类属性 - 从列表中删除字典

Question

我正在尝试为用户编写代码，以便能够删除之前添加的条目。当前列表如下所示：

[{"_Item__id": 1,"item_name": "MAC PowerBook", "item_type": "Computer", "date_add": "01/06/2020", "dom": "16/02/2000", "item_info": "description of product"}, 
{"_Item__id": 2,"item_name": "Nokia 6210", "item_type": "Phone", "date_add": "01/06/2020", "dom": "01/02/2000", "item_info": "description of product"},  
{"_Item__id": 3, "item_name": "Kodak Retina", "item_type": "Camera", "date_add": "04/06/2020", "dom": "20/12/1931", "item_info": "description of product"}]

尝试使用以下代码：

def delete_item():
    print("{0:3}\t{1:20}\t{2:10}\t{3:10}".format("ID", "Item", "Date added", "Date manufactured"))
    for i in Item.py_collection_list:
        print("{0:03d}\t{1:20}\t{2:10}\t{3:10}".format(i.get_id(), i.item_name, i.date_add, i.dom))
        remove_item = input('Type name of the item you would like to delete from collection> ')
        if remove_item == "item_name":
            Item.py_collection_list[{"item_name"}].remove()

然后被重定向到主菜单。

试过这段代码：

def delete_item():
    print("{0:3}\t{1:20}\t{2:10}\t{3:10}".format("ID", "Item", "Date added", "Date manufactured"))
    for i in Item.py_collection_list:
        print("{0:03d}\t{1:20}\t{2:10}\t{3:10}".format(i.get_id(), i.item_name, i.date_add, i.dom))
        remove_item = input('Type name of the item you would like to delete from collection> ')
        if remove_item == i.item_name:
            for item in Item.py_collection_list[:]:
                if item['remove_item'] <= 0:
                    Item.py_collection_list.remove(item)

得到了这个错误：

TypeError: 'Item' object is not subscriptable

试过这段代码：

def delete_item():
    print("{0:3}\t{1:20}\t{2:10}\t{3:10}".format("ID", "Item", "Date added", "Date manufactured"))
    for i in Item.py_collection_list:
        print("{0:03d}\t{1:20}\t{2:10}\t{3:10}".format(i.get_id(), i.item_name, i.date_add, i.dom))
        remove_item = input('Type name of the item you would like to delete from collection> ')
        if remove_item == i.item_name:
            Item.py_collection_list.remove(remove_item)

得到了这个错误：

Item.py_collection_list.remove(remove_item)

ValueError: list.remove(x): x 不在列表中

试过这段代码：

def delete_item():
    print("{0:3}\t{1:20}\t{2:10}\t{3:10}".format("ID", "Item", "Date added", "Date manufactured"))
    for i in Item.py_collection_list:
        print("{0:03d}\t{1:20}\t{2:10}\t{3:10}".format(i.get_id(), i.item_name, i.date_add, i.dom))
        remove_item = input('Type name of the item you would like to delete from collection> ')
        for i in range(len(Item.py_collection_list)):
            if Item.py_collection_list[i]["item_name"] == remove_item:
                del Item.py_collection_list[i]

得到了这个错误：

if Item.py_collection_list[i]["item_name"] == remove_item:

TypeError: 'Item' 对象不可下标

试过这段代码：

def delete_item():
    print("{0:3}\t{1:20}\t{2:10}\t{3:10}".format("ID", "Item", "Date added", "Date manufactured"))
    for i in Item.py_collection_list:
        print("{0:03d}\t{1:20}\t{2:10}\t{3:10}".format(i.get_id(), i.item_name, i.date_add, i.dom))
        remove_item = input('Type name of the item you would like to delete from collection> ')
        if remove_item in Item.py_collection_list:
            del Item.py_collection_list[i.item_name]
            return True
        return False

被重定向到主菜单

这似乎是一个非常直接的创建选项，但我似乎完全在监督这个选项。

Answer 1

我建议先单独打印字典，即，如果您想向用户提供可用项目的列表，然后再要求输入以删除项目。

接下来你可以像这样在循环外输入。

remove_item = input("Type name of the item you would like to delete from collection:")
for i in Item.py_collection_list:
   if remove_item == i.item_name:
      Item.py_collection_list.remove(i)

这会从列表中删除与该项目对应的对象。

如果您想删除项目对象的“item_name”属性，请使用以下内容。

remove_item = input("Type name of the item you would like to delete from collection:")
for i in Item.py_collection_list:
   if remove_item == i.item_name:
      delattr(i, "item_name")