197: Python project trove classifiers - Do you need this bit of pyproject.toml metadata? - Brett Cannon
Classifiers are one bit of Python project metadata that predates PyPI.
Classifiers are weird.
They were around in setuptools days, and are still here with pyproject.toml.
Classifiers are weird.
They were around in setuptools days, and are still here with pyproject.toml.
- What are they?
- Why do we need them?
- Do we need them?
- Which classifiers should I include?
- Why are they called "trove classifiers" in the Python docs
Brett Cannon joins the show to discuss these wacky bits of metadata.
Here's an example, from pytest-crayons:
[project] ... classifiers = [ "License :: OSI Approved :: MIT License", "Framework :: Pytest" ]
Links:
- Classifiers · PyPI
- PEP 621 – Storing project metadata in pyproject.toml | peps.python.org
- Packaging Python Projects — Python Packaging User Guide — Configuring metadata
- PEP 639 – Improving License Clarity with Better Package Metadata | peps.python.org
- SPDX
Sponsored by:
- The Complete pytest course is now a bundle, with each part available separately.
- pytest Primary Power teaches the super powers of pytest that you need to learn to use pytest effectively.
- Using pytest with Projects has lots of "when you need it" sections like debugging failed tests, mocking, testing strategy, and CI
- Then pytest Booster Rockets can help with advanced parametrization and building plugins.
- Whether you need to get started with pytest today, or want to power up your pytest skills, PythonTest has a course for you.
Creators and Guests

Guest
Brett Cannon (@brettcannon@fosstodon.org)
Python core developer. Dev lead for the Python extension for VS Code. Tall, snarky Canadian.
