factorial

from functools import reduce
from operator import mul

def factorial(n):
    result = 1
    for x in range(1, n + 1):
        result *= x
    return result

def factorial_reduce(n):
    return reduce(mul, range(1, n + 1))


n = 5
result1 = factorial(n)
result2 = factorial_reduce(n)

print('factorial(5) ==', result1)
print('factorial_reduce(5) ==', result2)