利用python实现简单登陆注册系统

 #！/usr/bin/env python
 # -*- coding:utf-8 -*-

 def login(username,password):
     '''

     :param username:用户名
     :param password:密码
     :return: True:登陆成功  False:登陆失败
     '''
     f = open('log','r',encoding='utf-8')
     for line in f:
         line = line.strip()
         line_list = line.split('$')
         if username ==line_list[0] and password ==line_list[1]:
             print('success')
             return True
         return False

 def register(username,password):
     '''

     :param username:
     :param password:
     :return:
     '''
     with open('log','a',encoding='utf-8') as f:
         temp = '\n' + username + '$' + password
         f.write(temp)
     return True

 def user_exit(username):
     '''

     :param username:
     :return:
     '''
     with open('log','r',encoding='utf-8') as f:
         for line in f:
             line = line.strip()
             line_list = line.split('$')
             if line_list[0]==username:
                 return True
     return False

 def main():
     print('欢迎登陆XX系统')
     inp = input('1:登陆；2：注册')
     user = input('user:')
     pwd = input('pwd:')
     if inp =='':
         is_login = login(user,pwd)
         if is_login:
             print('success')
         else:
             print('fail')
     elif inp =='':
         is_exit = user_exit(user)
         if is_exit:
             print('already register')
         else:
             result = register(user,pwd)
             if result:
                 print('register sucess')
             else:
                 print('resgister faild')
 main()