this is my code
def digit_sum(n): num_string = str(n) list_sum =  total = 0 for digit in num_string: list_sum.append(digit) for i in list_sum: total += int(i) print total digit_sum(434)
and this is my error
Oops, try again. Your function fails on digit_sum(434). It returns None when it should return 11.
and this is what is in my out put screen
what do I do?
i've refreshed the browser and it still wont pass.