[aur-general] [arch-dev-public] Python-3.x transition with python-2.7 update

[Gergely Imreh]

On 6 July 2010 20:09, Ng Oon-Ee <ngoonee at gmail.com> wrote:
> On Tue, 2010-07-06 at 10:51 +0200, Lukáš Jirkovský wrote:
>> On 6 July 2010 10:19, Isaac Dupree <ml at isaac.cedarswampstudios.org> wrote:
>> > On 07/06/10 01:57, Lukáš Jirkovský wrote:
>> >>
>> >> Hello Allan,
>> >> I know that I'm just a regular user but I'd like to express my opinion
>> >> too. I think the transition should be done when most modules and
>> >> applications support Python 3. I'd not be surprised if the transition
>> >> of majority of modules would take several years. By that time there
>> >> may be a way how to do a dual rename.
>> >
>> > Hi Lukas,
>> > Can you present a technical reason against doing the renaming now? Because
>> > as far as I can see, Allan has worked out the kinks and it will actually not
>> > harm you as a regular user at all...
>> >
>> > (unless you write personal scripts in python that you want to work with
>> > #!something on multiple distros? (then you probably want to run them in
>> > python version 2) .. I'm not sure I can think of an easy way to do that;
>> > maybe for each distro you use you could put a symlink in
>> > /usr/local/bin/python2 for example.)
>> >
>> > -Isaac
>> >
>>
>> Hi Isaac,
>> I don't write Python scripts but yeah, I think this is a real problem.
>> The other problem is that there are not many users of python 3 out
>> there.
>>
>> In a more subjective way I think whenever something is set as default
>> it should be the one which has most users (in both terms of people and
>> software).
>>
>> Lukas
>
> As another user (who doesn't write Python), I'd state that 'majority
> usage' is a pretty poor guideline for users of a Linux distro, and a
> relatively small one at that.
>
> I'm all for the option which reduces workload on the packagers. Of
> course if things break big-time then it may be a problem, but that's
> what [testing] is for, and those of us using it should know what to do
> if/when breakage occurs.
>
>


Some more background info for those who are not that familiar why the
Python 2 vs. 3 is such a big problem (there seem to plenty of people,
and sorry for the ones who already know this inside out):
http://wiki.python.org/moin/Python2orPython3

>From that page:
"Popular modules that don't yet support Python 3 include Twisted (for
networking and a bunch of other stuff), gevent (like Twisted but
different), Django and Pylons (for building websites), PyGTK and
PySide (for making GUIs), py2exe (for packaging your application for
Windows users), PIL (for processing images), numpy (for number
crunching)..."

Thus I would mind a rebuild less, than losing my daily numpy/scipy/PyGTK...

Arch is not in a position to force these packages to update to Python
3, and such I don't think it's a good idea to bump the default version
up to 3. On the other hand, there are plenty of people who are
experienced in code fixes, so maybe there would be some who would join
the porting effort for those packages that they use on a regular
basis. This could accelerate the transition.

Cheers,
    Greg