Soma dos dígitos do fatorial

factorialdigitssum.py

from math import factorial
from operator import add


def factorial_digits_sum(number):
    return reduce(
        add,
        [int(string_digit) for string_digit in str(
            factorial(number)
        )]
    )


if __name__ == '__main__':
    assert factorial_digits_sum(1) == 1
    assert factorial_digits_sum(2) == 2
    assert factorial_digits_sum(3) == 6
    assert factorial_digits_sum(4) == 6
    print factorial_digits_sum(100)