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Commits on Source (3)
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repos:
- repo: https://github.com/pre-commit/pre-commit-hooks
rev: v3.4.0
rev: v4.2.0
hooks:
- id: check-executables-have-shebangs
- id: check-merge-conflict
......@@ -10,13 +10,13 @@ repos:
- id: trailing-whitespace
- repo: https://github.com/Yelp/detect-secrets
rev: v0.14.3
rev: v1.2.0
hooks:
- id: detect-secrets
exclude: Pipfile\.lock|\.rst$
- repo: https://github.com/adrienverge/yamllint
rev: v1.25.0
rev: v1.26.3
hooks:
- id: yamllint
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exclude: LICENSE
- repo: https://github.com/ambv/black
rev: 20.8b1
rev: 22.3.0
hooks:
- id: black
args:
......@@ -42,12 +42,12 @@ repos:
args: [--allow-raw]
- repo: https://github.com/myint/rstcheck.git
rev: master
rev: v5.0.0
hooks:
- id: rstcheck
- repo: https://github.com/PyCQA/prospector
rev: 1.3.1
rev: 1.7.7
hooks:
- id: prospector
args:
......@@ -74,7 +74,7 @@ repos:
- pyroma
- repo: https://gitlab.com/pycqa/flake8.git
rev: 3.8.4
rev: 3.9.2
hooks:
- id: flake8
args:
......@@ -84,7 +84,7 @@ repos:
- flake8-bugbear
- repo: https://github.com/executablebooks/mdformat.git
rev: 0.7.9
rev: 0.7.14
hooks:
- id: mdformat
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PEP 621 and Setuptools
######################
:date: 2022-04-28
:summary: PEP 621 and Setuptools
In the world of Python packaging, the trend is moving to using
:code:`pyproject.toml` to store all of the package's metadata as well as
settings for different tools. Until recently, the trend meant adding another
tool like `Poetry <https://python-poetry.org/>`_, `Flit
<https://flit.pypa.io/>`_ or `PDM <https://pdm.fming.dev/>`_ instead of using
the regular Setuptools and maybe `build <https://pypa-build.readthedocs.io/>`_.
But with Setuptools 61.0.0, you can still use Setuptools and have a modern
Python package.
Why?
----
- Avoid having a plethora of Python package managers installed. This is more
noticeable when some are wrappers or replacements of virtualenv and then you
need to insall them globally.
- With Setuptools you keep close to the state of `PEP 621
<https://peps.python.org/pep-0621/>`_ and your :code:`pyproject.toml` generic
Why not?
--------
- You still need to manage virtual environments manually.
- You need a very recent version of Setuptools. At the time of writing this
post I didn't find a distribution that had a new enough version of Setuptools
pacakged.
- You need a supported version of Python. Currently this means Python 3.7 or
later.
- You can get very close with an equivalent :code:`setup.cfg` and get backwards
compatibility.
How?
----
I created a `sample Python project
<https://git.shore.co.il/nimrod/samplepyproject>`_ that has everything you need
to get started. It's tested to make sure a valid and working package, that
editable installation work, etc. You can skip directly to the `pyproject.toml
<https://git.shore.co.il/nimrod/samplepyproject/-/blob/main/pyproject.toml>`_
file.
A few notes. The only part that's Setuptools specific is specifying the
attribute for getting the version dynamically. You can specify the version
explicitly and be totally generic. The other settings that can be set
dynamically need to be read from other files which isn't great. I would like to
see the description be an attribute like version so I can point it to the
docstring like Flit does. For editable installations you still need a
:code:`setup.py` file but it's a 2 line that calls :code:`setup()`. You don't
need a :code:`setup.cfg` file at all.
Looking forward
---------------
I'm pretty sure that once PEP 621 is approved, other package managers will
adapt and tool specific configuration will be dropped. Also, support for using
:code:`pyproject.toml` in Setuptools will stop being experimental. I think that
once that's done and the only difference will be the 2 lines under
:code:`build-system` we will see projects that want easier onboarding adopt
Setuptools to avoid forcing more tools on users. Over time distributions will
package newer versions of Setuptools and you will be able to have a working
Python environment just with the distribution packages.
Appendix - PEP 582
------------------
Another PEP that's yet to be approved is `PEP 582
<https://peps.python.org/pep-0582/>`_. This propsal a package directory that's
local to a project (in the spirit of :code:`node_modules`). The reason I
mention it here is that this removes the need for virtual environments (and
thus the other major selling point for the different package managers). Now,
while it's not been approved and there's no version of Python that supports it
out of the box, we can mimic it with a little creative shell scripting:
.. code:: shell
PYTHON_VERSION="$(python3 -c 'from sys import version_info as v; print(f"{v[0]}.{v[1]}")')"
export PYTHONPATH="$PWD/__pypackages__/$PYTHON_VERSION:${PYTHONPATH:-}"
export PATH="$PWD/__pypackages__/$PYTHON_VERSION/bin:$PATH"
With the above snippet we point Python to load packages from
:code:`__pypackages__` directory and the :code:`bin` directory to the
:code:`PATH` so executables are available. Lastly to install packages in that
location we run :code:`python3 -m pip install -t
"__pypackages__/$PYTHON_VERSION" foo`. I use `direnv <https://direnv.net/>`_
quite a lot and I have the following snippet in a few projects:
.. code:: shell
PYTHON_VERSION="$(python3 -c 'from sys import version_info as v; print(f"{v[0]}.{v[1]}")')"
export PYTHONPATH="$PWD/__pypackages__/$PYTHON_VERSION:${PYTHONPATH:-}"
export PATH="$PWD/__pypackages__/$PYTHON_VERSION/bin:$PATH"
python3 -m pip install "__pypackages__/$PYTHON_VERSION" -e .
This performs an editable installation of the package and all it's
dependencies, so from that moment on I'm set and I don't any other package
manager or even a virtual environment.
# -*- coding: utf-8 -*- #
# pylint: disable=import-error
"""Pelican configuration."""
from __future__ import unicode_literals
import seafoam
......
# -*- coding: utf-8 -*- #
"""Pelican configuration for publishing to the production site."""
from __future__ import unicode_literals
# This file is only used if you explicitly specify it as your config file.
......