Python代码之购物车

# -*- coding:utf-8 -*-
#Author:Mr Gan

不足之处：输入商品编号时必须是整型，其他类型会报错
import sys 
balance = int(input("your money:"))

shopping_bag = [] #创建购物包
shopping_list = [["iphone",5800],["watch",2600],["book",56],["computer",7800]]

while True:
    for index,i in enumerate (shopping_list):
        print(index,i)
    pro_num = input("production number:")

    with open("余额文件",'w+') as left_money:
        if pro_num == "q":
            left_money.write(balance)
            print("your balance left \033[31;1m%s\033[0m" % balance)
            sys.exit() 
        elif pro_num.isdigit(): #判断输入的商品编号是否是数字
            pro_num = int(pro_num)
            #pro_name = shopping_list[pro_num]

            if 0<= pro_num <len(shopping_list):# and pro_name[1] <= balance: # 动态判断，不要写死掉
                pro_name = shopping_list[pro_num]
                if pro_name[1] <= balance:
                    shopping_bag.append(shopping_list[pro_num][0])
                    balance -= pro_name[1]
                else:
                    print("your banlance is not ennough,please choose others")
            else:
                print("no production,choose again")
            for i in shopping_bag: #遍历已购买的商品
                print("\033[31;1m%s\033[0m" % i)#打印所有已经购买的商品
            print("your balance left \033[31;1m%s\033[0m" % balance)
        pass