Allow lzma compressed data file

[tornaria]

An attempt at #3.

This will use CPimport.txt.lzma if available, else fallback to CPimport.txt as before.

Note that this doesn't attempt to compress the file at install time, since I don't know how to do that. But one could e.g. compress the file when packaging for a distro, and it would work transparently. I do this for pari data, which support replacing text files by gzipped files.

[orlitzky]

I'd like this too, but I'd prefer to just do it as part of the pip wheel or python -m build process so (a) the name will be predictable, (b) pip users will get the benefits, (c) distro packaging can remain uninteresting.

[orlitzky]

I should mention: I don't know how to do it with this week's python build tooling or else I would just do it. I'll ask around.

[mkoeppe]

Since you are using setuptools, it would just be done by customizing setuptools.command.build_py; there hasn't really been a change to this since the distutils era.

[tornaria]

I don't know how to fix this. It works if one builds a wheel (python -m build -w) but it doesn't work if one builds via sdist (python -m build, which is equivalent to what CI is doing here). It seems the sdist doesn't contain either CPimport.txt nor CPimport.txt.xz and so build_py cannot proceed. But if I keep CPimport.txt in the manifest, then the sdist contains CPimport.txt but the wheel contains both CPimport.txt and CPimport.txt.xz.

[tornaria]

Question: the sdist should contain the original txt file, or the compressed file?

[tornaria]

Ok, this seems to work: the CPimport.txt file is kept in the manifest, so it will be included in the sdist. And the build_py step replaces the installed file by the compressed one.

[orlitzky]

I spent at least an hour trying to find out what I needed to add to pyproject.toml to override build_py, and you're telling me it just works??

I think you did the right thing with the sdist. I pushed the changes, added some types, and tagged version 0.9. Matthias has to do the pypi release and then I guess we'll see how it all works in real life.

[mkoeppe]

Matthias has to do the pypi release

Actually it's all automated. It ran here when you pushed the tag: https://github.com/sagemath/conway-polynomials/actions/runs/7509952087/job/20447737402#step:7:82

[orlitzky]

Oh, even better. The first time you had to re-push my tag, I assumed it was a permissions issue, and not just a you had to push a tag issue.