Python杂货店

Question

我在这干了几天了。我需要能够在购物车列表中返回用户以前购买的项目。我不知道该怎么办！在

items = [('diapers', 10.00), ('peanuts', 5.00), ('butter', 6.25), ('cheese', 
3.00), ('milk', 3.5), ('yogurt', 1.99), ('eggs', 4.5), ('bread', 4), 
('shrimp', 2.5), ('coffee', 1.5)]

money = 50
ask = ('buy', 'return', 'quit')
cartList = []

while ask != 'quit':

    print("""

        Diapers ....10.00
        Peanuts ....5.00
        Butter .....6.25
        Cheese .....3.00
        Milk .......3.50
        Yogurt .....1.99
        Eggs .......4.50
        Bread ......4.00
        Shrimp .....2.50
        Coffee .....1.50
        """)

     ask = input('Do you want to buy, return or quit?\n').lower()

     if ask == 'buy':
         item = input('\nWhat item do you need?\n').lower()

         for i in items:
             if item == i[0]:
                 print(item, 'is $', i[1])
                 ques = input('\nDo you want to buy this item? 
                 [Y:N]\n').lower()

             if i[1] > money:
                 print('You do not have enough money for this item :(\n')
                 break

             if ques == 'n':
                 print('Sorry that you do not want that item :(')
                 break

             if ques == 'y':
                 money = money - i[1]
                 print('\nYou now have $', money)
                 cartList.insert(0, item)

                 print('You have these items in your cart:\n', cartList, 
                 '\n')

             else:
                print('You entered an incorrect value :(')

     if ask == 'return':
         ret = input('What item do you want to return?\n')

         for i in cartList:
             if ret == i[0]:
                 print(i[0], '$', i[1])
                 quest = input('Do you want to return this item? 
 [Y:N]]\n').lower()

         else:
             print('This item is not in your cart!\n')



 print('\nThank you for shopping with us!')

如果有ask=return，我需要用户能够返回他们购买的项目。我尝试了几次或多次尝试，试图让用户能够返回项目。在

Answer 1

把你认为问题所在的地方插入购物车。你只插入物品，而不是钱。所以在返回部分，必须是：

if ask == 'return':
    ret = input('What item do you want to return?\n')
    for i in cartList:
        if ret==i:
        ...

或者，如果要将项目和金钱同时插入cartList，则应为：

^{pr2}$

此外，您还没有为任务（Y/N）构建if-else部分 如果用户输入是Y，则可能需要使用del方法从cartList中删除该元素

Answer 2

除了缺少的逻辑（如从购物车列表中删除返回项）之外，代码中几乎没有小的缩进错误。 试着把所有的东西都打印出来

if ask=='return':
     print cartList

在您要求customer返回该项之后，请尝试python的remove方法从列表中返回该项。在

^{pr2}$