Source code for abydos.stemmer._clef_german

# Copyright 2014-2020 by Christopher C. Little.
# This file is part of Abydos.
# Abydos is free software: you can redistribute it and/or modify
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# Abydos is distributed in the hope that it will be useful,
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CLEF German stemmer

from unicodedata import normalize

from deprecation import deprecated

from ._stemmer import _Stemmer
from .. import __version__

__all__ = ['CLEFGerman', 'clef_german']

[docs]class CLEFGerman(_Stemmer): """CLEF German stemmer. The CLEF German stemmer is defined at :cite:`Savoy:2005`. .. versionadded:: 0.3.6 """ _umlauts = dict(zip((ord(_) for _ in 'äöü'), 'aou'))
[docs] def stem(self, word): """Return CLEF German stem. Parameters ---------- word : str The word to stem Returns ------- str Word stem Examples -------- >>> stmr = CLEFGerman() >>> stmr.stem('lesen') 'lese' >>> stmr.stem('graues') 'grau' >>> stmr.stem('buchstabieren') 'buchstabier' .. versionadded:: 0.1.0 .. versionchanged:: 0.3.6 Encapsulated in class """ # lowercase, normalize, and compose word = normalize('NFC', word.lower()) # remove umlauts word = word.translate(self._umlauts) # remove plurals wlen = len(word) - 1 if wlen > 3: if wlen > 5: if word[-3:] == 'nen': return word[:-3] if wlen > 4: if word[-2:] in {'en', 'se', 'es', 'er'}: return word[:-2] if word[-1] in {'e', 'n', 'r', 's'}: return word[:-1] return word
[docs]@deprecated( deprecated_in='0.4.0', removed_in='0.6.0', current_version=__version__, details='Use the CLEFGerman.stem method instead.', ) def clef_german(word): """Return CLEF German stem. This is a wrapper for :py:meth:`CLEFGerman.stem`. Parameters ---------- word : str The word to stem Returns ------- str Word stem Examples -------- >>> clef_german('lesen') 'lese' >>> clef_german('graues') 'grau' >>> clef_german('buchstabieren') 'buchstabier' .. versionadded:: 0.1.0 """ return CLEFGerman().stem(word)
if __name__ == '__main__': import doctest doctest.testmod()