前幾天寫的購物程式碼覺得特別冗餘，而且可操作性不強，很容易出錯，今天做如下簡化，好用多了。

 1 # -*- coding:utf-8 -*-
 2 # __Author__ : "110"
 3 # date:2018/12/27
 4 salary = 5000
 5 
 6 shop_list = [('iphone',9000),('mac book',10000),('python book',90),('coffee',32),
 7              ('bicycle',1500)]
 8 
 9 money = input("請輸入您的現金總數：
 
")
10 money = int(money)
11 have_buy_commodity = []
12 while True:
13     for i, v in enumerate(shop_list, 1):
14         print(i, v)
15 
16     query_buy_shop = input("請輸入要購買的商品編號，q[退出]：")
17 
18     if query_buy_shop.isdigit():
19         query_buy_shop = int(query_buy_shop)
20 
21         if query_buy_shop >=1 and
 
 query_buy_shop <=5:
22             spend_money = shop_list[query_buy_shop-1]
23             buy_commodity = shop_list[query_buy_shop-1][0]
24             money = money - spend_money[1]
25 
26             if money < 0:
27                 print("您的餘額不足,無法購買此商品！")
28                 print('--------Shop List--------
 
')
29                 print(have_buy_commodity)
30                 print('--------------------------')
31                 break
32             else:
33                 have_buy_commodity.append(buy_commodity)
34                 print("您的餘額為%s元!" % money)
35 
36     elif query_buy_shop == 'q':
37         print("已退出購物系統！")
38         print("您的餘額為%s元!" % money)
39         print('--------Shop List--------')
40         print(have_buy_commodity)
41         print('--------------------------')
42         break
43 
44     else:
45         print("輸入的字元非法,請重新選擇!")

程式碼解析：