How to find the factorial of an integer n in python?

Python method to find the factorial of an integer n: 1. First import the math module, and then use math.factorial(n) to calculate the factorial of n; 2. Use the reduce() function to find the factorial; 3. Through recursion Let’s find the factorial.

The factorial of an integer (English: factorial) is the product of all positive integers less than and equal to the number. The factorial of 0 is 1. That is: n!=1×2×3×...×n.

1. Use math.factorial(x)

First import the math module, and then call the factorial() function to calculate the factorial.

import math
 
value = math.factorial(x)

2. Use the reduce function

def factorial(n):
 
return reduce(lambda x,y:x*y,[1]+range(1,n+1))

3. Recursive implementation

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

Recommended learning: Python video Tutorial

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