You're adding type hints to your Python code, your editor is happy, autocomplete is working great. But then you switch tools and suddenly there are red squiggles everywhere. Who decides what a float annotation actually means? Or whether passing None where an int is expected should be an error? It turns out there's a five-person council dedicated to exactly these questions -- and two brand-new Rust-based type checkers are raising the bar. On this episode, I sit down with three members of the Python Typing Council -- Jelle Zijlstra, Rebecca Chen, and Carl Meyer -- to learn how the type system is governed, where the spec and the type checkers agree and disagree, and get the council's official advice on how much typing is just enough.

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Links from the show

Carl Meyer: github.com

Jelle Zijlstra: jellezijlstra.github.io

Rebecca Chen: github.com

Typing Council: github.com

typing.python.org: typing.python.org

details here: github.com

ty: docs.astral.sh

pyrefly: pyrefly.org

conformance test suite project: github.com

typeshed: github.com

Stub files: mypy.readthedocs.io

Pydantic: pydantic.dev

Beartype: github.com

TOAD AI: github.com

PEP 747 – Annotating Type Forms: peps.python.org

PEP 724 – Stricter Type Guards: peps.python.org

Python Typing Repo (PRs and Issues): github.com

Watch this episode on YouTube: youtube.com

Episode #539 deep-dive: talkpython.fm/539

Episode transcripts: talkpython.fm

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