[Python-ideas] Create Python 2.8 as a transition step to Python 3.x

[Chris Angelico]

On Mon, Jan 20, 2014 at 2:06 PM, Stephen J. Turnbull <stephen at xemacs.org> wrote:
> Steven D'Aprano writes:
>
>  > To me, that's a step backwards.
>
> I agree, but this kind of "step backwards" is a "consenting adults"
> issue.  So let's avoid such pejorative terminology, and stick to the
> line that a lot of resources would be required to create such a Python
> 2.8, and there's little benefit to be had.

No, I'm with Steven on this. (Steven with a v, as opposed to Stephen
with a ph. It's like talking to the detectives in Tintin.) Even if it
cost no resources at all - if Python 2.8 already existed, exactly as
described - it would be a third Python to aim for (as well as 2.7 and
3.x). It's already hard enough to span lots of Python versions; adding
another that's deliberately and consciously incompatible with both the
primary branches would be a major problem. It may be that code that
runs on 2.7 and 3.4 will also automatically run on 2.8 (which seems
possible, but far from certain), but if not, 2.8 would cause problems
for everyone who tries to write code for every supported version. For
anything other than in-house scripts where one person/team controls
both the script and the interpreter it runs on, compatibility with
multiple versions will be critical; and adding something incompatible
with both current versions is an XKCD 927 situation [1]. No matter how
cheap or expensive it is to do, that's a problem *in itself*, so the
proposal has to justify itself enough to overcome that.

ChrisA

[1] http://xkcd.com/927/