Shortest way to calculate the Factorial

Question

What is the shortest way to calculate the factorial of a number without using any libraries.
I just want to optimize my code.
https://code.sololearn.com/c7m1MD6M4IsP/?ref=app

Answer 1

https://code.sololearn.com/c3eg8MvlATAf/?ref=app
https://code.sololearn.com/cOInw4yJq7wi/?ref=app
https://code.sololearn.com/c4phTP2wUQ3u/?ref=app
https://code.sololearn.com/cE7lXk0wwKMN/?ref=app
https://code.sololearn.com/cOfMIY803RdZ/?ref=app
https://code.sololearn.com/cj7pAcAEmqTm/?ref=app
https://code.sololearn.com/c4Q0rFUFxZIP/?ref=app

Answer 2

This is how I did it in one of my programs.

def fact(x):
y=x
for m in range(x-1,1,-1):
y*=m
return y

Answer 3

Pretty short already.

I would subtly tighten it like this:

n=1
for i in range(2, int(input())+1):
n *= i
print(n)

You could import the builtin tool:

from math import factorial
print(factorial(5))

Another method:

from functools import reduce
print(reduce(int.__mul__, range(1, 6)))

Recursion version with function:

def fact(n):
return 1 if n<2 else n*fact(n-1)
print(fact(5))