if_else

判断一个用户，密码是否对

#!/usr/bin/env python

# -*- coding:utf-8 -*-

_username="Lucky"

_password="123"

username=input("username:")

password=input("password:")

if _username==username and _password==password:

print("welcome to login system!")

else:

print("invalid username or password!")

2.结果如图：