How to write factorial in python

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.

How to write factorial in python?

Example

#!/usr/bin/python3
 
# Filename : test.py

 
# 通过用户输入数字计算阶乘
 
# 获取用户输入的数字
num = int(input("请输入一个数字: "))
factorial = 1
 
# 查看数字是负数，0 或 正数
if num < 0:
   print("抱歉，负数没有阶乘")
elif num == 0:
   print("0 的阶乘为 1")
else:
   for i in range(1,num + 1):
       factorial = factorial*i
   print("%d 的阶乘为 %d" %(num,factorial))

The output result of executing the above code is:

请输入一个数字: 3
3 的阶乘为 6

Related recommendations: "Python Tutorial"

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