[Distutils] Current Python packaging status (from my point of view)

[Paul Moore]

On 3 November 2016 at 21:48, Chris Barker <chris.barker at noaa.gov> wrote:
> On Thu, Nov 3, 2016 at 3:50 AM, Paul Moore <p.f.moore at gmail.com> wrote:
>
>>
>> Even on the "hard" cases like Windows, it may be possible to define a
>> standard approach that goes something along the lines of defining a
>> standard location that (somehow) gets added to the load path, and
>> interested parties provide DLLs for external dependencies, which the
>> users can then manually place in those locations.
>
> that't pretty much what conda is :-)

Well, it doesn't feel like that. Maybe we're not understanding each
other. Am I able to take a non-conda installation of Python, use conda
to install *just* a set of non-Python DLLs (libxml, libyaml, ...) and
then use pip to install wheels for lxml, pyyaml, etc? I understand
that there currently isn't a way to *build* an lxml wheel that links
to a conda-installed libxml, but that's not the point I'm making - if
conda provided a way to manage external DLLs only, then it would be
possible in theory to contribute a setup.py fix to a project like lxml
that detected and linked to a conda-installed libxml. That single
source could then be used to build *both* wheels and conda packages,
avoiding the current situation where effort on getting lxml to build
is duplicated, once for conda and once for wheel.

> though it adds the ability to handle multiple environments, and tools so you
> don't have to manually place anything.

Well, there are other tools (virtualenv, venv) to do this as well, so
again conda is to an extent offering a "buy into our infrastructure or
you're on your own" proposition. That's absolutely the right thing for
people wanting an integrated "just get on with it" solution, so don't
assume this is a criticism - just an explanation of why conda doesn't
suit *my* needs.

> It would probably be feasible to make a
> conda-for-everything-but-python-itself. I'm just not sure that would buy you
> much.

It would buy *me* flexibility to use python.org build of Python, or my
own builds. And not to have to wait for conda to release a build of a
new version. Of course, I have specialised needs, so that's not an
important consideration for the conda developers.

Paul