Collection of natural language parsing utilities


Keywords
context-free-grammar, finnish, finnish-language-analysis, natural-language-processing
License
GPL-2.0+
Install
pip install suomilog==0.9

Documentation

Suomilog

Suomilog is a toolkit for parsing context-free grammars that have embedded morphological information. It's intended use is parsing Finnish sentences and it includes a module that can parse and generate inflected Finnish sentences using libvoikko as back-end.

Context-free grammars

The suomilog.patternparser module is used for parsing context-free grammars. Suomilog grammars are context-free grammars that have additional morphological information. Below is an example.

.FEATURE ::= .HUMAN{omanto} nimi{$}
.FEATURE ::= .HUMAN{omanto} ikä{$}

.HUMAN ::= mies{$}
.HUMAN ::= nainen{$}
.HUMAN ::= ihminen{$}
.HUMAN ::= .ADJECTIVE{$} .HUMAN{$}

.ADJECTIVE ::= ahkera{$}
.ADJECTIVE ::= kaunis{$}
.ADJECTIVE ::= erittäin .ADJECTIVE{$}

In Suomilog grammars nonterminals are marked with a dot and all other symbols are terminals.

Morphological information is written in braces after a symbol. For example kaunis{omanto} would match the word kauniin. A dollar $ means that the morphological information is passed forward. So .HUMAN{omanto} for example mathes miehen, naisen, ihmisen, ahkeran miehen, and so on.

The braces can contain multiple form names separated with commas. For example, tehdä{-minen,omanto} would match tekemisen. In code these form names are called "bits".

For example usage, see the examples/ folder.

Finnish morphology

The suomilog.finnish module contains tools for Finnish morphological parsing and generation. It uses libvoikko as its back-end.

Supported forms are at least (there can be others as some are directly from Voikko's format and not all supported by Voikko are listed here):

Bit name Description Example
nimento nominative case kissa
omanto genitive case kissan
osanto partitive case kissaa
olento essive case kissana
tulento translative case kissaksi
ulkotulento allative case kissalle
ulkoolento adessive case kissalla
ulkoeronto ablative case kissalta
sisatulento illative case kissaan
sisaolento inessive case kissassa
sisaeronto elative case kissasta
vajanto abessive case kissatta
keinonto instructive case kissoin
seuranto comiitative case kissoineni
kerrontosti adverb kauniisti
yksikkö singular kissa
monikko plural kissat
nimisana noun kissa
laatusana adjective kaunis
teonsana verb nähdä
lukusana numeral kaksi
-minen MINEN-infinitive näkeminen
-ma MA-infinitive näkemä
-e E-infinitive nähden
-a A-infinitive nähdä
imperatiivi imperative näe
indikatiivi indicative näet
konditionaali conditional näkisit
potentiaali potential nähnet
1 first person näen
2 second person näet
3 third person näkee

The function suomilog.finnish.tokenize(text) is used to tokenize words:

import suomilog.finnish as f
print(f.tokenize("kissa käveli kadulla"))
# [Token('kissa', [('kissa', {'nimento', 'yksikkö', 'nimisana'})]), Token('käveli', [('kävellä', {'3', 'teonsana', 'yksikkö', 'indikatiivi'})]), Token('kadulla', [('katu', {'ulkoolento', 'yksikkö', 'nimisana'})])]

The function suomilog.finnish.inflect(word, case, plural) is used to inflect nouns, adjectives and numerals:

import suomilog.finnish as f
print(f.inflect("kissa", "osanto", True)) # kissoja