[Python-Dev] Deprecate __ private (was Re: PEP 8 updates/clarifications)

[Guido van Rossum]

On 12/12/05, Jim Fulton <jim at zope.com> wrote:
> In practice, I don't agree that it works fine.  Inevitably, someone
> finds a need to access a "private" variable in a subclass.  Or
> even in the original class, you find some need to use something like
> __getattr__ where the implicit name mangling doesn't come into play
> and you have to emulate the name mangling.  Or perhaps someone wants
> to examine the value of one of these variables in the debugger.
> In my experience, almost every time someone uses the __private
> trick, they or someone else comes to regret it.
>
> OTOH, explicit name mangling provides the benefits of implicit
> name mangling without it's drawbacks.

I half agree. I've seen many classes overuse __private. But that's a
separate issue from not having the feature at all; you might as well
argue against private in Java or C++.

--
--Guido van Rossum (home page: http://www.python.org/~guido/)