What is the function for Factorial in Python

Question

How do I go about computing a factorial of an integer in Python?

Answer 1

Easiest way: math.factorial(x) (available in 2.6 and above).

If you want/have to write it yourself, use:

def factorial(n):

    return reduce(lambda x,y:x*y,[1]+range(1,n+1))

or something more readable:

def factorial(n):

    if n == 0: 

        return 1 

    else: 

        return n * factorial(n-1)

As always, Google is your friend ;)