diy2.py

username = "python"
userpassword = "123456"
while True:
    name = input("请输入用户名:")
    password = input("请输入密码:")
    if name == username and password == userpassword:
        print("登录成功!")
        break
    if name != username 
        print("你叫啥你都忘了牛啤")
    if password != userpassword
        print("你健忘莫")
    
print("欢迎来到贝尔编程!")