Ruff

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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.tomlsupport
• 🤝 Python 3.13 compatibility
• ⚖️ Drop-in parity withFlake8,isort, and Black
• 📦 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-implementations of popular Flake8 plugins, like flake8-bugbear
• ⌨️ First-partyeditor integrationsfor VS Codeandmore
• 🌎 Monorepo-friendly, withhierarchical and cascading configuration

Ruff aims to be orders of magnitude faster than alternative tools while integrating more functionality 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 of times 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.

Testimonials

Sebastián Ramírez,creator ofFastAPI:

Ruff is so fast that sometimes I add an intentional bug in the code just to confirm it's actually running 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. On our largest module (dagster itself, 250k LOC) pylint takes about 2.5 minutes, parallelized across 4 cores on my M1. Running ruff against ourentirecodebase takes.4 seconds.

Bryan Van de Ven,co-creator ofBokeh,original author ofConda:

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 added it 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 believe it was working till I intentionally introduced some errors.

Tim Abbott,lead developer ofZulip:

This is just ridiculously fast...ruffis amazing.

Table of Contents

For more, see thedocumentation.

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

Getting Started

For more, see thedocumentation.

Installation

Ruff is available asruffon 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/0.5.5/install.sh|sh
powershell -c"irm https://astral.sh/ruff/0.5.5/install.ps1 | iex"

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

Usage

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-commithook viaruff-pre-commit:

-repo:https://github.com/astral-sh/ruff-pre-commit
#Ruff version.
rev:v0.5.5
hooks:
#Run the linter.
-id:ruff
args:[ --fix ]
#Run the formatter.
-id:ruff-format

Ruff can also be used as aVS Code extensionor alongside any other editor through theRuff LSP.

Ruff can also be used as aGitHub Actionvia ruff-action:

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

Configuration

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

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

#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=88
indent-width=4

#Assume Python 3.8
target-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.For example,[lint]should be replaced with[tool.ruff.lint].

Some configuration options can be provided via dedicated command-line arguments, such as those related 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--configargument:

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, enable preview modeby settingpreview = truein your configuration file or passing--previewon the command line. Preview mode enables a collection of unstable features that may change prior to stabilization.

Seeruff helpfor more on Ruff's top-level commands, orruff help checkandruff help format for more on the linting and formatting commands, respectively.

Rules

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 in Rust as a first-party feature.

By default, Ruff enables Flake8'sFrules, along with a subset of theErules, omitting any stylistic rules that overlap with the use of a formatter, likeruff formator Black.

If you're just getting started with Ruff,the default rule set is a great place to start:it catches 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 code quality 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.

Contributing

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

You can also join us onDiscord.

Support

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

You can also ask for help onDiscord.

Acknowledgements

Ruff's linter draws on both the APIs and implementation details of many other tools 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 all the 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, like ClippyandESLint.

Ruff is the beneficiary of a large number ofcontributors.

Ruff is released under the MIT license.

Who's Using Ruff?

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)
• 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

Show Your Support

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>

License

This repository is licensed under theMIT License