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# -*- coding: utf-8 -*- |
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# Copyright 2018 by Christopher C. Little. |
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# This file is part of Abydos. |
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# |
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# Abydos is free software: you can redistribute it and/or modify |
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# it under the terms of the GNU General Public License as published by |
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# the Free Software Foundation, either version 3 of the License, or |
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# (at your option) any later version. |
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# |
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# Abydos is distributed in the hope that it will be useful, |
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# but WITHOUT ANY WARRANTY; without even the implied warranty of |
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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# GNU General Public License for more details. |
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# |
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# You should have received a copy of the GNU General Public License |
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# along with Abydos. If not, see <http://www.gnu.org/licenses/>. |
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"""abydos.stemmer._s_stemmer. |
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S-stemmer. |
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""" |
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from __future__ import ( |
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absolute_import, |
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division, |
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print_function, |
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unicode_literals, |
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) |
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from ._stemmer import _Stemmer |
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__all__ = ['SStemmer', 's_stemmer'] |
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class SStemmer(_Stemmer): |
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"""S-stemmer. |
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The S stemmer is defined in :cite:`Harman:1991`. |
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""" |
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def stem(self, word): |
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"""Return the S-stemmed form of a word. |
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Parameters |
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---------- |
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word : str |
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The word to stem |
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Returns |
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------- |
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str |
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Word stem |
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Examples |
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-------- |
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>>> stmr = SStemmer() |
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>>> stmr.stem('summaries') |
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'summary' |
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>>> stmr.stem('summary') |
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'summary' |
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>>> stmr.stem('towers') |
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'tower' |
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>>> stmr.stem('reading') |
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'reading' |
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>>> stmr.stem('census') |
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'census' |
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""" |
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lowered = word.lower() |
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if lowered[-3:] == 'ies' and lowered[-4:-3] not in {'e', 'a'}: |
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return word[:-3] + ('Y' if word[-1:].isupper() else 'y') |
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if lowered[-2:] == 'es' and lowered[-3:-2] not in {'a', 'e', 'o'}: |
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return word[:-1] |
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if lowered[-1:] == 's' and lowered[-2:-1] not in {'u', 's'}: |
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return word[:-1] |
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return word |
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def s_stemmer(word): |
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"""Return the S-stemmed form of a word. |
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This is a wrapper for :py:meth:`SStemmer.stem`. |
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Parameters |
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---------- |
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word : str |
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The word to stem |
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Returns |
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------- |
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str |
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Word stem |
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Examples |
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-------- |
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>>> s_stemmer('summaries') |
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'summary' |
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>>> s_stemmer('summary') |
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'summary' |
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>>> s_stemmer('towers') |
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'tower' |
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>>> s_stemmer('reading') |
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'reading' |
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>>> s_stemmer('census') |
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'census' |
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""" |
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return SStemmer().stem(word) |
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if __name__ == '__main__': |
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import doctest |
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doctest.testmod() |
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chrislit /
abydos
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