30-seconds-of-code/snippets/factorial.md

factorial

Calculates the factorial of a number.

Use recursion. If num is less than or equal to 1, return 1. Otherwise, return the product of num and the factorial of num - 1. Throws an exception if num is a negative or a floating point number.

def factorial(num):
    if not ((num >= 0) & (num % 1 == 0)):
        raise Exception(
            f"Number( {num} ) can't be floating point or negative ")
    return 1 if num == 0 else num * factorial(num - 1)