In Practice makes Perfect 4 .digit_sum I get this error message:
Oops, try again. Your function fails on digit_sum(434). It returns None when it should return 11.
And the funny thing is that I get the result 11 when I put 434 in the function.
Here is my code, I don't have any syntax errors in it .
def digit_sum(n): x=str(n) k= z=0 for i in range(len(x)): k.append(x[i]) for j in k: z+=int(j) print z digit_sum(434)