delete_item doesn't return empty Attributes when specifying ALL_OLD ReturnValues

[markonosetypless]

removed_item = table_resource.delete_item(
    Key={
        "PK": "PK",
        "SK": "SK",
    },
    ReturnValues="ALL_OLD",
)

if not removed_item["Attributes"]:
    pass # item did not exist

It used to be that deleting a non existing item would return an empty Attributes property in the response, but this seems to no longer be the case? When deleting a non existing item the property Attributes no longer exists in the response, when was this changed?

[tayfuryldz]

For DeleteItem, the safe contract is to treat Attributes as optional, not as an always-present mapping.

With ReturnValues="ALL_OLD", DynamoDB returns the item's old attributes if there was an item to return. For a key that did not exist, there are no old attributes, and the response may omit the Attributes member entirely. Boto3's generated response shape reflects that: Attributes is not a required response member.

So write the check as:

response = table_resource.delete_item(
    Key={"PK": "PK", "SK": "SK"},
    ReturnValues="ALL_OLD",
)

old_item = response.get("Attributes")
if old_item is None:
    # No previous item was returned.
    ...
else:
    # old_item contains the deleted item's previous attributes.
    ...

If older behavior happened to give you "Attributes": {}, relying on that representation is brittle because absence and an empty mapping both represent "no returned old item" at the SDK boundary. .get("Attributes") handles both forms without depending on the serialization detail.

If you need the delete to occur only when the item exists, use a condition expression instead; then nonexistence is an explicit conditional failure rather than inferred from returned attributes.