An implementation of Amazon Ion for Python.

This package is designed to work with Python 3.8+. Newer language features will be used as deemed valuable. Support may be dropped for versions more than six months past EOL.

Install using pip with the following command.

python3 -m pip install amazon.ion

Start with the simpleion module, which provides four APIs (dump, dumps, load, loads) that will be familiar to users of Python's built-in JSON parsing module. Simpleion module's performance is improved by an optional C extension.

For example:

>>> import amazon.ion.simpleion as ion
>>> obj = ion.loads('{abc: 123}')
>>> obj['abc']
123
>>> ion.dumps(obj, binary=False)
'$ion_1_0 {abc:123}'

For additional examples, consult the cookbook.

This repository contains two git submodules. ion-tests holds test data used by ion-python's unit tests and ion-c speeds up ion-python's simpleion module.

The easiest way to clone the ion-python repository and initialize its ion-tests submodule is to run the following command.

$ git clone --recursive https://github.com/amazon-ion/ion-python.git ion-python

Alternatively, the submodule may be initialized independently from the clone by running the following commands.

$ git submodule init
$ git submodule update

It is recommended to use venv to create a clean environment to build/test Ion Python.

$ python3 -m venv ./venv
...
$ . venv/bin/activate
$ python -m pip install build
$ python -m pip install '.[test]'

You can run the tests through py.test directly:

$ py.test --ignore tests/test_benchmark_cli.py --ignore tests/test_benchmark_spec.py

This recipe skips the benchmark tests because they require additional dependencies:

When in doubt, look at .github/workflows/main.yml to see CI setup and learn how to build/test the project. See also ion-python#379 for a writeup of our adoption of pyproject.toml.

In order to verify that all platforms we support work with Ion Python, we use a combination of tox with pyenv.

We recommend that you use tox within a virtual environment to isolate from whatever is in the system installed Python.

Install relevant versions of Python:

$ for V in 3.8.10 3.9.5 do pyenv install $V; done

Once you have these installations, add them as a local pyenv configuration

$ pyenv local 3.8.10 3.9.5

Assuming you have pyenv properly set up (making sure pyenv init is evaluated into your shell), you can now run tox:

# Run tox for all versions of python which executes py.test.
$ tox

# Run tox for just Python 3.8 and 3.9.
$ tox -e py38,py39

# Run tox for a specific version and run py.test with high verbosity
$ tox -e py39 -- py.test -vv

# Run tox for a specific version and just the virtual env REPL.
$ tox -e py39 -- python

The following build, deployment, or release tasks are required:

• Add support for code coverage reporting.
  • Publish coverage to something like Coverage.io
• Consider using something like PyPy.js to build an interactive shell for playing with Ion python and provide a client-side Ion playground.

tests/test_vectors.py defines skipList variables referencing test vectors that are not expected to work at this time.