nothing returned in iterating Python function

Question

Nothing is returned when I try iterating a function in Python. Code is like this

def count(num):
    if (num > 10):
        return(num)
    if(num<=10):
        new = num + 1
        count(new)     
nummer = count(8)

If I do count(22), it returns 22. But when I do count(8), it doesnt return anything. I would like this function to return '11' but it return nothing. Probably something wrong in my thinking but I really can't figure it out. I hope someone can help me.

Thx, Peter

then it starts the function again. It adds +1 and then goes to the function again until it reaches 11. So, it only should return 11 or if you have entered a higher number, it should return this one. — Aurora Borealis, Jul 15 '22 at 07:25
No, it doesnt. It *calls* the function again, but the original function call still needs something to return (likewise for any subsequent function calls) — Sayse, Jul 15 '22 at 07:25

score 2 · Answer 1 · answered Jul 15 '22 at 07:25

2

Your second recursive call lacks a return statement, so that branch will always return None. You will need to explicitly return the result of count there, i.e.

return count(new)

answered Jul 15 '22 at 07:25

mitch_

1,048
5
14

score 1 · Answer 2 · answered Jul 15 '22 at 07:25

1

you cannot return the value in other conditions. Try this

def count(num):
    if (num > 10):
        return(num)
    if(num<=10):
        new = num + 1
        return count(new)     
nummer = count(8)

answered Jul 15 '22 at 07:25

Mehmaam

573
7
22

score 1 · Accepted Answer · answered Jul 15 '22 at 07:27

You actually need to include a second return, in case your number is lower or equal than 10. Besides, you could have a slightly shorter code. Calling the function is not sufficient.

You are trying to evaluated whether a number x is greater or lower than 10. But this number can EITHER be greater OR lower. Therefore when you put

if num>10:
  pass

you don't need another if statement, since if num is not greater than 10 it is lower or equal to 10.

def count(num):
    if (num > 10):
        return(num)
    else:
        new = num + 1
        return count(new)     
nummer = count(8)

nothing returned in iterating Python function

3 Answers3