[Zope-dev] dropping Python 2.4 support in the Zope Toolkit?

[Martin Aspeli]

Lennart Regebro wrote:
> On Tue, May 5, 2009 at 11:55, Martin Aspeli <optilude+lists at gmail.com> wrote:
>> We've had some more discussions about this and the Plone release
>> schedule. The upshot is that if Zope 3/Toolkit drops Python 2.4 support,
>> it will effectively render it inaccessible to Plone users for the next
>> 12-18 months. We're not comfortable moving to Zope 2.12 for the 3.x
>> series. We may be able to move to Zope 2.11, which *may* work with
>> Python 2.5, but this is not clear.
> 
> Can you expand on this argument, because I don't understand it. Zope
> 2.10 doesn't stop working because Zope 2.12 no longer supports Python
> 2.4. And you are not expected to use Zope Toolkit with Zope 2.10, as
> Zope 2.10 uses Zope 3.3 rather than Zope Toolkit.

  - I think that as a principle, dropping support for a Python version 
that's commonly used in our community, should be a decision that 
requires a strong argument *for*, not a strong argument *against*.

  - The Zope Tool Kit aims to be a bridge between our different 
communities, and possibly other communities that may want to consume 
Zope software (are all of those using Python 2.5?). That means that 
those of us who are not in a position to move to Python 2.5+ soon 
deserve to be heard. Of course, Plone's point of view shouldn't be 
overriding to other concerns, but see point 1.

  - If you count the "Zope community" as those who also maintain Zope 2, 
we need to recognise that there's been no viable way for Plone to get to 
Python 2.5 until now, and the other changes in 2.12 mean it's not 
feasible to upgrade to it in the 3.x series. This is nobody's fault, of 
course, but it does leave a chasm that'll only widen as time goes on.

  - Once the ZTK is decreed to no longer need to support Python 2.4, I 
suspect no new development on the Zope platform will bother with it 
either. That means users of Plone can't use these packages. That in turn 
deprives those Zope packages of testers and potential contributors.

  - We are using Zope 3.4+ packages successfully with Zope 2.10 right 
now. I don't see that the ZTK will be any different. In fact, ZTK should 
help here, because we're getting a saner dependency structure.

The Plone community is working hard to move to Python 2.5, but reality 
is we won't get there for another 12-18 months, in part because Zope 
2.12 is only now entering alpha and incorporates a lot of other (good!) 
changes that we need more time to integrate and work out a migration 
story for.

Martin

-- 
Author of `Professional Plone Development`, a book for developers who
want to work with Plone. See http://martinaspeli.net/plone-book