# Copyright 2014-2020 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.fingerprint._q_gram_fingerprint.
q-gram fingerprint
"""
from unicodedata import normalize as unicode_normalize
from deprecation import deprecated
from ._fingerprint import _Fingerprint
from .. import __version__
from ..tokenizer import QGrams
__all__ = ['QGram', 'qgram_fingerprint']
[docs]class QGram(_Fingerprint):
"""Q-Gram Fingerprint.
A q-gram fingerprint is a string consisting of all of the unique q-grams
in a string, alphabetized & concatenated. This fingerprint is described at
:cite:`OpenRefine:2012`.
.. versionadded:: 0.3.6
"""
def __init__(self, qval=2, start_stop='', joiner='', skip=0):
"""Initialize Q-Gram fingerprinter.
qval : int
The length of each q-gram (by default 2)
start_stop : str
The start & stop symbol(s) to concatenate on either end of the
phrase, as defined in :py:class:`tokenizer.QGrams`
joiner : str
The string that will be placed between each word
skip : int or Iterable
The number of characters to skip, can be an integer, range object,
or list
.. versionadded:: 0.4.0
"""
self._tokenizer = QGrams(qval, start_stop, skip)
self._joiner = joiner
[docs] def fingerprint(self, phrase):
"""Return Q-Gram fingerprint.
Parameters
----------
phrase : str
The string from which to calculate the q-gram fingerprint
Returns
-------
str
The q-gram fingerprint of the phrase
Examples
--------
>>> qf = QGram()
>>> qf.fingerprint('The quick brown fox jumped over the lazy dog.')
'azbrckdoedeleqerfoheicjukblampnfogovowoxpequrortthuiumvewnxjydzy'
>>> qf.fingerprint('Christopher')
'cherhehrisopphristto'
>>> qf.fingerprint('Niall')
'aliallni'
.. versionadded:: 0.1.0
.. versionchanged:: 0.3.6
Encapsulated in class
"""
phrase = unicode_normalize('NFKD', phrase.strip().lower())
phrase = ''.join(c for c in phrase if c.isalnum())
phrase = self._tokenizer.tokenize(phrase).get_set()
phrase = self._joiner.join(sorted(phrase))
return phrase
[docs]@deprecated(
deprecated_in='0.4.0',
removed_in='0.6.0',
current_version=__version__,
details='Use the QGram.fingerprint method instead.',
)
def qgram_fingerprint(phrase, qval=2, start_stop='', joiner=''):
"""Return Q-Gram fingerprint.
This is a wrapper for :py:meth:`QGram.fingerprint`.
Parameters
----------
phrase : str
The string from which to calculate the q-gram fingerprint
qval : int
The length of each q-gram (by default 2)
start_stop : str
The start & stop symbol(s) to concatenate on either end of the phrase,
as defined in :py:class:`tokenizer.QGrams`
joiner : str
The string that will be placed between each word
Returns
-------
str
The q-gram fingerprint of the phrase
Examples
--------
>>> qgram_fingerprint('The quick brown fox jumped over the lazy dog.')
'azbrckdoedeleqerfoheicjukblampnfogovowoxpequrortthuiumvewnxjydzy'
>>> qgram_fingerprint('Christopher')
'cherhehrisopphristto'
>>> qgram_fingerprint('Niall')
'aliallni'
.. versionadded:: 0.1.0
"""
return QGram(qval=qval, start_stop=start_stop, joiner=joiner).fingerprint(
phrase
)
if __name__ == '__main__':
import doctest
doctest.testmod()