def igetattr(self, name, context=None):
"""Retrieve the inferred values of the given attribute name."""
if name in self.special_attributes:
yield self.special_attributes.lookup(name)
return
try:
mro = self.super_mro()
# Don't let invalid MROs or invalid super calls
# leak out as is from this function.
except exceptions.SuperError as exc:
util.reraise(exceptions.AttributeInferenceError(
('Lookup for {name} on {target!r} because super call {super!r} '
'is invalid.'),
target=self, attribute=name, context=context, super_=exc.super_))
except exceptions.MroError as exc:
util.reraise(exceptions.AttributeInferenceError(
('Lookup for {name} on {target!r} failed because {cls!r} has an '
'invalid MRO.'),
target=self, attribute=name, context=context, mros=exc.mros,
cls=exc.cls))
found = False
for cls in mro:
if name not in cls.locals:
continue
found = True
for inferred in bases._infer_stmts([cls[name]], context, frame=self):
if not isinstance(inferred, scoped_nodes.FunctionDef):
yield inferred
continue
# We can obtain different descriptors from a super depending
# on what we are accessing and where the super call is.
if inferred.type == 'classmethod':
yield bases.BoundMethod(inferred, cls)
elif self._scope.type == 'classmethod' and inferred.type == 'method':
yield inferred
elif self._class_based or inferred.type == 'staticmethod':
yield inferred
elif bases._is_property(inferred):
# TODO: support other descriptors as well.
for value in inferred.infer_call_result(self, context):
yield value
else:
yield bases.BoundMethod(inferred, cls)
if not found:
raise exceptions.AttributeInferenceError(target=self,
attribute=name,
context=context)
def infer_call_result(self, caller, context=None):
if len(caller.args) != 2:
raise exceptions.InferenceError(
"Invalid arguments for descriptor binding",
target=self,
context=context)
context = contextmod.copy_context(context)
cls = next(caller.args[0].infer(context=context))
if cls is astroid.Uninferable:
raise exceptions.InferenceError("Invalid class inferred",
target=self,
context=context)
# For some reason func is a Node that the below
# code is not expecting
if isinstance(func, bases.BoundMethod):
yield func
return
# Rebuild the original value, but with the parent set as the
# class where it will be bound.
new_func = func.__class__(name=func.name,
doc=func.doc,
lineno=func.lineno,
col_offset=func.col_offset,
parent=cls)
# pylint: disable=no-member
new_func.postinit(func.args, func.body, func.decorators,
func.returns)
# Build a proper bound method that points to our newly built function.
proxy = bases.UnboundMethod(new_func)
yield bases.BoundMethod(proxy=proxy, bound=cls)
def attr___new__(self) -> bases.BoundMethod:
"""Calling cls.__new__(type) on an object returns an instance of 'type'."""
node: nodes.FunctionDef = builder.extract_node(
"""def __new__(self, cls): return cls()"""
)
# We set the parent as being the ClassDef of 'object' as that
# triggers correct inference as a call to __new__ in bases.py
node.parent: nodes.ClassDef = AstroidManager().builtins_module["object"]
return bases.BoundMethod(proxy=node, bound=_get_bound_node(self))
def attr___init__(self) -> bases.BoundMethod:
"""Calling cls.__init__() normally returns None."""
# The *args and **kwargs are necessary not to trigger warnings about missing
# or extra parameters for '__init__' methods we don't infer correctly.
# This BoundMethod is the fallback value for those.
node: nodes.FunctionDef = builder.extract_node(
"""def __init__(self, *args, **kwargs): return None"""
)
# We set the parent as being the ClassDef of 'object' as that
# is where this method originally comes from
node.parent: nodes.ClassDef = AstroidManager().builtins_module["object"]
return bases.BoundMethod(proxy=node, bound=_get_bound_node(self))
def infer_call_result(self, caller, context=None):
if len(caller.args) != 2:
raise exceptions.InferenceError(
"Invalid arguments for descriptor binding",
target=self,
context=context)
context = contextmod.copy_context(context)
cls = next(caller.args[0].infer(context=context))
# Rebuild the original value, but with the parent set as the
# class where it will be bound.
new_func = func.__class__(name=func.name,
doc=func.doc,
lineno=func.lineno,
col_offset=func.col_offset,
parent=cls)
new_func.postinit(func.args, func.body, func.decorators,
func.returns)
# Build a proper bound method that points to our newly built function.
proxy = bases.UnboundMethod(new_func)
yield bases.BoundMethod(proxy=proxy, bound=cls)
def igetattr(self, name: str, context: InferenceContext | None = None):
"""Retrieve the inferred values of the given attribute name."""
# '__class__' is a special attribute that should be taken directly
# from the special attributes dict
if name == "__class__":
yield self.special_attributes.lookup(name)
return
try:
mro = self.super_mro()
# Don't let invalid MROs or invalid super calls
# leak out as is from this function.
except SuperError as exc:
raise AttributeInferenceError(
("Lookup for {name} on {target!r} because super call {super!r} "
"is invalid."),
target=self,
attribute=name,
context=context,
super_=exc.super_,
) from exc
except MroError as exc:
raise AttributeInferenceError(
("Lookup for {name} on {target!r} failed because {cls!r} has an "
"invalid MRO."),
target=self,
attribute=name,
context=context,
mros=exc.mros,
cls=exc.cls,
) from exc
found = False
for cls in mro:
if name not in cls.locals:
continue
found = True
for inferred in bases._infer_stmts([cls[name]],
context,
frame=self):
if not isinstance(inferred, scoped_nodes.FunctionDef):
yield inferred
continue
# We can obtain different descriptors from a super depending
# on what we are accessing and where the super call is.
if inferred.type == "classmethod":
yield bases.BoundMethod(inferred, cls)
elif self._scope.type == "classmethod" and inferred.type == "method":
yield inferred
elif self._class_based or inferred.type == "staticmethod":
yield inferred
elif isinstance(inferred, Property):
function = inferred.function
try:
yield from function.infer_call_result(caller=self,
context=context)
except InferenceError:
yield util.Uninferable
elif bases._is_property(inferred):
# TODO: support other descriptors as well.
try:
yield from inferred.infer_call_result(self, context)
except InferenceError:
yield util.Uninferable
else:
yield bases.BoundMethod(inferred, cls)
# Only if we haven't found any explicit overwrites for the
# attribute we look it up in the special attributes
if not found and name in self.special_attributes:
yield self.special_attributes.lookup(name)
return
if not found:
raise AttributeInferenceError(target=self,
attribute=name,
context=context)
