用户登录程序

# __author__ = Leo li
# !/usr/bin/env python
# -*- coding:utf-8 -*-
a = open("username.txt","r+")
x = open("password.txt","r+")
y = x.readlines()
b = a.readlines()
f = open("msg.txt","r+")
m = f.readlines()
counter = 0
cmd = 0
ax = 0
while cmd < 1:
    a = open("username.txt","r+")
    x = open("password.txt","r+")
    y = x.readlines()
    b = a.readlines()
    print("欢迎来到Python论坛登陆界面")
    print("1.注册用户")
    print("2.登录用户")
    print("3.退出")
    chose = input("请输入你的选项：")
    if chose == '1':
        while chose:
            user = input("请输入您要注册的用户名:")
            if user+"\n" in b:
                print("该用户名已存在，请重新输入")
            else:
                pwd = input("请输入您的密码：")
                c = open("password.txt","a+")
                c.write(pwd+"\n")
                a = open("username.txt","a+")
                a.write(user+"\n")
                p = open("msg.txt","a+")
                p.write("True\n")
                p.close()
                c.close()
                a.close()
                x.close()
                print("注册成功！请重新运行登录程序！")
                exit()
    elif chose == '2':
        while chose:
            username = input("请输入您的用户名：")
            password = input("请输入您的密码：")
            d = open("username.txt",'r+')
            if username+"\n" not in d:
                print("您输入的用户名不存在，请重新输入")
                d.close()


            else:
                q = open("msg.txt",'r+')
                w = q.readlines()
                e = b.index(username+"\n")
                if w[e] == "True\n":

                        if counter <2:
                            if password+"\n" == y[e]:
                                print("登录成功！欢迎进入")
                                exit()

                            else:
                                print("你的密码错误，请重新输入")
                                counter+=1
                                continue
                        else:
                            g = open("msg.txt","w+")
                            m[e] = "False\n"
                            g.writelines(m)
                            g.close()
                            print("由于你尝试太多次，系统已锁定此账户，请联系管理员后重试")
                            print("正在退出程序…………")
                            exit()

                else:
                    print("您好，由于你的密码输入错误次数过多，系统已锁定此账户，请联系管理员后重试")
                    print("正在返回登录界面……")
                    print("\n")
                    break


    elif chose == '3':
        print("正在退出……")
        exit()
    else:
        print("您的输入有误，请输入您要选择的序号（“1”，“2”，“3”）")