Re: Questions regarding Python packaging

[Hartmut Goebel <h.goebel@crazy-compilers.com>]

Hi,

seems like another messages of mine, regarding the first thread  about a 
poetry build system, did not make it to the list.

Am 08.11.20 um 15:27 schrieb Tanguy Le Carrour:
> I've just learned, by accident (working on `python-keyring` [1]), that
> `python setup.py install` was somehow deprecated

This statement is not exactly true - well, depending on interpretation 
of "somehow". I've not set seen an official deprecation.

It's true that users are encouraged to use pip for installing packages. 
But the official Python Packaging Tutorial [1] is still based on 
setuptools (not even recommending a setup.cfg file). Thus setuptools 
will be around for quite some more time, as will "python setup.py install".

In the future Python world, any build-tool can be specified in 
"pyproject.toml". User will then call "pip install", and pip will 
(AFAIU) call a Python function (aka entry-point) specified in that file. 
(If this file does not exist, setuptools are assumed). For our 
python-build-system, we would use "pip wheel" (for phase build) and "pip 
install" (for phase install).

So, if we switch to "pip wheel" and "pip install", different python 
build systems could share a common base, just redefining some 
dependencies (setuptools, poetry, build, ...) and some tool-dependent 
flags. Is this the direction you are working towards?

[1] https://packaging.python.org/tutorials/packaging-projects/


> in favor of tools like`pep517` or `build`.

Thanks for point to these, both are new to me.

"build" sounds interesting, esp. for guix: "It is a simple build tool 
and does not perform any dependency management." This would help us 
spliting dependency management and build phase. Anyhow, it's quite new 
(half an year old) and implements a PEP 517 package builder - and PEP 
517 (defining the build system in pyproject.toml) is not yet adopted widely.

"pep517" seems o be a library used for "build". Its high-level interface 
has been deprecated in favor for "build".

I as just about to write "So, while this might be one road to go, this 
is not of much use for us yet.". Anyhow, this might be a good base for 
pep517 based packages. On the other hand: Maybe we'd better stick with 
"pip wheel" and "pip install", see above.

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |