购物车程序

需求：

1、启动程序后，让用户输入工资，然后打印商品列表

2、允许用户根据商品编号购买商品

3、用户选择商品后，检查余额是否够，够就直接扣款，不够就提醒

4、可随时退出，退出时，打印已购买商品和余额

Python代码实现如下：

# -*- coding: UTF-8 -*-
product_list = [
    ("Iphone",6888),
    ("Mac pro",9500),
    ("iwatch",10800),
    ("bike",960),
    ("book",56),
]
shopping_list = []
salary = input("input your salary:")
if salary.isdigit():
    salary = int(salary)
    while True:
        for index,item in enumerate(product_list):
            print(index,item)
        user_choice = input("选择要买吗？》》》：")
        if user_choice.isdigit():
                 user_choice = int(user_choice)
                 if user_choice < len(product_list) and user_choice >=0:
                     p_item = product_list[user_choice]#获取商品价格下标
                     if p_item[1] <=salary: #买的起
                         shopping_list.append(p_item) #选好的放入购物车
                         salary -= p_item[1]
                         print("added %s into shopping cart,your current balance is \033[31;1m%s\033[0m"%(p_item,salary))
                     else:
                        print("\033[41;1m你的余额只剩[%s]啦，还买个毛线啊\033[0m"%salary) #"\033[41;1m,,,\033[0m"加入颜色显示
                 else:
                     print("product code [%s] is not exist!"%user_choice)
        elif user_choice == "q":
            print("----shopping_list----") #打印已买商品列表
            for p in shopping_list:
                print(p)
            print("your current balance:",salary)
            exit()
        else:
            print("invalid option")
else:
    print("you input [%s] is not number!"%salary)