1.py

username='llllllllllllllllllllllllllllllllllllllllllllllllll'
userpassword='1234567890qwertyuiopo'
while True:
    name=input("账户:")
    password=input("密码:")
    if name==username and password==userpassword:
        print("登录成功!")
        break
    if name !=username:
        print("用户名不存在！请重新输入")
    if password !=userpassword:
        print("密码错误！请重新输入")
print("欢迎来到贝尔编程！")