Hello, there has been quite some discussion on why PEP 487's __init_subclass__ initializes subclasses, and not the class itself. I think the most important details have been already thoroughly discussed here.
One thing I was missing in the discussion is practical examples. I have been using PEP 487-like metaclasses since several years now, and I have never come across an application where it would have even been nice to initialize the class itself. Also, while researching other people's code when I wrote PEP 487, I couldn't find any such code elsewhere, yet I found a lot of code where people took the wildest measure to prevent a metaclass in doing its job on the first class it is used for. One example is enum.EnumMeta, which contains code not to make enum.Enum an enum (I do not try to propose that the enum module should use PEP 487, it's way to complicated for that). So once we have a practical example, we could start discussing how to mitigate the problem. Btw, everyone is still invited to review the patch for PEP 487 at http://bugs.python.org/issue27366. Many thanks to Nick who already reviewed, and also to Guido who left helpful comments! Greetings Martin _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
