"Private" attributes - a possible idea (maybe PEP-worthy).

[Delaney, Timothy]

> From: Skip Montanaro [mailto:skip at pobox.com]
>     Tim> a.Klass -> _1__attr1 and _1__attr2
>     Tim> b.Klass -> _2__attr1 and _2__attr2
> 
> This would be unworkable.  Private attributes couldn't be pickled.

Damn - knew there had to be *something* big against it.

However, I can't help but feel that there must be *some* way to enforce that
a "private" variable won't be accidentally used by a subclass.

Hmm - would it be possible to save a class:id mapping in the pickle, and
have the private attributes re-written with the "real" class ID when
unpickling? No - don't think that would be possible - and would be
undesirable - we need a solution that doesn't require a change to the pickle
code (and hence everything that emulates the pickle code).

Any other ideas of how to get around this problem?

Unfortunately, whilst it's not a problem that is likely to crop up commonly,
it's one that when it *does* crop up is likely to cause real debugging
headaches. It is also (IMO) a wart in the language because it can cause such
obscure problems.

Tim Delaney