python check if function accepts **kwargs

Question

is there a way to check if a function accepts **kwargs before calling it e.g.

def FuncA(**kwargs):
    print 'ok'

def FuncB(id = None):
    print 'ok'

def FuncC():
    print 'ok'

args = {'id': '1'}

FuncA(**args)
FuncB(**args)
FuncC(**args)

When I run this FuncA and FuncB would be okay but FuncC errors with got an unexpected keyword argument 'id' as it doesn't accept any arguments

Answer 1

try:
    f(**kwargs)
except TypeError:
    #do stuff

It's easier to ask forgiveness than permission.

Answer 2

def foo(a, b, **kwargs):
  pass

import inspect
args, varargs, varkw, defaults = inspect.getargspec(foo)
assert(varkw=='kwargs')

This only works for Python functions. Functions defined in C extensions (and built-ins) may be tricky and sometimes interpret their arguments in quite creative ways. There's no way to reliably detect which arguments such functions expect. Refer to function's docstring and other human-readable documentation.