Question

Let’s say I have a function in Python like so:

def foo(x): pass

According to Python, ‘foo’ alone is a function reference, right?

>>> def foo(x): pass
...
>>> foo
<function foo at 0xb7f3d1b4>

Is there any way I can examine the function reference to determine the number of arguments it expects?

Answer 1

You need inspect.getfullargspec in py3k or inspect.getargspec in earlier versions.

 >>> def foo(x): pass

>>> import inspect
>>> inspect.getfullargspec(foo)
FullArgSpec(args=['x'], varargs=None, varkw=None, defaults=None, kwonlyargs=[], kwonlydefaults=None, annotations={})