[Python-3000] Py3k release schedule worries

[Guido van Rossum]

On 12/18/06, Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
> Brett Cannon wrote:
> > I think another big reason, though, is people are taking the view of
> > Py3k really far in terms of it being a clean slate.  I have always viewd
> > Python 3.0 as Python 2.x cleaned up.  That leaves Python 3.whatever for
> > new additions.  But I think a lot of people have skipped past the goal
> > of getting a cleaned-up Python 3.0 and made that the whiz-bang version.
>
> I think the reason for this is that we've been given
> the impression that the 2.x -> 3.0 transition is the
> one and only chance we'll get in our lifetimes for
> backward-incompatible changes -- so if we don't get
> them in now, we never will.

But many of the proposals being discussed aren't backwards compatible
at all! They could be added to 2.6 just as easily as to 3.0. (Not all,
just many.)

Even if 3.0 *was* the only chance we ever get, and even if we were
only discussing changes that *were* incompatible, I *still* would like
to limit such discussions because otherwise we might as well set the
release date for the year 3000. I'm not interested in waiting until
it's perfect -- "good enough" is good enough for me.

> But maybe this is the wrong impression. If it's
> going to be allowable to incorprorate more backward
> incompatible features as the 3.x series progresses,
> it would be good to make that clear to everyone.
> I'm sure it would do a lot to reduce the amount of
> radical stuff being suggested for 3.0.

No, after 3.2 or so we'll be as backward compatible as we ever were,
probably more so if we are successful -- the more users we have the
more compatible we must be. We could try for another incompatibility
step at 4.0 but it's not clear that that will be possible.

I'm allowing for small incompatibilities between 3.0, 3.1 and 3.2 only
because I expect that 3.0, when it comes out, will be the first
version that most users will try, and we will surely have to release a
few quick upgrades to address the most egregious mistakes. But by 3.2
we should be stable.

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