How to exclude characters when counting digits

[juliabrushett]

Hello
I am trying to write a program that will count only numeric digits within a string, excluding all letters. What I have currently counts EVERYTHING. How do I fix this?

def countDigits(digits) :
    digits = 0
    x = len(s)

    for i in range(0, x, 1) :
        ((ord(s[i]) >= 65) and (ord(s[i]) <= 57))
        digits += 1
    return digits


s = input("Enter a string\n")

print("There are", countDigits(s), "digits in your string.")