Gradual typing

How to build it

1. Enable type checking for the modules that already have annotations.
2. Set per-module strictness, such as [[tool.mypy.overrides]] or per-file pyright strict comments.
3. Raise strictness for each module once it is annotated and record the list in config.

Signals in a repository

• A [tool.mypy] section with overrides for selected modules in pyproject.toml.
• A pyright configuration or '# pyright: strict' comments in some source files.

In practice

44 repositories run a tool for this check in the scanned set.

• mypy · 35 repos
• pyright · 16 repos

Examples

• langflow-ai/langflow · mypy

  mypy --namespace-packages -p langflow

• fastapi/fastapi · mypy

  mypy fastapi

• home-assistant/core · mypy

  mypy --num-workers=4 homeassistant packages/pylint-home-assistant

• python/cpython · mypy

  mypy --num-workers 4 --config-file $EXPR/mypy.ini

• pallets/flask · mypy

  mypy