How to exclude characters when counting digits

[DeaD_EyE]

def count_func(s):
    return sum(c.isdigit() for c in s)

would be pretty efficient, but I didn't run time it.

I like this solution also, but I can't test it.
My CPU Speed is not fixed, so I get not usable results.

I guess the methodcall isdigit() takes bit time.
Maybe this can be faster:

import string


def count_func(s):
    return sum(1 for c in s if c in set(string.digits))

But again, I can't benchmark it :-/