Ukrainian ITN

Fast WFST-based Inverse Text Normalization (ITN) for Ukrainian. The Python package uses a Rust runtime and ships with compiled grammars, so using it does not require Pynini, OpenFST, or a C++ toolchain.

Supported semiotic classes: cardinal, ordinal, decimal, fraction, measure, money, date, time, telephone, electronic (e-mail/URL), century (Roman numerals), number sign (№), ranges (numeric/time/date), durations & half-quantities, decades, legal references, scores, versions, IPv4, postal codes, street addresses. Also supports high-priority spoken abbreviations and time day-period/time-zone forms. Punctuation-aware (built for ASR output): "сто гривень, будь ласка!" -> ₴100, будь ласка!, "нуль шістдесят сім, сто двадцять три, сорок п'ять, шістдесят сім" -> 0671234567 Common Ukrainian apostrophes (', ’, ʼ) and uppercase ASR/text input are accepted without changing the spelling or case of ordinary words.

Installation

pip install ukrainian_itn

Installing from source also requires a current Rust toolchain. Published wheels include the compiled extension and grammar files.

Usage

from ukrainian_itn import normalize

normalize("це трапилося дві тисячі дев'ятнадцятого числа")  # це трапилося 2019-го числа
normalize("мінус п'ять цілих одна десята відсотка")  # -5.1 %
normalize("двадцять дві тисячі сто один")  # 22101
normalize("сьома година двадцять п'ять хвилин")  # 07:25
normalize("МІНУС П’ЯТЬ ГРИВЕНЬ")  # -₴5
normalize("третя година дня за київським часом")  # 15:00 Europe/Kyiv
normalize("підключи ю ес бі та вай фай")  # підключи USB та Wi-Fi

The bundled grammars are loaded lazily on the first call and cached for the lifetime of the process. normalize is thread-safe.

From command line

echo "це трапилося дві тисячі дев'ятнадцятого числа" | python -m ukrainian_itn
# or, after `pip install ukrainian_itn`:
echo "це трапилося дві тисячі дев'ятнадцятого числа" | ukrainian-itn

Options:
  -h, --help     Show this help message and exit
  -j, --json     Return result as JSON
  -v, --verbose  Print original input and normalized to compare
  --version      Show version

Will return це трапилося 2019-го числа. Lines the grammar cannot parse are reported to stderr and skipped (exit code 1).

JSON output

For more advanced usage you can get json output

from ukrainian_itn import normalize

normalize("це трапилося дві тисячі дев'ятнадцятого числа", json=True)
# >>> '[{"word": "це"}, {"word": "трапилося"}, {"ordinal": "2019"}, {"word": "числа"}]'

The returned string is guaranteed to be valid JSON, including when pass-through tokens contain quotes, backslashes, control characters, or non-BMP Unicode.

Rust runtime

The reusable crate uses rustfst and can be embedded in another Rust application without Python or PyO3 at runtime. To regenerate/export grammars, install the optional grammar tooling first:

pip install "ukrainian_itn[grammar]"
python -m ukrainian_itn.export grammars_export
cargo test
cargo build --release
echo "двадцять дві тисячі сто один" | ./target/release/ukrainian_itn_cli  # 22101

The repository root is also the reusable Rust crate. Its default feature set is PyO3-free, so another Rust application can depend on it directly:

[dependencies]
ukrainian-itn = "0.4"

use ukrainian_itn::InverseNormalizer;

let normalizer = InverseNormalizer::new()?;
assert_eq!(normalizer.normalize("двадцять дві тисячі сто один")?, "22101");
# Ok::<(), anyhow::Error>(())

Python bindings are available behind the optional python Cargo feature. Maturin enables that feature when building the Python wheel; ordinary Rust builds leave it disabled. Backend-specific Python types remain internal so the public Python API is implementation-independent.

Grammar development

Pynini is only used to edit, test, and recompile the grammar definitions. It is not imported by the public Python API and is not an installation dependency. Install it with:

pip install "ukrainian_itn[grammar]"

On platforms without a Pynini wheel, OpenFST development headers may also be needed. The grammar tooling exposes taggers and verbalizers directly. For example:

from ukrainian_itn.wfst import get_normalizer, apply_fst_text

apply_fst_text("мінус п'ять цілих одна десята відсотка", get_normalizer().classify.fst)

This returns tokens { measure { negative: "true" integer_part: "5" fractional_part: "1" units: "%" } }.

Development

uv sync                         # install the native package and standard test tools
uv sync --extra grammar         # additionally install Pynini for grammar work/full tests
uv run pytest          # run tests
uv run ruff check .    # lint
uv build               # build sdist + wheel