spaCy/spacy/lang/pl/lemmatizer.py
2020-06-21 22:34:10 +02:00

79 lines
3.0 KiB
Python

from ...lemmatizer import Lemmatizer
from ...parts_of_speech import NAMES
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.
def __call__(self, string, univ_pos, morphology=None):
if isinstance(univ_pos, int):
univ_pos = NAMES.get(univ_pos, "X")
univ_pos = univ_pos.upper()
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, morphology, lookup_table):
# 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, morphology, lookup_table):
# 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, morphology, lookup_table):
# 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)]
def lookup(self, string, orth=None):
return string.lower()
def lemmatize(self, string, index, exceptions, rules):
raise NotImplementedError