编写一个登陆接口，要求如下

• 1. 输入用户名密码
• 1. 认证成功后显示欢迎信息
• 1. 输错三次后锁定

import oscount = 0#读取用户列表user_check = open('userlist.txt','r')userlist = user_check.read()user_check.close()#读取锁定用户列表user_lock = open('userlock.txt','r')lock = user_lock.read()user_lock.close()username = input("输入用户名：")while count < 3:    passwd = input("请输入密码：")    if username in lock:        print("账号已锁定，请联系管理员")        break    else:        if username in userlist:            if passwd == '123456':                print("welcome "+username)                break            else:                print("密码错误")                count += 1        else:            print("您输入的账号不存在")            breakelse:    print("连续三次输错密码，账号被错定")    #开始将连续三次输错密码的账号写入锁定用户列表    add_lock = open('userlock.txt','a')    add_lock.write(username)    add_lock.close()