cpython/Misc/mypy

Mypy path symlinks

This directory stores symlinks to standard library modules and packages that are fully type-annotated and ready to be used in type checking of the rest of the stdlib or Tools/ and so on.

Why this is necessary

Due to most of the standard library being untyped, we prefer not to point mypy directly at Lib/ for type checking. Additionally, mypy as a tool does not support shadowing typing-related standard libraries like types, typing, and collections.abc.

So instead, we set mypy_path to include this directory, which only links modules and packages we know are safe to be type-checked themselves and used as dependencies. See Lib/_pyrepl/mypy.ini for a usage example.

I want to add a new type-checked module

Add it to typed-stdlib.txt and run make_symlinks.py --symlink.

I don't see any symlinks in this directory

The symlinks in this directory are skipped in source tarballs in Python releases. This ensures they don't end up in the SBOM. To recreate them, run the make_symlinks.py --symlink script.