Function returning None for recursive function for factorial function

Question

I'm trying to write a code that returns the factorial of the input num but this code is returning "None" when I run it, I'm not sure why.

def factorial(num):
    if type(num) is not int():
        return None
    elif num == 0:
        return 1
    elif num < 0:
        return None
    else:
        return num * factorial(num - 1)

factorial5 = factorial(5)
print(factorial5)

Answer 1

You have an extra parenthesis .. see the correction from int() to int:

def factorial(num):
    if type(num) is not int:
        return None
    elif num == 0:
        return 1
    elif num < 0:
        return None
    else:
        return num * factorial(num - 1)

factorial5 = factorial(5)
print(factorial5)

NOTE: ran with Python3

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