ruff-format
Python bindings for the Ruff code formatter, built with Rust and PyO3.
Decision gist · record as of 2026-08-14
Yes, if you need to format Python code programmatically in your application. The package is actively maintained, has no runtime dependencies, and is backed by Ruff's well-regarded formatter. The medium install friction (compiled bindings) is offset by prebuilt wheels for most platforms. No known security issues.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.8 or later; prebuilt wheels available for most platforms, but source builds require Rust and maturin.
- Medium install friction due to compiled Rust bindings, but prebuilt wheels are available for most platforms.
- Actively maintained with recent releases.
License · maintenance · safety
MIT (permissive) — MIT license permits unrestricted use, modification, and distribution with minimal restrictions.
last release 2026-08-10 (4 days) · last repo commit 2026-08-10 · 1 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 97,853 downloads/mo, #13,124 on PyPI
Alternatives
Verify before relying
from ruff_format import format_string
code = "def hello( x,y, z ):\n print( x+y+z )"
formatted = format_string(code)
print(formatted)- Whether format_string handles all Python syntax edge cases or has known limitations
- Performance comparison with other formatters on large codebases
- Whether custom formatting rules beyond line_width are supported
What it is and what it does
ruff-format is a Python package that wraps Ruff's formatting engine, written in Rust and exposed via PyO3 bindings. It lets you format Python code from within your own Python programs rather than only via the command line. The package provides three main functions: is_valid_syntax to check syntax, parse_code to parse without formatting, and format_string to reformat code with a configurable line width (default 80).
The package has no runtime dependencies and is distributed as prebuilt wheels for most platforms, though it does require Rust to build from source. It supports Python 3.8 through 3.14 and is actively maintained, with recent releases available.
Use it for
- Programmatically format code snippets or user-submitted Python in a web application or IDE
- Integrate code formatting into a custom linting or code review pipeline
- Format Python code with a specific line width in a build or CI/CD workflow
- Validate Python syntax before attempting to format or execute it
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes, if you need to format Python code programmatically in your application.
The package is actively maintained, has no runtime dependencies, and is backed by Ruff's well-regarded formatter. The medium install friction (compiled bindings) is offset by prebuilt wheels for most platforms. No known security issues.
Install
ruff-format on PyPI
Before you install
Medium install friction due to compiled Rust bindings, but prebuilt wheels are available for most platforms. Actively maintained with recent releases.
Requires Python 3.8 or later; prebuilt wheels available for most platforms, but source builds require Rust and maturin.
License in practice
MIT license permits unrestricted use, modification, and distribution with minimal restrictions.
Quickstart
from ruff_format import format_string
code = "def hello( x,y, z ):\n print( x+y+z )"
formatted = format_string(code)
print(formatted)Verify before relying
- Whether format_string handles all Python syntax edge cases or has known limitations
- Performance comparison with other formatters on large codebases
- Whether custom formatting rules beyond line_width are supported
Package facts
| License | MIT permissive |
| Python support | Supports the current Python release >=3.8 |
| Install friction | Medium. Platform-specific wheel |
| Runtime dependencies | None |
| Maintenance | Actively maintained 4 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 97,853 / month, #13,124 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Programming Language :: Python :: 3Programming Language :: Python :: 3 :: OnlyProgramming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.8Programming Language :: Python :: 3.9Programming Language :: Python :: Implementation :: CPythonProgramming Language :: Python :: Implementation :: PyPyProgramming Language :: Rust |
Evidence: ruff_format-0.5.4-cp314-cp314t-macosx_10_12_x86_64.whl; ruff_format-0.5.4-cp314-cp314t-macosx_11_0_arm64.whl; ruff_format-0.5.4-cp314-cp314t-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; ruff_format-0.5.4-cp314-cp314t-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; ruff_format-0.5.4-cp314-cp314t-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl; ruff_format-0.5.4-cp314-cp314t-manylinux_2_17_s390x.manylinux2014_s390x.whl; ruff_format-0.5.4-cp314-cp314t-manylinux_2_17_x86_64.manylinux2014_x86_64.whl; ruff_format-0.5.4-cp314-cp314t-manylinux_2_5_i686.manylinux1_i686.whl; ruff_format-0.5.4-cp314-cp314t-musllinux_1_2_aarch64.whl; ruff_format-0.5.4-cp314-cp314t-musllinux_1_2_armv7l.whl; ruff_format-0.5.4-cp314-cp314t-musllinux_1_2_i686.whl; ruff_format-0.5.4-cp314-cp314t-musllinux_1_2_x86_64.whl; ruff_format-0.5.4-cp314-cp314t-win32.whl; ruff_format-0.5.4-cp314-cp314t-win_amd64.whl; ruff_format-0.5.4-cp314-cp314t-win_arm64.whl; ruff_format-0.5.4-cp38-abi3-macosx_10_12_x86_64.whl; ruff_format-0.5.4-cp38-abi3-macosx_11_0_arm64.whl; ruff_format-0.5.4-cp38-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl; ruff_format-0.5.4-cp38-abi3-manylinux_2_17_armv7l.manylinux2014_armv7l.whl; ruff_format-0.5.4-cp38-abi3-manylinux_2_17_ppc64le.manylinux2014_ppc64le.whl
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