diy2.py

i = 3
username = "python"
userpassword = "123456"
while True:
    if i > 0:
        i = i -1
        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
        elif name!=username:
            print("用户名错误")
        else:
            print("账号错误")
    else:
        print("超过次数，锁定账号")
        exit()
print("欢迎来到贝尔编程!")