An implementation of Amazon Ion Hash in Python.
This package is designed to work with Python 3.4+.
Computing the Ion hash of a simpleion value may be done by calling the ion_hash() method. For example:
>>> import amazon.ion.simpleion as ion
>>> import ionhash
>>> obj = ion.loads('[1, 2, 3]')
>>> digest = obj.ion_hash('md5')
>>> print('digest:', ''.join(' %02x' % x for x in digest))
digest: 8f 3b f4 b1 93 5c f4 69 c9 c1 0c 31 52 4b 26 25
Alternatively, lower-level hash_reader/hash_writer APIs may be used to compute an Ion hash:
from io import BytesIO from amazon.ion.core import IonEventType from amazon.ion.reader import blocking_reader from amazon.ion.reader import NEXT_EVENT from amazon.ion.reader_managed import managed_reader from amazon.ion.reader_text import text_reader from ionhash.hasher import hash_reader from ionhash.hasher import hashlib_hash_function_provider from ionhash.hasher import HashEvent ion = b'[1, 2, 3]' hash_function = "md5" reader = hash_reader( blocking_reader(managed_reader(text_reader(), None), BytesIO(ion)), hashlib_hash_function_provider(hash_function)) while True: event = reader.send(NEXT_EVENT) if event.event_type == IonEventType.STREAM_END: break digest = reader.send(HashEvent.DIGEST) print('digest:', ''.join(' %02x' % x for x in digest))
When run, it produces the following output:
digest: 8f 3b f4 b1 93 5c f4 69 c9 c1 0c 31 52 4b 26 25
This repository contains a git submodule called ion-hash-test which holds data used by ion-hash-python's unit tests.
The easiest way to clone the ion-hash-python repository and initialize its ion-hash-test submodule is to run the
following command:
$ git clone --recursive https://github.com/amzn/ion-hash-python.git ion-hash-python
Alternatively, the submodule may be initialized independently from the clone by running the following commands:
$ git submodule init $ git submodule update
Once the repository has been fully initialized, cd into it:
$ cd ion-hash-python
Then use venv to create a clean environment to build/test ion-hash-python as follows:
$ python3 -m venv venv
$ . venv/bin/activate
$ pip install -r requirements.txt
$ pip install -e .
You should then be able to run the test suite by executing python setup.py test, or simply running py.test.
In order to verify that ion-hash-python works on all supported platforms, we use a combination of tox with pyenv.
Install relevant versions of Python:
$ for V in 3.4.10 3.5.7 3.6.8 3.7.3 pypy3.6-7.1.0; do pyenv install $V; done
Once you have these installations, add each as a local pyenv configuration:
$ pyenv local 3.4.10 3.5.7 3.6.8 3.7.3 pypy3.6-7.1.0
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 (this executes `py.test` for each supported platform):
$ tox
# Run tox for just Python 3.4 and 3.5:
$ tox -e py34,py35
# Run tox for a specific version and run py.test with high verbosity:
$ tox -e py34 -- py.test -vv
# Run tox for a specific version and start the virtual env's Python REPL:
$ tox -e py35 -- python
This library is licensed under the Apache 2.0 License.