How to calculate the factorial of n in python

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

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

Related recommendations: "Python Basic Tutorial"

1 math.factorial(x)

import math
value = math.factorial(x)

2. 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)

The above is the detailed content of How to calculate the factorial of n in python. For more information, please follow other related articles on the PHP Chinese website!