mirror of https://github.com/explosion/spaCy.git
150 lines
4.9 KiB
Python
150 lines
4.9 KiB
Python
# coding: utf8
|
|
from __future__ import unicode_literals
|
|
|
|
from ....symbols import NOUN, VERB, ADJ, NUM, DET, PRON, ADP, AUX, ADV
|
|
|
|
|
|
class DutchLemmatizer(object):
|
|
# Note: CGN does not distinguish AUX verbs, so we treat AUX as VERB.
|
|
univ_pos_name_variants = {
|
|
NOUN: "noun",
|
|
"NOUN": "noun",
|
|
"noun": "noun",
|
|
VERB: "verb",
|
|
"VERB": "verb",
|
|
"verb": "verb",
|
|
AUX: "verb",
|
|
"AUX": "verb",
|
|
"aux": "verb",
|
|
ADJ: "adj",
|
|
"ADJ": "adj",
|
|
"adj": "adj",
|
|
ADV: "adv",
|
|
"ADV": "adv",
|
|
"adv": "adv",
|
|
PRON: "pron",
|
|
"PRON": "pron",
|
|
"pron": "pron",
|
|
DET: "det",
|
|
"DET": "det",
|
|
"det": "det",
|
|
ADP: "adp",
|
|
"ADP": "adp",
|
|
"adp": "adp",
|
|
NUM: "num",
|
|
"NUM": "num",
|
|
"num": "num",
|
|
}
|
|
|
|
@classmethod
|
|
def load(cls, path, index=None, exc=None, rules=None, lookup=None):
|
|
return cls(index, exc, rules, lookup)
|
|
|
|
def __init__(self, index=None, exceptions=None, rules=None, lookup=None):
|
|
self.index = index
|
|
self.exc = exceptions
|
|
self.rules = rules or {}
|
|
self.lookup_table = lookup if lookup is not None else {}
|
|
|
|
def __call__(self, string, univ_pos, morphology=None):
|
|
# Difference 1: self.rules is assumed to be non-None, so no
|
|
# 'is None' check required.
|
|
# String lowercased from the get-go. All lemmatization results in
|
|
# lowercased strings. For most applications, this shouldn't pose
|
|
# any problems, and it keeps the exceptions indexes small. If this
|
|
# creates problems for proper nouns, we can introduce a check for
|
|
# univ_pos == "PROPN".
|
|
string = string.lower()
|
|
try:
|
|
univ_pos = self.univ_pos_name_variants[univ_pos]
|
|
except KeyError:
|
|
# Because PROPN not in self.univ_pos_name_variants, proper names
|
|
# are not lemmatized. They are lowercased, however.
|
|
return [string]
|
|
# if string in self.lemma_index.get(univ_pos)
|
|
lemma_index = self.index.get(univ_pos, {})
|
|
# string is already lemma
|
|
if string in lemma_index:
|
|
return [string]
|
|
exceptions = self.exc.get(univ_pos, {})
|
|
# string is irregular token contained in exceptions index.
|
|
try:
|
|
lemma = exceptions[string]
|
|
return [lemma[0]]
|
|
except KeyError:
|
|
pass
|
|
# string corresponds to key in lookup table
|
|
lookup_table = self.lookup_table
|
|
looked_up_lemma = lookup_table.get(string)
|
|
if looked_up_lemma and looked_up_lemma in lemma_index:
|
|
return [looked_up_lemma]
|
|
|
|
forms, is_known = lemmatize(
|
|
string, lemma_index, exceptions, self.rules.get(univ_pos, [])
|
|
)
|
|
|
|
# Back-off through remaining return value candidates.
|
|
if forms:
|
|
if is_known:
|
|
return forms
|
|
else:
|
|
for form in forms:
|
|
if form in exceptions:
|
|
return [form]
|
|
if looked_up_lemma:
|
|
return [looked_up_lemma]
|
|
else:
|
|
return forms
|
|
elif looked_up_lemma:
|
|
return [looked_up_lemma]
|
|
else:
|
|
return [string]
|
|
|
|
# Overrides parent method so that a lowercased version of the string is
|
|
# used to search the lookup table. This is necessary because our lookup
|
|
# table consists entirely of lowercase keys.
|
|
def lookup(self, string, orth=None):
|
|
string = string.lower()
|
|
if orth is not None:
|
|
return self.lookup_table.get(orth, string)
|
|
else:
|
|
return self.lookup_table.get(string, string)
|
|
|
|
def noun(self, string, morphology=None):
|
|
return self(string, "noun", morphology)
|
|
|
|
def verb(self, string, morphology=None):
|
|
return self(string, "verb", morphology)
|
|
|
|
def adj(self, string, morphology=None):
|
|
return self(string, "adj", morphology)
|
|
|
|
def det(self, string, morphology=None):
|
|
return self(string, "det", morphology)
|
|
|
|
def pron(self, string, morphology=None):
|
|
return self(string, "pron", morphology)
|
|
|
|
def adp(self, string, morphology=None):
|
|
return self(string, "adp", morphology)
|
|
|
|
def punct(self, string, morphology=None):
|
|
return self(string, "punct", morphology)
|
|
|
|
|
|
# Reimplemented to focus more on application of suffix rules and to return
|
|
# as early as possible.
|
|
def lemmatize(string, index, exceptions, rules):
|
|
# returns (forms, is_known: bool)
|
|
oov_forms = []
|
|
for old, new in rules:
|
|
if string.endswith(old):
|
|
form = string[: len(string) - len(old)] + new
|
|
if not form:
|
|
pass
|
|
elif form in index:
|
|
return [form], True # True = Is known (is lemma)
|
|
else:
|
|
oov_forms.append(form)
|
|
return list(set(oov_forms)), False
|