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