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. 

• 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