Development

To build ONNX from source please follow the instructions listed here.

Then, after you have made changes to Python and C++ files:

• Python files: the changes are effective immediately in your installation. You don’t need to install these again.

• C++ files: you need to install these again to trigger the native extension build.

Assuming build succeed in the initial step, simply running

pip install -e .

from onnx root dir should work.

Folder structure

• onnx/: the main folder that all code lies under

  • onnx.proto: the protobuf that contains all the structures

  • checker.py: a utility to check whether a serialized ONNX proto is legal

  • shape_inference.py: a utility to infer types and shapes for ONNX models

  • version_converter.py: a utility to upgrade or downgrade version for ONNX models

  • parser.py: a utility to create an ONNX model or graph from a textual representation

  • hub.py: a utility for downloading models from ONNX Model Zoo

  • compose.py: a utility to merge ONNX models

  • helper.py: tools for graph operation

  • defs/: a subfolder that defines the ONNX operators

  • test/: test files

Generated operator documentation

Operator docs in Operators.md are automatically generated based on C++ operator definitions and backend Python snippets. To refresh these docs, run the following commands from the repo root and commit the results. Note ONNX_ML=0 updates Operators.md whereas ONNX_ML=1 updates Operators-ml.md:

set ONNX_ML=0
pip install setup.py
python onnx/defs/gen_doc.py

Adding a new operator

ONNX is an open standard, and we encourage developers to contribute high quality operators to ONNX specification. Before proposing a new operator, please read the tutorial.

Testing

ONNX uses pytest as a test driver. To run tests, you’ll first need to install pytest:

pip install pytest nbval

After installing pytest, run from the root of the repo:

pytest

to begin the tests.

You’ll need to regenerate test coverage too, by running this command from the root of the repo:

python onnx\backend\test\stat_coverage.py

Static typing (mypy)

We use mypy to run static type checks on the onnx code base. To check that your code passes, you’ll first need to install the mypy type checker. If you’re using python 3, call from your onnx source folder:

pip install -e .[mypy]

The type checker cannot run in a python 2 environment (but it will check python 2 code). If you’re using python 2, you need to install mypy into your system packages instead:

pip3 install mypy==[version]

Note: You’ll find the version we’re currently using in setup.py.

After having installed mypy, you can run the type checks:

python setup.py typecheck

CI Pipelines

Every PR needs to pass CIs before merge. CI pipelines details are here.

Other developer documentation

• How to implement ONNX backend (ONNX to something converter)

• Backend test infrastructure and how to add tests

License

Apache License v2.0

Code of Conduct

ONNX Open Source Code of Conduct