day1

day1.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#user:Felix
#date:2016-10-11
#mail:wudonghang@wudonghang.com
#If you have questions or suggestions, please contact the author.

import getpass
import os
import json

#退出程序用，后续会重复调用。
def end():
    print('\nProgram is over!')
    exit()

#判断是否有用户文件
def file_exists():
    if os.path.exists(userlist):
        pass
    else:
        print('User list file not defined!')
        end() #没有检测到用户文件，

#判断用户是否存在文件中
def user_exists():
   if username not in userlist_message:
      print('User name does not exist in the system!')
      end()

#开始登陆流程
userlist = 'userlist'
file_exists()
username = input("Please input your username:")
with open(userlist, 'r') as userlist_json:  #将文件内容读取出来
  userlist_message = json.load(userlist_json) #转换json
user_exists()
#判断用户名密码是否正确，输入正确显示welcome+用户名，输入不正确3次后将跳出循环并锁定该用户。
real_password = userlist_message[username][0]['password'] #根据用户输入username取出json中的password
if int(userlist_message[username][0]['lock']) == 0:
    print('Your user has been locked, please contact the administrator to unlock.!')
    end()
elif int(userlist_message[username][0]['lock']) == 1:
    pass
else:
    print('Your user status is abnormal, please contact the administrator!')
    end()
password = getpass.getpass(prompt='please input your password: ') #输入密码
for count in range(3):
    if username == username in userlist_message and password == real_password:
        print("Welcome! %s"%username)
        end()
    elif count == 2:
        print('Sorry, your user name has been locked, temporarily not allowed to use!')
        userlist_message[username][0]['lock'] = 0
        json.dump(userlist_message, open(userlist, 'w'))
        break #输错次数到3次跳出循环，并加入黑名单
    else:
        print("wrong username or password!") #提示密码输入错误
        password = getpass.getpass(prompt='Please enter your password again: ') #重新输入一次密码
end()

userlist:

{"huangxu": [{"password": "huangxu123", "lock": 1}], "liuyao": [{"password": "liuyao123", "lock": 1}], "wudonghang": [{"password": "wudonghang123", "lock": 1}], "administrator": [{"password": "administrator123", "lock": 1}]}

readme:

###博客园地址：[Python之路,Day1 - Python基础1](http://www.cnblogs.com/wudonghang/p/d40bdbbd1a87e6c907ac76f8c6f4c024.html "我的博客园地址")
***
###程序简介：
>背景

[作业：](http://www.cnblogs.com/alex3714/articles/5465198.html#3519330 "大王留下的作业")

* 编写登陆接口

* 输入用户名密码

* 认证成功后显示欢迎信息

* 输错三次后锁定
***
>构想流程图

![](http://i.imgur.com/DYvmgC2.png)

***

>实现方式

1. 用户数据文件形式采用了json形式 （lock值为0时，用户为锁定状态）

   json格式如下

      {

       "wudonghang": [

           {

               "password": "wudonghang123",

               "lock": 0

           }

       ],

       "administrator": [

              {

                  "password": "administrator123",

                  "lock": 1

           }

       ]

      }
2. 查询json文件数据方法

      with open(userlist, 'r') as userlist_json:
         userlist_message = json.load(userlist_json)

      real_password = userlist_message[username][0]['password'] #查询文件中password
      real_lock = userlist_message[username][0]['lock'] #查询用户锁定状态
3. 采集username以及password方法

      input("Please input your username:") #输入用户名
      getpass.getpass(prompt='Please enter your password again: ') #这里我采用了getpass模块

4. 利用for循环与if判断来实现对username和password的判断，以及用户lock值的修改

      for count in range(3):
   
       if username == username in userlist_message and password == real_password:
   
           print("Welcome! %s"%username)
   
           end() #登陆成功跳出程序
   
       elif count == 2:
   
           print('Sorry, your user name has been locked, temporarily not allowed to use!')
   
           userlist_message[username][0]['lock'] = 0
   
           json.dump(userlist_message, open(userlist, 'w'))
   
           break #输错次数到3次跳出循环，并加入黑名单
   
       else:
   
           print("wrong username or password!") #提示密码输入错误
   
           password = getpass.getpass(prompt='Please enter your password again: ') #重新输入一次密码

***

来自为知笔记(Wiz)