python 购物小程序

'''
购物车
启动程序，要用户输入有多少钱
显示商品列单 1 iphone 5000
2 mac 9000
3 coffer 50
4 python book 80
用户在输入买的物品的序号
买不起的话，输入余额不足，还差多少
买的起的话加入购物车，还剩余额
继续
如果用户输入quit
打印买了多少东西
显示余额
欢迎下次光临
'''
import operator
while True:
    money=input("请输入你的金钱:")
    if money.isdigit():
        money=int(money)
        break
    else:
        print ("非法输入！")
product=[["book",30],["iphone",5000],["mac",8000],["coffer",20]]
shopping_list={}
money_leave=money
while True:
    print ("***********************")
    for i,v in enumerate(product,1):
        print(i,"--->",v)
    buy_index=input("请输入你要买的商品编号: 或者退出输入q:")
    if buy_index.isdigit():
        buy_index=int(buy_index)
        if buy_index>0 and buy_index<=len(product):
            buy_num=input("请输入你的购买数量:")
            if buy_num.isdigit():
                buy_num=int(buy_num)
                buy_money=buy_num*product[buy_index-1][1]
                if buy_money<=money_leave:
                    if product[buy_index-1][0] not in shopping_list:
                        print("第一次购买%s"%product[buy_index-1][0])
                        shopping_list[product[buy_index-1][0]]=buy_num
                        money_leave-=buy_money
                        print("你本次买了%d个%s"%(buy_num,product[buy_index-1][0]))
                    else:
                        shopping_list[product[buy_index-1][0]]=buy_num+shopping_list[product[buy_index-1][0]]
                        money_leave-=buy_money
                        print("你本次又买了%d个%s"%(buy_num,product[buy_index-1][0]))
                else:
                    print ("你的余额不足")
                    print("还差钱%d"%abs(money_leave-buy_money))
            else:
                print ("非法输入！")
        else:
            print ("输入的标号不在商品列表内")
    else:
        if operator.eq(buy_index,"q"):
            print ("你还剩%d钱,购买东西如下:"%money_leave)
            for s in shopping_list:
                print (s,"    x%d"%shopping_list[s])
            print ('''欢迎下次光临\n
------------------------------''')
            break
        else:
            print ("非法输入！")