===============
python-crfsuite
===============

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    :target: https://github.com/scrapinghub/python-crfsuite/actions/workflows/tests.yml

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    :alt: conda Version

python-crfsuite is a python binding to CRFsuite_.

Installation
============

Using ``pip``::

    pip install python-crfsuite

Using ``conda``::

    conda install -c conda-forge python-crfsuite

Usage
=====

See docs_ and an example_.

.. _docs: http://python-crfsuite.rtfd.org/
.. _example: https://github.com/scrapinghub/python-crfsuite/blob/master/examples/CoNLL%202002.ipynb

See Also
========

sklearn-crfsuite_ is a python-crfsuite wrapper which provides
API similar to scikit-learn.

.. _sklearn-crfsuite: https://github.com/TeamHG-Memex/sklearn-crfsuite

Contributing
============

* Source code: https://github.com/scrapinghub/python-crfsuite
* Issue tracker: https://github.com/scrapinghub/python-crfsuite/issues

Feel free to submit ideas, bugs reports, pull requests or regular patches.

Please don't commit generated cpp files in the same commit as other files.

.. _Cython: http://cython.org/
.. _tox: http://tox.testrun.org

Authors and Contributors
========================

Original authors are Terry Peng <[email protected]> and
Mikhail Korobov <[email protected]>. Many other people contributed;
some of them can be found at github Contributors_ page.

Bundled CRFSuite_ C/C++ library is by Naoaki Okazaki & contributors.

.. _Contributors: https://github.com/scrapinghub/python-crfsuite/graphs/contributors

License
=======

python-crfsuite is licensed under MIT license.
CRFsuite_ library is licensed under BSD license.

.. _CRFsuite: https://github.com/chokkan/crfsuite

Alternatives
============

* https://github.com/chokkan/crfsuite/tree/master/swig/python - official
  Python wrapper, exposes C++ API using SWIG.
* https://github.com/jakevdp/pyCRFsuite - uses C API instead of C++ API;
  allows to use scipy sparse matrices as an input. At the time of writing
  it is unmaintained.
* https://github.com/bosondata/crfsuite-rs - uses a Rust wrapper with CFFI instead of C++ API;
  allows to tag with GIL released for better performance.

This package (python-crfsuite) wraps CRFsuite C++ API using Cython.
It is faster than official SWIG wrapper and has a simpler codebase than
a more advanced pyCRFsuite. python-crfsuite works in Python 2 and Python 3,
doesn't have external dependencies (CRFsuite is bundled, numpy/scipy stack
is not needed) and workarounds some of the issues with C++ CRFsuite library.