tokenize-uk

Ukrainian tokenization: paragraphs → sentences → words. Small, fast and robust, now with LanguageTool-grade engines.

Since 2.0 the default engines are ports of what LanguageTool uses for Ukrainian, both verified byte-identical to their Java originals on multi-million-token real-world corpora:

• words: a port of LanguageTool's UkrainianWordTokenizer (Andriy Rysin's abbreviation-aware tokenizer) — verified on 3.87M tokens across four corpora, zero differences, faster than the Java original;
• sentences: choppa-srx, the Python port of the Java segment SRX library with LanguageTool's rules.

The original 2016 regex engines are preserved and one argument away.

Quick Start

pip install tokenize_uk

import tokenize_uk

tokenize_uk.tokenize_words("Це проф. Артюхов.")
# ['Це', 'проф.', 'Артюхов', '.']

tokenize_uk.tokenize_sents("Це проф. Артюхов. Він приїхав у м. Київ.")
# ['Це проф. Артюхов.', 'Він приїхав у м. Київ.']

tokenize_uk.tokenize_text("Перший абзац. Ще речення.\nДругий абзац.")
# [[['Перший', 'абзац', '.'], ['Ще', 'речення', '.']], [['Другий', 'абзац', '.']]]

Command line:

echo "Це проф. Артюхов. Він приїхав у м. Київ." | tokenize-uk -l sents

The two engines

Every function keeps the pre-2.0 signature and return shape. If the new behavior breaks your pipeline, fall back per call:

tokenize_uk.tokenize_words(text, legacy=True)   # 2016 regex engine

or import the old engines directly from tokenize_uk.legacy. The legacy code is preserved byte-for-byte (regexes included) and covered by the original test fixtures.

Differences you will notice with the default engine:

• abbreviations keep their dots and don't split (проф., т., зв., чл.-кор.), and don't end sentences where they shouldn't;
• dates (12.03.2022), times (15:30), decimals (10,5) and web entities (Цензор.НЕТ) stay single tokens;
• sentence splitting follows LanguageTool's segment.srx rules instead of a punctuation-plus-uppercase heuristic.

For raw LanguageTool-compatible word tokens (including whitespace tokens), use the class directly:

from tokenize_uk import UkrainianWordTokenizer
UkrainianWordTokenizer().tokenize("а б")
# ['а', ' ', 'б']

Using with spaCy

pip install tokenize_uk[spacy]

from tokenize_uk.spacy import blank_pipeline

nlp = blank_pipeline()
doc = nlp("Це проф. Артюхов. Він приїхав у м. Київ.")
[t.text for t in doc]              # LT-grade word tokens
[sent.text for sent in doc.sents]  # LT-grade sentences

doc.text round-trips the input exactly, token offsets are exact, and token text is taken verbatim from the input (unlike tokenize_words, which canonicalizes a few apostrophe/quote characters). nlp.to_disk()/spacy.load() work (the tokenizer is a registered spaCy factory). You can also drop UkrainianTokenizer or the tokenize_uk_sentencizer component into an existing pipeline — with the caveat that pretrained statistical components were trained on spaCy's own tokenization.

Verification and performance

The word tokenizer is compared byte-for-byte against LanguageTool master's UkrainianWordTokenizer (compiled from source; harness in scripts/java-harness/):

The sentence layer's own verification (byte-identity with the Java segment library on ~136k segments) is documented in choppa's README.

Reproduce with scripts/benchmark.py (see docs/design.md).

Documentation

• API — functions, shapes, engines, CLI
• Design — how the LT port works and how it's verified
• History — 2016 origins, the LanguageTool ports

Copyrights and kudos

• Vsevolod Dyomkin, Dmytro Chaplynskyi — original library, lang-uk project
• Andriy Rysin and the LanguageTool team — the original UkrainianWordTokenizer and the Ukrainian SRX rules
• Jarek Lipski — the segment library behind the sentence layer

MIT licensed.