An article about the "attrs" library was posted here a couple weeks ago. Really highlighted the tedium of Python objects while offering a neat solution.

https://glyph.twistedmatrix.com/2016/08/attrs.html

Regarding protobuf, I'm a bit disappointed with the direction of version 3. Fields can no longer be marked as required - everything is optional; i.e. almost every protobuf needs to be wrapped with some sort of validator to ensure that necessary fields are present. I understand the arguments, but I did enjoy letting protobuf do the bulk of the work making sure fields were present.