diy2.py

username = "python"
i=3
userpassword = "123456"
while True:
    name = input("请输入用户名:")
    password = input("请输入密码:")
    i=i-1
    if i > 0:
        if name == username and password == userpassword:
            print("登录成功!")
            break
        if username != name :
            print("用户名不存在，请重新输入") 
            continue 

        if password != userpassword :
            print("密码不存在，请重新输入")
    else :
        print("你的账户已被锁定，请带身份证来我司解锁")    
        exit()
print("欢迎来到贝尔编程!")