diy2.py

i=3
username = "python"
userpassword = "123456"
while True:
    if i>0:
        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
        if name != "username":
            print("用户名错误，请重新输入:")
            continue
        if password != "userpassword":
            print("密码错误，请重新输入：")
    else:
        print("您的账号已锁定，请到我司解锁")
        exit()        
print("欢迎来到贝尔编程!")