abydos.phonetic._soundex

Complexity

Total Complexity

14

Size/Duplication

Total Lines	262
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes

0

1 Function

Rating	Name	Duplication	Size	Complexity
A	soundex()	0	66	1

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

# Copyright 2014-2018 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.phonetic._soundex.

American Soundex
"""

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

from unicodedata import normalize as unicode_normalize

from six import text_type

from ._phonetic import _Phonetic

__all__ = ['Soundex', 'soundex']


class Soundex(_Phonetic):

The variable __class__ seems to be unused.

    """Soundex.

    Three variants of Soundex are implemented:

    - 'American' follows the American Soundex algorithm, as described at
      :cite:`US:2007` and in :cite:`Knuth:1998`; this is also called
      Miracode
    - 'special' follows the rules from the 1880-1910 US Census
      retrospective re-analysis, in which h & w are not treated as blocking
      consonants but as vowels. Cf. :cite:`Repici:2013`.
    - 'Census' follows the rules laid out in GIL 55 :cite:`US:1997` by the
      US Census, including coding prefixed and unprefixed versions of some
      names
    """

    _trans = dict(
        zip(
            (ord(_) for _ in 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'),

The variable _ does not seem to be defined.

            '01230129022455012623019202',
        )
    )

    def encode(

Too many arguments (6/5)

Parameters differ from overridden 'encode' method

        self, word, max_length=4, var='American', reverse=False, zero_pad=True

Wrong hanging indentation before block (add 4 spaces).

    ):
        """Return the Soundex code for a word.

        Parameters
        ----------
        word : str
            The word to transform
        max_length : int
            The length of the code returned (defaults to 4)
        var : str
            The variant of the algorithm to employ (defaults to ``American``):

                - ``American`` follows the American Soundex algorithm, as
                  described at :cite:`US:2007` and in :cite:`Knuth:1998`; this
                  is also called Miracode
                - ``special`` follows the rules from the 1880-1910 US Census
                  retrospective re-analysis, in which h & w are not treated as
                  blocking consonants but as vowels. Cf. :cite:`Repici:2013`.
                - ``Census`` follows the rules laid out in GIL 55
                  :cite:`US:1997` by the US Census, including coding prefixed
                  and unprefixed versions of some names

        reverse : bool
            Reverse the word before computing the selected Soundex (defaults to
            False); This results in "Reverse Soundex", which is useful for
            blocking in cases where the initial elements may be in error.
        zero_pad : bool
            Pad the end of the return value with 0s to achieve a max_length
            string

        Returns
        -------
        str
            The Soundex value

        Examples
        --------
        >>> pe = Soundex()
        >>> pe.encode("Christopher")
        'C623'
        >>> pe.encode("Niall")
        'N400'
        >>> pe.encode('Smith')
        'S530'
        >>> pe.encode('Schmidt')
        'S530'

        >>> pe.encode('Christopher', max_length=-1)
        'C623160000000000000000000000000000000000000000000000000000000000'
        >>> pe.encode('Christopher', max_length=-1, zero_pad=False)
        'C62316'

        >>> pe.encode('Christopher', reverse=True)
        'R132'

        >>> pe.encode('Ashcroft')
        'A261'
        >>> pe.encode('Asicroft')
        'A226'
        >>> pe.encode('Ashcroft', var='special')
        'A226'
        >>> pe.encode('Asicroft', var='special')
        'A226'

        """
        # Require a max_length of at least 4 and not more than 64
        if max_length != -1:
            max_length = min(max(4, max_length), 64)
        else:
            max_length = 64

        # uppercase, normalize, decompose, and filter non-A-Z out
        word = unicode_normalize('NFKD', text_type(word.upper()))
        word = word.replace('ß', 'SS')

        if var == 'Census':
            if word[:3] in {'VAN', 'CON'} and len(word) > 4:
                return (
                    soundex(word, max_length, 'American', reverse, zero_pad),
                    soundex(
                        word[3:], max_length, 'American', reverse, zero_pad
                    ),
                )
            if word[:2] in {'DE', 'DI', 'LA', 'LE'} and len(word) > 3:
                return (
                    soundex(word, max_length, 'American', reverse, zero_pad),
                    soundex(
                        word[2:], max_length, 'American', reverse, zero_pad
                    ),
                )
            # Otherwise, proceed as usual (var='American' mode, ostensibly)

        word = ''.join(c for c in word if c in self._uc_set)

        # Nothing to convert, return base case
        if not word:
            if zero_pad:
                return '0' * max_length
            return '0'

        # Reverse word if computing Reverse Soundex
        if reverse:
            word = word[::-1]

        # apply the Soundex algorithm
        sdx = word.translate(self._trans)

        if var == 'special':
            sdx = sdx.replace('9', '0')  # special rule for 1880-1910 census
        else:
            sdx = sdx.replace('9', '')  # rule 1
        sdx = self._delete_consecutive_repeats(sdx)  # rule 3

        if word[0] in 'HW':
            sdx = word[0] + sdx
        else:
            sdx = word[0] + sdx[1:]
        sdx = sdx.replace('0', '')  # rule 1

        if zero_pad:
            sdx += '0' * max_length  # rule 4

        return sdx[:max_length]


def soundex(word, max_length=4, var='American', reverse=False, zero_pad=True):
    """Return the Soundex code for a word.

    This is a wrapper for :py:meth:`Soundex.encode`.

    Parameters
    ----------
    word : str
        The word to transform
    max_length : int
        The length of the code returned (defaults to 4)
    var : str
        The variant of the algorithm to employ (defaults to ``American``):

            - ``American`` follows the American Soundex algorithm, as described
              at :cite:`US:2007` and in :cite:`Knuth:1998`; this is also called
              Miracode
            - ``special`` follows the rules from the 1880-1910 US Census
              retrospective re-analysis, in which h & w are not treated as
              blocking consonants but as vowels. Cf. :cite:`Repici:2013`.
            - ``Census`` follows the rules laid out in GIL 55 :cite:`US:1997`
              by the US Census, including coding prefixed and unprefixed
              versions of some names

    reverse : bool
        Reverse the word before computing the selected Soundex (defaults to
        False); This results in "Reverse Soundex", which is useful for blocking
        in cases where the initial elements may be in error.
    zero_pad : bool
        Pad the end of the return value with 0s to achieve a max_length string

    Returns
    -------
    str
        The Soundex value

    Examples
    --------
    >>> soundex("Christopher")
    'C623'
    >>> soundex("Niall")
    'N400'
    >>> soundex('Smith')
    'S530'
    >>> soundex('Schmidt')
    'S530'

    >>> soundex('Christopher', max_length=-1)
    'C623160000000000000000000000000000000000000000000000000000000000'
    >>> soundex('Christopher', max_length=-1, zero_pad=False)
    'C62316'

    >>> soundex('Christopher', reverse=True)
    'R132'

    >>> soundex('Ashcroft')
    'A261'
    >>> soundex('Asicroft')
    'A226'
    >>> soundex('Ashcroft', var='special')
    'A226'
    >>> soundex('Asicroft', var='special')
    'A226'

    """
    return Soundex().encode(word, max_length, var, reverse, zero_pad)


if __name__ == '__main__':
    import doctest

    doctest.testmod()