generic-inspection

Utilities for generic type inspection. Supports Python 3.10+.

Inferring specialised type arguments

Consider the following code:

from typing import Generic, TypeVar

InputT = TypeVar("InputT")
OutputT = TypeVar("OutputT")

class Machine(Generic[InputT, OutputT]):
    pass

class TextMachine(Machine[InputT, str]):
    pass

class NumberTextMachine(TextMachine[float]):
    pass

We can infer the specialised type arguments of a subclass with respect to the class type parameters of a particular base class using the infer_generic_args function.

>>> from generic_inspection import infer_generic_args
>>> infer_generic_args(Machine, NumberTextMachine)
(<class 'float'>, <class 'str'>)

The results here tell us that InputT is float and OutputT is str.

Development environment

# Set up the virtual environment.
uv sync --frozen --all-groups
# Run tests.
just test

Release process

The release process is automatic after pushing a semver tag to main.

# Ensure that the correct version number is in pyproject.toml.
head pyproject.toml
# Create the tag.
git tag -a v0.1.0 -m "Release v0.1.0"
# Push the tag.
git push --tags
# Check GitHub Actions and PyPI to verify successful publication.

Similar projects

• https://github.com/Hochfrequenz/python-generics

License

Copyright 2026 Aiden Nibali

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.