use pyproject.toml and PDM

[davidism]

Use the pyproject.toml standard to specify project metadata and dependencies. Use PDM to lock development dependencies and manage the environment.

Tool configuration was moved to pyproject.toml, except for flake8, which does not support that file. Flake8 config remains in setup.cfg. setup.py remains for GitHub's dependency graph, although PDM might write a GitHub action for updating the dependency graph eventually.

Read the Docs doesn't support non-pip tools natively, but they recently added support for custom build steps. This uses post_install to install PDM and run pdm sync -dG docs after RTD sets up the virtualenv and installs its own packages.

Contributors can use PDM to set up a virtualenv and sync development dependencies. Install PDM, then do pdm sync. This will create a virtualenv in the .venv folder if it doesn't exist, then install the locked versions of all development dependencies, and install the project in editable mode. Commands are run with pdm run ... without requiring activating the virtualenv. Alternatively, you can use a tool like pew to manage virtualenvs, PDM will detect an active virtualenv and use that instead, and pip install -e . will continue to work as well.

Common commands:

• pdm sync install the current set of locked dependencies
• pdm run pytest
• pdm run mypy
• pdm run tox -p run all test envs in parallel
• cd docs && make html make the docs locally, caching changes

Advanced / maintainer commands:

• pdm update --update-all update all versions in the lock file
• eval $(pdm venv activate) activate the virtualenv so pdm run ... isn't needed
• pew workon flask-sqlalchemy use pew to manage the virtualenv and switch to the project, then pdm sync will install to that env.

[davidism]

Looks like Read the Docs is going to be more difficult. It doesn't activate the virtualenv it creates, so PDM creates its own env.

[frostming]

You may be interested: pdm-project/pdm#1365 (comment)

[davidism]

Thanks, docs are building now. Reported this to RTD here: readthedocs/readthedocs.org#9629