CQ002: HasTypeHints

Overview

Checks for a py.typed marker file indicating the package provides type hints.

PEP 561 defines how packages can indicate they include type information. This enables:

The check looks for py.typed file in:

Create an empty py.typed marker file:

touch src/my_package/py.typed

Ensure the file is included in your distribution. Most build backends include it automatically, but verify in pyproject.toml:

[tool.hatch.build.targets.wheel]
packages = ["src/my_package"]

Once you have py.typed, add type hints to your code:

def greet(name: str) -> str:
    """Greet someone by name."""
    return f"Hello, {name}!"

pip install mypy
mypy src/my_package

This check is a NOTE because:

[tool.pycmdcheck]
skip = ["CQ002"]

pycmdcheck --skip CQ002