[python] How to decorate a class?

There's actually a pretty good implementation of a class decorator here:

https://github.com/agiliq/Django-parsley/blob/master/parsley/decorators.py

I actually think this is a pretty interesting implementation. Because it subclasses the class it decorates, it will behave exactly like this class in things like isinstance checks.

It has an added benefit: it's not uncommon for the __init__ statement in a custom django Form to make modifications or additions to self.fields so it's better for changes to self.fields to happen after all of __init__ has run for the class in question.

Very clever.

However, in your class you actually want the decoration to alter the constructor, which I don't think is a good use case for a class decorator.