Source code for abydos.fingerprint._count

# -*- coding: utf-8 -*-

# Copyright 2018 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._count.

Cisłak & Grabowski's count fingerprint
"""

from __future__ import (
    absolute_import,
    division,
    print_function,
    unicode_literals,
)

from collections import Counter

from ._fingerprint import MOST_COMMON_LETTERS_CG, _Fingerprint

__all__ = ['Count', 'count_fingerprint']


[docs]class Count(_Fingerprint): """Count Fingerprint. Based on the count fingerprint from :cite:`Cislak:2017`. """
[docs] def fingerprint(self, word, n_bits=16, most_common=MOST_COMMON_LETTERS_CG): """Return the count fingerprint. Parameters ---------- word : str The word to fingerprint n_bits : int Number of bits in the fingerprint returned most_common : list The most common tokens in the target language, ordered by frequency Returns ------- int The count fingerprint Examples -------- >>> cf = Count() >>> bin(cf.fingerprint('hat')) '0b1010000000001' >>> bin(cf.fingerprint('niall')) '0b10001010000' >>> bin(cf.fingerprint('colin')) '0b101010000' >>> bin(cf.fingerprint('atcg')) '0b1010000000000' >>> bin(cf.fingerprint('entreatment')) '0b1111010000100000' """ if n_bits % 2: n_bits += 1 word = Counter(word) fingerprint = 0 for letter in most_common: if n_bits: fingerprint <<= 2 fingerprint += word[letter] & 3 n_bits -= 2 else: break if n_bits: fingerprint <<= n_bits return fingerprint
[docs]def count_fingerprint(word, n_bits=16, most_common=MOST_COMMON_LETTERS_CG): """Return the count fingerprint. This is a wrapper for :py:meth:`Count.fingerprint`. Parameters ---------- word : str The word to fingerprint n_bits : int Number of bits in the fingerprint returned most_common : list The most common tokens in the target language, ordered by frequency Returns ------- int The count fingerprint Examples -------- >>> bin(count_fingerprint('hat')) '0b1010000000001' >>> bin(count_fingerprint('niall')) '0b10001010000' >>> bin(count_fingerprint('colin')) '0b101010000' >>> bin(count_fingerprint('atcg')) '0b1010000000000' >>> bin(count_fingerprint('entreatment')) '0b1111010000100000' """ return Count().fingerprint(word, n_bits, most_common)
if __name__ == '__main__': import doctest doctest.testmod()