获取 function python 中 arguments 的数量

Question

I want to verify if the client gave the right amount of arguments to the server.

I have this function:

def invite_player(addr, active_users):

how can I verify the number of arguments of this function?

Answer 1

You can get the argument count of a function and then compare it.

I assume that your function don't takes any keyword argument.

>>> def invite_player(addr, active_users):
    ...


>>> invite_player.__code__.co_argcount
2

The better way would be using builtin inspect module:

>>> import inspect
>>> def invite_player(addr, active_users):
    ...


>>> inspect.getfullargspec(invite_player)
FullArgSpec(args=['addr', 'active_users'], varargs=None, varkw=None, defaults=None, kwonlyargs=[], kwonlydefaults=None, annotations={})
>>> inspect.getfullargspec(invite_player)[0]
['addr', 'active_users']
>>> len(inspect.getfullargspec(invite_player)[0])
2

Also a TypeError would raise if you don't pass right amount of arguments to the function, but this is not the only thing that raises TypeError .

Answer 2

As mentioned in the comments, the function can only be called with 2 arguments. If not, a TypeError will be raised.