购物车程序优化2

前几天写的购物代码觉得特别冗余，而且可操作性不强，很容易出错，今天做如下简化，好用多了。

# -*- coding:utf-8 -*-
# __Author__ : "110"
# date:2018/12/27
salary = 5000

shop_list = [('iphone',9000),('mac book',10000),('python book',90),('coffee',32),
             ('bicycle',1500)]

money = input("请输入您的现金总数：")
money = int(money)
have_buy_commodity = []
while True:
    for i, v in enumerate(shop_list, 1):
        print(i, v)

    query_buy_shop = input("请输入要购买的商品编号，q[退出]：")

    if query_buy_shop.isdigit():
        query_buy_shop = int(query_buy_shop)

        if query_buy_shop >=1 and query_buy_shop <=5:
            spend_money = shop_list[query_buy_shop-1]
            buy_commodity = shop_list[query_buy_shop-1][0]
            money = money - spend_money[1]

            if money < 0:
                print("您的余额不足,无法购买此商品！")
                print('--------Shop List--------')
                print(have_buy_commodity)
                print('--------------------------')
                break
            else:
                have_buy_commodity.append(buy_commodity)
                print("您的余额为%s元!" % money)

    elif query_buy_shop == 'q':
        print("已退出购物系统！")
        print("您的余额为%s元!" % money)
        print('--------Shop List--------')
        print(have_buy_commodity)
        print('--------------------------')
        break

    else:
        print("输入的字符非法,请重新选择!")

代码解析：