1 # 简单的购物小程序
 2 
 3 product_list = [
 4     [‘surface pro 4‘, 7800],
 5     [‘dell xps 15‘, 12000],
 6     [‘macbook‘, 12000],
 7     [‘小米6‘, 2499],
 8     [‘iphone7‘, 4600],
 9     [‘坚果Pro‘, 1499]
10 ]
11 shopping_list = []
12 
13 
14 # 判断输入的薪水格式是否正确
15 while True:
16     salary = input(‘\n请输入您的薪水：‘)
17     if not salary.isdigit():                    # 薪水不是数字，结束循环
18         print(‘\n输入格式有误！请重新输入...‘)
19         continue
20     break
21 
22 
23 balance = salary = int(salary)
24 
25 print(‘\n-----------欢迎购买------------\n‘)
26 
27 # 生成带序号的商品列表
28 for index, item in enumerate(product_list):
29     print(index, item)
30 
31 
32 # 判断输入的序号是否符合要求
33 while True:
34 
35     while True:
36         i = input(‘\n输入您要购买的商品序号，或输入 q 取消购买：‘)
37         if i == ‘q‘:                                 # 输入 q 退出购买界面
38             while True:
39                 a = input(‘\n是否继续购买？(Y/N)：‘)
40                 if a != ‘n‘ and a != ‘N‘ and a != ‘y‘ and a != ‘Y‘:
41                     print(‘\n输入格式有误，请重试...‘)
42                     continue
43                 elif a == ‘y‘ or a == ‘Y‘:                  # 继续购买
44                     break
45                 else:                                       # 购买完毕
46                     if balance == salary:              # 没有买任何东西
47                         print(‘\n交易结束，购买失败...‘)
48                         exit()
49                     else:                              # 结算   
50                         print(‘\n您已成功购买以下商品：\n‘)
51                         for item in shopping_list:
52                             print(item)
53                         print(‘\n共消费金额 %d 元，余额 %d 元‘ % (salary - balance, balance))
54                         exit()
55             continue
56 
57         if not i.isdigit():                          # 序号不是数字，结束循环
58             print(‘\n输入格式有误！请重新输入...‘)
59             continue
60 
61         i = int(i)
62 
63         if i < 0 or i >= len(product_list):   # 序号范围不正确，结束循环
64             print(‘\n此商品不存在，请重新输入...‘)
65             continue
66         break
67 
68     product = product_list[i]
69     price = int(product[1])
70 
71     # 判断余额是否充足，够就直接扣款，不够提醒
72     if price <= balance:
73         balance -= price
74         shopping_list.append(product_list[i])
75         print(‘\n您已成功购买 %s ，当前余额为 %d 元‘ %(product, balance))
76     else:
77         print(‘\n购买失败，您的余额不足...‘)
78 
79     while True:
80         a = input(‘\n是否继续购买？(Y/N)：‘)
81         if a != ‘n‘ and a != ‘N‘ and a != ‘y‘ and a != ‘Y‘:
82             print(‘\n输入格式有误，请重试...‘)
83             continue
84         break
85 
86     if a == ‘Y‘ or a == ‘y‘:
87         continue
88     else:
89         break
90 
91 if balance == salary:
92     print(‘\n交易结束，购买失败...‘)
93     exit()
94 else:
95     print(‘\n您已成功购买以下商品：\n‘)
96     for item in shopping_list:
97         print(item)
98     print(‘\n共消费金额 %d 元，余额 %d 元‘ %(salary-balance, balance))
99     exit()