Python3 Shopping Cart applet, balance write file Save

Python3 Shopping Cart applet, balance write file Save

#!/usr/bin/env python#-*-coding:utf-8-*-# Author:hiuhung wangoods = (("MiNote3", 2499), ("Bike", 799), ("MACB    Ook ", 6999), (" Coffee ", +), (" RedMiNote3 ", 1099), (" Python 3 ", ()) def main ():" Entry: Return: "    # Create a file to store the balance. Try:with open (' Balance.txt ', ' R ') as F:data_str = F.read () if Data_str and (not data_str.is Space ()): # has content, balance = Int (data_str) Else: # There is a file, but no content balance = input ("please                    Enter your wallet balance: ") if Balance.isnumeric (): balance = Int (balance) Else:                    Print ("Please enter a positive integer") exit () with open (' Balance.txt ', ' W ') as F:  F.write (str (balance)) except Filenotfounderror as E: # Create and write content without this file balance = input ("Please enter your wallet balance:") if Balance.isnumeric (): balance = Int (balance) else:print ("Please enter a positive integer") exit () W ItH Open (' Balance.txt ', ' W ') as F:f.write (str (balance)) Finally:f.close () # closes the file. Go_back_flag = True Shopping_list = [] While go_back_flag:for I, j in Enumerate (goods): print (I, j) User_chiose = input ("Wallet balance is:%. 2f, what do you want to buy?") "% (balance)) if User_chiose = = (" q "or" Q "): Go_back_flag = False Continue elif user _chiose.isnumeric (): user_chiose = Int (user_chiose) else:print ("Please enter the above serial number") Contin                UE if User_chiose <= len (Goods)-1: #符合 if goods[user_chiose][1] <= balance: #买得起 Balance-= goods[user_chiose][1] with open (' Balance.txt ', ' W ') as F: # Update balance (overwrite) F.WR                ITE (str (balance)) F.close () print ("%s added to your cart"% (goods[user_chiose][0)) Shopping_list.append (Goods[user_chiose]) else:print ("The balance is not enough to buy.     ") Else:       Print ("Out of range, no this serial number") print ("Your wallet balance is:%.2f.")  "% (balance)) If Len (shopping_list) = = 0:print (" You don't have to buy anything ") Else:print (" The product you have purchased below ") for I In Shopping_list:print (i) if __name__ = = "__main__": Main ()

　　

The effect is as follows:

C:\Python36\python.exe d:/py/1704/day05/shopping cart. Py Please enter your wallet balance: 66660 (' MiNote3 ', 2499) 1 (' Bike ', 799) 2 (' MacBook ', 6999) 3 (' Coffee ', 4 (' RedMiNote3 ', 1099) 5 (' Python 3 ', 59) wallet balance is: 6666.00, what do you want to buy? 3 added Coffee to your cart 0 (' MiNote3 ', 2499) 1 (' Bike ', ' 799 ') 2 (' MacBook ', 6999) 3 (' Coffee ', ' 4 ') + (' RedMiNote3 ', 1099) 5 (' Python 3 ') , 59) Wallet balance is: 6641.00, what do you want to buy? 2 The balance is not enough to buy. 0 (' MiNote3 ', 2499) 1 (' Bike ', 799) 2 (' MacBook ', ' 6999 ') 3 (' Coffee ', ' + 4 ') 5 (' RedMiNote3 ', ' 1099 ') (' Python 3 ', 59) wallet balance is: 6641.0 0, what do you want to buy? 1 added Bike to your cart 0 (' MiNote3 ', 2499) 1 (' Bike ', 799) 2 (' MacBook ', ' 6999 ') 3 (' Coffee ', ' 4 ') + (' RedMiNote3 ', 1099) 5 (' Python 3 ', 59) Wallet balance is: 5842.00, what do you want to buy? Q Your wallet balance is: 5842.00. Below will list the items you have purchased (' Coffee ', ' + ') (' Bike ', 799) Process finished with exit code 0

　　

Python3 Shopping Cart applet, balance write file Save