Snowball stemming library collection for Python
===============================================

Both Python 2 and Python 3 (>= 3.3) are supported.

How to use library
------------------

The ``snowballstemmer`` module has two functions.

The ``snowballstemmer.algorithms`` function returns a list of available algorithm names.

The ``snowballstemmer.stemmer`` function accepts algorithm name and returns ``Stemmer`` objects.

``Stemmer`` objects have ``Stemmer.stemWord(word)`` method and ``Stemmer.stemWords(word[])`` method.

.. code-block:: python

   import snowballstemmer

   stemmer = snowballstemmer.stemmer('english');
   print(stemmer.stemWords("We are the world".split()));

``Stemmer`` objects have ``Stemmer.maxCacheSize`` property. They cache result within the value. Default is ``10000``.

Accelerates Stemming
--------------------

if **PyStemmer** is installed, ``snowballstemmer.stemmer`` returns ``PyStemmer``\ 's ``Stemmer`` objects. This ``Stemmer`` object has same methods (``Stemmer.stemWord()``, ``Stemmer.stemWords()``).

**PyStemmer** is a Snowball's ``libstemmer_c`` wrapper module and it returns 100% compatible result with **snowballstemmer**.

**PyStemmer** has faster speed because it uses C-lang module, and **snowballstemmer** has higher usability because it is pure Python module.

* `PyStemmer <http://pypi.python.org/pypi/PyStemmer/>`_

Benchmark
~~~~~~~~~

Test Case: Snowball stemmer check data (16 algorithms, total 582560 words, cache hit 0%)
Computer: MacBook Pro 3rd Gen Corei7 2.3GHz

* Python 2.7 + **snowballstemmer** : 2m 30s
* PyPy 1.9 + **snowballstemmer** : 45s
* Python 2.7 + **PyStemmer** : 5s

This test case is much harder than usual usecases!

The TestApp example
-------------------

The ``testapp.py`` example program allows you to run any of the stemmers
on a sample vocabulary.

Usage::

   testapp.py <algorithm> "sentences ... "

.. code-block:: bash

   $ python testapp.py English "sentences... "

License
-------

It is a BSD licensed library.

Copyright (c) 2013, Yoshiki Shibukawa
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

   Redistributions of source code must retain the above copyright notice,
   this list of conditions and the following disclaimer.

   Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

   Neither the name of the <ORGANIZATION> nor the names of its contributors
   may be used to endorse or promote products derived from this software
   without specific prior written permission.

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