购物车简单程序

#流程：显示购物单，提醒选择加入购物车，余额不足，退出购物

product_list = [
    ("Mac",9000),
    ("tesla",11000),
    ("python book",50),
    ("bike",194),
    ("kindle",2400),
]
#显示购物单
saving = input("请存入金额：")
if saving.isdigit():
    saving = int(saving)
for i , v in enumerate(product_list,1) :
    print( i, v )
shopping_cart = []
#提醒选择选择加入购物车
while True:
    choice = input("前选择商品序号，退出[q]")
    if choice.isdigit():
        choice = int(choice)
        if 0 < choice <= len(product_list):
            p_item = product_list[choice]
            if saving >= p_item[1]:
                shopping_cart.append(p_item)
                saving = saving - p_item[1]
            else :
                print("余额不足，还剩%s元钱"%saving)
        else :
            print("请输入正确序号")
    elif choice == "q": #余额不足，退出购物
        print("购物单如下")
        for i in shopping_cart:
            print( i )
        print("您还剩%s元钱"%saving)
        break
    else :
        print("请输入正确内容")