python小程序实现简单简单的购物车功能

#！/usr/bin/env python
# -*- coding:utf-8 -*-
#Author:QiFeng Zhang

#初始化商品列表
goods_list = [("iphone",8500),("xiaomi",2900),("huawei",3500),("S6",5500),("小米电源",100)]
#初始化账户余额
user_acount = input("请输入您的余额：")
shoping_list = []
if user_acount.isdigit():
    user_acount = int(user_acount)
    while True:
        for i,k in enumerate(goods_list):#打印商品列表
             print(i,k)
        user_select = input("请输入您要购买的商品前面的编号>>>")
        if user_select.isdigit():#校验用户输入
            user_select = int(user_select)
            if user_select >= 0 and user_select < len(goods_list):
                if user_acount >= goods_list[user_select][1]:
                    shoping_list.append(goods_list[user_select])
                    user_acount -= goods_list[user_select][1]
                    print("Added %s into shoppint cart,your current balance is \033[31;1m%s\033[0m"%(goods_list[user_select],user_acount))
                else:
                    print("您的余额不足以支付所购商品金额，请选择其他商品")
            else:
                print("输入的商品编码不存在")
        elif user_select == 'q':   #输入q打印购买商品并退出程序
            print("您购买的商品是>>>");[print(line) for line in shoping_list]
            exit()
        else:
            print("无效的输入，请重新输入")
            continue
else:
    print("您输入的余额不正确。")