def infer_len(node, context=None):
"""Infer length calls
:param nodes.Call node: len call to infer
:param context.InferenceContext: node context
:rtype nodes.Const: a Const node with the inferred length, if possible
"""
call = arguments.CallSite.from_call(node, context=context)
if call.keyword_arguments:
raise UseInferenceDefault("TypeError: len() must take no keyword arguments")
if len(call.positional_arguments) != 1:
raise UseInferenceDefault(
"TypeError: len() must take exactly one argument "
"({len}) given".format(len=len(call.positional_arguments))
)
[argument_node] = call.positional_arguments
try:
return nodes.Const(helpers.object_len(argument_node, context=context))
except (AstroidTypeError, InferenceError) as exc:
raise UseInferenceDefault(str(exc)) from exc
def infer_len(node, context=None):
"""Infer length calls
:param nodes.Call node: len call to infer
:param context.InferenceContext: node context
:rtype nodes.Const: a Const node with the inferred length, if possible
"""
call = arguments.CallSite.from_call(node)
if call.keyword_arguments:
raise UseInferenceDefault("TypeError: len() must take no keyword arguments")
if len(call.positional_arguments) != 1:
raise UseInferenceDefault(
"TypeError: len() must take exactly one argument "
"({len}) given".format(len=len(call.positional_arguments))
)
[argument_node] = call.positional_arguments
try:
return nodes.Const(helpers.object_len(argument_node))
except (AstroidTypeError, InferenceError) as exc:
raise UseInferenceDefault(str(exc)) from exc
