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An extremely fast Python linter and code formatter, written in Rust.

Linting the CPython codebase from scratch.

• ⚡️ 10-100x faster than existing linters (like Flake8) and formatters (like Black)
• 🐍 Installable viapip
• 🛠️pyproject.toml support
• 🤝 Python 3.13 compatibility
• ⚖️ Drop-in parity withFlake8, isort, andBlack
• 📦 Built-in caching, to avoid re-analyzing unchanged files
• 🔧 Fix support, for automatic error correction (e.g., automatically remove unused imports)
• 📏 Over800 built-in rules, with native re-implementationsof popular Flake8 plugins, like flake8-bugbear
• ⌨️ First-partyeditor integrations forVS Code andmore
• 🌎 Monorepo-friendly, withhierarchical and cascading configuration

Ruff aims to be orders of magnitude faster than alternative tools while integrating morefunctionality behind a single, common interface.

Ruff can be used to replaceFlake8 (plus dozens of plugins),Black,isort,pydocstyle,pyupgrade,autoflake, and more, all while executing tens or hundreds oftimes faster than any individual tool.

Ruff is extremely actively developed and used in major open-source projects like:

• Apache Airflow
• Apache Superset
• FastAPI
• Hugging Face
• Pandas
• SciPy

...andmany more.

Ruff is backed byAstral. Read thelaunch post,or the originalproject announcement.

Sebastián Ramírez, creatorofFastAPI:

Ruff is so fast that sometimes I add an intentional bug in the code just to confirm it's actuallyrunning and checking the code.

Nick Schrock, founder ofElementl,co-creator ofGraphQL:

Why is Ruff a gamechanger? Primarily because it is nearly 1000x faster. Literally. Not a typo. Onour largest module (dagster itself, 250k LOC) pylint takes about 2.5 minutes, parallelized across 4cores on my M1. Running ruff against ourentire codebase takes .4 seconds.

Bryan Van de Ven, co-creatorofBokeh, original authorofConda:

Ruff is ~150-200x faster than flake8 on my machine, scanning the whole repo takes ~0.2s instead of~20s. This is an enormous quality of life improvement for local dev. It's fast enough that I addedit as an actual commit hook, which is terrific.

Timothy Crosley,creator ofisort:

Just switched my first project to Ruff. Only one downside so far: it's so fast I couldn't believeit was working till I intentionally introduced some errors.

Tim Abbott, leaddeveloper ofZulip:

This is just ridiculously fast...ruff is amazing.

For more, see thedocumentation.

1. Getting Started
2. Configuration
3. Rules
4. Contributing
5. Support
6. Acknowledgements
7. Who's Using Ruff?
8. License

For more, see thedocumentation.

Ruff is available asruff on PyPI:

# With pip.pip install ruff# With pipx.pipx install ruff

Starting with version0.5.0, Ruff can be installed with our standalone installers:

# On macOS and Linux.curl -LsSf https://astral.sh/ruff/install.sh| sh# On Windows.powershell -c"irm https://astral.sh/ruff/install.ps1 | iex"# For a specific version.curl -LsSf https://astral.sh/ruff/0.5.7/install.sh| shpowershell -c"irm https://astral.sh/ruff/0.5.7/install.ps1 | iex"

You can also install Ruff viaHomebrew,Conda,and witha variety of other package managers.

To run Ruff as a linter, try any of the following:

ruff check# Lint all files in the current directory (and any subdirectories).ruff check path/to/code/# Lint all files in `/path/to/code` (and any subdirectories).ruff check path/to/code/*.py# Lint all `.py` files in `/path/to/code`.ruff check path/to/code/to/file.py# Lint `file.py`.ruff check @arguments.txt# Lint using an input file, treating its contents as newline-delimited command-line arguments.

Or, to run Ruff as a formatter:

ruff format# Format all files in the current directory (and any subdirectories).ruff format path/to/code/# Format all files in `/path/to/code` (and any subdirectories).ruff format path/to/code/*.py# Format all `.py` files in `/path/to/code`.ruff format path/to/code/to/file.py# Format `file.py`.ruff format @arguments.txt# Format using an input file, treating its contents as newline-delimited command-line arguments.

Ruff can also be used as apre-commit hook viaruff-pre-commit:

-repo:https://github.com/astral-sh/ruff-pre-commit# Ruff version.rev:v0.5.7hooks:# Run the linter.    -id:ruffargs:[ --fix ]# Run the formatter.    -id:ruff-format

Ruff can also be used as aVS Code extension or withvarious other editors.

Ruff can also be used as aGitHub Action viaruff-action:

name:Ruffon:[ push, pull_request ]jobs:ruff:runs-on:ubuntu-lateststeps:      -uses:actions/checkout@v4      -uses:chartboost/ruff-action@v1

Ruff can be configured through apyproject.toml,ruff.toml, or.ruff.toml file (see:Configuration, orSettingsfor a complete list of all configuration options).

If left unspecified, Ruff's default configuration is equivalent to the followingruff.toml file:

# Exclude a variety of commonly ignored directories.exclude = [".bzr",".direnv",".eggs",".git",".git-rewrite",".hg",".ipynb_checkpoints",".mypy_cache",".nox",".pants.d",".pyenv",".pytest_cache",".pytype",".ruff_cache",".svn",".tox",".venv",".vscode","__pypackages__","_build","buck-out","build","dist","node_modules","site-packages","venv",]# Same as Black.line-length =88indent-width =4# Assume Python 3.8target-version ="py38"[lint]# Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`)  codes by default.select = ["E4","E7","E9","F"]ignore = []# Allow fix for all enabled rules (when `--fix`) is provided.fixable = ["ALL"]unfixable = []# Allow unused variables when underscore-prefixed.dummy-variable-rgx ="^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"[format]# Like Black, use double quotes for strings.quote-style ="double"# Like Black, indent with spaces, rather than tabs.indent-style ="space"# Like Black, respect magic trailing commas.skip-magic-trailing-comma =false# Like Black, automatically detect the appropriate line ending.line-ending ="auto"

Note that, in apyproject.toml, each section header should be prefixed withtool.ruff. Forexample,[lint] should be replaced with[tool.ruff.lint].

Some configuration options can be provided via dedicated command-line arguments, such as thoserelated to rule enablement and disablement, file discovery, and logging level:

ruff check --select F401 --select F403 --quiet

The remaining configuration options can be provided through a catch-all--config argument:

ruff check --config"lint.per-file-ignores = {'some_file.py' = ['F841']}"

To opt in to the latest lint rules, formatter style changes, interface updates, and more, enablepreview mode by settingpreview = true in your configurationfile or passing--preview on the command line. Preview mode enables a collection of unstablefeatures that may change prior to stabilization.

Seeruff help for more on Ruff's top-level commands, orruff help check andruff help formatfor more on the linting and formatting commands, respectively.

Ruff supports over 800 lint rules, many of which are inspired by popular tools like Flake8,isort, pyupgrade, and others. Regardless of the rule's origin, Ruff re-implements every rule inRust as a first-party feature.

By default, Ruff enables Flake8'sF rules, along with a subset of theE rules, omitting anystylistic rules that overlap with the use of a formatter, likeruff format orBlack.

If you're just getting started with Ruff,the default rule set is a great place to start: itcatches a wide variety of common errors (like unused imports) with zero configuration.

Beyond the defaults, Ruff re-implements some of the most popular Flake8 plugins and related codequality tools, including:

• autoflake
• eradicate
• flake8-2020
• flake8-annotations
• flake8-async
• flake8-bandit (#1646)
• flake8-blind-except
• flake8-boolean-trap
• flake8-bugbear
• flake8-builtins
• flake8-commas
• flake8-comprehensions
• flake8-copyright
• flake8-datetimez
• flake8-debugger
• flake8-django
• flake8-docstrings
• flake8-eradicate
• flake8-errmsg
• flake8-executable
• flake8-future-annotations
• flake8-gettext
• flake8-implicit-str-concat
• flake8-import-conventions
• flake8-logging
• flake8-logging-format
• flake8-no-pep420
• flake8-pie
• flake8-print
• flake8-pyi
• flake8-pytest-style
• flake8-quotes
• flake8-raise
• flake8-return
• flake8-self
• flake8-simplify
• flake8-slots
• flake8-super
• flake8-tidy-imports
• flake8-todos
• flake8-type-checking
• flake8-use-pathlib
• flynt (#2102)
• isort
• mccabe
• pandas-vet
• pep8-naming
• pydocstyle
• pygrep-hooks
• pylint-airflow
• pyupgrade
• tryceratops
• yesqa

For a complete enumeration of the supported rules, seeRules.

Contributions are welcome and highly appreciated. To get started, check out thecontributing guidelines.

You can also join us onDiscord.

Having trouble? Check out the existing issues onGitHub,or feel free toopen a new one.

You can also ask for help onDiscord.

Ruff's linter draws on both the APIs and implementation details of many othertools in the Python ecosystem, especiallyFlake8,Pyflakes,pycodestyle,pydocstyle,pyupgrade, andisort.

In some cases, Ruff includes a "direct" Rust port of the corresponding tool.We're grateful to the maintainers of these tools for their work, and for allthe value they've provided to the Python community.

Ruff's formatter is built on a fork of Rome'srome_formatter,and again draws on both API and implementation details fromRome,Prettier, andBlack.

Ruff's import resolver is based on the import resolution algorithm fromPyright.

Ruff is also influenced by a number of tools outside the Python ecosystem, likeClippy andESLint.

Ruff is the beneficiary of a large number ofcontributors.

Ruff is released under the MIT license.

Ruff is used by a number of major open-source projects and companies, including:

• Albumentations
• Amazon (AWS SAM)
• Anthropic (Python SDK)
• Apache Airflow
• AstraZeneca (Magnus)
• Babel
• Benchling (Refac)
• Bokeh
• Cryptography (PyCA)
• CERN (Indico)
• DVC
• Dagger
• Dagster
• Databricks (MLflow)
• Dify
• FastAPI
• Godot
• Gradio
• Great Expectations
• HTTPX
• Hatch
• Home Assistant
• Hugging Face (Transformers,Datasets,Diffusers)
• IBM (Qiskit)
• ING Bank (popmon,probatus)
• Ibis
• ivy
• Jupyter
• Kraken Tech
• LangChain
• Litestar
• LlamaIndex
• Matrix (Synapse)
• MegaLinter
• Meltano (Meltano CLI,Singer SDK)
• Microsoft (Semantic Kernel,ONNX Runtime,LightGBM)
• Modern Treasury (Python SDK)
• Mozilla (Firefox)
• Mypy
• Nautobot
• Netflix (Dispatch)
• Neon
• Nokia
• NoneBot
• NumPyro
• ONNX
• OpenBB
• Open Wine Components
• PDM
• PaddlePaddle
• Pandas
• Pillow
• Poetry
• Polars
• PostHog
• Prefect (Python SDK,Marvin)
• PyInstaller
• PyMC
• PyMC-Marketing
• pytest
• PyTorch
• Pydantic
• Pylint
• PyVista
• Reflex
• River
• Rippling
• Robyn
• Saleor
• Scale AI (Launch SDK)
• SciPy
• Snowflake (SnowCLI)
• Sphinx
• Stable Baselines3
• Starlette
• Streamlit
• The Algorithms
• Vega-Altair
• WordPress (Openverse)
• ZenML
• Zulip
• build (PyPA)
• cibuildwheel (PyPA)
• delta-rs
• featuretools
• meson-python
• nox
• pip

If you're using Ruff, consider adding the Ruff badge to your project'sREADME.md:

[![Ruff](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json)](https://github.com/astral-sh/ruff)

...orREADME.rst:

..image::https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json:target:https://github.com/astral-sh/ruff:alt:Ruff

...or, as HTML:

<ahref="https://github.com/astral-sh/ruff"><imgsrc="https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/astral-sh/ruff/main/assets/badge/v2.json"alt="Ruff"style="max-width:100%;"></a>

This repository is licensed under theMIT License