[Python-Dev] Python 2.x and 3.x use survey, 2014 edition

[Petr Viktorin]

Also keep in mind that not all Python libraries are on PyPI.
For non-Python projects with Python bindings (think video players,
OpenCV, systemd, Samba), distribution via PyPI doesn't make much
sense. And since the Python bindings are usually second-class
citizens, the porting doesn't have a high priority.

If anyone is wondering why their favorite Linux distribution is stuck
with Python 2 – well, I can only speak for Fedora, but nowadays most
of what's left are CPython bindings.
No pylint --py3k or 2to3 will help there...


On Fri, Dec 12, 2014 at 7:24 PM, Mark Roberts <wizzat at gmail.com> wrote:
> So, I'm more than aware of how to write Python 2/3 compatible code. I've
> ported 10-20 libraries to Python 3 and write Python 2/3 compatible code at
> work. I'm also aware of how much writing 2/3 compatible code makes me hate
> Python as a language. It'll be a happy day when one of the two languages
> dies so that I never have to write code like that again. However, my point
> was that just because the core libraries by usage are *starting* to roll out
> Python 3 support doesn't mean that things are "easy" or "convenient" yet.
> There are too many libraries in the long tail which fulfill semi-common
> purposes and haven't been moved over yet. Yeah, sure, they haven't been
> updated in years... but neither has the language they're built on.
>
> I suppose what I'm saying is that the long tail of libraries is far more
> valuable than it seems the Python3 zealots are giving it credit for. Please
> don't claim it's "easy" to move over just because merely most of the top 20
> libraries have been moved over. :-/
>
> -Mark
>
> On Thu, Dec 11, 2014 at 12:14 PM, Dan Stromberg <drsalists at gmail.com> wrote:
>>
>> On Thu, Dec 11, 2014 at 11:35 AM, Mark Roberts <wizzat at gmail.com> wrote:
>> > I disagree. I know there's a huge focus on The Big Libraries (and
>> > wholesale
>> > migration is all but impossible without them), but the long tail of
>> > libraries is still incredibly important. It's like saying that migrating
>> > the
>> > top 10 Perl libraries to Perl 6 would allow people to completely ignore
>> > all
>> > of CPAN. It just doesn't make sense.
>>
>> Things in the Python 2.x vs 3.x world aren't that bad.
>>
>> See:
>> https://python3wos.appspot.com/ and
>> https://wiki.python.org/moin/PortingPythonToPy3k
>> http://stromberg.dnsalias.org/~strombrg/Intro-to-Python/ (writing code
>> to run on 2.x and 3.x)
>>
>> I believe just about everything I've written over the last few years
>> either ran on 2.x and 3.x unmodified, or ran on 3.x alone.  If you go
>> the former route, you don't need to wait for your libraries to be
>> updated.
>>
>> I usually run pylint twice for my projects (after each change, prior
>> to checkin), once with a 2.x interpreter, and once with a 3.x
>> interpreter (using
>> http://stromberg.dnsalias.org/svn/this-pylint/trunk/this-pylint) , but
>> I gather pylint has the option of running on a 2.x interpreter and
>> warning about anything that wouldn't work on 3.x.