spaCy/spacy/ja/__init__.py
Paul O'Leary McCann 53e17296e9 Fix pronoun handling
Missed this case earlier.

連体詞 have three classes for UD purposes:

- その -> DET
- それ -> PRON
- 同じ -> ADJ

-POLM
2017-08-22 00:01:49 +09:00

119 lines
3.8 KiB
Python

# encoding: utf8
from __future__ import unicode_literals, print_function
from os import path
from ..language import Language, BaseDefaults
from ..tokenizer import Tokenizer
from ..tagger import Tagger
from ..attrs import LANG
from ..tokens import Doc
from .language_data import *
import re
from collections import namedtuple
ShortUnitWord = namedtuple('ShortUnitWord', ['surface', 'base_form', 'part_of_speech'])
def try_mecab_import():
"""Mecab is required for Japanese support, so check for it.
It it's not available blow up and explain how to fix it."""
try:
import MeCab
return MeCab
except ImportError:
raise ImportError("Japanese support requires MeCab: "
"https://github.com/SamuraiT/mecab-python3")
class JapaneseTokenizer(object):
def __init__(self, cls, nlp=None):
self.vocab = nlp.vocab if nlp is not None else cls.create_vocab(nlp)
MeCab = try_mecab_import()
self.tokenizer = MeCab.Tagger()
def __call__(self, text):
words = [x.surface for x in detailed_tokens(self.tokenizer, text)]
return Doc(self.vocab, words=words, spaces=[False]*len(words))
def resolve_pos(token):
"""If necessary, add a field to the POS tag for UD mapping.
Under Universal Dependencies, sometimes the same Unidic POS tag can
be mapped differently depending on the literal token or its context
in the sentence. This function adds information to the POS tag to
resolve ambiguous mappings.
"""
# NOTE: This is a first take. The rules here are crude approximations.
# For many of these, full dependencies are needed to properly resolve
# PoS mappings.
if token.part_of_speech == '連体詞,*,*,*':
if re.match('^[こそあど此其彼]の', token.surface):
return token.part_of_speech + ',DET'
if re.match('^[こそあど此其彼]', token.surface):
return token.part_of_speech + ',PRON'
else:
return token.part_of_speech + ',ADJ'
return token.part_of_speech
def detailed_tokens(tokenizer, text):
"""Format Mecab output into a nice data structure, based on Janome."""
node = tokenizer.parseToNode(text)
node = node.next # first node is beginning of sentence and empty, skip it
words = []
while node.posid != 0:
parts = node.feature.split(',')
pos = ','.join(parts[0:4])
reading = parts[6]
base = parts[7]
surface = parts[8]
words.append( ShortUnitWord(surface, base, pos) )
node = node.next
return words
class JapaneseTagger(object):
def __init__(self, vocab):
MeCab = try_mecab_import()
self.tagger = Tagger(vocab)
self.tokenizer = MeCab.Tagger()
def __call__(self, tokens):
# two parts to this:
# 1. get raw JP tags
# 2. add features to tags as necessary for UD
# TODO: if the text has been tokenized, this info is already available
# How to set the data when tokenizing or save it for the tagger to find?
dtokens = detailed_tokens(self.tokenizer, tokens.text)
rawtags = list(map(resolve_pos, dtokens))
self.tagger.tag_from_strings(tokens, rawtags)
class JapaneseDefaults(BaseDefaults):
tag_map = TAG_MAP
@classmethod
def create_tokenizer(cls, nlp=None):
return JapaneseTokenizer(cls, nlp)
@classmethod
def create_tagger(cls, tokenizer):
return JapaneseTagger(tokenizer.vocab)
class Japanese(Language):
lang = 'ja'
Defaults = JapaneseDefaults
def make_doc(self, text):
words = [str(t) for t in self.tokenizer(text)]
doc = Doc(self.vocab, words=words, spaces=[False]*len(words))
tagger = JapaneseDefaults.create_tagger(self.tokenizer)
tagger(doc)
return doc