How do you call a function several times in this context??

[kofi]

Using python 3.1, I have written a function called "isEvenDigit"

Below is the code for the "isEvenDigit" function:

def isEvenDigit():
    ste=input("Please input a single character string: ")
    li=["0","2","4", "6", "8"]
    if ste in li:
        print("True")
    else:
        print("False")

I am now trying to write a function that takes a string as an argument and makes several calls to the isEvenDigit function in order to calculate and return the number of even digits in the string.How do i do this please? This is what i have done so far.

def isEvenDigit2():
    number = input("Enter a digit: ")