def infer_isinstance(callnode, context=None):
"""Infer isinstance calls
:param nodes.Call callnode: an isinstance call
:param InferenceContext: context for call
(currently unused but is a common interface for inference)
:rtype nodes.Const: Boolean Const value of isinstance call
:raises UseInferenceDefault: If the node cannot be inferred
"""
call = arguments.CallSite.from_call(callnode, context=context)
if call.keyword_arguments:
# isinstance doesn't support keyword arguments
raise UseInferenceDefault("TypeError: isinstance() takes no keyword arguments")
if len(call.positional_arguments) != 2:
raise UseInferenceDefault(
"Expected two arguments, got {count}".format(
count=len(call.positional_arguments)
)
)
# The left hand argument is the obj to be checked
obj_node, class_or_tuple_node = call.positional_arguments
# The right hand argument is the class(es) that the given
# obj is to be check is an instance of
try:
class_container = _class_or_tuple_to_container(
class_or_tuple_node, context=context
)
except InferenceError as exc:
raise UseInferenceDefault from exc
try:
isinstance_bool = helpers.object_isinstance(obj_node, class_container, context)
except AstroidTypeError as exc:
raise UseInferenceDefault("TypeError: " + str(exc)) from exc
except MroError as exc:
raise UseInferenceDefault from exc
if isinstance_bool is util.Uninferable:
raise UseInferenceDefault
return nodes.Const(isinstance_bool)
def infer_isinstance(callnode, context=None):
"""Infer isinstance calls
:param nodes.Call callnode: an isinstance call
:param InferenceContext: context for call
(currently unused but is a common interface for inference)
:rtype nodes.Const: Boolean Const value of isinstance call
:raises UseInferenceDefault: If the node cannot be inferred
"""
call = arguments.CallSite.from_call(callnode)
if call.keyword_arguments:
# isinstance doesn't support keyword arguments
raise UseInferenceDefault("TypeError: isinstance() takes no keyword arguments")
if len(call.positional_arguments) != 2:
raise UseInferenceDefault(
"Expected two arguments, got {count}".format(
count=len(call.positional_arguments)
)
)
# The left hand argument is the obj to be checked
obj_node, class_or_tuple_node = call.positional_arguments
# The right hand argument is the class(es) that the given
# obj is to be check is an instance of
try:
class_container = _class_or_tuple_to_container(
class_or_tuple_node, context=context
)
except InferenceError:
raise UseInferenceDefault
try:
isinstance_bool = helpers.object_isinstance(obj_node, class_container, context)
except AstroidTypeError as exc:
raise UseInferenceDefault("TypeError: " + str(exc))
except MroError as exc:
raise UseInferenceDefault from exc
if isinstance_bool is util.Uninferable:
raise UseInferenceDefault
return nodes.Const(isinstance_bool)
