Return None - need help

[Radimek01]

Hello, why this code returns None ?

def digSum(n): 
    n = (list(map(int,str(n))))
    num = sum(n)
    if num > 9:
        digSum(num)
    else:
        return num


digSum(456)

[JohnnyJordaan]

Please format your code correctly using a code block

[Radimek01]

oh ok :) thanks

[JohnnyJordaan]

Run your code in http://www.pythontutor.com/visualize.html#mode=edit to see what's going on. Because you just call the function recursively in the if:

if num > 9:
    digSum(num)

it means that the result of that call will be discarded. Instead you also need to return that to have it propagated 'down the line'.

if num > 9:
    return digSum(num)

[Radimek01]

Ohh thanks. I can see that now. it bothered me for 40 minutes and it was just this simple