import pickle    #导入pickle模块

 pickle_file=open('userandcodes.pkl','rb')

 userdict=pickle.load(pickle_file)  #打开存储用户密码和账户的文件，并把里面的字典类型给userdict

 pickle_file.close()

 pickle_file1=open('userlock.pkl','rb')

 locklist=pickle.load(pickle_file1)   #打开被锁定用户的文件，并把里面的列表类型给locklist

 count=0

 while count<3:

     username = input('username:')

     while username not in userdict.keys():

         print('Wrong Username,input again!')   #检测用户名是否存在，直至用户输入正确的用户名（输错用户名不被计数）

         username = input('username:')

     password = input('password:')

     if username not in locklist:

         if password==userdict.get(username):

              print('Welcome!.The user {0} loging...'.format(username))

              break

         else:

              print('Wrong password....Input again')

              count+=1

     else:

         print('You have tried 3 times before,your username has been locked')

         break

 else:

     print('You have tried 3 times,your username is being locked')

     locklist.append(username)

     pickle_file1 = open('userlock.pkl', 'wb')

     pickle.dump(locklist,pickle_file1)

 pickle_file1.close()