ごく適当なMeCabのPythonラッパー

mecab_wrapper.py

import re
from collections import namedtuple

import MeCab

Node = namedtuple('Node', [
    'surface',
    'base',
    'reading',
    'pos',
    'pos_detail_1',
    'pos_detail_2',
    'pos_detail_3',
    'conjugated_type',
    'conjugated_form',
])


class Parser:
    _WHITESPACE = re.compile(r'\s+')
    _DICDIR = {
        'neologd': '/usr/local/lib/mecab/dic/mecab-ipadic-neologd'
    }

    def __init__(self, mecab_dic):
        option = self._mecab_option(mecab_dic)
        self._tagger = MeCab.Tagger(option)

    def _mecab_option(self, mecab_dic):
        options = {'-O': 'chasen'}
        if mecab_dic is not None:
            options['-d'] = self._DICDIR[mecab_dic]
        return ' '.join(f'{k} {v}' for k, v in options.items())

    def parse(self, text):
        ntext = self._WHITESPACE.sub(' ', text)  # 改行やタブを除去
        result = self._tagger.parse(ntext)
        return [self._node(l) for l in result.splitlines() if l != 'EOS']

    def _node(self, line):
        fields = line.split('\t')
        pos_fields = fields[3].split('-')
        return Node(
            surface=fields[0],
            base=fields[2],
            reading=fields[1],
            pos=pos_fields[0],
            pos_detail_1=self._get(pos_fields, 1),
            pos_detail_2=self._get(pos_fields, 2),
            pos_detail_3=self._get(pos_fields, 3),
            conjugated_type=fields[4] or None,
            conjugated_form=fields[5] or None,
        )

    @staticmethod
    def _get(l, i):
        return l[i] if len(l) > i else None