判斷一個用戶，密碼是否對
#!/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.結果如圖：
