Referring to objects inside a list without using references or indices

Question

I'm using python for my shopping cart class which has a list of items. When a customer wants to edit an item, I need to pass the JavaScript front-end some way to refer to the item so that it can call AJAX methods to manipulate it.

Basically, I need a simple way to point to a particular item that isn't its index, and isn't a reference to the object itself.

I can't use an index, because another item in the list might be added or removed while the identifier is "held" by the front end. If I were to pass the index forward, if an item got deleted from the list then that index wouldn't point to the right object.

One solution seems to be to use UUIDs, but that seems particularly heavyweight for a very small list. What's the simplest/best way to do this?

Answer 1

Instead of using a list, why not use a dictionary and use small integers as the keys? Adding and removing items from the dictionary will not change the indices into the dictionary. You will want to keep one value in the dictionary that lets you know what the next assigned index will be.

Answer 2

A UUID seems perfect for this. Why don't you want to do that?

Do the items have any sort of product_id? Can the shopping cart have more than one of the same product_id, or does it store a quantity? What I'm getting at is: If product_id's in the cart are unique, you can just use that.