用户登录

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

'''
说明：
如果登录用户在用户列表里，每个用户只有3次登录机会，失败后锁定账户，下次启动账户提示账户被锁定
如果登录用户不在用户列表里，提示用户不存在,并且尝试3次登录，如果失败退出程序
'''

import sys

def checklock(username):
    with open("loginlock.txt", 'r') as lock_t:
        for line in lock_t.readlines():
            if len(line) == 0:
                continue
            if username == line.strip():
                print("login fail too much! User locked")
                # sys.exit()
                return 'lock'


def userlock(username):
    f = open("loginlock.txt", 'a')
    f.write(username + '\n')
    f.close()


def userlogin(userinfo):
    count = 3                    #计数器
    flag = 'success'             #标记登录状态
    userid = 0                   #标记用户编号
    while True:
        username = input('please enter your name: ')
        if checklock(username) == 'lock':
            # continue
            break
        password = input('please enter your password: ')
        for i,user in enumerate(userinfo):
            if user['username'] == username and user['password'] == password:
                flag = 'success'
                break
            elif user['username'] == username and user['password'] != password:
                flag = 'fail'
                userid = int(i)
                break
            else:
               flag = 'nouser'
        if flag == 'success':
            print('login successful, welcome!')
            break
        elif flag == 'fail':
            # count -= 1
            # print('who ', userinfo[userid])
            failnum = int(userinfo[userid]['login_fail'])             #统计登录失败次数
            failnum -= 1
            if userinfo[userid]['login_fail'] == 1:
                print('your account lock')
                userlock(userinfo[userid]['username'])
                sys.exit()
            else:
                userinfo[userid]['login_fail'] = failnum
                print('login fail, you have %s chance' % (failnum))
        else:
            count -= 1
            if count == 0:
                print('you login too much time')
                sys.exit()
            print('Sorry no user, you have %s chance' % (count))


if __name__ == '__main__':
    userinfo = [
        {'username':'eric', 'password':'123456', 'login_fail':'3'},
        {'username':'tom', 'password':'123456', 'login_fail':'3'},
        {'username':'jerry', 'password':'123456', 'login_fail':'3'},
    ]

    userlogin(userinfo)