mirror of
https://github.com/explosion/spaCy.git
synced 2024-12-25 17:36:30 +03:00
123 lines
4.5 KiB
Python
123 lines
4.5 KiB
Python
from typing import List, Tuple
|
|
|
|
from ...pipeline import Lemmatizer
|
|
from ...tokens import Token
|
|
|
|
|
|
class DutchLemmatizer(Lemmatizer):
|
|
@classmethod
|
|
def get_lookups_config(cls, mode: str) -> Tuple[List[str], List[str]]:
|
|
if mode == "rule":
|
|
required = ["lemma_lookup", "lemma_rules", "lemma_exc", "lemma_index"]
|
|
return (required, [])
|
|
else:
|
|
return super().get_lookups_config(mode)
|
|
|
|
def lookup_lemmatize(self, token: Token) -> List[str]:
|
|
"""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."""
|
|
lookup_table = self.lookups.get_table("lemma_lookup", {})
|
|
string = token.text.lower()
|
|
return [lookup_table.get(string, string)]
|
|
|
|
# Note: CGN does not distinguish AUX verbs, so we treat AUX as VERB.
|
|
def rule_lemmatize(self, token: Token) -> List[str]:
|
|
# 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".
|
|
cache_key = (token.lower, token.pos)
|
|
if cache_key in self.cache:
|
|
return self.cache[cache_key]
|
|
string = token.text
|
|
univ_pos = token.pos_.lower()
|
|
if univ_pos in ("", "eol", "space"):
|
|
forms = [string.lower()]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
|
|
index_table = self.lookups.get_table("lemma_index", {})
|
|
exc_table = self.lookups.get_table("lemma_exc", {})
|
|
rules_table = self.lookups.get_table("lemma_rules", {})
|
|
index = index_table.get(univ_pos, {})
|
|
exceptions = exc_table.get(univ_pos, {})
|
|
rules = rules_table.get(univ_pos, {})
|
|
|
|
string = string.lower()
|
|
if univ_pos not in (
|
|
"noun",
|
|
"verb",
|
|
"aux",
|
|
"adj",
|
|
"adv",
|
|
"pron",
|
|
"det",
|
|
"adp",
|
|
"num",
|
|
):
|
|
forms = [string]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
lemma_index = index_table.get(univ_pos, {})
|
|
# string is already lemma
|
|
if string in lemma_index:
|
|
forms = [string]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
exc_table = self.lookups.get_table("lemma_exc", {})
|
|
exceptions = exc_table.get(univ_pos, {})
|
|
# string is irregular token contained in exceptions index.
|
|
try:
|
|
forms = [exceptions[string][0]]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
except KeyError:
|
|
pass
|
|
# string corresponds to key in lookup table
|
|
lookup_table = self.lookups.get_table("lemma_lookup", {})
|
|
looked_up_lemma = lookup_table.get(string)
|
|
if looked_up_lemma and looked_up_lemma in lemma_index:
|
|
forms = [looked_up_lemma]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
rules_table = self.lookups.get_table("lemma_rules", {})
|
|
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:
|
|
forms = [form]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
else:
|
|
oov_forms.append(form)
|
|
forms = list(set(oov_forms))
|
|
# Back-off through remaining return value candidates.
|
|
if forms:
|
|
for form in forms:
|
|
if form in exceptions:
|
|
forms = [form]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
if looked_up_lemma:
|
|
forms = [looked_up_lemma]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
else:
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
elif looked_up_lemma:
|
|
forms = [looked_up_lemma]
|
|
self.cache[cache_key] = forms
|
|
return forms
|
|
else:
|
|
forms = [string]
|
|
self.cache[cache_key] = forms
|
|
return forms
|