Refactoring Optimization python shopping cart

# -*- coding:utf-8 -*-def regiter ():    while true:         username = input ("Please enter your account number:"). Strip ()          password = input ("Please enter your password:"). Strip () #去除空格及换号符          with open (' register ', encoding= ' UTF-8 ') as f1:       &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;FOR&NBSP;LINE&NBSP;IN&NBSP;F1: #循环读取注册文件中的内容                  line_list=line.strip (). Replace (', ', ', '). Split (', ') #去除空格及换号符以及把中文逗号换成英文逗号                   #print (Type (line_list))                  if username==line_list[0]:             &nbsP;       print ("User name already exists, please re-enter")                      break             else:                 with open (' register ',  encoding= ' UTF-8 ', mode= ' a ') as f2 :                     f2.write (' \n{},{} '. Format (Username,password))                      print ("Congratulations on your registration success%s"%username)                       return True  #结束函数def  login ():     i=0# counter     while  i<3: #超过3次后, Login failed  &Nbsp;      username = input ("Please enter your account number:"). Strip ()          password = input ("Please enter your password:"). Strip ()   #  remove space and change symbol          with open (' register ', encoding= ' UTF-8 ') as f1:   &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;FOR&NBSP;LINE&NBSP;IN&NBSP;F1: #循环读取注册文件中的内容                  line_list=line.strip (). Replace (', ', ', '). Split (', ') #去除空格及换号符以及把中文逗号换成英文逗号                   #print (Type (line_list))                  if username==line_list[0]and password==line_ list[1]:                     print ("* * *Login success ******* ")                      return True             else:                 print ("Incorrect account or password entry")                  i+=1def shopping ():     list_he=[]    offer=input (" Please enter your stored value card amount: "). Strip ()     if offer.isdigit ():         offer=int (offer)         while True:             shipin2 = [[' milk ',  20], [' jerky ',  30], [' rice ',  15], [' bread ',  15], [' beer ', 3.5]]            &nbsP;for i, a in enumerate (shipin2, 1):  #  cycle Print product List                  print ("Ordinal:%s"  % i,   "Goods:%s"  % a[0],  "Price:%s Yuan"  % a[1])              huo_qu = input ("Please enter the item you want to buy, enter [0] to exit"). Strip ()              if huo_qu.isdigit ():                 huo_qu=int (Huo_qu)                  if huo_qu > 0 and  huo_qu <= len (shipin2):  #  Verify input is correct                      j = shipin2[huo_ qu - 1]  #  PurchaseBuy Goods and Prices                      if j[1] > offer:  #  determine if the price of the item you want to buy exceeds the balance                           print ("Your balance is insufficient, please recharge in time")                      else:                         offer =  offer - j[1]  #  calculate the price after the purchase of the goods                          print ("The item you purchased is %s " % j[0], " Remaining amount is%s " % offer)   #  output purchased items                          list_he.append (J[0])    #  add purchased items to the collection                          print ("You have purchased%s"  % list_he)   #   Purchased goods collection                          continue                 elif huo_qu == 0:                     print ("Exit program, Goodbye")                       for m in list_he:                         print ("You have purchased%s"  % m)                      break                 else:                      Print ("The mall cargo is temporarily short, please enter the correct product serial number")     else:        print ("You have entered an illegal character, please re-enter") choice_dict={    1:regiter,    2:login,     3:shopping}while true:    print ("-------Welcome to Shopping malls-------           1: Registration            2: Login           3: Shopping            4: Exit            ')     choice=input ("Please select the serial number"). Strip ()     if choice.isdigit ():         choice =int (choice)         if choice>0 and choice<=len ( choice_dict):             choice_dict[choice] ()         else:             print ("You entered out of range")     else:         print ("You have entered an illegal character")

Refactoring Optimization python shopping cart