python-can 3.3.4 breaks functionality in a minor version

[albireox]

Commit 0c34e50 introduced this change in message.py

if key not in self.__slots__:
    raise AttributeError

This effectively disables the use of custom attributes in Message. It seems that's planned for version 4.0, but this change breaks any code that adds attributes to Message and does so in a patch version instead of a major one.

[hardbyte]

Thanks for reporting, if there is a clean way to still support custom attributes l'm happy to make a quick 3.3.5 release.

I'll note that we documented custom attributes on the Message class haven't been supported since the 3.0 release (See the Message docs)

Messages do not support “dynamic” attributes, meaning any others that the documented ones.

@karlding this was introduced from fixing #804, ensuring a message can be pickled. Any ideas for how can we might continue to support both custom attributes and pickling?

[albireox]

Thanks for the quick reply. For some reason I don't think I've ever seen one of the deprecation warnings, so I wasn't aware of this change. On my side I've updated my code to use a subclass of Message in which I override __slots__ to add my custom attributes, and I expect that will work fine for any version before or after 3.3.4, but I wanted to alert of the problem because I assume other users may be in the same situation.

[felixdivo]

Is there still some action needed on this?

[hardbyte]

I don't think any PRs were opened to fix 3.3.4, and there haven't been any other comments in half a year so I think it is safe to close.