购物车：

product_list=[
    ("TV",2000),
    ("Ipad",4000),
    ("Bike",1000),
    ("Book",500)
]
shopping_list=[]

money=input("Please input your current money:")

if money.isdigit():
    money=int(money)
    while True:
        for index,item in enumerate(product_list):
            print(index,item)
        user_choice=input("Please choose what you want to buy:")
        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]
                if p_item[1] <= money:
                    shopping_list.append(p_item)
                    money -= p_item[1]
                    print("Added %s into shopping cart,your current money is