Factorial in Python

Example for versions Python 2.5.2, Python 2.6.5

This example uses iterative method of calculating factorials. 

def factorial(n):
    if n == 0:
        return 1
    
    f = 1
    for i in range(1, n + 1):
        f *= i
    return f

for n in range(16 + 1):
    print "%d! = %d" % (n, factorial(n))