Python functions returning none for some reason

Question

I'm having some issues with these python functions. Whenever I run them, it saying function by_three is returning none. Any help would be appreciated.

def cube(number):
 result = number**3
 return result

def by_three(number):
 if number%3 == 0:
  cube(number)
 else:
  return False

All the duplicates are about recursion - the canonical is https://stackoverflow.com/questions/17778372 - but this one clearly isn't. It seems to be a typo, but I think perhaps we need a canonical for this sort of problem? — Karl Knechtel, Aug 13 '22 at 13:04
I replaced the duplicate with the best I could find, but it's still not really accurate. — Karl Knechtel, Aug 13 '22 at 13:09
Hint: think about why the code for `cube` (correctly) **does not** just say `number ** 3`. What would happen if that were the code instead? Do you see how that compares to using `cube(number)` without `return`? — Karl Knechtel, Aug 13 '22 at 13:15

score 1 · Accepted Answer · answered Aug 19 '17 at 18:33

In the if case your function ends without returning anything. This is why you get None back. You probably meant:

def cube(number): 
    result = number**3 
    return result
def by_three(number): 
    if number%3 == 0:
        return cube(number)
    else:
        return False

Python functions returning none for some reason

1 Answers1