[Python-Dev] [RELEASED] Python 2.7 alpha 2

Andrew Bennetts andrew at bemusement.org
Tue Jan 12 01:07:26 CET 2010


"Martin v. Löwis" wrote:
[...]
> I've done a fair bit of 3.x porting, and I'm firmly convinced that
> 2.x can do nothing:
[...]
> Inherently, 2.8 can't improve on that.

I agree that there are limitations like the ones you've listed, but I
disagree with your conclusion.  Maybe you assume that it's just as hard
to move to 2.8 (using the py3k backports not available in say 2.5) as it
is to 3.x?

But a hypothetical 2.8 would also give people a way to move closer to
py3k without giving up on using all their 2.x-only dependencies.  I
think it's much more likely that libraries like Twisted can support 2.8
in the near future than 3.x.

Then, when all of your dependencies (or viable alternatives to those
dependencies) are available for 3.x, you'll have an easier transition if
you can start from a 2.x with fewer differences in features.

Fundamentally the more 2.x can converge on 3.x, the easier it will be
for users to make the leap, because it will be a smaller leap.  The
longer the 2.x series lives, the more these newer 2.x versions like 2.7
and maybe even 2.8 will be available on common platforms for people to
depend upon as minimum versions, which means that as time goes by they
can depend on a version that's closer to 3.x.  And so again, the leap
becomes easier to make.  So to me it's pretty clear that 2.8 *can*
improve the transition path to 3.x.  It may or may not be a worthwhile
use of effort for python-dev to make 2.8, but that's different to saying
it's inherently pointless.

-Andrew.



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