Python做的第一个小项目-模拟登陆

1. 用户输入帐号密码进行登陆
2. 用户信息保存在文件内
3. 用户密码输入错误三次后锁定用户

主要采用循环语句和条件语句进行程序流程的控制，加入文件的读写操作

 while True:
     choice = input("登陆L 注册R 退出Q：").strip()
 #用户登录流程
     if choice.lower() == 'l':
         l_flag = False
         count = 1
         tmp = ''
         while True:
             user_name =input("请输入用户名（或者'q'退出）：").strip()
             if not user_name:continue
             if user_name == 'q':
                 print("退出成功！")
                 exit()
             user_pwd = input("请输入用户密码（或者'q'退出）：").strip()
             if not user_pwd:
                 print("密码不能为空，请重新输入！")
                 continue
             if user_pwd == 'q':
                 print("退出成功！")
                 exit()
             with open("locked_id",mode="r",encoding="utf8") as f_locked:
                 for line in f_locked:
                     if line.startswith("username:") and user_name in line and len(user_name)!=0:
                         print("该用户已经被锁定，请联系管理员！")
                         exit()
             with open("user_id",mode="r",encoding="utf8") as f_reed:
                 for line in f_reed:
                     if line.startswith("username:") and user_name in line and len(user_name) != 0:
                         l_flag = True
                         tmp = line
                 if l_flag:
                     if tmp.split(":")[2].strip() == user_pwd:
                         print("用户登录成功！")
                         l_flag =  False
                         exit()
                     elif count >= 3:
                         with open("locked_id",mode="a",encoding="utf8") as f_locked:
                             f_locked.write("\nusername:"+user_name)
                             print("您的密码错误三次，用户被锁定！")
                             l_flag =False
                             exit()
                     else:
                         count += 1
                         l_flag =False
                         print("密码错误，请重新输入！")
                         continue
                 else:
                     print('用户名不存在，请重新登录！')

 #用户注册流程
     if choice.lower() == 'r':
         r_flag = False    #注册过程标志位
         while True:
             new_user_name =input("请输入注册用户名（或者'q'退出）：").strip()
             if not new_user_name:continue    #用户名为空开始下一个循环
             if new_user_name == 'q':
                 print("退出成功！")
                 exit()
             new_pwd = input("请输入用户密码且不少于6位（或者'q'退出）：").strip()
             if new_pwd == 'q':
                 print("退出成功！")
                 exit()
             if len(new_pwd) < 6:
                 print('密码不能为空且不少于6位！')
                 continue
             with open("user_id",mode="r+",encoding="utf8") as f:
                 f.seek(0)
                 for line in f:
                     if line.startswith("username:") and new_user_name in line: #判断是否已经有该用户
                         print("该用户已经被注册！")
                         r_flag = True
                         break
                 if not r_flag:
                     f.write("\nusername:" + new_user_name)
                     f.write("\t|password:" + new_pwd)
                     print("新用户注册成功！")
                 r_flag = False
                 break

 #退出流程
     if choice.lower() == 'q':
         print("退出成功！")
         exit()

模拟登陆代码