#!/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()

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