Python package policies

From Alpine Linux
Revision as of 15:08, 24 January 2020 by Ddevault (talk | contribs) (More Python 2 removal)
Jump to: navigation, search

Python packages in Alpine Linux should follow a general set of standards for their APKBUILDs.

Underconstruction clock icon gray.svg
This material is work-in-progress ...

Pending consensus on this approach, some discussion is taking place on the talk page
(Last edited by Ddevault on 24 Jan 2020.)

Guidelines

  • Prefix Python 3 libraries with py3-. Do not prefix programs (distinct from libraries) at all.

General Template

Be sure to make the following changes:

  • Update maintainer to yourself
  • Set the pkgname to the Alpine package name (prefixed with "py-")
  • Set _pyname to the name of the package on PyPI
  • Update the version number, pkgdesc, url, and license
  • Build it and address any issues that come up
  • Read the build output and be vigilant for issues listed in the following sections - the build may complete successfully even though these issues are present

Package template

Note that if you are removing python2 support from a package which previously had it, you should add

replaces="py2-example"

as well. If the old package was a split package, also add

replaces="py-example"
provides="py-example=$pkgver-r$pkgrel"

.

# Maintainer: Joe Bloe <joe@example.org>
pkgname=py3-alpine-name
_pyname=pypi-name
pkgver=1.2.3
pkgrel=0
pkgdesc="Example Python package"
url="https://example.org"
arch="noarch"
license="MIT"
depends="python3"
makedepends="py3-setuptools"
_pypiprefix="${_pyname%${_pyname#?}}"
source="https://files.pythonhosted.org/packages/source/$_pypiprefix/$_pyname/$_pyname-$pkgver.tar.gz"
builddir=$srcdir/$_pyname-$pkgver

build() {
	python3 setup.py build
}

check() {
	python3 setup.py test
}

package() {
	python3 setup.py install --prefix=/usr --root="$pkgdir"
}

Common issues

No source package available (only the wheel is on PyPI)

Seek out the upstream source (e.g. GitHub) and swap out the URL.

No tests in PyPI package "(0 tests run)"

Seek out the upstream source (e.g. GitHub) and swap out the URL.

setup.py test downloads a lot of dependencies

Watch out for this and be sure to add any of these packages to checkdepends so that setuptools isn't downloading and testing against packages/versions which aren't in aports.

You need to use the 'tox' utility to run tests

tox (knows as py3-tox on Alpine Linux) downloads all dependencies into a virtual environment by default, which bypasses the system tooling, making testing somewhat less useful.

Remember to use *--sitepackages* on your invocation of tox in the check() phase so it uses the system packages instead of downloading ones into a virtual environment.

Alpine+Python projects

aports normalization project

Many Python packages in aports (if not most) do not follow these guidelines.

TODO: obtain consensus and organize this work.

Python 2 deprecation

Underconstruction clock icon gray.svg
This material is work-in-progress ...

Pending consensus on this approach
(Last edited by Ddevault on 24 Jan 2020.)

The general approach to Python 2 deprecation and removal requires three broad steps:

  1. Do not add new python 2 packages to aports, effective immediately.
  2. In the course of the aports normalization project, drop Python 2 support if it's easy or triage it and make a note for later if not.
  3. Making judgement calls for difficult packages on a case-by-case basis, based on the upstream's progress/amicability towards a Python 3 port. Upstreams which are unwilling to port to Python 3 should be removed from aports.

TODO: Prepare some discussion place, git repos, scripts, etc, to organize this work.