i=3
username = "python"
userpassword = "123456"

while True:
    if i>3 :
        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")
            print("你还有"+str(i)+"次登陆机会")
            continue
        if  password != userpassword :
            print("密码错误,请重新输入")
            print("你还有"+str(i)+"次登陆机会")
    else:
        print:("你的账号已被锁定,请带身份证到我司解锁") 
        exit()
print("欢迎来到贝尔编程!")