import timeit
# Add a memoization method?

def factorial(n):
    if n == 0:
        return 1
    else:
        return n * factorial(n - 1)


def factorial_iterative(n):
    product = 1
    for i in range(1, n + 1):
        product *= i
    return product


if __name__ == '__main__':
    print('factorial():')
    print(timeit.timeit('factorial(15)', number=10000,
                        setup='from __main__ import factorial'))
    print('factorial_iterative():')
    print(timeit.timeit('factorial_iterative(15)', number=10000,
                        setup='from __main__ import factorial_iterative'))