mirror of
https://github.com/explosion/spaCy.git
synced 2025-10-30 23:47:31 +03:00
63 lines
2.1 KiB
Python
63 lines
2.1 KiB
Python
from typing import List
|
|
|
|
from ...pipeline import Lemmatizer
|
|
from ...tokens import Token
|
|
|
|
|
|
class GreekLemmatizer(Lemmatizer):
|
|
"""
|
|
Greek language lemmatizer applies the default rule based lemmatization
|
|
procedure with some modifications for better Greek language support.
|
|
|
|
The first modification is that it checks if the word for lemmatization is
|
|
already a lemma and if yes, it just returns it.
|
|
The second modification is about removing the base forms function which is
|
|
not applicable for Greek language.
|
|
"""
|
|
|
|
def rule_lemmatize(self, token: Token) -> List[str]:
|
|
"""Lemmatize using a rule-based approach.
|
|
|
|
token (Token): The token to lemmatize.
|
|
RETURNS (list): The available lemmas for the string.
|
|
"""
|
|
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"):
|
|
return [string.lower()]
|
|
|
|
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()
|
|
forms = []
|
|
if string in index:
|
|
forms.append(string)
|
|
return forms
|
|
forms.extend(exceptions.get(string, []))
|
|
oov_forms = []
|
|
if not 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 or not form.isalpha():
|
|
forms.append(form)
|
|
else:
|
|
oov_forms.append(form)
|
|
if not forms:
|
|
forms.extend(oov_forms)
|
|
if not forms:
|
|
forms.append(string)
|
|
forms = list(dict.fromkeys(forms))
|
|
self.cache[cache_key] = forms
|
|
return forms
|