类属性 - 从列表中删除字典

Question

我正在尝试为用户编写代码，以便能够删除以前添加的条目。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"}]

已尝试使用以下代码：

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()

并被重定向到主菜单。

尝试了以下代码：

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 == i.item_name:
for item in Item.py_collection_list[:]:
if item['remove_item'] <= 0:
Item.py_collection_list.remove(item)

并得到此错误：

TypeError: 'Item' object is not subscriptable

尝试了以下代码：

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 == i.item_name:
Item.py_collection_list.remove(remove_item)

并得到此错误：

Item.py_collection_list.remove(remove_item)

ValueError： list.remove(x(： x 不在列表中

尝试了以下代码：

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> ')
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]

并得到此错误：

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

类型错误："项"对象不可下标

尝试了以下代码：

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 in Item.py_collection_list:
del Item.py_collection_list[i.item_name]
return True
return False

已重定向到主菜单

这似乎是一个非常直接的选择，但我似乎完全监督了这个选项。

Answer 1

我建议先单独打印词典，即如果您想向用户提供可用项目列表，然后再要求输入删除项目。

接下来，您可以将输入带到循环之外，如下所示。

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)

这将从列表中删除与该项对应的对象。

如果要删除项对象的"item_name"属性，请使用以下命令。

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")