There has been a lot of discussion about updates to PEP 8. The contributing discussion is summarized in this python-dev summary, although the link to the work-in-progress summary is broken. I use instead the subversion snapshot for the PEP. A lot of the discussion makes sense to me, although I personally are in the "deprecate leading double underscore as private camp", despite Tim Peters's sensible arguments. I think the Timbot's arguments point instead to a need for a clearer declarative mechanism for privates variables. I'll be burned at the stake for making a suggestion that could whiff of C++ or Java envy, but I'll counter that even if the language has such a mechanism, I'll likely never use it.