The information in this page is primarily for those who wish to contribute to the c2pa-python library project itself, rather than those who simply wish to use it in an application. For general contribution guidelines, see CONTRIBUTING.md.

It is best to set up a virtual environment for development and testing:

python -m venv .venv

Activate the virtual environment.

• On Windows:

  .venv\Scripts\activate

• On macOS/Linux:

  source .venv/bin/activate

Load project dependencies:

pip install -r requirements.txt
pip install -r requirements-dev.txt

Download c2pa-rs library artifacts for the current version you want, (for example, as shown below for v0.73.1):

python scripts/download_artifacts.py c2pa-v0.73.1

Install the package in development mode:

pip install -e .

This command:

• Copies the appropriate libraries for your platform from artifacts/ to src/c2pa/libs/
• Installs the package in development mode, so you can make changes to the Python code without reinstalling.

Build the wheel for your platform (from the root of the repository):

source .venv/bin/activate
pip install -r requirements.txt
python3 -m pip install build
pip install -U pytest

python3 -m build --wheel

To test local wheels locally, enter this command:

make test-local-wheel-build

To verify the builds, enter this command:

make verify-wheel-build

.
├── .github/                  # GitHub configuration files
├── artifacts/                # Platform-specific libraries for building (per subfolder)
│   └── your_target_platform/ # Platform-specific artifacts
├── docs/                     # Project documentation
├── examples/                 # Example scripts demonstrating usage
├── scripts/                  # Utility scripts (eg. artifacts download)
├── src/                      # Source code
│   └── c2pa/                 # Main package directory
│       └── libs/             # Platform-specific libraries
├── tests/                    # Unit tests and benchmarks
├── .gitignore                # Git ignore rules
├── Makefile                  # Build and development commands
├── pyproject.toml            # Python project configuration
├── requirements.txt          # Python dependencies
├── requirements-dev.txt      # Development dependencies
└── setup.py                  # Package setup script

The project uses PyTest and unittest for testing.

Run tests by following these steps:

1. Activate the virtual environment: source .venv/bin/activate
2. (optional) Install dependencies: pip install -r requirements.txt
3. Run the tests:

   make test

4. Alternatively, install pytest (if not already installed) and run it:

   pip install pytest
   pytest

   Warning: Using pytest can lead to issues if you often switch between virtual environments.

While developing bindings locally, we use unittest, since PyTest can get confused by virtual environment re-deployments (especially if you bump the version number).

To run tests while developing bindings, enter this command:

make test

To rebuild and test, enter these commands:

make build-python
make test

We use Sphinx autodoc to generate API docs.

Install development dependencies:

cd c2pa-python
python3 -m pip install -r requirements-dev.txt

Build docs by entering make -C docs or:

python3 scripts/generate_api_docs.py

View the output by loading api-docs/build/html/index.html in a web browser.

This uses sphinx-autoapi to parse src/c2pa directly, avoiding imports of native libs.

• Entry script: scripts/generate_api_docs.py
• Config: api-docs/conf.py; index: api-docs/index.rst

Sphinx config is in api-docs/conf.py, which uses index.rst.