Sum the digits of a number

Question

If I want to find the sum of the digits of a number, i.e.:

• Input: 932
• Output: 14, which is (9 + 3 + 2)

Answer 1

The best way is to use math.
I knew this from school.(kinda also from codewars)

def digital_sum(num):
    return (num % 9) or num and 9

Just don't know how this works in code, but I know it's maths

If a number is divisible by 9 then, it's digital_sum will be 9,
if that's not the case then num % 9 will be the digital sum.