunder) method."""
frame_name = node.frame(future=_True).name
return frame_name and frame_name in PYMETHODS
def _is_type_self_call(self, expr: nodes.NodeNG) -> bool:
return (
isinstance(expr, nodes.Call)
and isinstance(expr.func, nodes.Name)
and expr.func.name == "type"
and len(expr.args) == 1
and self._is_mandatory_method_param(expr.args[0])
)
@staticmethod
def _is_classmethod(func):
"""Check if the given *func* node is a class method."""
return isinstance(func, nodes.FunctionDef) and (
func.type == "classmethod" or func.name == "__class_getitem__"
)
@staticmethod
def _is_inferred_instance(expr, klass):
"""Check if the inferred value of the given *expr* is an instance of *klass*."""
inferred = safe_infer(expr)
if not isinstance(inferred, astroid.Instance):
return _False
return inferred._proxied is klass
@staticmethod
def _is_class_attribute(name, klass):
"""Check if the given attribute *name* is a class or instance member of the given *klass*.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
klass.getattr(name)
return _True
except astroid.NotFoundError:
pass
try:
klass.instance_attr(name)
return _True
except astroid.NotFoundError:
return _False
def visit_name(self, node: nodes.Name) -> None:
"""Check if the name handle an access to a class member
if so, register it
"""
if self._first_attrs and (
node.name == self._first_attrs[-1] or not self._first_attrs[-1]
):
self._meth_could_be_func = _False
def _check_accessed_members(self, node, accessed):
"""Check that accessed members are defined."""
excs = ("AttributeError", "Exception", "BaseException")
for attr, nodes_lst in accessed.items():
try:
# is it a class attribute ?
node.local_attr(attr)
# yes, stop here
continue
except astroid.NotFoundError:
pass
# is it an instance attribute of a parent class ?
try:
next(node.instance_attr_ancestors(attr))
# yes, stop here
continue
except StopIteration:
pass
# is it an instance attribute ?
try:
defstmts = node.instance_attr(attr)
except astroid.NotFoundError:
pass
else:
# filter out augment assignment nodes
defstmts = [stmt for stmt in defstmts if stmt not in nodes_lst]
if not defstmts:
# only augment assignment for this node, no-member should be
# triggered by the typecheck checker
continue
# filter defstmts to only pick the first one when there are
# several assignments in the same scope
scope = defstmts[0].scope()
defstmts = [
stmt
for i, stmt in enumerate(defstmts)
if i == 0 or stmt.scope() is not scope
]
# if there are still more than one, don't attempt to be smarter
# than we can be
if len(defstmts) == 1:
defstmt = defstmts[0]
# check that if the node is accessed in the same method as
# it's defined, it's accessed after the initial assignment
frame = defstmt.frame(future=_True)
lno = defstmt.fromlineno
for _node in nodes_lst:
if (
_node.frame(future=_True) is frame
and _node.fromlineno < lno
and not astroid.are_exclusive(
_node.statement(future=_True), defstmt, excs
)
):
self.add_message(
"access-member-before-definition",
node=_node,
args=(attr, lno),
)
def _check_first_arg_for_type(self, node, metaclass=0):
"""Check the name of first argument, expect:.
* 'self' for a regular method
* 'cls' for a class method or a metaclass regular method (actually
valid-classmethod-first-arg value)
* 'mcs' for a metaclass class method (actually
valid-metaclass-classmethod-first-arg)
* not one of the above for a static method
"""
# don't care about functions with unknown argument (builtins)
if node.args.args is None:
return
if node.args.posonlyargs:
first_arg = node.args.posonlyargs[0].name
elif node.args.args:
first_arg = node.argnames()[0]
else:
first_arg = None
self._first_attrs.append(first_arg)
first = self._first_attrs[-1]
# static method
if node.type == "staticmethod":
if (
first_arg == "self"
or first_arg in self.config.valid_classmethod_first_arg
or first_arg in self.config.valid_metaclass_classmethod_first_arg
):
self.add_message("bad-staticmethod-argument", args=first, node=node)
return
self._first_attrs[-1] = None
# class / regular method with no args
elif not node.args.args and not node.args.posonlyargs:
self.add_message("no-method-argument", node=node)
# metaclass
elif metaclass:
# metaclass __new__ or classmethod
if node.type == "classmethod":
self._check_first_arg_config(
first,
self.config.valid_metaclass_classmethod_first_arg,
node,
"bad-mcs-classmethod-argument",
node.name,
)
# metaclass regular method
else:
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-mcs-method-argument",
node.name,
)
# regular class with class method
elif node.type == "classmethod" or node.name == "__class_getitem__":
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-classmethod-argument",
node.name,
)
# regular class with regular method without self as argument
elif first != "self":
self.add_message("no-self-argument", node=node)
def _check_first_arg_config(self, first, config, node, message, method_name):
if first not in config:
if len(config) == 1:
valid = repr(config[0])
else:
valid = ", ".join(repr(v) for v in config[:-1])
valid = f"{valid} or {config[-1]!r}"
self.add_message(message, args=(method_name, valid), node=node)
def _check_bases_classes(self, node):
"""Check that the given class node implements abstract methods from
base classes
"""
def is_abstract(method):
return method.is_abstract(pass_is_abstract=_False)
# check if this class abstract
if class_is_abstract(node):
return
methods = sorted(
unimplemented_abstract_methods(node, is_abstract).items(),
key=lambda item: item[0],
)
for name, method in methods:
owner = method.parent.frame(future=_True)
if owner is node:
continue
# owner is not this class, it must be a parent class
# check that the ancestor's method is not abstract
if name in node.locals:
# it is redefined as an attribute or with a descriptor
continue
self.add_message("abstract-method", node=node, args=(name, owner.name))
def _check_init(self, node: nodes.FunctionDef, klass_node: nodes.ClassDef) -> None:
"""Check that the __init__ method call super or ancestors'__init__
method (unless it is used for type hinting with `typing.overload`)
"""
if not self.linter.is_message_enabled(
"super-init-not-called"
) and not self.linter.is_message_enabled("non-parent-init-called"):
return
to_call = _ancestors_to_call(klass_node)
not_called_yet = dict(to_call)
parents_with_called_inits: Set[bases.UnboundMethod] = set()
for stmt in node.nodes_of_class(nodes.Call):
expr = stmt.func
if not isinstance(expr, nodes.Attribute) or expr.attrname != "__init__":
continue
# skip the test if using super
if (
isinstance(expr.expr, nodes.Call)
and isinstance(expr.expr.func, nodes.Name)
and expr.expr.func.name == "super"
):
return
try:
for klass in expr.expr.infer():
if klass is astroid.Uninferable:
continue
# The inferred klass can be super(), which was
# assigned to a variable and the `__init__`
# was called later.
#
# base = super()
# base.__init__(...)
if (
isinstance(klass, astroid.Instance)
and isinstance(klass._proxied, nodes.ClassDef)
and is_builtin_object(klass._proxied)
and klass._proxied.name == "super"
):
return
if isinstance(klass, astroid.objects.Super):
return
try:
method = not_called_yet.pop(klass)
# Record that the class' init has been called
parents_with_called_inits.add(node_frame_class(method))
except KeyError:
if klass not in to_call:
self.add_message(
"non-parent-init-called", node=expr, args=klass.name
)
except astroid.InferenceError:
continue
for klass, method in not_called_yet.items():
# Check if the init of the class that defines this init has already
# been called.
if node_frame_class(method) in parents_with_called_inits:
return
# Return if klass is protocol
if klass.qname() in utils.TYPING_PROTOCOLS:
return
# Return if any of the klass' first-order bases is protocol
for base in klass.bases:
# We don't need to catch InferenceError here as _ancestors_to_call
# already does this for us.
for inf_base in base.infer():
if inf_base.qname() in utils.TYPING_PROTOCOLS:
return
if decorated_with(node, ["typing.overload"]):
continue
cls = node_frame_class(method)
if klass.name == "object" or (cls and cls.name == "object"):
continue
self.add_message(
"super-init-not-called",
args=klass.name,
node=node,
confidence=INFERENCE,
)
def _check_signature(self, method1, refmethod, class_type, cls):
"""Check that the signature of the two given methods match."""
if not (
isinstance(method1, nodes.FunctionDef)
and isinstance(refmethod, nodes.FunctionDef)
):
self.add_message(
"method-check-failed", args=(method1, refmethod), node=method1
)
return
instance = cls.instantiate_class()
method1 = astroid.scoped_nodes.function_to_method(method1, instance)
refmethod = astroid.scoped_nodes.function_to_method(refmethod, instance)
# Don't care about functions with unknown argument (builtins).
if method1.args.args is None or refmethod.args.args is None:
return
# Ignore private to class methods.
if is_attr_private(method1.name):
return
# Ignore setters, they have an implicit extra argument,
# which shouldn't be taken in consideration.
if is_property_setter(method1):
return
arg_differ_output = _different_parameters(
refmethod, method1, dummy_parameter_regex=self._dummy_rgx
)
if len(arg_differ_output) > 0:
for msg in arg_differ_output:
if "Number" in msg:
total_args_method1 = len(method1.args.args)
if method1.args.vararg:
total_args_method1 += 1
if method1.args.kwarg:
total_args_method1 += 1
if method1.args.kwonlyargs:
total_args_method1 += len(method1.args.kwonlyargs)
total_args_refmethod = len(refmethod.args.args)
if refmethod.args.vararg:
total_args_refmethod += 1
if refmethod.args.kwarg:
total_args_refmethod += 1
if refmethod.args.kwonlyargs:
total_args_refmethod += len(refmethod.args.kwonlyargs)
error_type = "arguments-differ"
msg_args = (
msg
+ f"was {total_args_refmethod} in '{refmethod.parent.frame().name}.{refmethod.name}' and "
f"is now {total_args_method1} in",
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
elif "renamed" in msg:
error_type = "arguments-renamed"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
else:
error_type = "arguments-differ"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
self.add_message(error_type, args=msg_args, node=method1)
elif (
len(method1.args.defaults) < len(refmethod.args.defaults)
and not method1.args.vararg
):
self.add_message(
"signature-differs", args=(class_type, method1.name), node=method1
)
def _uses_mandatory_method_param(self, node):
"""Check that attribute lookup name use first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
return self._is_mandatory_method_param(node.expr)
def _is_mandatory_method_param(self, node: nodes.NodeNG) -> bool:
"""Check if nodes.Name corresponds to first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
if self._first_attrs:
first_attr = self._first_attrs[-1]
else:
# It's possible the function was already unregistered.
closest_func = utils.get_node_first_ancestor_of_type(
node, nodes.FunctionDef
)
if closest_func is None:
return _False
if not closest_func.args.args:
return _False
first_attr = closest_func.args.args[0].name
return isinstance(node, nodes.Name) and node.name == first_attr
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 818 | mro | ref | function | node.mro()
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 820 | add_message | ref | function | self.add_message("inconsistent-mro", args=node.name, node=node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 822 | add_message | ref | function | self.add_message("duplicate-bases", args=node.name, node=node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 827 | _check_proper_bases | def | function | def _check_proper_bases(self, node):
"""Detect that a class inherits something which is not
a class or a type.
"""
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, astroid.Instance) and ancestor.is_subtype_of(
"builtins.type"
):
continue
if not isinstance(ancestor, nodes.ClassDef) or _is_invalid_base_class(
ancestor
):
self.add_message("inherit-non-class", args=base.as_string(), node=node)
if ancestor.name == object.__name__:
self.add_message(
"useless-object-inheritance", args=node.name, node=node
)
def _check_typing_final(self, node: nodes.ClassDef) -> None:
"""Detect that a class does not subclass a class decorated with `typing.final`."""
if not self._py38_plus:
return
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, nodes.ClassDef) and (
decorated_with(ancestor, ["typing.final"])
or uninferable_final_decorators(ancestor.decorators)
):
self.add_message(
"subclassed-final-class",
args=(node.name, ancestor.name),
node=node,
)
@check_messages("unused-private-member", "attribute-defined-outside-init")
def leave_classdef(self, node: nodes.ClassDef) -> None:
"""Close a class node:
check that instance attributes are defined in __init__ and check
access to existent members
"""
self._check_unused_private_functions(node)
self._check_unused_private_variables(node)
self._check_unused_private_attributes(node)
self._check_attribute_defined_outside_init(node)
def _check_unused_private_functions(self, node: nodes.ClassDef) -> None:
for function_def in node.nodes_of_class(nodes.FunctionDef):
if not is_attr_private(function_def.name):
continue
parent_scope = function_def.parent.scope()
if isinstance(parent_scope, nodes.FunctionDef):
# Handle nested functions
if function_def.name in (
n.name for n in parent_scope.nodes_of_class(nodes.Name)
):
continue
for attribute in node.nodes_of_class(nodes.Attribute):
if (
attribute.attrname != function_def.name
or attribute.scope() == function_def # We ignore recursive calls
):
continue
if isinstance(attribute.expr, nodes.Name) and attribute.expr.name in (
"self",
"cls",
node.name,
):
# self.__attrname
# cls.__attrname
# node_name.__attrname
break
if isinstance(attribute.expr, nodes.Call):
# type(self).__attrname
inferred = safe_infer(attribute.expr)
if (
isinstance(inferred, nodes.ClassDef)
and inferred.name == node.name
):
break
else:
name_stack = []
curr = parent_scope
# Generate proper names for nested functions
while curr != node:
name_stack.append(curr.name)
curr = curr.parent.scope()
outer_level_names = f"{'.'.join(reversed(name_stack))}"
function_repr = f"{outer_level_names}.{function_def.name}({function_def.args.as_string()})"
self.add_message(
"unused-private-member",
node=function_def,
args=(node.name, function_repr.lstrip(".")),
)
def _check_unused_private_variables(self, node: nodes.ClassDef) -> None:
"""Check if private variables are never used within a class."""
for assign_name in node.nodes_of_class(nodes.AssignName):
if isinstance(assign_name.parent, nodes.Arguments):
continue # Ignore function arguments
if not is_attr_private(assign_name.name):
continue
for child in node.nodes_of_class((nodes.Name, nodes.Attribute)):
if isinstance(child, nodes.Name) and child.name == assign_name.name:
break
if isinstance(child, nodes.Attribute):
if not isinstance(child.expr, nodes.Name):
break
if child.attrname == assign_name.name and child.expr.name in (
"self",
"cls",
node.name,
):
break
else:
args = (node.name, assign_name.name)
self.add_message("unused-private-member", node=assign_name, args=args)
def _check_unused_private_attributes(self, node: nodes.ClassDef) -> None:
for assign_attr in node.nodes_of_class(nodes.AssignAttr):
if not is_attr_private(assign_attr.attrname) or not isinstance(
assign_attr.expr, nodes.Name
):
continue
# Logic for checking false positive when using __new__,
# Get the returned object names of the __new__ magic function
# Then check if the attribute was consumed in other instance methods
acceptable_obj_names: List[str] = ["self"]
scope = assign_attr.scope()
if isinstance(scope, nodes.FunctionDef) and scope.name == "__new__":
acceptable_obj_names.extend(
[
return_node.value.name
for return_node in scope.nodes_of_class(nodes.Return)
if isinstance(return_node.value, nodes.Name)
]
)
for attribute in node.nodes_of_class(nodes.Attribute):
if attribute.attrname != assign_attr.attrname:
continue
if self._is_type_self_call(attribute.expr):
continue
if assign_attr.expr.name in {
"cls",
node.name,
} and attribute.expr.name in {"cls", "self", node.name}:
# If assigned to cls or class name, can be accessed by cls/self/class name
break
if (
assign_attr.expr.name in acceptable_obj_names
and attribute.expr.name == "self"
):
# If assigned to self.attrib, can only be accessed by self
# Or if __new__ was used, the returned object names are acceptable
break
if assign_attr.expr.name == attribute.expr.name == node.name:
# Recognise attributes which are accessed via the class name
break
else:
args = (node.name, assign_attr.attrname)
self.add_message("unused-private-member", node=assign_attr, args=args)
def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
# check access to existent members on non metaclass classes
if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
# We are in a mixin class. No need to try to figure out if
# something is missing, since it is most likely that it will
# miss.
return
accessed = self._accessed.accessed(cnode)
if cnode.type != "metaclass":
self._check_accessed_members(cnode, accessed)
# checks attributes are defined in an allowed method such as __init__
if not self.linter.is_message_enabled("attribute-defined-outside-init"):
return
defining_methods = self.config.defining_attr_methods
current_module = cnode.root()
for attr, nodes_lst in cnode.instance_attrs.items():
# Exclude `__dict__` as it is already defined.
if attr == "__dict__":
continue
# Skip nodes which are not in the current module and it may screw up
# the output, while it's not worth it
nodes_lst = [
n
for n in nodes_lst
if not isinstance(
n.statement(future=_True), (nodes.Delete, nodes.AugAssign)
)
and n.root() is current_module
]
if not nodes_lst:
continue # error detected by typechecking
# Check if any method attr is defined in is a defining method
# or if we have the attribute defined in a setter.
frames = (node.frame(future=_True) for node in nodes_lst)
if any(
frame.name in defining_methods or is_property_setter(frame)
for frame in frames
):
continue
# check attribute is defined in a parent's __init__
for parent in cnode.instance_attr_ancestors(attr):
attr_defined = _False
# check if any parent method attr is defined in is a defining method
for node in parent.instance_attrs[attr]:
if node.frame(future=_True).name in defining_methods:
attr_defined = _True
if attr_defined:
# we're done :)
break
else:
# check attribute is defined as a class attribute
try:
cnode.local_attr(attr)
except astroid.NotFoundError:
for node in nodes_lst:
if node.frame(future=_True).name not in defining_methods:
# If the attribute was set by a call in any
# of the defining methods, then don't emit
# the warning.
if _called_in_methods(
node.frame(future=_True), cnode, defining_methods
):
continue
self.add_message(
"attribute-defined-outside-init", args=attr, node=node
)
def visit_functiondef(self, node: nodes.FunctionDef) -> None:
"""Check method arguments, overriding."""
# ignore actual functions
if not node.is_method():
return
self._check_useless_super_delegation(node)
self._check_property_with_parameters(node)
# 'is_method()' is called and makes sure that this is a 'nodes.ClassDef'
klass = node.parent.frame(future=_True) # type: nodes.ClassDef
self._meth_could_be_func = _True
# check first argument is self if this is actually a method
self._check_first_arg_for_type(node, klass.type == "metaclass")
if node.name == "__init__":
self._check_init(node, klass)
return
# check signature if the method overloads inherited method
for overridden in klass.local_attr_ancestors(node.name):
# get astroid for the searched method
try:
parent_function = overridden[node.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if not isinstance(parent_function, nodes.FunctionDef):
continue
self._check_signature(node, parent_function, "overridden", klass)
self._check_invalid_overridden_method(node, parent_function)
break
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, nodes.Attribute) and decorator.attrname in {
"getter",
"setter",
"deleter",
}:
# attribute affectation will call this method, not hiding it
return
if isinstance(decorator, nodes.Name):
if decorator.name == "property":
# attribute affectation will either call a setter or raise
# an attribute error, anyway not hiding the function
return
# Infer the decorator and see if it returns something useful
inferred = safe_infer(decorator)
if not inferred:
return
if isinstance(inferred, nodes.FunctionDef):
# Okay, it's a decorator, let's see what it can infer.
try:
inferred = next(inferred.infer_call_result(inferred))
except astroid.InferenceError:
return
try:
if (
isinstance(inferred, (astroid.Instance, nodes.ClassDef))
and inferred.getattr("__get__")
and inferred.getattr("__set__")
):
return
except astroid.AttributeInferenceError:
pass
# check if the method is hidden by an attribute
try:
overridden = klass.instance_attr(node.name)[0]
overridden_frame = overridden.frame(future=_True)
if (
isinstance(overridden_frame, nodes.FunctionDef)
and overridden_frame.type == "method"
):
overridden_frame = overridden_frame.parent.frame(future=_True)
if not (
isinstance(overridden_frame, nodes.ClassDef)
and klass.is_subtype_of(overridden_frame.qname())
):
return
# If a subclass defined the method then it's not our fault.
for ancestor in klass.ancestors():
if node.name in ancestor.instance_attrs and is_attr_private(node.name):
return
for obj in ancestor.lookup(node.name)[1]:
if isinstance(obj, nodes.FunctionDef):
return
args = (overridden.root().name, overridden.fromlineno)
self.add_message("method-hidden", args=args, node=node)
except astroid.NotFoundError:
pass
visit_asyncfunctiondef = visit_functiondef
def _check_useless_super_delegation(self, function):
"""Check if the given function node is an useless method override.
We consider it *useless* if it uses the super() builtin, but having
nothing additional whatsoever than not implementing the method at all.
If the method uses super() to delegate an operation to the rest of the MRO,
and if the method called is the same as the current one, the arguments
passed to super() are the same as the parameters that were passed to
this method, then the method could be removed altogether, by letting
other implementation to take precedence.
"""
if (
not function.is_method()
# With decorators is a change of use
or function.decorators
):
return
body = function.body
if len(body) != 1:
# Multiple statements, which means this overridden method
# could do multiple things we are not aware of.
return
statement = body[0]
if not isinstance(statement, (nodes.Expr, nodes.Return)):
# Doing something else than what we are interested into.
return
call = statement.value
if (
not isinstance(call, nodes.Call)
# Not a super() attribute access.
or not isinstance(call.func, nodes.Attribute)
):
return
# Should be a super call.
try:
super_call = next(call.func.expr.infer())
except astroid.InferenceError:
return
else:
if not isinstance(super_call, astroid.objects.Super):
return
# The name should be the same.
if call.func.attrname != function.name:
return
# Should be a super call with the MRO pointer being the
# current class and the type being the current instance.
current_scope = function.parent.scope()
if (
super_call.mro_pointer != current_scope
or not isinstance(super_call.type, astroid.Instance)
or super_call.type.name != current_scope.name
):
return
# Check values of default args
klass = function.parent.frame(future=_True)
meth_node = None
for overridden in klass.local_attr_ancestors(function.name):
# get astroid for the searched method
try:
meth_node = overridden[function.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if (
not isinstance(meth_node, nodes.FunctionDef)
# If the method have an ancestor which is not a
# function then it is legitimate to redefine it
or _has_different_parameters_default_value(
meth_node.args, function.args
)
):
return
break
# Detect if the parameters are the same as the call's arguments.
params = _signature_from_arguments(function.args)
args = _signature_from_call(call)
if meth_node is not None:
def form_annotations(arguments):
annotations = chain(
(arguments.posonlyargs_annotations or []), arguments.annotations
)
return [ann.as_string() for ann in annotations if ann is not None]
called_annotations = form_annotations(function.args)
overridden_annotations = form_annotations(meth_node.args)
if called_annotations and overridden_annotations:
if called_annotations != overridden_annotations:
return
if _definition_equivalent_to_call(params, args):
self.add_message(
"useless-super-delegation", node=function, args=(function.name,)
)
def _check_property_with_parameters(self, node):
if (
node.args.args
and len(node.args.args) > 1
and decorated_with_property(node)
and not is_property_setter(node)
):
self.add_message("property-with-parameters", node=node)
def _check_invalid_overridden_method(self, function_node, parent_function_node):
parent_is_property = decorated_with_property(
parent_function_node
) or is_property_setter_or_deleter(parent_function_node)
current_is_property = decorated_with_property(
function_node
) or is_property_setter_or_deleter(function_node)
if parent_is_property and not current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "property", function_node.type),
node=function_node,
)
elif not parent_is_property and current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "method", "property"),
node=function_node,
)
parent_is_async = isinstance(parent_function_node, nodes.AsyncFunctionDef)
current_is_async = isinstance(function_node, nodes.AsyncFunctionDef)
if parent_is_async and not current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "async", "non-async"),
node=function_node,
)
elif not parent_is_async and current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "non-async", "async"),
node=function_node,
)
if (
decorated_with(parent_function_node, ["typing.final"])
or uninferable_final_decorators(parent_function_node.decorators)
) and self._py38_plus:
self.add_message(
"overridden-final-method",
args=(function_node.name, parent_function_node.parent.frame().name),
node=function_node,
)
def _check_slots(self, node: nodes.ClassDef) -> None:
if "__slots__" not in node.locals:
return
for slots in node.igetattr("__slots__"):
# check if __slots__ is a valid type
if slots is astroid.Uninferable:
continue
if not is_iterable(slots) and not is_comprehension(slots):
self.add_message("invalid-slots", node=node)
continue
if isinstance(slots, nodes.Const):
# a string, ignore the following checks
self.add_message("single-string-used-for-slots", node=node)
continue
if not hasattr(slots, "itered"):
# we can't obtain the values, maybe a .deque?
continue
if isinstance(slots, nodes.Dict):
values = [item[0] for item in slots.items]
else:
values = slots.itered()
if values is astroid.Uninferable:
return
for elt in values:
try:
self._check_slots_elt(elt, node)
except astroid.InferenceError:
continue
self._check_redefined_slots(node, slots, values)
def _check_redefined_slots(
self,
node: nodes.ClassDef,
slots_node: nodes.NodeNG,
slots_list: List[nodes.NodeNG],
) -> None:
"""Check if `node` redefines a slot which is defined in an ancestor class."""
slots_names: List[str] = []
for slot in slots_list:
if isinstance(slot, nodes.Const):
slots_names.append(slot.value)
else:
inferred_slot = safe_infer(slot)
if inferred_slot:
slots_names.append(inferred_slot.value)
# Slots of all parent classes
ancestors_slots_names = {
slot.value
for ancestor in node.local_attr_ancestors("__slots__")
for slot in ancestor.slots() or []
}
# Slots which are common to `node` and its parent classes
redefined_slots = ancestors_slots_names.intersection(slots_names)
if redefined_slots:
self.add_message(
"redefined-slots-in-subclass",
args=([name for name in slots_names if name in redefined_slots],),
node=slots_node,
)
def _check_slots_elt(self, elt, node):
for inferred in elt.infer():
if inferred is astroid.Uninferable:
continue
if not isinstance(inferred, nodes.Const) or not isinstance(
inferred.value, str
):
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
continue
if not inferred.value:
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
# Check if we have a conflict with a class variable.
class_variable = node.locals.get(inferred.value)
if class_variable:
# Skip annotated assignments which don't conflict at all with slots.
if len(class_variable) == 1:
parent = class_variable[0].parent
if isinstance(parent, nodes.AnnAssign) and parent.value is None:
return
self.add_message(
"class-variable-slots-conflict", args=(inferred.value,), node=elt
)
def leave_functiondef(self, node: nodes.FunctionDef) -> None:
"""On method node, check if this method couldn't be a function.
ignore class, static and abstract methods, initializer,
methods overridden from a parent class.
"""
if node.is_method():
if node.args.args is not None:
self._first_attrs.pop()
if not self.linter.is_message_enabled("no-self-use"):
return
class_node = node.parent.frame(future=_True)
if (
self._meth_could_be_func
and node.type == "method"
and node.name not in PYMETHODS
and not (
node.is_abstract()
or overrides_a_method(class_node, node.name)
or decorated_with_property(node)
or _has_bare_super_call(node)
or is_protocol_class(class_node)
or is_overload_stub(node)
)
):
self.add_message("no-self-use", node=node)
leave_asyncfunctiondef = leave_functiondef
def visit_attribute(self, node: nodes.Attribute) -> None:
"""Check if the getattr is an access to a class member
if so, register it. Also check for access to protected
class member from outside its class (but ignore __special__
methods)
"""
# Check self
if self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
return
if not self.linter.is_message_enabled("protected-access"):
return
self._check_protected_attribute_access(node)
@check_messages("assigning-non-slot", "invalid-class-object")
def visit_assignattr(self, node: nodes.AssignAttr) -> None:
if isinstance(
node.assign_type(), nodes.AugAssign
) and self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
self._check_in_slots(node)
self._check_invalid_class_object(node)
def _check_invalid_class_object(self, node: nodes.AssignAttr) -> None:
if not node.attrname == "__class__":
return
inferred = safe_infer(node.parent.value)
if isinstance(inferred, nodes.ClassDef) or inferred is astroid.Uninferable:
# If is uninferrable, we allow it to prevent false positives
return
self.add_message("invalid-class-object", node=node)
def _check_in_slots(self, node):
"""Check that the given AssignAttr node
is defined in the class slots.
"""
inferred = safe_infer(node.expr)
if not isinstance(inferred, astroid.Instance):
return
klass = inferred._proxied
if not has_known_bases(klass):
return
if "__slots__" not in klass.locals or not klass.newstyle:
return
# If `__setattr__` is defined on the class, then we can't reason about
# what will happen when assigning to an attribute.
if any(
base.locals.get("__setattr__")
for base in klass.mro()
if base.qname() != "builtins.object"
):
return
# If 'typing.Generic' is a base of bases of klass, the cached version
# of 'slots()' might have been evaluated incorrectly, thus deleted cache entry.
if any(base.qname() == "typing.Generic" for base in klass.mro()):
cache = getattr(klass, "__cache", None)
if cache and cache.get(klass.slots) is not None:
del cache[klass.slots]
slots = klass.slots()
if slots is None:
return
# If any ancestor doesn't use slots, the slots
# defined for this class are superfluous.
if any(
"__slots__" not in ancestor.locals and ancestor.name != "object"
for ancestor in klass.ancestors()
):
return
if not any(slot.value == node.attrname for slot in slots):
# If we have a '__dict__' in slots, then
# assigning any name is valid.
if not any(slot.value == "__dict__" for slot in slots):
if _is_attribute_property(node.attrname, klass):
# Properties circumvent the slots mechanism,
# so we should not emit a warning for them.
return
if node.attrname in klass.locals:
for local_name in klass.locals.get(node.attrname):
statement = local_name.statement(future=_True)
if (
isinstance(statement, nodes.AnnAssign)
and not statement.value
):
return
if _has_data_descriptor(klass, node.attrname):
# Descriptors circumvent the slots mechanism as well.
return
if node.attrname == "__class__" and _has_same_layout_slots(
slots, node.parent.value
):
return
self.add_message("assigning-non-slot", args=(node.attrname,), node=node)
@check_messages(
"protected-access", "no-classmethod-decorator", "no-staticmethod-decorator"
)
def visit_assign(self, assign_node: nodes.Assign) -> None:
self._check_classmethod_declaration(assign_node)
node = assign_node.targets[0]
if not isinstance(node, nodes.AssignAttr):
return
if self._uses_mandatory_method_param(node):
return
self._check_protected_attribute_access(node)
def _check_classmethod_declaration(self, node):
"""Checks for uses of classmethod() or staticmethod().
When a @classmethod or @staticmethod decorator should be used instead.
A message will be emitted only if the assignment is at a class scope
and only if the classmethod's argument belongs to the class where it
is defined.
`node` is an assign node.
"""
if not isinstance(node.value, nodes.Call):
return
# check the function called is "classmethod" or "staticmethod"
func = node.value.func
if not isinstance(func, nodes.Name) or func.name not in (
"classmethod",
"staticmethod",
):
return
msg = (
"no-classmethod-decorator"
if func.name == "classmethod"
else "no-staticmethod-decorator"
)
# assignment must be at a class scope
parent_class = node.scope()
if not isinstance(parent_class, nodes.ClassDef):
return
# Check if the arg passed to classmethod is a class member
classmeth_arg = node.value.args[0]
if not isinstance(classmeth_arg, nodes.Name):
return
method_name = classmeth_arg.name
if any(method_name == member.name for member in parent_class.mymethods()):
self.add_message(msg, node=node.targets[0])
def _check_protected_attribute_access(self, node: nodes.Attribute):
"""Given an attribute access node (set or get), check if attribute
access is legitimate. Call _check_first_attr with node before calling
this method. Valid cases are:
* self._attr in a method or cls._attr in a classmethod. Checked by
_check_first_attr.
* Klass._attr inside "Klass" class.
* Klass2._attr inside "Klass" class when Klass2 is a base class of
Klass.
"""
attrname = node.attrname
if (
is_attr_protected(attrname)
and attrname not in self.config.exclude_protected
):
klass = node_frame_class(node)
# In classes, check we are not getting a parent method
# through the class object or through super
callee = node.expr.as_string()
# Typing annotations in function definitions can include protected members
if utils.is_node_in_type_annotation_context(node):
return
# We are not in a class, no remaining valid case
if klass is None:
self.add_message("protected-access", node=node, args=attrname)
return
# If the expression begins with a call to super, that's ok.
if (
isinstance(node.expr, nodes.Call)
and isinstance(node.expr.func, nodes.Name)
and node.expr.func.name == "super"
):
return
# If the expression begins with a call to type(self), that's ok.
if self._is_type_self_call(node.expr):
return
# Check if we are inside the scope of a class or nested inner class
inside_klass = _True
outer_klass = klass
parents_callee = callee.split(".")
parents_callee.reverse()
for callee in parents_callee:
if not outer_klass or callee != outer_klass.name:
inside_klass = _False
break
# Move up one level within the nested classes
outer_klass = get_outer_class(outer_klass)
# We are in a class, one remaining valid cases, Klass._attr inside
# Klass
if not (inside_klass or callee in klass.basenames):
# Detect property assignments in the body of the class.
# This is acceptable:
#
# class A:
# b = property(lambda: self._b)
stmt = node.parent.statement(future=_True)
if (
isinstance(stmt, nodes.Assign)
and len(stmt.targets) == 1
and isinstance(stmt.targets[0], nodes.AssignName)
):
name = stmt.targets[0].name
if _is_attribute_property(name, klass):
return
if (
self._is_classmethod(node.frame(future=_True))
and self._is_inferred_instance(node.expr, klass)
and self._is_class_attribute(attrname, klass)
):
return
licit_protected_member = not attrname.startswith("__")
if (
not self.config.check_protected_access_in_special_methods
and licit_protected_member
and self._is_called_inside_special_method(node)
):
return
self.add_message("protected-access", node=node, args=attrname)
@staticmethod
def _is_called_inside_special_method(node: nodes.NodeNG) -> bool:
"""Returns true if the node is located inside a special (aka dunder) method."""
frame_name = node.frame(future=_True).name
return frame_name and frame_name in PYMETHODS
def _is_type_self_call(self, expr: nodes.NodeNG) -> bool:
return (
isinstance(expr, nodes.Call)
and isinstance(expr.func, nodes.Name)
and expr.func.name == "type"
and len(expr.args) == 1
and self._is_mandatory_method_param(expr.args[0])
)
@staticmethod
def _is_classmethod(func):
"""Check if the given *func* node is a class method."""
return isinstance(func, nodes.FunctionDef) and (
func.type == "classmethod" or func.name == "__class_getitem__"
)
@staticmethod
def _is_inferred_instance(expr, klass):
"""Check if the inferred value of the given *expr* is an instance of *klass*."""
inferred = safe_infer(expr)
if not isinstance(inferred, astroid.Instance):
return _False
return inferred._proxied is klass
@staticmethod
def _is_class_attribute(name, klass):
"""Check if the given attribute *name* is a class or instance member of the given *klass*.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
klass.getattr(name)
return _True
except astroid.NotFoundError:
pass
try:
klass.instance_attr(name)
return _True
except astroid.NotFoundError:
return _False
def visit_name(self, node: nodes.Name) -> None:
"""Check if the name handle an access to a class member
if so, register it
"""
if self._first_attrs and (
node.name == self._first_attrs[-1] or not self._first_attrs[-1]
):
self._meth_could_be_func = _False
def _check_accessed_members(self, node, accessed):
"""Check that accessed members are defined."""
excs = ("AttributeError", "Exception", "BaseException")
for attr, nodes_lst in accessed.items():
try:
# is it a class attribute ?
node.local_attr(attr)
# yes, stop here
continue
except astroid.NotFoundError:
pass
# is it an instance attribute of a parent class ?
try:
next(node.instance_attr_ancestors(attr))
# yes, stop here
continue
except StopIteration:
pass
# is it an instance attribute ?
try:
defstmts = node.instance_attr(attr)
except astroid.NotFoundError:
pass
else:
# filter out augment assignment nodes
defstmts = [stmt for stmt in defstmts if stmt not in nodes_lst]
if not defstmts:
# only augment assignment for this node, no-member should be
# triggered by the typecheck checker
continue
# filter defstmts to only pick the first one when there are
# several assignments in the same scope
scope = defstmts[0].scope()
defstmts = [
stmt
for i, stmt in enumerate(defstmts)
if i == 0 or stmt.scope() is not scope
]
# if there are still more than one, don't attempt to be smarter
# than we can be
if len(defstmts) == 1:
defstmt = defstmts[0]
# check that if the node is accessed in the same method as
# it's defined, it's accessed after the initial assignment
frame = defstmt.frame(future=_True)
lno = defstmt.fromlineno
for _node in nodes_lst:
if (
_node.frame(future=_True) is frame
and _node.fromlineno < lno
and not astroid.are_exclusive(
_node.statement(future=_True), defstmt, excs
)
):
self.add_message(
"access-member-before-definition",
node=_node,
args=(attr, lno),
)
def _check_first_arg_for_type(self, node, metaclass=0):
"""Check the name of first argument, expect:.
* 'self' for a regular method
* 'cls' for a class method or a metaclass regular method (actually
valid-classmethod-first-arg value)
* 'mcs' for a metaclass class method (actually
valid-metaclass-classmethod-first-arg)
* not one of the above for a static method
"""
# don't care about functions with unknown argument (builtins)
if node.args.args is None:
return
if node.args.posonlyargs:
first_arg = node.args.posonlyargs[0].name
elif node.args.args:
first_arg = node.argnames()[0]
else:
first_arg = None
self._first_attrs.append(first_arg)
first = self._first_attrs[-1]
# static method
if node.type == "staticmethod":
if (
first_arg == "self"
or first_arg in self.config.valid_classmethod_first_arg
or first_arg in self.config.valid_metaclass_classmethod_first_arg
):
self.add_message("bad-staticmethod-argument", args=first, node=node)
return
self._first_attrs[-1] = None
# class / regular method with no args
elif not node.args.args and not node.args.posonlyargs:
self.add_message("no-method-argument", node=node)
# metaclass
elif metaclass:
# metaclass __new__ or classmethod
if node.type == "classmethod":
self._check_first_arg_config(
first,
self.config.valid_metaclass_classmethod_first_arg,
node,
"bad-mcs-classmethod-argument",
node.name,
)
# metaclass regular method
else:
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-mcs-method-argument",
node.name,
)
# regular class with class method
elif node.type == "classmethod" or node.name == "__class_getitem__":
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-classmethod-argument",
node.name,
)
# regular class with regular method without self as argument
elif first != "self":
self.add_message("no-self-argument", node=node)
def _check_first_arg_config(self, first, config, node, message, method_name):
if first not in config:
if len(config) == 1:
valid = repr(config[0])
else:
valid = ", ".join(repr(v) for v in config[:-1])
valid = f"{valid} or {config[-1]!r}"
self.add_message(message, args=(method_name, valid), node=node)
def _check_bases_classes(self, node):
"""Check that the given class node implements abstract methods from
base classes
"""
def is_abstract(method):
return method.is_abstract(pass_is_abstract=_False)
# check if this class abstract
if class_is_abstract(node):
return
methods = sorted(
unimplemented_abstract_methods(node, is_abstract).items(),
key=lambda item: item[0],
)
for name, method in methods:
owner = method.parent.frame(future=_True)
if owner is node:
continue
# owner is not this class, it must be a parent class
# check that the ancestor's method is not abstract
if name in node.locals:
# it is redefined as an attribute or with a descriptor
continue
self.add_message("abstract-method", node=node, args=(name, owner.name))
def _check_init(self, node: nodes.FunctionDef, klass_node: nodes.ClassDef) -> None:
"""Check that the __init__ method call super or ancestors'__init__
method (unless it is used for type hinting with `typing.overload`)
"""
if not self.linter.is_message_enabled(
"super-init-not-called"
) and not self.linter.is_message_enabled("non-parent-init-called"):
return
to_call = _ancestors_to_call(klass_node)
not_called_yet = dict(to_call)
parents_with_called_inits: Set[bases.UnboundMethod] = set()
for stmt in node.nodes_of_class(nodes.Call):
expr = stmt.func
if not isinstance(expr, nodes.Attribute) or expr.attrname != "__init__":
continue
# skip the test if using super
if (
isinstance(expr.expr, nodes.Call)
and isinstance(expr.expr.func, nodes.Name)
and expr.expr.func.name == "super"
):
return
try:
for klass in expr.expr.infer():
if klass is astroid.Uninferable:
continue
# The inferred klass can be super(), which was
# assigned to a variable and the `__init__`
# was called later.
#
# base = super()
# base.__init__(...)
if (
isinstance(klass, astroid.Instance)
and isinstance(klass._proxied, nodes.ClassDef)
and is_builtin_object(klass._proxied)
and klass._proxied.name == "super"
):
return
if isinstance(klass, astroid.objects.Super):
return
try:
method = not_called_yet.pop(klass)
# Record that the class' init has been called
parents_with_called_inits.add(node_frame_class(method))
except KeyError:
if klass not in to_call:
self.add_message(
"non-parent-init-called", node=expr, args=klass.name
)
except astroid.InferenceError:
continue
for klass, method in not_called_yet.items():
# Check if the init of the class that defines this init has already
# been called.
if node_frame_class(method) in parents_with_called_inits:
return
# Return if klass is protocol
if klass.qname() in utils.TYPING_PROTOCOLS:
return
# Return if any of the klass' first-order bases is protocol
for base in klass.bases:
# We don't need to catch InferenceError here as _ancestors_to_call
# already does this for us.
for inf_base in base.infer():
if inf_base.qname() in utils.TYPING_PROTOCOLS:
return
if decorated_with(node, ["typing.overload"]):
continue
cls = node_frame_class(method)
if klass.name == "object" or (cls and cls.name == "object"):
continue
self.add_message(
"super-init-not-called",
args=klass.name,
node=node,
confidence=INFERENCE,
)
def _check_signature(self, method1, refmethod, class_type, cls):
"""Check that the signature of the two given methods match."""
if not (
isinstance(method1, nodes.FunctionDef)
and isinstance(refmethod, nodes.FunctionDef)
):
self.add_message(
"method-check-failed", args=(method1, refmethod), node=method1
)
return
instance = cls.instantiate_class()
method1 = astroid.scoped_nodes.function_to_method(method1, instance)
refmethod = astroid.scoped_nodes.function_to_method(refmethod, instance)
# Don't care about functions with unknown argument (builtins).
if method1.args.args is None or refmethod.args.args is None:
return
# Ignore private to class methods.
if is_attr_private(method1.name):
return
# Ignore setters, they have an implicit extra argument,
# which shouldn't be taken in consideration.
if is_property_setter(method1):
return
arg_differ_output = _different_parameters(
refmethod, method1, dummy_parameter_regex=self._dummy_rgx
)
if len(arg_differ_output) > 0:
for msg in arg_differ_output:
if "Number" in msg:
total_args_method1 = len(method1.args.args)
if method1.args.vararg:
total_args_method1 += 1
if method1.args.kwarg:
total_args_method1 += 1
if method1.args.kwonlyargs:
total_args_method1 += len(method1.args.kwonlyargs)
total_args_refmethod = len(refmethod.args.args)
if refmethod.args.vararg:
total_args_refmethod += 1
if refmethod.args.kwarg:
total_args_refmethod += 1
if refmethod.args.kwonlyargs:
total_args_refmethod += len(refmethod.args.kwonlyargs)
error_type = "arguments-differ"
msg_args = (
msg
+ f"was {total_args_refmethod} in '{refmethod.parent.frame().name}.{refmethod.name}' and "
f"is now {total_args_method1} in",
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
elif "renamed" in msg:
error_type = "arguments-renamed"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
else:
error_type = "arguments-differ"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
self.add_message(error_type, args=msg_args, node=method1)
elif (
len(method1.args.defaults) < len(refmethod.args.defaults)
and not method1.args.vararg
):
self.add_message(
"signature-differs", args=(class_type, method1.name), node=method1
)
def _uses_mandatory_method_param(self, node):
"""Check that attribute lookup name use first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
return self._is_mandatory_method_param(node.expr)
def _is_mandatory_method_param(self, node: nodes.NodeNG) -> bool:
"""Check if nodes.Name corresponds to first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
if self._first_attrs:
first_attr = self._first_attrs[-1]
else:
# It's possible the function was already unregistered.
closest_func = utils.get_node_first_ancestor_of_type(
node, nodes.FunctionDef
)
if closest_func is None:
return _False
if not closest_func.args.args:
return _False
first_attr = closest_func.args.args[0].name
return isinstance(node, nodes.Name) and node.name == first_attr
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 832 | safe_infer | ref | function | ancestor = safe_infer(base)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 835 | is_subtype_of | ref | function | if isinstance(ancestor, astroid.Instance) and ancestor.is_subtype_of(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 840 | _is_invalid_base_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 843 | add_message | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 843 | as_string | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 846 | add_message | ref | function | self.add_message(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 850 | _check_typing_final | def | function | def _check_typing_final(self, node: nodes.ClassDef) -> None:
"""Detect that a class does not subclass a class decorated with `typing.final`."""
if not self._py38_plus:
return
for base in node.bases:
ancestor = safe_infer(base)
if not ancestor:
continue
if isinstance(ancestor, nodes.ClassDef) and (
decorated_with(ancestor, ["typing.final"])
or uninferable_final_decorators(ancestor.decorators)
):
self.add_message(
"subclassed-final-class",
args=(node.name, ancestor.name),
node=node,
)
@check_messages("unused-private-member", "attribute-defined-outside-init")
def leave_classdef(self, node: nodes.ClassDef) -> None:
"""Close a class node:
check that instance attributes are defined in __init__ and check
access to existent members
"""
self._check_unused_private_functions(node)
self._check_unused_private_variables(node)
self._check_unused_private_attributes(node)
self._check_attribute_defined_outside_init(node)
def _check_unused_private_functions(self, node: nodes.ClassDef) -> None:
for function_def in node.nodes_of_class(nodes.FunctionDef):
if not is_attr_private(function_def.name):
continue
parent_scope = function_def.parent.scope()
if isinstance(parent_scope, nodes.FunctionDef):
# Handle nested functions
if function_def.name in (
n.name for n in parent_scope.nodes_of_class(nodes.Name)
):
continue
for attribute in node.nodes_of_class(nodes.Attribute):
if (
attribute.attrname != function_def.name
or attribute.scope() == function_def # We ignore recursive calls
):
continue
if isinstance(attribute.expr, nodes.Name) and attribute.expr.name in (
"self",
"cls",
node.name,
):
# self.__attrname
# cls.__attrname
# node_name.__attrname
break
if isinstance(attribute.expr, nodes.Call):
# type(self).__attrname
inferred = safe_infer(attribute.expr)
if (
isinstance(inferred, nodes.ClassDef)
and inferred.name == node.name
):
break
else:
name_stack = []
curr = parent_scope
# Generate proper names for nested functions
while curr != node:
name_stack.append(curr.name)
curr = curr.parent.scope()
outer_level_names = f"{'.'.join(reversed(name_stack))}"
function_repr = f"{outer_level_names}.{function_def.name}({function_def.args.as_string()})"
self.add_message(
"unused-private-member",
node=function_def,
args=(node.name, function_repr.lstrip(".")),
)
def _check_unused_private_variables(self, node: nodes.ClassDef) -> None:
"""Check if private variables are never used within a class."""
for assign_name in node.nodes_of_class(nodes.AssignName):
if isinstance(assign_name.parent, nodes.Arguments):
continue # Ignore function arguments
if not is_attr_private(assign_name.name):
continue
for child in node.nodes_of_class((nodes.Name, nodes.Attribute)):
if isinstance(child, nodes.Name) and child.name == assign_name.name:
break
if isinstance(child, nodes.Attribute):
if not isinstance(child.expr, nodes.Name):
break
if child.attrname == assign_name.name and child.expr.name in (
"self",
"cls",
node.name,
):
break
else:
args = (node.name, assign_name.name)
self.add_message("unused-private-member", node=assign_name, args=args)
def _check_unused_private_attributes(self, node: nodes.ClassDef) -> None:
for assign_attr in node.nodes_of_class(nodes.AssignAttr):
if not is_attr_private(assign_attr.attrname) or not isinstance(
assign_attr.expr, nodes.Name
):
continue
# Logic for checking false positive when using __new__,
# Get the returned object names of the __new__ magic function
# Then check if the attribute was consumed in other instance methods
acceptable_obj_names: List[str] = ["self"]
scope = assign_attr.scope()
if isinstance(scope, nodes.FunctionDef) and scope.name == "__new__":
acceptable_obj_names.extend(
[
return_node.value.name
for return_node in scope.nodes_of_class(nodes.Return)
if isinstance(return_node.value, nodes.Name)
]
)
for attribute in node.nodes_of_class(nodes.Attribute):
if attribute.attrname != assign_attr.attrname:
continue
if self._is_type_self_call(attribute.expr):
continue
if assign_attr.expr.name in {
"cls",
node.name,
} and attribute.expr.name in {"cls", "self", node.name}:
# If assigned to cls or class name, can be accessed by cls/self/class name
break
if (
assign_attr.expr.name in acceptable_obj_names
and attribute.expr.name == "self"
):
# If assigned to self.attrib, can only be accessed by self
# Or if __new__ was used, the returned object names are acceptable
break
if assign_attr.expr.name == attribute.expr.name == node.name:
# Recognise attributes which are accessed via the class name
break
else:
args = (node.name, assign_attr.attrname)
self.add_message("unused-private-member", node=assign_attr, args=args)
def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
# check access to existent members on non metaclass classes
if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
# We are in a mixin class. No need to try to figure out if
# something is missing, since it is most likely that it will
# miss.
return
accessed = self._accessed.accessed(cnode)
if cnode.type != "metaclass":
self._check_accessed_members(cnode, accessed)
# checks attributes are defined in an allowed method such as __init__
if not self.linter.is_message_enabled("attribute-defined-outside-init"):
return
defining_methods = self.config.defining_attr_methods
current_module = cnode.root()
for attr, nodes_lst in cnode.instance_attrs.items():
# Exclude `__dict__` as it is already defined.
if attr == "__dict__":
continue
# Skip nodes which are not in the current module and it may screw up
# the output, while it's not worth it
nodes_lst = [
n
for n in nodes_lst
if not isinstance(
n.statement(future=_True), (nodes.Delete, nodes.AugAssign)
)
and n.root() is current_module
]
if not nodes_lst:
continue # error detected by typechecking
# Check if any method attr is defined in is a defining method
# or if we have the attribute defined in a setter.
frames = (node.frame(future=_True) for node in nodes_lst)
if any(
frame.name in defining_methods or is_property_setter(frame)
for frame in frames
):
continue
# check attribute is defined in a parent's __init__
for parent in cnode.instance_attr_ancestors(attr):
attr_defined = _False
# check if any parent method attr is defined in is a defining method
for node in parent.instance_attrs[attr]:
if node.frame(future=_True).name in defining_methods:
attr_defined = _True
if attr_defined:
# we're done :)
break
else:
# check attribute is defined as a class attribute
try:
cnode.local_attr(attr)
except astroid.NotFoundError:
for node in nodes_lst:
if node.frame(future=_True).name not in defining_methods:
# If the attribute was set by a call in any
# of the defining methods, then don't emit
# the warning.
if _called_in_methods(
node.frame(future=_True), cnode, defining_methods
):
continue
self.add_message(
"attribute-defined-outside-init", args=attr, node=node
)
def visit_functiondef(self, node: nodes.FunctionDef) -> None:
"""Check method arguments, overriding."""
# ignore actual functions
if not node.is_method():
return
self._check_useless_super_delegation(node)
self._check_property_with_parameters(node)
# 'is_method()' is called and makes sure that this is a 'nodes.ClassDef'
klass = node.parent.frame(future=_True) # type: nodes.ClassDef
self._meth_could_be_func = _True
# check first argument is self if this is actually a method
self._check_first_arg_for_type(node, klass.type == "metaclass")
if node.name == "__init__":
self._check_init(node, klass)
return
# check signature if the method overloads inherited method
for overridden in klass.local_attr_ancestors(node.name):
# get astroid for the searched method
try:
parent_function = overridden[node.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if not isinstance(parent_function, nodes.FunctionDef):
continue
self._check_signature(node, parent_function, "overridden", klass)
self._check_invalid_overridden_method(node, parent_function)
break
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, nodes.Attribute) and decorator.attrname in {
"getter",
"setter",
"deleter",
}:
# attribute affectation will call this method, not hiding it
return
if isinstance(decorator, nodes.Name):
if decorator.name == "property":
# attribute affectation will either call a setter or raise
# an attribute error, anyway not hiding the function
return
# Infer the decorator and see if it returns something useful
inferred = safe_infer(decorator)
if not inferred:
return
if isinstance(inferred, nodes.FunctionDef):
# Okay, it's a decorator, let's see what it can infer.
try:
inferred = next(inferred.infer_call_result(inferred))
except astroid.InferenceError:
return
try:
if (
isinstance(inferred, (astroid.Instance, nodes.ClassDef))
and inferred.getattr("__get__")
and inferred.getattr("__set__")
):
return
except astroid.AttributeInferenceError:
pass
# check if the method is hidden by an attribute
try:
overridden = klass.instance_attr(node.name)[0]
overridden_frame = overridden.frame(future=_True)
if (
isinstance(overridden_frame, nodes.FunctionDef)
and overridden_frame.type == "method"
):
overridden_frame = overridden_frame.parent.frame(future=_True)
if not (
isinstance(overridden_frame, nodes.ClassDef)
and klass.is_subtype_of(overridden_frame.qname())
):
return
# If a subclass defined the method then it's not our fault.
for ancestor in klass.ancestors():
if node.name in ancestor.instance_attrs and is_attr_private(node.name):
return
for obj in ancestor.lookup(node.name)[1]:
if isinstance(obj, nodes.FunctionDef):
return
args = (overridden.root().name, overridden.fromlineno)
self.add_message("method-hidden", args=args, node=node)
except astroid.NotFoundError:
pass
visit_asyncfunctiondef = visit_functiondef
def _check_useless_super_delegation(self, function):
"""Check if the given function node is an useless method override.
We consider it *useless* if it uses the super() builtin, but having
nothing additional whatsoever than not implementing the method at all.
If the method uses super() to delegate an operation to the rest of the MRO,
and if the method called is the same as the current one, the arguments
passed to super() are the same as the parameters that were passed to
this method, then the method could be removed altogether, by letting
other implementation to take precedence.
"""
if (
not function.is_method()
# With decorators is a change of use
or function.decorators
):
return
body = function.body
if len(body) != 1:
# Multiple statements, which means this overridden method
# could do multiple things we are not aware of.
return
statement = body[0]
if not isinstance(statement, (nodes.Expr, nodes.Return)):
# Doing something else than what we are interested into.
return
call = statement.value
if (
not isinstance(call, nodes.Call)
# Not a super() attribute access.
or not isinstance(call.func, nodes.Attribute)
):
return
# Should be a super call.
try:
super_call = next(call.func.expr.infer())
except astroid.InferenceError:
return
else:
if not isinstance(super_call, astroid.objects.Super):
return
# The name should be the same.
if call.func.attrname != function.name:
return
# Should be a super call with the MRO pointer being the
# current class and the type being the current instance.
current_scope = function.parent.scope()
if (
super_call.mro_pointer != current_scope
or not isinstance(super_call.type, astroid.Instance)
or super_call.type.name != current_scope.name
):
return
# Check values of default args
klass = function.parent.frame(future=_True)
meth_node = None
for overridden in klass.local_attr_ancestors(function.name):
# get astroid for the searched method
try:
meth_node = overridden[function.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if (
not isinstance(meth_node, nodes.FunctionDef)
# If the method have an ancestor which is not a
# function then it is legitimate to redefine it
or _has_different_parameters_default_value(
meth_node.args, function.args
)
):
return
break
# Detect if the parameters are the same as the call's arguments.
params = _signature_from_arguments(function.args)
args = _signature_from_call(call)
if meth_node is not None:
def form_annotations(arguments):
annotations = chain(
(arguments.posonlyargs_annotations or []), arguments.annotations
)
return [ann.as_string() for ann in annotations if ann is not None]
called_annotations = form_annotations(function.args)
overridden_annotations = form_annotations(meth_node.args)
if called_annotations and overridden_annotations:
if called_annotations != overridden_annotations:
return
if _definition_equivalent_to_call(params, args):
self.add_message(
"useless-super-delegation", node=function, args=(function.name,)
)
def _check_property_with_parameters(self, node):
if (
node.args.args
and len(node.args.args) > 1
and decorated_with_property(node)
and not is_property_setter(node)
):
self.add_message("property-with-parameters", node=node)
def _check_invalid_overridden_method(self, function_node, parent_function_node):
parent_is_property = decorated_with_property(
parent_function_node
) or is_property_setter_or_deleter(parent_function_node)
current_is_property = decorated_with_property(
function_node
) or is_property_setter_or_deleter(function_node)
if parent_is_property and not current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "property", function_node.type),
node=function_node,
)
elif not parent_is_property and current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "method", "property"),
node=function_node,
)
parent_is_async = isinstance(parent_function_node, nodes.AsyncFunctionDef)
current_is_async = isinstance(function_node, nodes.AsyncFunctionDef)
if parent_is_async and not current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "async", "non-async"),
node=function_node,
)
elif not parent_is_async and current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "non-async", "async"),
node=function_node,
)
if (
decorated_with(parent_function_node, ["typing.final"])
or uninferable_final_decorators(parent_function_node.decorators)
) and self._py38_plus:
self.add_message(
"overridden-final-method",
args=(function_node.name, parent_function_node.parent.frame().name),
node=function_node,
)
def _check_slots(self, node: nodes.ClassDef) -> None:
if "__slots__" not in node.locals:
return
for slots in node.igetattr("__slots__"):
# check if __slots__ is a valid type
if slots is astroid.Uninferable:
continue
if not is_iterable(slots) and not is_comprehension(slots):
self.add_message("invalid-slots", node=node)
continue
if isinstance(slots, nodes.Const):
# a string, ignore the following checks
self.add_message("single-string-used-for-slots", node=node)
continue
if not hasattr(slots, "itered"):
# we can't obtain the values, maybe a .deque?
continue
if isinstance(slots, nodes.Dict):
values = [item[0] for item in slots.items]
else:
values = slots.itered()
if values is astroid.Uninferable:
return
for elt in values:
try:
self._check_slots_elt(elt, node)
except astroid.InferenceError:
continue
self._check_redefined_slots(node, slots, values)
def _check_redefined_slots(
self,
node: nodes.ClassDef,
slots_node: nodes.NodeNG,
slots_list: List[nodes.NodeNG],
) -> None:
"""Check if `node` redefines a slot which is defined in an ancestor class."""
slots_names: List[str] = []
for slot in slots_list:
if isinstance(slot, nodes.Const):
slots_names.append(slot.value)
else:
inferred_slot = safe_infer(slot)
if inferred_slot:
slots_names.append(inferred_slot.value)
# Slots of all parent classes
ancestors_slots_names = {
slot.value
for ancestor in node.local_attr_ancestors("__slots__")
for slot in ancestor.slots() or []
}
# Slots which are common to `node` and its parent classes
redefined_slots = ancestors_slots_names.intersection(slots_names)
if redefined_slots:
self.add_message(
"redefined-slots-in-subclass",
args=([name for name in slots_names if name in redefined_slots],),
node=slots_node,
)
def _check_slots_elt(self, elt, node):
for inferred in elt.infer():
if inferred is astroid.Uninferable:
continue
if not isinstance(inferred, nodes.Const) or not isinstance(
inferred.value, str
):
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
continue
if not inferred.value:
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
# Check if we have a conflict with a class variable.
class_variable = node.locals.get(inferred.value)
if class_variable:
# Skip annotated assignments which don't conflict at all with slots.
if len(class_variable) == 1:
parent = class_variable[0].parent
if isinstance(parent, nodes.AnnAssign) and parent.value is None:
return
self.add_message(
"class-variable-slots-conflict", args=(inferred.value,), node=elt
)
def leave_functiondef(self, node: nodes.FunctionDef) -> None:
"""On method node, check if this method couldn't be a function.
ignore class, static and abstract methods, initializer,
methods overridden from a parent class.
"""
if node.is_method():
if node.args.args is not None:
self._first_attrs.pop()
if not self.linter.is_message_enabled("no-self-use"):
return
class_node = node.parent.frame(future=_True)
if (
self._meth_could_be_func
and node.type == "method"
and node.name not in PYMETHODS
and not (
node.is_abstract()
or overrides_a_method(class_node, node.name)
or decorated_with_property(node)
or _has_bare_super_call(node)
or is_protocol_class(class_node)
or is_overload_stub(node)
)
):
self.add_message("no-self-use", node=node)
leave_asyncfunctiondef = leave_functiondef
def visit_attribute(self, node: nodes.Attribute) -> None:
"""Check if the getattr is an access to a class member
if so, register it. Also check for access to protected
class member from outside its class (but ignore __special__
methods)
"""
# Check self
if self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
return
if not self.linter.is_message_enabled("protected-access"):
return
self._check_protected_attribute_access(node)
@check_messages("assigning-non-slot", "invalid-class-object")
def visit_assignattr(self, node: nodes.AssignAttr) -> None:
if isinstance(
node.assign_type(), nodes.AugAssign
) and self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
self._check_in_slots(node)
self._check_invalid_class_object(node)
def _check_invalid_class_object(self, node: nodes.AssignAttr) -> None:
if not node.attrname == "__class__":
return
inferred = safe_infer(node.parent.value)
if isinstance(inferred, nodes.ClassDef) or inferred is astroid.Uninferable:
# If is uninferrable, we allow it to prevent false positives
return
self.add_message("invalid-class-object", node=node)
def _check_in_slots(self, node):
"""Check that the given AssignAttr node
is defined in the class slots.
"""
inferred = safe_infer(node.expr)
if not isinstance(inferred, astroid.Instance):
return
klass = inferred._proxied
if not has_known_bases(klass):
return
if "__slots__" not in klass.locals or not klass.newstyle:
return
# If `__setattr__` is defined on the class, then we can't reason about
# what will happen when assigning to an attribute.
if any(
base.locals.get("__setattr__")
for base in klass.mro()
if base.qname() != "builtins.object"
):
return
# If 'typing.Generic' is a base of bases of klass, the cached version
# of 'slots()' might have been evaluated incorrectly, thus deleted cache entry.
if any(base.qname() == "typing.Generic" for base in klass.mro()):
cache = getattr(klass, "__cache", None)
if cache and cache.get(klass.slots) is not None:
del cache[klass.slots]
slots = klass.slots()
if slots is None:
return
# If any ancestor doesn't use slots, the slots
# defined for this class are superfluous.
if any(
"__slots__" not in ancestor.locals and ancestor.name != "object"
for ancestor in klass.ancestors()
):
return
if not any(slot.value == node.attrname for slot in slots):
# If we have a '__dict__' in slots, then
# assigning any name is valid.
if not any(slot.value == "__dict__" for slot in slots):
if _is_attribute_property(node.attrname, klass):
# Properties circumvent the slots mechanism,
# so we should not emit a warning for them.
return
if node.attrname in klass.locals:
for local_name in klass.locals.get(node.attrname):
statement = local_name.statement(future=_True)
if (
isinstance(statement, nodes.AnnAssign)
and not statement.value
):
return
if _has_data_descriptor(klass, node.attrname):
# Descriptors circumvent the slots mechanism as well.
return
if node.attrname == "__class__" and _has_same_layout_slots(
slots, node.parent.value
):
return
self.add_message("assigning-non-slot", args=(node.attrname,), node=node)
@check_messages(
"protected-access", "no-classmethod-decorator", "no-staticmethod-decorator"
)
def visit_assign(self, assign_node: nodes.Assign) -> None:
self._check_classmethod_declaration(assign_node)
node = assign_node.targets[0]
if not isinstance(node, nodes.AssignAttr):
return
if self._uses_mandatory_method_param(node):
return
self._check_protected_attribute_access(node)
def _check_classmethod_declaration(self, node):
"""Checks for uses of classmethod() or staticmethod().
When a @classmethod or @staticmethod decorator should be used instead.
A message will be emitted only if the assignment is at a class scope
and only if the classmethod's argument belongs to the class where it
is defined.
`node` is an assign node.
"""
if not isinstance(node.value, nodes.Call):
return
# check the function called is "classmethod" or "staticmethod"
func = node.value.func
if not isinstance(func, nodes.Name) or func.name not in (
"classmethod",
"staticmethod",
):
return
msg = (
"no-classmethod-decorator"
if func.name == "classmethod"
else "no-staticmethod-decorator"
)
# assignment must be at a class scope
parent_class = node.scope()
if not isinstance(parent_class, nodes.ClassDef):
return
# Check if the arg passed to classmethod is a class member
classmeth_arg = node.value.args[0]
if not isinstance(classmeth_arg, nodes.Name):
return
method_name = classmeth_arg.name
if any(method_name == member.name for member in parent_class.mymethods()):
self.add_message(msg, node=node.targets[0])
def _check_protected_attribute_access(self, node: nodes.Attribute):
"""Given an attribute access node (set or get), check if attribute
access is legitimate. Call _check_first_attr with node before calling
this method. Valid cases are:
* self._attr in a method or cls._attr in a classmethod. Checked by
_check_first_attr.
* Klass._attr inside "Klass" class.
* Klass2._attr inside "Klass" class when Klass2 is a base class of
Klass.
"""
attrname = node.attrname
if (
is_attr_protected(attrname)
and attrname not in self.config.exclude_protected
):
klass = node_frame_class(node)
# In classes, check we are not getting a parent method
# through the class object or through super
callee = node.expr.as_string()
# Typing annotations in function definitions can include protected members
if utils.is_node_in_type_annotation_context(node):
return
# We are not in a class, no remaining valid case
if klass is None:
self.add_message("protected-access", node=node, args=attrname)
return
# If the expression begins with a call to super, that's ok.
if (
isinstance(node.expr, nodes.Call)
and isinstance(node.expr.func, nodes.Name)
and node.expr.func.name == "super"
):
return
# If the expression begins with a call to type(self), that's ok.
if self._is_type_self_call(node.expr):
return
# Check if we are inside the scope of a class or nested inner class
inside_klass = _True
outer_klass = klass
parents_callee = callee.split(".")
parents_callee.reverse()
for callee in parents_callee:
if not outer_klass or callee != outer_klass.name:
inside_klass = _False
break
# Move up one level within the nested classes
outer_klass = get_outer_class(outer_klass)
# We are in a class, one remaining valid cases, Klass._attr inside
# Klass
if not (inside_klass or callee in klass.basenames):
# Detect property assignments in the body of the class.
# This is acceptable:
#
# class A:
# b = property(lambda: self._b)
stmt = node.parent.statement(future=_True)
if (
isinstance(stmt, nodes.Assign)
and len(stmt.targets) == 1
and isinstance(stmt.targets[0], nodes.AssignName)
):
name = stmt.targets[0].name
if _is_attribute_property(name, klass):
return
if (
self._is_classmethod(node.frame(future=_True))
and self._is_inferred_instance(node.expr, klass)
and self._is_class_attribute(attrname, klass)
):
return
licit_protected_member = not attrname.startswith("__")
if (
not self.config.check_protected_access_in_special_methods
and licit_protected_member
and self._is_called_inside_special_method(node)
):
return
self.add_message("protected-access", node=node, args=attrname)
@staticmethod
def _is_called_inside_special_method(node: nodes.NodeNG) -> bool:
"""Returns true if the node is located inside a special (aka dunder) method."""
frame_name = node.frame(future=_True).name
return frame_name and frame_name in PYMETHODS
def _is_type_self_call(self, expr: nodes.NodeNG) -> bool:
return (
isinstance(expr, nodes.Call)
and isinstance(expr.func, nodes.Name)
and expr.func.name == "type"
and len(expr.args) == 1
and self._is_mandatory_method_param(expr.args[0])
)
@staticmethod
def _is_classmethod(func):
"""Check if the given *func* node is a class method."""
return isinstance(func, nodes.FunctionDef) and (
func.type == "classmethod" or func.name == "__class_getitem__"
)
@staticmethod
def _is_inferred_instance(expr, klass):
"""Check if the inferred value of the given *expr* is an instance of *klass*."""
inferred = safe_infer(expr)
if not isinstance(inferred, astroid.Instance):
return _False
return inferred._proxied is klass
@staticmethod
def _is_class_attribute(name, klass):
"""Check if the given attribute *name* is a class or instance member of the given *klass*.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
klass.getattr(name)
return _True
except astroid.NotFoundError:
pass
try:
klass.instance_attr(name)
return _True
except astroid.NotFoundError:
return _False
def visit_name(self, node: nodes.Name) -> None:
"""Check if the name handle an access to a class member
if so, register it
"""
if self._first_attrs and (
node.name == self._first_attrs[-1] or not self._first_attrs[-1]
):
self._meth_could_be_func = _False
def _check_accessed_members(self, node, accessed):
"""Check that accessed members are defined."""
excs = ("AttributeError", "Exception", "BaseException")
for attr, nodes_lst in accessed.items():
try:
# is it a class attribute ?
node.local_attr(attr)
# yes, stop here
continue
except astroid.NotFoundError:
pass
# is it an instance attribute of a parent class ?
try:
next(node.instance_attr_ancestors(attr))
# yes, stop here
continue
except StopIteration:
pass
# is it an instance attribute ?
try:
defstmts = node.instance_attr(attr)
except astroid.NotFoundError:
pass
else:
# filter out augment assignment nodes
defstmts = [stmt for stmt in defstmts if stmt not in nodes_lst]
if not defstmts:
# only augment assignment for this node, no-member should be
# triggered by the typecheck checker
continue
# filter defstmts to only pick the first one when there are
# several assignments in the same scope
scope = defstmts[0].scope()
defstmts = [
stmt
for i, stmt in enumerate(defstmts)
if i == 0 or stmt.scope() is not scope
]
# if there are still more than one, don't attempt to be smarter
# than we can be
if len(defstmts) == 1:
defstmt = defstmts[0]
# check that if the node is accessed in the same method as
# it's defined, it's accessed after the initial assignment
frame = defstmt.frame(future=_True)
lno = defstmt.fromlineno
for _node in nodes_lst:
if (
_node.frame(future=_True) is frame
and _node.fromlineno < lno
and not astroid.are_exclusive(
_node.statement(future=_True), defstmt, excs
)
):
self.add_message(
"access-member-before-definition",
node=_node,
args=(attr, lno),
)
def _check_first_arg_for_type(self, node, metaclass=0):
"""Check the name of first argument, expect:.
* 'self' for a regular method
* 'cls' for a class method or a metaclass regular method (actually
valid-classmethod-first-arg value)
* 'mcs' for a metaclass class method (actually
valid-metaclass-classmethod-first-arg)
* not one of the above for a static method
"""
# don't care about functions with unknown argument (builtins)
if node.args.args is None:
return
if node.args.posonlyargs:
first_arg = node.args.posonlyargs[0].name
elif node.args.args:
first_arg = node.argnames()[0]
else:
first_arg = None
self._first_attrs.append(first_arg)
first = self._first_attrs[-1]
# static method
if node.type == "staticmethod":
if (
first_arg == "self"
or first_arg in self.config.valid_classmethod_first_arg
or first_arg in self.config.valid_metaclass_classmethod_first_arg
):
self.add_message("bad-staticmethod-argument", args=first, node=node)
return
self._first_attrs[-1] = None
# class / regular method with no args
elif not node.args.args and not node.args.posonlyargs:
self.add_message("no-method-argument", node=node)
# metaclass
elif metaclass:
# metaclass __new__ or classmethod
if node.type == "classmethod":
self._check_first_arg_config(
first,
self.config.valid_metaclass_classmethod_first_arg,
node,
"bad-mcs-classmethod-argument",
node.name,
)
# metaclass regular method
else:
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-mcs-method-argument",
node.name,
)
# regular class with class method
elif node.type == "classmethod" or node.name == "__class_getitem__":
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-classmethod-argument",
node.name,
)
# regular class with regular method without self as argument
elif first != "self":
self.add_message("no-self-argument", node=node)
def _check_first_arg_config(self, first, config, node, message, method_name):
if first not in config:
if len(config) == 1:
valid = repr(config[0])
else:
valid = ", ".join(repr(v) for v in config[:-1])
valid = f"{valid} or {config[-1]!r}"
self.add_message(message, args=(method_name, valid), node=node)
def _check_bases_classes(self, node):
"""Check that the given class node implements abstract methods from
base classes
"""
def is_abstract(method):
return method.is_abstract(pass_is_abstract=_False)
# check if this class abstract
if class_is_abstract(node):
return
methods = sorted(
unimplemented_abstract_methods(node, is_abstract).items(),
key=lambda item: item[0],
)
for name, method in methods:
owner = method.parent.frame(future=_True)
if owner is node:
continue
# owner is not this class, it must be a parent class
# check that the ancestor's method is not abstract
if name in node.locals:
# it is redefined as an attribute or with a descriptor
continue
self.add_message("abstract-method", node=node, args=(name, owner.name))
def _check_init(self, node: nodes.FunctionDef, klass_node: nodes.ClassDef) -> None:
"""Check that the __init__ method call super or ancestors'__init__
method (unless it is used for type hinting with `typing.overload`)
"""
if not self.linter.is_message_enabled(
"super-init-not-called"
) and not self.linter.is_message_enabled("non-parent-init-called"):
return
to_call = _ancestors_to_call(klass_node)
not_called_yet = dict(to_call)
parents_with_called_inits: Set[bases.UnboundMethod] = set()
for stmt in node.nodes_of_class(nodes.Call):
expr = stmt.func
if not isinstance(expr, nodes.Attribute) or expr.attrname != "__init__":
continue
# skip the test if using super
if (
isinstance(expr.expr, nodes.Call)
and isinstance(expr.expr.func, nodes.Name)
and expr.expr.func.name == "super"
):
return
try:
for klass in expr.expr.infer():
if klass is astroid.Uninferable:
continue
# The inferred klass can be super(), which was
# assigned to a variable and the `__init__`
# was called later.
#
# base = super()
# base.__init__(...)
if (
isinstance(klass, astroid.Instance)
and isinstance(klass._proxied, nodes.ClassDef)
and is_builtin_object(klass._proxied)
and klass._proxied.name == "super"
):
return
if isinstance(klass, astroid.objects.Super):
return
try:
method = not_called_yet.pop(klass)
# Record that the class' init has been called
parents_with_called_inits.add(node_frame_class(method))
except KeyError:
if klass not in to_call:
self.add_message(
"non-parent-init-called", node=expr, args=klass.name
)
except astroid.InferenceError:
continue
for klass, method in not_called_yet.items():
# Check if the init of the class that defines this init has already
# been called.
if node_frame_class(method) in parents_with_called_inits:
return
# Return if klass is protocol
if klass.qname() in utils.TYPING_PROTOCOLS:
return
# Return if any of the klass' first-order bases is protocol
for base in klass.bases:
# We don't need to catch InferenceError here as _ancestors_to_call
# already does this for us.
for inf_base in base.infer():
if inf_base.qname() in utils.TYPING_PROTOCOLS:
return
if decorated_with(node, ["typing.overload"]):
continue
cls = node_frame_class(method)
if klass.name == "object" or (cls and cls.name == "object"):
continue
self.add_message(
"super-init-not-called",
args=klass.name,
node=node,
confidence=INFERENCE,
)
def _check_signature(self, method1, refmethod, class_type, cls):
"""Check that the signature of the two given methods match."""
if not (
isinstance(method1, nodes.FunctionDef)
and isinstance(refmethod, nodes.FunctionDef)
):
self.add_message(
"method-check-failed", args=(method1, refmethod), node=method1
)
return
instance = cls.instantiate_class()
method1 = astroid.scoped_nodes.function_to_method(method1, instance)
refmethod = astroid.scoped_nodes.function_to_method(refmethod, instance)
# Don't care about functions with unknown argument (builtins).
if method1.args.args is None or refmethod.args.args is None:
return
# Ignore private to class methods.
if is_attr_private(method1.name):
return
# Ignore setters, they have an implicit extra argument,
# which shouldn't be taken in consideration.
if is_property_setter(method1):
return
arg_differ_output = _different_parameters(
refmethod, method1, dummy_parameter_regex=self._dummy_rgx
)
if len(arg_differ_output) > 0:
for msg in arg_differ_output:
if "Number" in msg:
total_args_method1 = len(method1.args.args)
if method1.args.vararg:
total_args_method1 += 1
if method1.args.kwarg:
total_args_method1 += 1
if method1.args.kwonlyargs:
total_args_method1 += len(method1.args.kwonlyargs)
total_args_refmethod = len(refmethod.args.args)
if refmethod.args.vararg:
total_args_refmethod += 1
if refmethod.args.kwarg:
total_args_refmethod += 1
if refmethod.args.kwonlyargs:
total_args_refmethod += len(refmethod.args.kwonlyargs)
error_type = "arguments-differ"
msg_args = (
msg
+ f"was {total_args_refmethod} in '{refmethod.parent.frame().name}.{refmethod.name}' and "
f"is now {total_args_method1} in",
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
elif "renamed" in msg:
error_type = "arguments-renamed"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
else:
error_type = "arguments-differ"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
self.add_message(error_type, args=msg_args, node=method1)
elif (
len(method1.args.defaults) < len(refmethod.args.defaults)
and not method1.args.vararg
):
self.add_message(
"signature-differs", args=(class_type, method1.name), node=method1
)
def _uses_mandatory_method_param(self, node):
"""Check that attribute lookup name use first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
return self._is_mandatory_method_param(node.expr)
def _is_mandatory_method_param(self, node: nodes.NodeNG) -> bool:
"""Check if nodes.Name corresponds to first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
if self._first_attrs:
first_attr = self._first_attrs[-1]
else:
# It's possible the function was already unregistered.
closest_func = utils.get_node_first_ancestor_of_type(
node, nodes.FunctionDef
)
if closest_func is None:
return _False
if not closest_func.args.args:
return _False
first_attr = closest_func.args.args[0].name
return isinstance(node, nodes.Name) and node.name == first_attr
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 855 | safe_infer | ref | function | ancestor = safe_infer(base)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 860 | decorated_with | ref | function | decorated_with(ancestor, ["typing.final"])
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 861 | uninferable_final_decorators | ref | function | or uninferable_final_decorators(ancestor.decorators)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 863 | add_message | ref | function | self.add_message(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 869 | check_messages | ref | function | @check_messages("unused-private-member", "attribute-defined-outside-init")
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 870 | leave_classdef | def | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 875 | _check_unused_private_functions | ref | function | self._check_unused_private_functions(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 876 | _check_unused_private_variables | ref | function | self._check_unused_private_variables(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 877 | _check_unused_private_attributes | ref | function | self._check_unused_private_attributes(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 878 | _check_attribute_defined_outside_init | ref | function | self._check_attribute_defined_outside_init(node)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 880 | _check_unused_private_functions | def | function | def _check_unused_private_functions(self, node: nodes.ClassDef) -> None:
for function_def in node.nodes_of_class(nodes.FunctionDef):
if not is_attr_private(function_def.name):
continue
parent_scope = function_def.parent.scope()
if isinstance(parent_scope, nodes.FunctionDef):
# Handle nested functions
if function_def.name in (
n.name for n in parent_scope.nodes_of_class(nodes.Name)
):
continue
for attribute in node.nodes_of_class(nodes.Attribute):
if (
attribute.attrname != function_def.name
or attribute.scope() == function_def # We ignore recursive calls
):
continue
if isinstance(attribute.expr, nodes.Name) and attribute.expr.name in (
"self",
"cls",
node.name,
):
# self.__attrname
# cls.__attrname
# node_name.__attrname
break
if isinstance(attribute.expr, nodes.Call):
# type(self).__attrname
inferred = safe_infer(attribute.expr)
if (
isinstance(inferred, nodes.ClassDef)
and inferred.name == node.name
):
break
else:
name_stack = []
curr = parent_scope
# Generate proper names for nested functions
while curr != node:
name_stack.append(curr.name)
curr = curr.parent.scope()
outer_level_names = f"{'.'.join(reversed(name_stack))}"
function_repr = f"{outer_level_names}.{function_def.name}({function_def.args.as_string()})"
self.add_message(
"unused-private-member",
node=function_def,
args=(node.name, function_repr.lstrip(".")),
)
def _check_unused_private_variables(self, node: nodes.ClassDef) -> None:
"""Check if private variables are never used within a class."""
for assign_name in node.nodes_of_class(nodes.AssignName):
if isinstance(assign_name.parent, nodes.Arguments):
continue # Ignore function arguments
if not is_attr_private(assign_name.name):
continue
for child in node.nodes_of_class((nodes.Name, nodes.Attribute)):
if isinstance(child, nodes.Name) and child.name == assign_name.name:
break
if isinstance(child, nodes.Attribute):
if not isinstance(child.expr, nodes.Name):
break
if child.attrname == assign_name.name and child.expr.name in (
"self",
"cls",
node.name,
):
break
else:
args = (node.name, assign_name.name)
self.add_message("unused-private-member", node=assign_name, args=args)
def _check_unused_private_attributes(self, node: nodes.ClassDef) -> None:
for assign_attr in node.nodes_of_class(nodes.AssignAttr):
if not is_attr_private(assign_attr.attrname) or not isinstance(
assign_attr.expr, nodes.Name
):
continue
# Logic for checking false positive when using __new__,
# Get the returned object names of the __new__ magic function
# Then check if the attribute was consumed in other instance methods
acceptable_obj_names: List[str] = ["self"]
scope = assign_attr.scope()
if isinstance(scope, nodes.FunctionDef) and scope.name == "__new__":
acceptable_obj_names.extend(
[
return_node.value.name
for return_node in scope.nodes_of_class(nodes.Return)
if isinstance(return_node.value, nodes.Name)
]
)
for attribute in node.nodes_of_class(nodes.Attribute):
if attribute.attrname != assign_attr.attrname:
continue
if self._is_type_self_call(attribute.expr):
continue
if assign_attr.expr.name in {
"cls",
node.name,
} and attribute.expr.name in {"cls", "self", node.name}:
# If assigned to cls or class name, can be accessed by cls/self/class name
break
if (
assign_attr.expr.name in acceptable_obj_names
and attribute.expr.name == "self"
):
# If assigned to self.attrib, can only be accessed by self
# Or if __new__ was used, the returned object names are acceptable
break
if assign_attr.expr.name == attribute.expr.name == node.name:
# Recognise attributes which are accessed via the class name
break
else:
args = (node.name, assign_attr.attrname)
self.add_message("unused-private-member", node=assign_attr, args=args)
def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
# check access to existent members on non metaclass classes
if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
# We are in a mixin class. No need to try to figure out if
# something is missing, since it is most likely that it will
# miss.
return
accessed = self._accessed.accessed(cnode)
if cnode.type != "metaclass":
self._check_accessed_members(cnode, accessed)
# checks attributes are defined in an allowed method such as __init__
if not self.linter.is_message_enabled("attribute-defined-outside-init"):
return
defining_methods = self.config.defining_attr_methods
current_module = cnode.root()
for attr, nodes_lst in cnode.instance_attrs.items():
# Exclude `__dict__` as it is already defined.
if attr == "__dict__":
continue
# Skip nodes which are not in the current module and it may screw up
# the output, while it's not worth it
nodes_lst = [
n
for n in nodes_lst
if not isinstance(
n.statement(future=_True), (nodes.Delete, nodes.AugAssign)
)
and n.root() is current_module
]
if not nodes_lst:
continue # error detected by typechecking
# Check if any method attr is defined in is a defining method
# or if we have the attribute defined in a setter.
frames = (node.frame(future=_True) for node in nodes_lst)
if any(
frame.name in defining_methods or is_property_setter(frame)
for frame in frames
):
continue
# check attribute is defined in a parent's __init__
for parent in cnode.instance_attr_ancestors(attr):
attr_defined = _False
# check if any parent method attr is defined in is a defining method
for node in parent.instance_attrs[attr]:
if node.frame(future=_True).name in defining_methods:
attr_defined = _True
if attr_defined:
# we're done :)
break
else:
# check attribute is defined as a class attribute
try:
cnode.local_attr(attr)
except astroid.NotFoundError:
for node in nodes_lst:
if node.frame(future=_True).name not in defining_methods:
# If the attribute was set by a call in any
# of the defining methods, then don't emit
# the warning.
if _called_in_methods(
node.frame(future=_True), cnode, defining_methods
):
continue
self.add_message(
"attribute-defined-outside-init", args=attr, node=node
)
def visit_functiondef(self, node: nodes.FunctionDef) -> None:
"""Check method arguments, overriding."""
# ignore actual functions
if not node.is_method():
return
self._check_useless_super_delegation(node)
self._check_property_with_parameters(node)
# 'is_method()' is called and makes sure that this is a 'nodes.ClassDef'
klass = node.parent.frame(future=_True) # type: nodes.ClassDef
self._meth_could_be_func = _True
# check first argument is self if this is actually a method
self._check_first_arg_for_type(node, klass.type == "metaclass")
if node.name == "__init__":
self._check_init(node, klass)
return
# check signature if the method overloads inherited method
for overridden in klass.local_attr_ancestors(node.name):
# get astroid for the searched method
try:
parent_function = overridden[node.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if not isinstance(parent_function, nodes.FunctionDef):
continue
self._check_signature(node, parent_function, "overridden", klass)
self._check_invalid_overridden_method(node, parent_function)
break
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, nodes.Attribute) and decorator.attrname in {
"getter",
"setter",
"deleter",
}:
# attribute affectation will call this method, not hiding it
return
if isinstance(decorator, nodes.Name):
if decorator.name == "property":
# attribute affectation will either call a setter or raise
# an attribute error, anyway not hiding the function
return
# Infer the decorator and see if it returns something useful
inferred = safe_infer(decorator)
if not inferred:
return
if isinstance(inferred, nodes.FunctionDef):
# Okay, it's a decorator, let's see what it can infer.
try:
inferred = next(inferred.infer_call_result(inferred))
except astroid.InferenceError:
return
try:
if (
isinstance(inferred, (astroid.Instance, nodes.ClassDef))
and inferred.getattr("__get__")
and inferred.getattr("__set__")
):
return
except astroid.AttributeInferenceError:
pass
# check if the method is hidden by an attribute
try:
overridden = klass.instance_attr(node.name)[0]
overridden_frame = overridden.frame(future=_True)
if (
isinstance(overridden_frame, nodes.FunctionDef)
and overridden_frame.type == "method"
):
overridden_frame = overridden_frame.parent.frame(future=_True)
if not (
isinstance(overridden_frame, nodes.ClassDef)
and klass.is_subtype_of(overridden_frame.qname())
):
return
# If a subclass defined the method then it's not our fault.
for ancestor in klass.ancestors():
if node.name in ancestor.instance_attrs and is_attr_private(node.name):
return
for obj in ancestor.lookup(node.name)[1]:
if isinstance(obj, nodes.FunctionDef):
return
args = (overridden.root().name, overridden.fromlineno)
self.add_message("method-hidden", args=args, node=node)
except astroid.NotFoundError:
pass
visit_asyncfunctiondef = visit_functiondef
def _check_useless_super_delegation(self, function):
"""Check if the given function node is an useless method override.
We consider it *useless* if it uses the super() builtin, but having
nothing additional whatsoever than not implementing the method at all.
If the method uses super() to delegate an operation to the rest of the MRO,
and if the method called is the same as the current one, the arguments
passed to super() are the same as the parameters that were passed to
this method, then the method could be removed altogether, by letting
other implementation to take precedence.
"""
if (
not function.is_method()
# With decorators is a change of use
or function.decorators
):
return
body = function.body
if len(body) != 1:
# Multiple statements, which means this overridden method
# could do multiple things we are not aware of.
return
statement = body[0]
if not isinstance(statement, (nodes.Expr, nodes.Return)):
# Doing something else than what we are interested into.
return
call = statement.value
if (
not isinstance(call, nodes.Call)
# Not a super() attribute access.
or not isinstance(call.func, nodes.Attribute)
):
return
# Should be a super call.
try:
super_call = next(call.func.expr.infer())
except astroid.InferenceError:
return
else:
if not isinstance(super_call, astroid.objects.Super):
return
# The name should be the same.
if call.func.attrname != function.name:
return
# Should be a super call with the MRO pointer being the
# current class and the type being the current instance.
current_scope = function.parent.scope()
if (
super_call.mro_pointer != current_scope
or not isinstance(super_call.type, astroid.Instance)
or super_call.type.name != current_scope.name
):
return
# Check values of default args
klass = function.parent.frame(future=_True)
meth_node = None
for overridden in klass.local_attr_ancestors(function.name):
# get astroid for the searched method
try:
meth_node = overridden[function.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if (
not isinstance(meth_node, nodes.FunctionDef)
# If the method have an ancestor which is not a
# function then it is legitimate to redefine it
or _has_different_parameters_default_value(
meth_node.args, function.args
)
):
return
break
# Detect if the parameters are the same as the call's arguments.
params = _signature_from_arguments(function.args)
args = _signature_from_call(call)
if meth_node is not None:
def form_annotations(arguments):
annotations = chain(
(arguments.posonlyargs_annotations or []), arguments.annotations
)
return [ann.as_string() for ann in annotations if ann is not None]
called_annotations = form_annotations(function.args)
overridden_annotations = form_annotations(meth_node.args)
if called_annotations and overridden_annotations:
if called_annotations != overridden_annotations:
return
if _definition_equivalent_to_call(params, args):
self.add_message(
"useless-super-delegation", node=function, args=(function.name,)
)
def _check_property_with_parameters(self, node):
if (
node.args.args
and len(node.args.args) > 1
and decorated_with_property(node)
and not is_property_setter(node)
):
self.add_message("property-with-parameters", node=node)
def _check_invalid_overridden_method(self, function_node, parent_function_node):
parent_is_property = decorated_with_property(
parent_function_node
) or is_property_setter_or_deleter(parent_function_node)
current_is_property = decorated_with_property(
function_node
) or is_property_setter_or_deleter(function_node)
if parent_is_property and not current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "property", function_node.type),
node=function_node,
)
elif not parent_is_property and current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "method", "property"),
node=function_node,
)
parent_is_async = isinstance(parent_function_node, nodes.AsyncFunctionDef)
current_is_async = isinstance(function_node, nodes.AsyncFunctionDef)
if parent_is_async and not current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "async", "non-async"),
node=function_node,
)
elif not parent_is_async and current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "non-async", "async"),
node=function_node,
)
if (
decorated_with(parent_function_node, ["typing.final"])
or uninferable_final_decorators(parent_function_node.decorators)
) and self._py38_plus:
self.add_message(
"overridden-final-method",
args=(function_node.name, parent_function_node.parent.frame().name),
node=function_node,
)
def _check_slots(self, node: nodes.ClassDef) -> None:
if "__slots__" not in node.locals:
return
for slots in node.igetattr("__slots__"):
# check if __slots__ is a valid type
if slots is astroid.Uninferable:
continue
if not is_iterable(slots) and not is_comprehension(slots):
self.add_message("invalid-slots", node=node)
continue
if isinstance(slots, nodes.Const):
# a string, ignore the following checks
self.add_message("single-string-used-for-slots", node=node)
continue
if not hasattr(slots, "itered"):
# we can't obtain the values, maybe a .deque?
continue
if isinstance(slots, nodes.Dict):
values = [item[0] for item in slots.items]
else:
values = slots.itered()
if values is astroid.Uninferable:
return
for elt in values:
try:
self._check_slots_elt(elt, node)
except astroid.InferenceError:
continue
self._check_redefined_slots(node, slots, values)
def _check_redefined_slots(
self,
node: nodes.ClassDef,
slots_node: nodes.NodeNG,
slots_list: List[nodes.NodeNG],
) -> None:
"""Check if `node` redefines a slot which is defined in an ancestor class."""
slots_names: List[str] = []
for slot in slots_list:
if isinstance(slot, nodes.Const):
slots_names.append(slot.value)
else:
inferred_slot = safe_infer(slot)
if inferred_slot:
slots_names.append(inferred_slot.value)
# Slots of all parent classes
ancestors_slots_names = {
slot.value
for ancestor in node.local_attr_ancestors("__slots__")
for slot in ancestor.slots() or []
}
# Slots which are common to `node` and its parent classes
redefined_slots = ancestors_slots_names.intersection(slots_names)
if redefined_slots:
self.add_message(
"redefined-slots-in-subclass",
args=([name for name in slots_names if name in redefined_slots],),
node=slots_node,
)
def _check_slots_elt(self, elt, node):
for inferred in elt.infer():
if inferred is astroid.Uninferable:
continue
if not isinstance(inferred, nodes.Const) or not isinstance(
inferred.value, str
):
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
continue
if not inferred.value:
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
# Check if we have a conflict with a class variable.
class_variable = node.locals.get(inferred.value)
if class_variable:
# Skip annotated assignments which don't conflict at all with slots.
if len(class_variable) == 1:
parent = class_variable[0].parent
if isinstance(parent, nodes.AnnAssign) and parent.value is None:
return
self.add_message(
"class-variable-slots-conflict", args=(inferred.value,), node=elt
)
def leave_functiondef(self, node: nodes.FunctionDef) -> None:
"""On method node, check if this method couldn't be a function.
ignore class, static and abstract methods, initializer,
methods overridden from a parent class.
"""
if node.is_method():
if node.args.args is not None:
self._first_attrs.pop()
if not self.linter.is_message_enabled("no-self-use"):
return
class_node = node.parent.frame(future=_True)
if (
self._meth_could_be_func
and node.type == "method"
and node.name not in PYMETHODS
and not (
node.is_abstract()
or overrides_a_method(class_node, node.name)
or decorated_with_property(node)
or _has_bare_super_call(node)
or is_protocol_class(class_node)
or is_overload_stub(node)
)
):
self.add_message("no-self-use", node=node)
leave_asyncfunctiondef = leave_functiondef
def visit_attribute(self, node: nodes.Attribute) -> None:
"""Check if the getattr is an access to a class member
if so, register it. Also check for access to protected
class member from outside its class (but ignore __special__
methods)
"""
# Check self
if self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
return
if not self.linter.is_message_enabled("protected-access"):
return
self._check_protected_attribute_access(node)
@check_messages("assigning-non-slot", "invalid-class-object")
def visit_assignattr(self, node: nodes.AssignAttr) -> None:
if isinstance(
node.assign_type(), nodes.AugAssign
) and self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
self._check_in_slots(node)
self._check_invalid_class_object(node)
def _check_invalid_class_object(self, node: nodes.AssignAttr) -> None:
if not node.attrname == "__class__":
return
inferred = safe_infer(node.parent.value)
if isinstance(inferred, nodes.ClassDef) or inferred is astroid.Uninferable:
# If is uninferrable, we allow it to prevent false positives
return
self.add_message("invalid-class-object", node=node)
def _check_in_slots(self, node):
"""Check that the given AssignAttr node
is defined in the class slots.
"""
inferred = safe_infer(node.expr)
if not isinstance(inferred, astroid.Instance):
return
klass = inferred._proxied
if not has_known_bases(klass):
return
if "__slots__" not in klass.locals or not klass.newstyle:
return
# If `__setattr__` is defined on the class, then we can't reason about
# what will happen when assigning to an attribute.
if any(
base.locals.get("__setattr__")
for base in klass.mro()
if base.qname() != "builtins.object"
):
return
# If 'typing.Generic' is a base of bases of klass, the cached version
# of 'slots()' might have been evaluated incorrectly, thus deleted cache entry.
if any(base.qname() == "typing.Generic" for base in klass.mro()):
cache = getattr(klass, "__cache", None)
if cache and cache.get(klass.slots) is not None:
del cache[klass.slots]
slots = klass.slots()
if slots is None:
return
# If any ancestor doesn't use slots, the slots
# defined for this class are superfluous.
if any(
"__slots__" not in ancestor.locals and ancestor.name != "object"
for ancestor in klass.ancestors()
):
return
if not any(slot.value == node.attrname for slot in slots):
# If we have a '__dict__' in slots, then
# assigning any name is valid.
if not any(slot.value == "__dict__" for slot in slots):
if _is_attribute_property(node.attrname, klass):
# Properties circumvent the slots mechanism,
# so we should not emit a warning for them.
return
if node.attrname in klass.locals:
for local_name in klass.locals.get(node.attrname):
statement = local_name.statement(future=_True)
if (
isinstance(statement, nodes.AnnAssign)
and not statement.value
):
return
if _has_data_descriptor(klass, node.attrname):
# Descriptors circumvent the slots mechanism as well.
return
if node.attrname == "__class__" and _has_same_layout_slots(
slots, node.parent.value
):
return
self.add_message("assigning-non-slot", args=(node.attrname,), node=node)
@check_messages(
"protected-access", "no-classmethod-decorator", "no-staticmethod-decorator"
)
def visit_assign(self, assign_node: nodes.Assign) -> None:
self._check_classmethod_declaration(assign_node)
node = assign_node.targets[0]
if not isinstance(node, nodes.AssignAttr):
return
if self._uses_mandatory_method_param(node):
return
self._check_protected_attribute_access(node)
def _check_classmethod_declaration(self, node):
"""Checks for uses of classmethod() or staticmethod().
When a @classmethod or @staticmethod decorator should be used instead.
A message will be emitted only if the assignment is at a class scope
and only if the classmethod's argument belongs to the class where it
is defined.
`node` is an assign node.
"""
if not isinstance(node.value, nodes.Call):
return
# check the function called is "classmethod" or "staticmethod"
func = node.value.func
if not isinstance(func, nodes.Name) or func.name not in (
"classmethod",
"staticmethod",
):
return
msg = (
"no-classmethod-decorator"
if func.name == "classmethod"
else "no-staticmethod-decorator"
)
# assignment must be at a class scope
parent_class = node.scope()
if not isinstance(parent_class, nodes.ClassDef):
return
# Check if the arg passed to classmethod is a class member
classmeth_arg = node.value.args[0]
if not isinstance(classmeth_arg, nodes.Name):
return
method_name = classmeth_arg.name
if any(method_name == member.name for member in parent_class.mymethods()):
self.add_message(msg, node=node.targets[0])
def _check_protected_attribute_access(self, node: nodes.Attribute):
"""Given an attribute access node (set or get), check if attribute
access is legitimate. Call _check_first_attr with node before calling
this method. Valid cases are:
* self._attr in a method or cls._attr in a classmethod. Checked by
_check_first_attr.
* Klass._attr inside "Klass" class.
* Klass2._attr inside "Klass" class when Klass2 is a base class of
Klass.
"""
attrname = node.attrname
if (
is_attr_protected(attrname)
and attrname not in self.config.exclude_protected
):
klass = node_frame_class(node)
# In classes, check we are not getting a parent method
# through the class object or through super
callee = node.expr.as_string()
# Typing annotations in function definitions can include protected members
if utils.is_node_in_type_annotation_context(node):
return
# We are not in a class, no remaining valid case
if klass is None:
self.add_message("protected-access", node=node, args=attrname)
return
# If the expression begins with a call to super, that's ok.
if (
isinstance(node.expr, nodes.Call)
and isinstance(node.expr.func, nodes.Name)
and node.expr.func.name == "super"
):
return
# If the expression begins with a call to type(self), that's ok.
if self._is_type_self_call(node.expr):
return
# Check if we are inside the scope of a class or nested inner class
inside_klass = _True
outer_klass = klass
parents_callee = callee.split(".")
parents_callee.reverse()
for callee in parents_callee:
if not outer_klass or callee != outer_klass.name:
inside_klass = _False
break
# Move up one level within the nested classes
outer_klass = get_outer_class(outer_klass)
# We are in a class, one remaining valid cases, Klass._attr inside
# Klass
if not (inside_klass or callee in klass.basenames):
# Detect property assignments in the body of the class.
# This is acceptable:
#
# class A:
# b = property(lambda: self._b)
stmt = node.parent.statement(future=_True)
if (
isinstance(stmt, nodes.Assign)
and len(stmt.targets) == 1
and isinstance(stmt.targets[0], nodes.AssignName)
):
name = stmt.targets[0].name
if _is_attribute_property(name, klass):
return
if (
self._is_classmethod(node.frame(future=_True))
and self._is_inferred_instance(node.expr, klass)
and self._is_class_attribute(attrname, klass)
):
return
licit_protected_member = not attrname.startswith("__")
if (
not self.config.check_protected_access_in_special_methods
and licit_protected_member
and self._is_called_inside_special_method(node)
):
return
self.add_message("protected-access", node=node, args=attrname)
@staticmethod
def _is_called_inside_special_method(node: nodes.NodeNG) -> bool:
"""Returns true if the node is located inside a special (aka dunder) method."""
frame_name = node.frame(future=_True).name
return frame_name and frame_name in PYMETHODS
def _is_type_self_call(self, expr: nodes.NodeNG) -> bool:
return (
isinstance(expr, nodes.Call)
and isinstance(expr.func, nodes.Name)
and expr.func.name == "type"
and len(expr.args) == 1
and self._is_mandatory_method_param(expr.args[0])
)
@staticmethod
def _is_classmethod(func):
"""Check if the given *func* node is a class method."""
return isinstance(func, nodes.FunctionDef) and (
func.type == "classmethod" or func.name == "__class_getitem__"
)
@staticmethod
def _is_inferred_instance(expr, klass):
"""Check if the inferred value of the given *expr* is an instance of *klass*."""
inferred = safe_infer(expr)
if not isinstance(inferred, astroid.Instance):
return _False
return inferred._proxied is klass
@staticmethod
def _is_class_attribute(name, klass):
"""Check if the given attribute *name* is a class or instance member of the given *klass*.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
klass.getattr(name)
return _True
except astroid.NotFoundError:
pass
try:
klass.instance_attr(name)
return _True
except astroid.NotFoundError:
return _False
def visit_name(self, node: nodes.Name) -> None:
"""Check if the name handle an access to a class member
if so, register it
"""
if self._first_attrs and (
node.name == self._first_attrs[-1] or not self._first_attrs[-1]
):
self._meth_could_be_func = _False
def _check_accessed_members(self, node, accessed):
"""Check that accessed members are defined."""
excs = ("AttributeError", "Exception", "BaseException")
for attr, nodes_lst in accessed.items():
try:
# is it a class attribute ?
node.local_attr(attr)
# yes, stop here
continue
except astroid.NotFoundError:
pass
# is it an instance attribute of a parent class ?
try:
next(node.instance_attr_ancestors(attr))
# yes, stop here
continue
except StopIteration:
pass
# is it an instance attribute ?
try:
defstmts = node.instance_attr(attr)
except astroid.NotFoundError:
pass
else:
# filter out augment assignment nodes
defstmts = [stmt for stmt in defstmts if stmt not in nodes_lst]
if not defstmts:
# only augment assignment for this node, no-member should be
# triggered by the typecheck checker
continue
# filter defstmts to only pick the first one when there are
# several assignments in the same scope
scope = defstmts[0].scope()
defstmts = [
stmt
for i, stmt in enumerate(defstmts)
if i == 0 or stmt.scope() is not scope
]
# if there are still more than one, don't attempt to be smarter
# than we can be
if len(defstmts) == 1:
defstmt = defstmts[0]
# check that if the node is accessed in the same method as
# it's defined, it's accessed after the initial assignment
frame = defstmt.frame(future=_True)
lno = defstmt.fromlineno
for _node in nodes_lst:
if (
_node.frame(future=_True) is frame
and _node.fromlineno < lno
and not astroid.are_exclusive(
_node.statement(future=_True), defstmt, excs
)
):
self.add_message(
"access-member-before-definition",
node=_node,
args=(attr, lno),
)
def _check_first_arg_for_type(self, node, metaclass=0):
"""Check the name of first argument, expect:.
* 'self' for a regular method
* 'cls' for a class method or a metaclass regular method (actually
valid-classmethod-first-arg value)
* 'mcs' for a metaclass class method (actually
valid-metaclass-classmethod-first-arg)
* not one of the above for a static method
"""
# don't care about functions with unknown argument (builtins)
if node.args.args is None:
return
if node.args.posonlyargs:
first_arg = node.args.posonlyargs[0].name
elif node.args.args:
first_arg = node.argnames()[0]
else:
first_arg = None
self._first_attrs.append(first_arg)
first = self._first_attrs[-1]
# static method
if node.type == "staticmethod":
if (
first_arg == "self"
or first_arg in self.config.valid_classmethod_first_arg
or first_arg in self.config.valid_metaclass_classmethod_first_arg
):
self.add_message("bad-staticmethod-argument", args=first, node=node)
return
self._first_attrs[-1] = None
# class / regular method with no args
elif not node.args.args and not node.args.posonlyargs:
self.add_message("no-method-argument", node=node)
# metaclass
elif metaclass:
# metaclass __new__ or classmethod
if node.type == "classmethod":
self._check_first_arg_config(
first,
self.config.valid_metaclass_classmethod_first_arg,
node,
"bad-mcs-classmethod-argument",
node.name,
)
# metaclass regular method
else:
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-mcs-method-argument",
node.name,
)
# regular class with class method
elif node.type == "classmethod" or node.name == "__class_getitem__":
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-classmethod-argument",
node.name,
)
# regular class with regular method without self as argument
elif first != "self":
self.add_message("no-self-argument", node=node)
def _check_first_arg_config(self, first, config, node, message, method_name):
if first not in config:
if len(config) == 1:
valid = repr(config[0])
else:
valid = ", ".join(repr(v) for v in config[:-1])
valid = f"{valid} or {config[-1]!r}"
self.add_message(message, args=(method_name, valid), node=node)
def _check_bases_classes(self, node):
"""Check that the given class node implements abstract methods from
base classes
"""
def is_abstract(method):
return method.is_abstract(pass_is_abstract=_False)
# check if this class abstract
if class_is_abstract(node):
return
methods = sorted(
unimplemented_abstract_methods(node, is_abstract).items(),
key=lambda item: item[0],
)
for name, method in methods:
owner = method.parent.frame(future=_True)
if owner is node:
continue
# owner is not this class, it must be a parent class
# check that the ancestor's method is not abstract
if name in node.locals:
# it is redefined as an attribute or with a descriptor
continue
self.add_message("abstract-method", node=node, args=(name, owner.name))
def _check_init(self, node: nodes.FunctionDef, klass_node: nodes.ClassDef) -> None:
"""Check that the __init__ method call super or ancestors'__init__
method (unless it is used for type hinting with `typing.overload`)
"""
if not self.linter.is_message_enabled(
"super-init-not-called"
) and not self.linter.is_message_enabled("non-parent-init-called"):
return
to_call = _ancestors_to_call(klass_node)
not_called_yet = dict(to_call)
parents_with_called_inits: Set[bases.UnboundMethod] = set()
for stmt in node.nodes_of_class(nodes.Call):
expr = stmt.func
if not isinstance(expr, nodes.Attribute) or expr.attrname != "__init__":
continue
# skip the test if using super
if (
isinstance(expr.expr, nodes.Call)
and isinstance(expr.expr.func, nodes.Name)
and expr.expr.func.name == "super"
):
return
try:
for klass in expr.expr.infer():
if klass is astroid.Uninferable:
continue
# The inferred klass can be super(), which was
# assigned to a variable and the `__init__`
# was called later.
#
# base = super()
# base.__init__(...)
if (
isinstance(klass, astroid.Instance)
and isinstance(klass._proxied, nodes.ClassDef)
and is_builtin_object(klass._proxied)
and klass._proxied.name == "super"
):
return
if isinstance(klass, astroid.objects.Super):
return
try:
method = not_called_yet.pop(klass)
# Record that the class' init has been called
parents_with_called_inits.add(node_frame_class(method))
except KeyError:
if klass not in to_call:
self.add_message(
"non-parent-init-called", node=expr, args=klass.name
)
except astroid.InferenceError:
continue
for klass, method in not_called_yet.items():
# Check if the init of the class that defines this init has already
# been called.
if node_frame_class(method) in parents_with_called_inits:
return
# Return if klass is protocol
if klass.qname() in utils.TYPING_PROTOCOLS:
return
# Return if any of the klass' first-order bases is protocol
for base in klass.bases:
# We don't need to catch InferenceError here as _ancestors_to_call
# already does this for us.
for inf_base in base.infer():
if inf_base.qname() in utils.TYPING_PROTOCOLS:
return
if decorated_with(node, ["typing.overload"]):
continue
cls = node_frame_class(method)
if klass.name == "object" or (cls and cls.name == "object"):
continue
self.add_message(
"super-init-not-called",
args=klass.name,
node=node,
confidence=INFERENCE,
)
def _check_signature(self, method1, refmethod, class_type, cls):
"""Check that the signature of the two given methods match."""
if not (
isinstance(method1, nodes.FunctionDef)
and isinstance(refmethod, nodes.FunctionDef)
):
self.add_message(
"method-check-failed", args=(method1, refmethod), node=method1
)
return
instance = cls.instantiate_class()
method1 = astroid.scoped_nodes.function_to_method(method1, instance)
refmethod = astroid.scoped_nodes.function_to_method(refmethod, instance)
# Don't care about functions with unknown argument (builtins).
if method1.args.args is None or refmethod.args.args is None:
return
# Ignore private to class methods.
if is_attr_private(method1.name):
return
# Ignore setters, they have an implicit extra argument,
# which shouldn't be taken in consideration.
if is_property_setter(method1):
return
arg_differ_output = _different_parameters(
refmethod, method1, dummy_parameter_regex=self._dummy_rgx
)
if len(arg_differ_output) > 0:
for msg in arg_differ_output:
if "Number" in msg:
total_args_method1 = len(method1.args.args)
if method1.args.vararg:
total_args_method1 += 1
if method1.args.kwarg:
total_args_method1 += 1
if method1.args.kwonlyargs:
total_args_method1 += len(method1.args.kwonlyargs)
total_args_refmethod = len(refmethod.args.args)
if refmethod.args.vararg:
total_args_refmethod += 1
if refmethod.args.kwarg:
total_args_refmethod += 1
if refmethod.args.kwonlyargs:
total_args_refmethod += len(refmethod.args.kwonlyargs)
error_type = "arguments-differ"
msg_args = (
msg
+ f"was {total_args_refmethod} in '{refmethod.parent.frame().name}.{refmethod.name}' and "
f"is now {total_args_method1} in",
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
elif "renamed" in msg:
error_type = "arguments-renamed"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
else:
error_type = "arguments-differ"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
self.add_message(error_type, args=msg_args, node=method1)
elif (
len(method1.args.defaults) < len(refmethod.args.defaults)
and not method1.args.vararg
):
self.add_message(
"signature-differs", args=(class_type, method1.name), node=method1
)
def _uses_mandatory_method_param(self, node):
"""Check that attribute lookup name use first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
return self._is_mandatory_method_param(node.expr)
def _is_mandatory_method_param(self, node: nodes.NodeNG) -> bool:
"""Check if nodes.Name corresponds to first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
if self._first_attrs:
first_attr = self._first_attrs[-1]
else:
# It's possible the function was already unregistered.
closest_func = utils.get_node_first_ancestor_of_type(
node, nodes.FunctionDef
)
if closest_func is None:
return _False
if not closest_func.args.args:
return _False
first_attr = closest_func.args.args[0].name
return isinstance(node, nodes.Name) and node.name == first_attr
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 881 | nodes_of_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 882 | is_attr_private | ref | function | if not is_attr_private(function_def.name):
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 884 | scope | ref | function | parent_scope = function_def.parent.scope()
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 888 | nodes_of_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 891 | nodes_of_class | ref | class | |
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 894 | scope | ref | function | or attribute.scope() == function_def # We ignore recursive calls
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 908 | safe_infer | ref | function | inferred = safe_infer(attribute.expr)
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 920 | scope | ref | function | curr = curr.parent.scope()
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 923 | as_string | ref | function | function_repr = f"{outer_level_names}.{function_def.name}({function_def.args.as_string()})"
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 924 | add_message | ref | function | self.add_message(
|
playground/e9b22a58-260b-483f-88d7-7a5fe9f8b1d4/pylint/pylint/checkers/classes/class_checker.py | pylint/checkers/classes/class_checker.py | 930 | _check_unused_private_variables | def | function | def _check_unused_private_variables(self, node: nodes.ClassDef) -> None:
"""Check if private variables are never used within a class."""
for assign_name in node.nodes_of_class(nodes.AssignName):
if isinstance(assign_name.parent, nodes.Arguments):
continue # Ignore function arguments
if not is_attr_private(assign_name.name):
continue
for child in node.nodes_of_class((nodes.Name, nodes.Attribute)):
if isinstance(child, nodes.Name) and child.name == assign_name.name:
break
if isinstance(child, nodes.Attribute):
if not isinstance(child.expr, nodes.Name):
break
if child.attrname == assign_name.name and child.expr.name in (
"self",
"cls",
node.name,
):
break
else:
args = (node.name, assign_name.name)
self.add_message("unused-private-member", node=assign_name, args=args)
def _check_unused_private_attributes(self, node: nodes.ClassDef) -> None:
for assign_attr in node.nodes_of_class(nodes.AssignAttr):
if not is_attr_private(assign_attr.attrname) or not isinstance(
assign_attr.expr, nodes.Name
):
continue
# Logic for checking false positive when using __new__,
# Get the returned object names of the __new__ magic function
# Then check if the attribute was consumed in other instance methods
acceptable_obj_names: List[str] = ["self"]
scope = assign_attr.scope()
if isinstance(scope, nodes.FunctionDef) and scope.name == "__new__":
acceptable_obj_names.extend(
[
return_node.value.name
for return_node in scope.nodes_of_class(nodes.Return)
if isinstance(return_node.value, nodes.Name)
]
)
for attribute in node.nodes_of_class(nodes.Attribute):
if attribute.attrname != assign_attr.attrname:
continue
if self._is_type_self_call(attribute.expr):
continue
if assign_attr.expr.name in {
"cls",
node.name,
} and attribute.expr.name in {"cls", "self", node.name}:
# If assigned to cls or class name, can be accessed by cls/self/class name
break
if (
assign_attr.expr.name in acceptable_obj_names
and attribute.expr.name == "self"
):
# If assigned to self.attrib, can only be accessed by self
# Or if __new__ was used, the returned object names are acceptable
break
if assign_attr.expr.name == attribute.expr.name == node.name:
# Recognise attributes which are accessed via the class name
break
else:
args = (node.name, assign_attr.attrname)
self.add_message("unused-private-member", node=assign_attr, args=args)
def _check_attribute_defined_outside_init(self, cnode: nodes.ClassDef) -> None:
# check access to existent members on non metaclass classes
if self._ignore_mixin and self._mixin_class_rgx.match(cnode.name):
# We are in a mixin class. No need to try to figure out if
# something is missing, since it is most likely that it will
# miss.
return
accessed = self._accessed.accessed(cnode)
if cnode.type != "metaclass":
self._check_accessed_members(cnode, accessed)
# checks attributes are defined in an allowed method such as __init__
if not self.linter.is_message_enabled("attribute-defined-outside-init"):
return
defining_methods = self.config.defining_attr_methods
current_module = cnode.root()
for attr, nodes_lst in cnode.instance_attrs.items():
# Exclude `__dict__` as it is already defined.
if attr == "__dict__":
continue
# Skip nodes which are not in the current module and it may screw up
# the output, while it's not worth it
nodes_lst = [
n
for n in nodes_lst
if not isinstance(
n.statement(future=_True), (nodes.Delete, nodes.AugAssign)
)
and n.root() is current_module
]
if not nodes_lst:
continue # error detected by typechecking
# Check if any method attr is defined in is a defining method
# or if we have the attribute defined in a setter.
frames = (node.frame(future=_True) for node in nodes_lst)
if any(
frame.name in defining_methods or is_property_setter(frame)
for frame in frames
):
continue
# check attribute is defined in a parent's __init__
for parent in cnode.instance_attr_ancestors(attr):
attr_defined = _False
# check if any parent method attr is defined in is a defining method
for node in parent.instance_attrs[attr]:
if node.frame(future=_True).name in defining_methods:
attr_defined = _True
if attr_defined:
# we're done :)
break
else:
# check attribute is defined as a class attribute
try:
cnode.local_attr(attr)
except astroid.NotFoundError:
for node in nodes_lst:
if node.frame(future=_True).name not in defining_methods:
# If the attribute was set by a call in any
# of the defining methods, then don't emit
# the warning.
if _called_in_methods(
node.frame(future=_True), cnode, defining_methods
):
continue
self.add_message(
"attribute-defined-outside-init", args=attr, node=node
)
def visit_functiondef(self, node: nodes.FunctionDef) -> None:
"""Check method arguments, overriding."""
# ignore actual functions
if not node.is_method():
return
self._check_useless_super_delegation(node)
self._check_property_with_parameters(node)
# 'is_method()' is called and makes sure that this is a 'nodes.ClassDef'
klass = node.parent.frame(future=_True) # type: nodes.ClassDef
self._meth_could_be_func = _True
# check first argument is self if this is actually a method
self._check_first_arg_for_type(node, klass.type == "metaclass")
if node.name == "__init__":
self._check_init(node, klass)
return
# check signature if the method overloads inherited method
for overridden in klass.local_attr_ancestors(node.name):
# get astroid for the searched method
try:
parent_function = overridden[node.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if not isinstance(parent_function, nodes.FunctionDef):
continue
self._check_signature(node, parent_function, "overridden", klass)
self._check_invalid_overridden_method(node, parent_function)
break
if node.decorators:
for decorator in node.decorators.nodes:
if isinstance(decorator, nodes.Attribute) and decorator.attrname in {
"getter",
"setter",
"deleter",
}:
# attribute affectation will call this method, not hiding it
return
if isinstance(decorator, nodes.Name):
if decorator.name == "property":
# attribute affectation will either call a setter or raise
# an attribute error, anyway not hiding the function
return
# Infer the decorator and see if it returns something useful
inferred = safe_infer(decorator)
if not inferred:
return
if isinstance(inferred, nodes.FunctionDef):
# Okay, it's a decorator, let's see what it can infer.
try:
inferred = next(inferred.infer_call_result(inferred))
except astroid.InferenceError:
return
try:
if (
isinstance(inferred, (astroid.Instance, nodes.ClassDef))
and inferred.getattr("__get__")
and inferred.getattr("__set__")
):
return
except astroid.AttributeInferenceError:
pass
# check if the method is hidden by an attribute
try:
overridden = klass.instance_attr(node.name)[0]
overridden_frame = overridden.frame(future=_True)
if (
isinstance(overridden_frame, nodes.FunctionDef)
and overridden_frame.type == "method"
):
overridden_frame = overridden_frame.parent.frame(future=_True)
if not (
isinstance(overridden_frame, nodes.ClassDef)
and klass.is_subtype_of(overridden_frame.qname())
):
return
# If a subclass defined the method then it's not our fault.
for ancestor in klass.ancestors():
if node.name in ancestor.instance_attrs and is_attr_private(node.name):
return
for obj in ancestor.lookup(node.name)[1]:
if isinstance(obj, nodes.FunctionDef):
return
args = (overridden.root().name, overridden.fromlineno)
self.add_message("method-hidden", args=args, node=node)
except astroid.NotFoundError:
pass
visit_asyncfunctiondef = visit_functiondef
def _check_useless_super_delegation(self, function):
"""Check if the given function node is an useless method override.
We consider it *useless* if it uses the super() builtin, but having
nothing additional whatsoever than not implementing the method at all.
If the method uses super() to delegate an operation to the rest of the MRO,
and if the method called is the same as the current one, the arguments
passed to super() are the same as the parameters that were passed to
this method, then the method could be removed altogether, by letting
other implementation to take precedence.
"""
if (
not function.is_method()
# With decorators is a change of use
or function.decorators
):
return
body = function.body
if len(body) != 1:
# Multiple statements, which means this overridden method
# could do multiple things we are not aware of.
return
statement = body[0]
if not isinstance(statement, (nodes.Expr, nodes.Return)):
# Doing something else than what we are interested into.
return
call = statement.value
if (
not isinstance(call, nodes.Call)
# Not a super() attribute access.
or not isinstance(call.func, nodes.Attribute)
):
return
# Should be a super call.
try:
super_call = next(call.func.expr.infer())
except astroid.InferenceError:
return
else:
if not isinstance(super_call, astroid.objects.Super):
return
# The name should be the same.
if call.func.attrname != function.name:
return
# Should be a super call with the MRO pointer being the
# current class and the type being the current instance.
current_scope = function.parent.scope()
if (
super_call.mro_pointer != current_scope
or not isinstance(super_call.type, astroid.Instance)
or super_call.type.name != current_scope.name
):
return
# Check values of default args
klass = function.parent.frame(future=_True)
meth_node = None
for overridden in klass.local_attr_ancestors(function.name):
# get astroid for the searched method
try:
meth_node = overridden[function.name]
except KeyError:
# we have found the method but it's not in the local
# dictionary.
# This may happen with astroid build from living objects
continue
if (
not isinstance(meth_node, nodes.FunctionDef)
# If the method have an ancestor which is not a
# function then it is legitimate to redefine it
or _has_different_parameters_default_value(
meth_node.args, function.args
)
):
return
break
# Detect if the parameters are the same as the call's arguments.
params = _signature_from_arguments(function.args)
args = _signature_from_call(call)
if meth_node is not None:
def form_annotations(arguments):
annotations = chain(
(arguments.posonlyargs_annotations or []), arguments.annotations
)
return [ann.as_string() for ann in annotations if ann is not None]
called_annotations = form_annotations(function.args)
overridden_annotations = form_annotations(meth_node.args)
if called_annotations and overridden_annotations:
if called_annotations != overridden_annotations:
return
if _definition_equivalent_to_call(params, args):
self.add_message(
"useless-super-delegation", node=function, args=(function.name,)
)
def _check_property_with_parameters(self, node):
if (
node.args.args
and len(node.args.args) > 1
and decorated_with_property(node)
and not is_property_setter(node)
):
self.add_message("property-with-parameters", node=node)
def _check_invalid_overridden_method(self, function_node, parent_function_node):
parent_is_property = decorated_with_property(
parent_function_node
) or is_property_setter_or_deleter(parent_function_node)
current_is_property = decorated_with_property(
function_node
) or is_property_setter_or_deleter(function_node)
if parent_is_property and not current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "property", function_node.type),
node=function_node,
)
elif not parent_is_property and current_is_property:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "method", "property"),
node=function_node,
)
parent_is_async = isinstance(parent_function_node, nodes.AsyncFunctionDef)
current_is_async = isinstance(function_node, nodes.AsyncFunctionDef)
if parent_is_async and not current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "async", "non-async"),
node=function_node,
)
elif not parent_is_async and current_is_async:
self.add_message(
"invalid-overridden-method",
args=(function_node.name, "non-async", "async"),
node=function_node,
)
if (
decorated_with(parent_function_node, ["typing.final"])
or uninferable_final_decorators(parent_function_node.decorators)
) and self._py38_plus:
self.add_message(
"overridden-final-method",
args=(function_node.name, parent_function_node.parent.frame().name),
node=function_node,
)
def _check_slots(self, node: nodes.ClassDef) -> None:
if "__slots__" not in node.locals:
return
for slots in node.igetattr("__slots__"):
# check if __slots__ is a valid type
if slots is astroid.Uninferable:
continue
if not is_iterable(slots) and not is_comprehension(slots):
self.add_message("invalid-slots", node=node)
continue
if isinstance(slots, nodes.Const):
# a string, ignore the following checks
self.add_message("single-string-used-for-slots", node=node)
continue
if not hasattr(slots, "itered"):
# we can't obtain the values, maybe a .deque?
continue
if isinstance(slots, nodes.Dict):
values = [item[0] for item in slots.items]
else:
values = slots.itered()
if values is astroid.Uninferable:
return
for elt in values:
try:
self._check_slots_elt(elt, node)
except astroid.InferenceError:
continue
self._check_redefined_slots(node, slots, values)
def _check_redefined_slots(
self,
node: nodes.ClassDef,
slots_node: nodes.NodeNG,
slots_list: List[nodes.NodeNG],
) -> None:
"""Check if `node` redefines a slot which is defined in an ancestor class."""
slots_names: List[str] = []
for slot in slots_list:
if isinstance(slot, nodes.Const):
slots_names.append(slot.value)
else:
inferred_slot = safe_infer(slot)
if inferred_slot:
slots_names.append(inferred_slot.value)
# Slots of all parent classes
ancestors_slots_names = {
slot.value
for ancestor in node.local_attr_ancestors("__slots__")
for slot in ancestor.slots() or []
}
# Slots which are common to `node` and its parent classes
redefined_slots = ancestors_slots_names.intersection(slots_names)
if redefined_slots:
self.add_message(
"redefined-slots-in-subclass",
args=([name for name in slots_names if name in redefined_slots],),
node=slots_node,
)
def _check_slots_elt(self, elt, node):
for inferred in elt.infer():
if inferred is astroid.Uninferable:
continue
if not isinstance(inferred, nodes.Const) or not isinstance(
inferred.value, str
):
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
continue
if not inferred.value:
self.add_message(
"invalid-slots-object", args=inferred.as_string(), node=elt
)
# Check if we have a conflict with a class variable.
class_variable = node.locals.get(inferred.value)
if class_variable:
# Skip annotated assignments which don't conflict at all with slots.
if len(class_variable) == 1:
parent = class_variable[0].parent
if isinstance(parent, nodes.AnnAssign) and parent.value is None:
return
self.add_message(
"class-variable-slots-conflict", args=(inferred.value,), node=elt
)
def leave_functiondef(self, node: nodes.FunctionDef) -> None:
"""On method node, check if this method couldn't be a function.
ignore class, static and abstract methods, initializer,
methods overridden from a parent class.
"""
if node.is_method():
if node.args.args is not None:
self._first_attrs.pop()
if not self.linter.is_message_enabled("no-self-use"):
return
class_node = node.parent.frame(future=_True)
if (
self._meth_could_be_func
and node.type == "method"
and node.name not in PYMETHODS
and not (
node.is_abstract()
or overrides_a_method(class_node, node.name)
or decorated_with_property(node)
or _has_bare_super_call(node)
or is_protocol_class(class_node)
or is_overload_stub(node)
)
):
self.add_message("no-self-use", node=node)
leave_asyncfunctiondef = leave_functiondef
def visit_attribute(self, node: nodes.Attribute) -> None:
"""Check if the getattr is an access to a class member
if so, register it. Also check for access to protected
class member from outside its class (but ignore __special__
methods)
"""
# Check self
if self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
return
if not self.linter.is_message_enabled("protected-access"):
return
self._check_protected_attribute_access(node)
@check_messages("assigning-non-slot", "invalid-class-object")
def visit_assignattr(self, node: nodes.AssignAttr) -> None:
if isinstance(
node.assign_type(), nodes.AugAssign
) and self._uses_mandatory_method_param(node):
self._accessed.set_accessed(node)
self._check_in_slots(node)
self._check_invalid_class_object(node)
def _check_invalid_class_object(self, node: nodes.AssignAttr) -> None:
if not node.attrname == "__class__":
return
inferred = safe_infer(node.parent.value)
if isinstance(inferred, nodes.ClassDef) or inferred is astroid.Uninferable:
# If is uninferrable, we allow it to prevent false positives
return
self.add_message("invalid-class-object", node=node)
def _check_in_slots(self, node):
"""Check that the given AssignAttr node
is defined in the class slots.
"""
inferred = safe_infer(node.expr)
if not isinstance(inferred, astroid.Instance):
return
klass = inferred._proxied
if not has_known_bases(klass):
return
if "__slots__" not in klass.locals or not klass.newstyle:
return
# If `__setattr__` is defined on the class, then we can't reason about
# what will happen when assigning to an attribute.
if any(
base.locals.get("__setattr__")
for base in klass.mro()
if base.qname() != "builtins.object"
):
return
# If 'typing.Generic' is a base of bases of klass, the cached version
# of 'slots()' might have been evaluated incorrectly, thus deleted cache entry.
if any(base.qname() == "typing.Generic" for base in klass.mro()):
cache = getattr(klass, "__cache", None)
if cache and cache.get(klass.slots) is not None:
del cache[klass.slots]
slots = klass.slots()
if slots is None:
return
# If any ancestor doesn't use slots, the slots
# defined for this class are superfluous.
if any(
"__slots__" not in ancestor.locals and ancestor.name != "object"
for ancestor in klass.ancestors()
):
return
if not any(slot.value == node.attrname for slot in slots):
# If we have a '__dict__' in slots, then
# assigning any name is valid.
if not any(slot.value == "__dict__" for slot in slots):
if _is_attribute_property(node.attrname, klass):
# Properties circumvent the slots mechanism,
# so we should not emit a warning for them.
return
if node.attrname in klass.locals:
for local_name in klass.locals.get(node.attrname):
statement = local_name.statement(future=_True)
if (
isinstance(statement, nodes.AnnAssign)
and not statement.value
):
return
if _has_data_descriptor(klass, node.attrname):
# Descriptors circumvent the slots mechanism as well.
return
if node.attrname == "__class__" and _has_same_layout_slots(
slots, node.parent.value
):
return
self.add_message("assigning-non-slot", args=(node.attrname,), node=node)
@check_messages(
"protected-access", "no-classmethod-decorator", "no-staticmethod-decorator"
)
def visit_assign(self, assign_node: nodes.Assign) -> None:
self._check_classmethod_declaration(assign_node)
node = assign_node.targets[0]
if not isinstance(node, nodes.AssignAttr):
return
if self._uses_mandatory_method_param(node):
return
self._check_protected_attribute_access(node)
def _check_classmethod_declaration(self, node):
"""Checks for uses of classmethod() or staticmethod().
When a @classmethod or @staticmethod decorator should be used instead.
A message will be emitted only if the assignment is at a class scope
and only if the classmethod's argument belongs to the class where it
is defined.
`node` is an assign node.
"""
if not isinstance(node.value, nodes.Call):
return
# check the function called is "classmethod" or "staticmethod"
func = node.value.func
if not isinstance(func, nodes.Name) or func.name not in (
"classmethod",
"staticmethod",
):
return
msg = (
"no-classmethod-decorator"
if func.name == "classmethod"
else "no-staticmethod-decorator"
)
# assignment must be at a class scope
parent_class = node.scope()
if not isinstance(parent_class, nodes.ClassDef):
return
# Check if the arg passed to classmethod is a class member
classmeth_arg = node.value.args[0]
if not isinstance(classmeth_arg, nodes.Name):
return
method_name = classmeth_arg.name
if any(method_name == member.name for member in parent_class.mymethods()):
self.add_message(msg, node=node.targets[0])
def _check_protected_attribute_access(self, node: nodes.Attribute):
"""Given an attribute access node (set or get), check if attribute
access is legitimate. Call _check_first_attr with node before calling
this method. Valid cases are:
* self._attr in a method or cls._attr in a classmethod. Checked by
_check_first_attr.
* Klass._attr inside "Klass" class.
* Klass2._attr inside "Klass" class when Klass2 is a base class of
Klass.
"""
attrname = node.attrname
if (
is_attr_protected(attrname)
and attrname not in self.config.exclude_protected
):
klass = node_frame_class(node)
# In classes, check we are not getting a parent method
# through the class object or through super
callee = node.expr.as_string()
# Typing annotations in function definitions can include protected members
if utils.is_node_in_type_annotation_context(node):
return
# We are not in a class, no remaining valid case
if klass is None:
self.add_message("protected-access", node=node, args=attrname)
return
# If the expression begins with a call to super, that's ok.
if (
isinstance(node.expr, nodes.Call)
and isinstance(node.expr.func, nodes.Name)
and node.expr.func.name == "super"
):
return
# If the expression begins with a call to type(self), that's ok.
if self._is_type_self_call(node.expr):
return
# Check if we are inside the scope of a class or nested inner class
inside_klass = _True
outer_klass = klass
parents_callee = callee.split(".")
parents_callee.reverse()
for callee in parents_callee:
if not outer_klass or callee != outer_klass.name:
inside_klass = _False
break
# Move up one level within the nested classes
outer_klass = get_outer_class(outer_klass)
# We are in a class, one remaining valid cases, Klass._attr inside
# Klass
if not (inside_klass or callee in klass.basenames):
# Detect property assignments in the body of the class.
# This is acceptable:
#
# class A:
# b = property(lambda: self._b)
stmt = node.parent.statement(future=_True)
if (
isinstance(stmt, nodes.Assign)
and len(stmt.targets) == 1
and isinstance(stmt.targets[0], nodes.AssignName)
):
name = stmt.targets[0].name
if _is_attribute_property(name, klass):
return
if (
self._is_classmethod(node.frame(future=_True))
and self._is_inferred_instance(node.expr, klass)
and self._is_class_attribute(attrname, klass)
):
return
licit_protected_member = not attrname.startswith("__")
if (
not self.config.check_protected_access_in_special_methods
and licit_protected_member
and self._is_called_inside_special_method(node)
):
return
self.add_message("protected-access", node=node, args=attrname)
@staticmethod
def _is_called_inside_special_method(node: nodes.NodeNG) -> bool:
"""Returns true if the node is located inside a special (aka dunder) method."""
frame_name = node.frame(future=_True).name
return frame_name and frame_name in PYMETHODS
def _is_type_self_call(self, expr: nodes.NodeNG) -> bool:
return (
isinstance(expr, nodes.Call)
and isinstance(expr.func, nodes.Name)
and expr.func.name == "type"
and len(expr.args) == 1
and self._is_mandatory_method_param(expr.args[0])
)
@staticmethod
def _is_classmethod(func):
"""Check if the given *func* node is a class method."""
return isinstance(func, nodes.FunctionDef) and (
func.type == "classmethod" or func.name == "__class_getitem__"
)
@staticmethod
def _is_inferred_instance(expr, klass):
"""Check if the inferred value of the given *expr* is an instance of *klass*."""
inferred = safe_infer(expr)
if not isinstance(inferred, astroid.Instance):
return _False
return inferred._proxied is klass
@staticmethod
def _is_class_attribute(name, klass):
"""Check if the given attribute *name* is a class or instance member of the given *klass*.
Returns ``_True`` if the name is a property in the given klass,
``_False`` otherwise.
"""
try:
klass.getattr(name)
return _True
except astroid.NotFoundError:
pass
try:
klass.instance_attr(name)
return _True
except astroid.NotFoundError:
return _False
def visit_name(self, node: nodes.Name) -> None:
"""Check if the name handle an access to a class member
if so, register it
"""
if self._first_attrs and (
node.name == self._first_attrs[-1] or not self._first_attrs[-1]
):
self._meth_could_be_func = _False
def _check_accessed_members(self, node, accessed):
"""Check that accessed members are defined."""
excs = ("AttributeError", "Exception", "BaseException")
for attr, nodes_lst in accessed.items():
try:
# is it a class attribute ?
node.local_attr(attr)
# yes, stop here
continue
except astroid.NotFoundError:
pass
# is it an instance attribute of a parent class ?
try:
next(node.instance_attr_ancestors(attr))
# yes, stop here
continue
except StopIteration:
pass
# is it an instance attribute ?
try:
defstmts = node.instance_attr(attr)
except astroid.NotFoundError:
pass
else:
# filter out augment assignment nodes
defstmts = [stmt for stmt in defstmts if stmt not in nodes_lst]
if not defstmts:
# only augment assignment for this node, no-member should be
# triggered by the typecheck checker
continue
# filter defstmts to only pick the first one when there are
# several assignments in the same scope
scope = defstmts[0].scope()
defstmts = [
stmt
for i, stmt in enumerate(defstmts)
if i == 0 or stmt.scope() is not scope
]
# if there are still more than one, don't attempt to be smarter
# than we can be
if len(defstmts) == 1:
defstmt = defstmts[0]
# check that if the node is accessed in the same method as
# it's defined, it's accessed after the initial assignment
frame = defstmt.frame(future=_True)
lno = defstmt.fromlineno
for _node in nodes_lst:
if (
_node.frame(future=_True) is frame
and _node.fromlineno < lno
and not astroid.are_exclusive(
_node.statement(future=_True), defstmt, excs
)
):
self.add_message(
"access-member-before-definition",
node=_node,
args=(attr, lno),
)
def _check_first_arg_for_type(self, node, metaclass=0):
"""Check the name of first argument, expect:.
* 'self' for a regular method
* 'cls' for a class method or a metaclass regular method (actually
valid-classmethod-first-arg value)
* 'mcs' for a metaclass class method (actually
valid-metaclass-classmethod-first-arg)
* not one of the above for a static method
"""
# don't care about functions with unknown argument (builtins)
if node.args.args is None:
return
if node.args.posonlyargs:
first_arg = node.args.posonlyargs[0].name
elif node.args.args:
first_arg = node.argnames()[0]
else:
first_arg = None
self._first_attrs.append(first_arg)
first = self._first_attrs[-1]
# static method
if node.type == "staticmethod":
if (
first_arg == "self"
or first_arg in self.config.valid_classmethod_first_arg
or first_arg in self.config.valid_metaclass_classmethod_first_arg
):
self.add_message("bad-staticmethod-argument", args=first, node=node)
return
self._first_attrs[-1] = None
# class / regular method with no args
elif not node.args.args and not node.args.posonlyargs:
self.add_message("no-method-argument", node=node)
# metaclass
elif metaclass:
# metaclass __new__ or classmethod
if node.type == "classmethod":
self._check_first_arg_config(
first,
self.config.valid_metaclass_classmethod_first_arg,
node,
"bad-mcs-classmethod-argument",
node.name,
)
# metaclass regular method
else:
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-mcs-method-argument",
node.name,
)
# regular class with class method
elif node.type == "classmethod" or node.name == "__class_getitem__":
self._check_first_arg_config(
first,
self.config.valid_classmethod_first_arg,
node,
"bad-classmethod-argument",
node.name,
)
# regular class with regular method without self as argument
elif first != "self":
self.add_message("no-self-argument", node=node)
def _check_first_arg_config(self, first, config, node, message, method_name):
if first not in config:
if len(config) == 1:
valid = repr(config[0])
else:
valid = ", ".join(repr(v) for v in config[:-1])
valid = f"{valid} or {config[-1]!r}"
self.add_message(message, args=(method_name, valid), node=node)
def _check_bases_classes(self, node):
"""Check that the given class node implements abstract methods from
base classes
"""
def is_abstract(method):
return method.is_abstract(pass_is_abstract=_False)
# check if this class abstract
if class_is_abstract(node):
return
methods = sorted(
unimplemented_abstract_methods(node, is_abstract).items(),
key=lambda item: item[0],
)
for name, method in methods:
owner = method.parent.frame(future=_True)
if owner is node:
continue
# owner is not this class, it must be a parent class
# check that the ancestor's method is not abstract
if name in node.locals:
# it is redefined as an attribute or with a descriptor
continue
self.add_message("abstract-method", node=node, args=(name, owner.name))
def _check_init(self, node: nodes.FunctionDef, klass_node: nodes.ClassDef) -> None:
"""Check that the __init__ method call super or ancestors'__init__
method (unless it is used for type hinting with `typing.overload`)
"""
if not self.linter.is_message_enabled(
"super-init-not-called"
) and not self.linter.is_message_enabled("non-parent-init-called"):
return
to_call = _ancestors_to_call(klass_node)
not_called_yet = dict(to_call)
parents_with_called_inits: Set[bases.UnboundMethod] = set()
for stmt in node.nodes_of_class(nodes.Call):
expr = stmt.func
if not isinstance(expr, nodes.Attribute) or expr.attrname != "__init__":
continue
# skip the test if using super
if (
isinstance(expr.expr, nodes.Call)
and isinstance(expr.expr.func, nodes.Name)
and expr.expr.func.name == "super"
):
return
try:
for klass in expr.expr.infer():
if klass is astroid.Uninferable:
continue
# The inferred klass can be super(), which was
# assigned to a variable and the `__init__`
# was called later.
#
# base = super()
# base.__init__(...)
if (
isinstance(klass, astroid.Instance)
and isinstance(klass._proxied, nodes.ClassDef)
and is_builtin_object(klass._proxied)
and klass._proxied.name == "super"
):
return
if isinstance(klass, astroid.objects.Super):
return
try:
method = not_called_yet.pop(klass)
# Record that the class' init has been called
parents_with_called_inits.add(node_frame_class(method))
except KeyError:
if klass not in to_call:
self.add_message(
"non-parent-init-called", node=expr, args=klass.name
)
except astroid.InferenceError:
continue
for klass, method in not_called_yet.items():
# Check if the init of the class that defines this init has already
# been called.
if node_frame_class(method) in parents_with_called_inits:
return
# Return if klass is protocol
if klass.qname() in utils.TYPING_PROTOCOLS:
return
# Return if any of the klass' first-order bases is protocol
for base in klass.bases:
# We don't need to catch InferenceError here as _ancestors_to_call
# already does this for us.
for inf_base in base.infer():
if inf_base.qname() in utils.TYPING_PROTOCOLS:
return
if decorated_with(node, ["typing.overload"]):
continue
cls = node_frame_class(method)
if klass.name == "object" or (cls and cls.name == "object"):
continue
self.add_message(
"super-init-not-called",
args=klass.name,
node=node,
confidence=INFERENCE,
)
def _check_signature(self, method1, refmethod, class_type, cls):
"""Check that the signature of the two given methods match."""
if not (
isinstance(method1, nodes.FunctionDef)
and isinstance(refmethod, nodes.FunctionDef)
):
self.add_message(
"method-check-failed", args=(method1, refmethod), node=method1
)
return
instance = cls.instantiate_class()
method1 = astroid.scoped_nodes.function_to_method(method1, instance)
refmethod = astroid.scoped_nodes.function_to_method(refmethod, instance)
# Don't care about functions with unknown argument (builtins).
if method1.args.args is None or refmethod.args.args is None:
return
# Ignore private to class methods.
if is_attr_private(method1.name):
return
# Ignore setters, they have an implicit extra argument,
# which shouldn't be taken in consideration.
if is_property_setter(method1):
return
arg_differ_output = _different_parameters(
refmethod, method1, dummy_parameter_regex=self._dummy_rgx
)
if len(arg_differ_output) > 0:
for msg in arg_differ_output:
if "Number" in msg:
total_args_method1 = len(method1.args.args)
if method1.args.vararg:
total_args_method1 += 1
if method1.args.kwarg:
total_args_method1 += 1
if method1.args.kwonlyargs:
total_args_method1 += len(method1.args.kwonlyargs)
total_args_refmethod = len(refmethod.args.args)
if refmethod.args.vararg:
total_args_refmethod += 1
if refmethod.args.kwarg:
total_args_refmethod += 1
if refmethod.args.kwonlyargs:
total_args_refmethod += len(refmethod.args.kwonlyargs)
error_type = "arguments-differ"
msg_args = (
msg
+ f"was {total_args_refmethod} in '{refmethod.parent.frame().name}.{refmethod.name}' and "
f"is now {total_args_method1} in",
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
elif "renamed" in msg:
error_type = "arguments-renamed"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
else:
error_type = "arguments-differ"
msg_args = (
msg,
class_type,
f"{method1.parent.frame().name}.{method1.name}",
)
self.add_message(error_type, args=msg_args, node=method1)
elif (
len(method1.args.defaults) < len(refmethod.args.defaults)
and not method1.args.vararg
):
self.add_message(
"signature-differs", args=(class_type, method1.name), node=method1
)
def _uses_mandatory_method_param(self, node):
"""Check that attribute lookup name use first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
return self._is_mandatory_method_param(node.expr)
def _is_mandatory_method_param(self, node: nodes.NodeNG) -> bool:
"""Check if nodes.Name corresponds to first attribute variable name.
Name is `self` for method, `cls` for classmethod and `mcs` for metaclass.
"""
if self._first_attrs:
first_attr = self._first_attrs[-1]
else:
# It's possible the function was already unregistered.
closest_func = utils.get_node_first_ancestor_of_type(
node, nodes.FunctionDef
)
if closest_func is None:
return _False
if not closest_func.args.args:
return _False
first_attr = closest_func.args.args[0].name
return isinstance(node, nodes.Name) and node.name == first_attr
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