Hello here is my factorial program I wrote in Python

def fact (n):
if n == 0: return 1
return n*fact(n - 1);

number = int(raw_input("Enter a number:"))
if number < 0:
print "No"
else:
print fact(number)

>>8

import operator
def fact(x): return reduce(operator.mul, xrange(2, x+1))

>>9

fact(1)