how to tell if it's safe to go from new-style to classic class?

[Dave Brueck]

Skip Montanaro wrote:

> If I have a new-style class what are the restrictions that keep me from
> going back to a classic class?  I know use of __slots__, __new__ or the
> property() builtin make new-style a requirement.  What other constructs
> might the code be using that would prevent me from falling back to use of
> classic classes?

Code that uses super() would have to be refactored.

-Dave