spaCy/spacy/lang/pl/lemmatizer.py

87 lines
3.5 KiB
Python

from typing import Dict, List, Tuple
from ...pipeline import Lemmatizer
from ...tokens import Token
class PolishLemmatizer(Lemmatizer):
# This lemmatizer implements lookup lemmatization based on the Morfeusz
# dictionary (morfeusz.sgjp.pl/en) by Institute of Computer Science PAS.
# It utilizes some prefix based improvements for verb and adjectives
# lemmatization, as well as case-sensitive lemmatization for nouns.
@classmethod
def get_lookups_config(cls, mode: str) -> Tuple[List[str], List[str]]:
if mode == "pos_lookup":
# fmt: off
required = [
"lemma_lookup_adj", "lemma_lookup_adp", "lemma_lookup_adv",
"lemma_lookup_aux", "lemma_lookup_noun", "lemma_lookup_num",
"lemma_lookup_part", "lemma_lookup_pron", "lemma_lookup_verb"
]
# fmt: on
return (required, [])
else:
return super().get_lookups_config(mode)
def pos_lookup_lemmatize(self, token: Token) -> List[str]:
string = token.text
univ_pos = token.pos_
morphology = token.morph.to_dict()
lookup_pos = univ_pos.lower()
if univ_pos == "PROPN":
lookup_pos = "noun"
lookup_table = self.lookups.get_table("lemma_lookup_" + lookup_pos, {})
if univ_pos == "NOUN":
return self.lemmatize_noun(string, morphology, lookup_table)
if univ_pos != "PROPN":
string = string.lower()
if univ_pos == "ADJ":
return self.lemmatize_adj(string, morphology, lookup_table)
elif univ_pos == "VERB":
return self.lemmatize_verb(string, morphology, lookup_table)
return [lookup_table.get(string, string.lower())]
def lemmatize_adj(
self, string: str, morphology: dict, lookup_table: Dict[str, str]
) -> List[str]:
# this method utilizes different procedures for adjectives
# with 'nie' and 'naj' prefixes
if string[:3] == "nie":
search_string = string[3:]
if search_string[:3] == "naj":
naj_search_string = search_string[3:]
if naj_search_string in lookup_table:
return [lookup_table[naj_search_string]]
if search_string in lookup_table:
return [lookup_table[search_string]]
if string[:3] == "naj":
naj_search_string = string[3:]
if naj_search_string in lookup_table:
return [lookup_table[naj_search_string]]
return [lookup_table.get(string, string)]
def lemmatize_verb(
self, string: str, morphology: dict, lookup_table: Dict[str, str]
) -> List[str]:
# this method utilizes a different procedure for verbs
# with 'nie' prefix
if string[:3] == "nie":
search_string = string[3:]
if search_string in lookup_table:
return [lookup_table[search_string]]
return [lookup_table.get(string, string)]
def lemmatize_noun(
self, string: str, morphology: dict, lookup_table: Dict[str, str]
) -> List[str]:
# this method is case-sensitive, in order to work
# for incorrectly tagged proper names
if string != string.lower():
if string.lower() in lookup_table:
return [lookup_table[string.lower()]]
elif string in lookup_table:
return [lookup_table[string]]
return [string.lower()]
return [lookup_table.get(string, string)]