I recently had an opportunity to review some tooling for Python, and I thought I'd share some of my learnings.

pyproject.toml

This fancy new file is the replacement for setup.py and setup.cfg originally specified in PEP 518 (https://www.python.org/dev/peps/pep-0518/).

Simple and clean explanation, right? Well, no, not really.

Since its release, it's now the exclusive way to configure black for a project. Additional tools like poetry (somewhat of a pipenv competitor) and flit (a tool to make packaging and publishing to PyPI easier) have come out to also exclusively use pyproject.toml as their configuration file.

It's clear from the PEP that this was the intended consequence for other tools to use pyproject.toml. However, it seems to only have really touched brand new projects. Older, mature packages seem to still primarily be using setup.cfg for their tooling configs in their CI process.

I generally tend to adopt new trends like these in my projects, but in my existing packages I admit not seeing a whole lot of value presently in ripping out my setup.py and setup.cfg just for fun.

flake8

I used pylint for a very long time while at Worthwhile and began using flake8 at Peerfit. I really had no opinion of one over the other.

However, I can say now that holy crap does flake8 have so much stuff.
It wraps pyflakes, pycodestyle, and mccabe. Additionally, it's just got so many plugins: flake8-bugbear, flake8-import-order, flake8-print, etc (https://github.com/DmytroLitvinov/awesome-flake8-extensions).This rich ecosystem simply doesn't seem to exist for pylint.

Finally, a lot of major projects seems to use flake8, so the user base is consistent and mature:

• Django (https://github.com/django/django/blob/master/setup.cfg#L5)
• flask (https://github.com/pallets/flask/blob/master/setup.cfg#L22)
• even freaking youtube-dl (https://github.com/ytdl-org/youtube-dl/blob/master/setup.cfg)

So this has sold me on using flake8 for the foreseeable future.