# Copyright 2019-2020 by Christopher C. Little.
# This file is part of Abydos.
#
# Abydos is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Abydos is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Abydos. If not, see <http://www.gnu.org/licenses/>.
"""abydos.distance._fuzzywuzzy_partial_string.
FuzzyWuzzy Partial String similarity
"""
from difflib import SequenceMatcher
from ._distance import _Distance
__all__ = ['FuzzyWuzzyPartialString']
[docs]class FuzzyWuzzyPartialString(_Distance):
"""FuzzyWuzzy Partial String similarity.
This follows the FuzzyWuzzy Partial String similarity algorithm
:cite:`Cohen:2011`. Rather than returning an integer in the range [0, 100],
as demonstrated in the blog post, this implementation returns a float in
the range [0.0, 1.0].
.. versionadded:: 0.4.0
"""
[docs] def sim(self, src, tar):
"""Return the FuzzyWuzzy Partial String similarity of two strings.
Parameters
----------
src : str
Source string for comparison
tar : str
Target string for comparison
Returns
-------
float
FuzzyWuzzy Partial String similarity
Examples
--------
>>> cmp = FuzzyWuzzyPartialString()
>>> round(cmp.sim('cat', 'hat'), 12)
0.666666666667
>>> round(cmp.sim('Niall', 'Neil'), 12)
0.75
>>> round(cmp.sim('aluminum', 'Catalan'), 12)
0.428571428571
>>> cmp.sim('ATCG', 'TAGC')
0.5
.. versionadded:: 0.4.0
"""
max_sim = 0.0
start_pos = 0
if len(src) > len(tar):
src, tar = tar, src
src_len = len(src)
while max_sim < 1.0 and start_pos < len(tar) - src_len + 1:
max_sim = max(
max_sim,
SequenceMatcher(
None, src, tar[start_pos : start_pos + src_len]
).ratio(),
)
start_pos += 1
return max_sim
if __name__ == '__main__':
import doctest
doctest.testmod()