Will python never intend to support private, protected and public?

[Paul Boddie]

Paul Rubin wrote:
> If changing the way a class uses its own private variables breaks an application
> because another class was using the private variable unexpectedly,
> then that's bad, regardless of whether the other class's author was
> notified or not.  It's better to let the compiler automatically flag
> these things, than to depend on conventions.

The problem with Python's compiler as it is today is that it can't
generally detect private attribute access: information about an
object/class being accessed is only guaranteed to be available at
run-time. Of course, Bastion and its peers [1] "solve" this by
introducing run-time environments which seek to guarantee attribute
privacy.

As for the merits of private/protected/final attributes and methods,
I've seen enough time-wasting and premature "security" optimisations to
know that such facilities can also waste a tremendous amount of time in
multi-person projects.

Paul

[1] At EuroPython there was a talk about protecting object attributes
in Ubuntu Launchpad [2], for which the slides are apparently
unavailable, and while chatting about this later on I noted that I'd
seen something like it before. The realisation that mxProxy [3] was
this apparently often overlooked thing occurred more or less
simultaneously with the realisation that I was talking to its author.
:-)

[2]
http://www.python-in-business.org/ep2005/talk.chtml?talk=1610&track=692

[3] http://www.egenix.com/files/python/mxProxy.html