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 our entire codebase takes .4 seconds.
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.
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.
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 can be configured through a pyproject.toml, ruff.toml, or .ruff.toml file (see:
Configuration, or Settings
for a complete list of all configuration options).
If left unspecified, the default configuration is equivalent to:
Some configuration options can be provided via the command-line, such as those related to
rule enablement and disablement, file discovery, logging level, and more:
See ruff help for more on Ruff’s top-level commands, or ruff help check for more on the
linting command.
Rules
Ruff supports over 500 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’s E and F rules. Ruff supports all rules from the F category,
and a subset of the E category, omitting those
stylistic rules made obsolete by the use of an autoformatter, like
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:
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 autoformatter is built on a fork of Rome’s rome_formatter,
and again draws on both the APIs and implementation details of Rome,
Prettier, and Black.
Ruff is also influenced by a number of tools outside the Python ecosystem, like
Clippy and ESLint.
Ruff is the beneficiary of a large number of contributors.
Ruff is released under the MIT license.
Who’s Using Ruff?
Ruff is used in a number of major open-source projects, including:
@charliermarsh
Discord
Docs
Playground
An extremely fast Python linter, written in Rust.
Linting the CPython codebase from scratch.
⚡️ 10-100x faster than existing linters
🐍 Installable via
pip
🛠️
pyproject.toml
support🤝 Python 3.11 compatibility
📦 Built-in caching, to avoid re-analyzing unchanged files
🔧 Autofix support, for automatic error correction (e.g., automatically remove unused imports)
📏 Over 500 built-in rules
⚖️ Near-parity with the built-in Flake8 rule set
🔌 Native re-implementations of dozens of Flake8 plugins, like flake8-bugbear
⌨️ First-party editor integrations for VS Code and more
🌎 Monorepo-friendly, with hierarchical 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 replace Flake8 (plus dozens of plugins), isort, pydocstyle, yesqa, eradicate, pyupgrade, and autoflake, 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:
pandas
FastAPI
Transformers (Hugging Face)
Apache Airflow
SciPy
…and many more.
Read the launch blog post or the most recent project update.
Testimonials
Sebastián Ramírez, creator of FastAPI:
Nick Schrock, founder of Elementl, co-creator of GraphQL:
Bryan Van de Ven, co-creator of Bokeh, original author of Conda:
Timothy Crosley, creator of isort:
Tim Abbott, lead developer of Zulip:
Table of Contents
For more, see the documentation.
Getting Started
Configuration
Rules
Contributing
Support
Acknowledgements
Who’s Using Ruff?
License
Getting Started
For more, see the documentation.
readme
Installation
Ruff is available as
ruff
on PyPI:You can also install Ruff via Homebrew, Conda, and with a variety of other package managers.
Usage
To run Ruff, try any of the following:
Ruff can also be used as a pre-commit hook:
Ruff can also be used as a VS Code extension or alongside any other editor through the Ruff LSP.
Configuration
Ruff can be configured through a
pyproject.toml
,ruff.toml
, or.ruff.toml
file (see: Configuration, or Settings for a complete list of all configuration options).If left unspecified, the default configuration is equivalent to:
Some configuration options can be provided via the command-line, such as those related to rule enablement and disablement, file discovery, logging level, and more:
See
ruff help
for more on Ruff’s top-level commands, orruff help check
for more on the linting command.Rules
Ruff supports over 500 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’s
E
andF
rules. Ruff supports all rules from theF
category, and a subset of theE
category, omitting those stylistic rules made obsolete by the use of an autoformatter, like 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-bandit (#1646)
flake8-blind-except
flake8-boolean-trap
flake8-bugbear
flake8-builtins
flake8-commas
flake8-comprehensions
flake8-datetimez
flake8-debugger
flake8-django
flake8-docstrings
flake8-eradicate
flake8-errmsg
flake8-executable
flake8-gettext
flake8-implicit-str-concat
flake8-import-conventions
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-super
flake8-tidy-imports
flake8-type-checking
flake8-use-pathlib
isort
mccabe
pandas-vet
pep8-naming
pydocstyle
pygrep-hooks (#980)
pyupgrade
tryceratops
yesqa
For a complete enumeration of the supported rules, see Rules.
Contributing
Contributions are welcome and highly appreciated. To get started, check out the contributing guidelines.
You can also join us on Discord.
Support
Having trouble? Check out the existing issues on GitHub, or feel free to open a new one.
You can also ask for help on Discord.
Acknowledgements
Ruff’s linter draws on both the APIs and implementation details of many other tools in the Python ecosystem, especially Flake8, Pyflakes, pycodestyle, pydocstyle, pyupgrade, and isort.
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 autoformatter is built on a fork of Rome’s
rome_formatter
, and again draws on both the APIs and implementation details of Rome, Prettier, and Black.Ruff is also influenced by a number of tools outside the Python ecosystem, like Clippy and ESLint.
Ruff is the beneficiary of a large number of contributors.
Ruff is released under the MIT license.
Who’s Using Ruff?
Ruff is used in a number of major open-source projects, including:
pandas
FastAPI
Transformers (Hugging Face)
Diffusers (Hugging Face)
Apache Airflow
SciPy
Zulip
Bokeh
Pydantic
PostHog
Dagster
Dagger
Sphinx
Hatch
PDM
Jupyter
Great Expectations
ONNX
Polars
Ibis
Synapse (Matrix)
SnowCLI (Snowflake)
Dispatch (Netflix)
Saleor
Pynecone
OpenBB
Home Assistant
Pylint
Cryptography (PyCA)
cibuildwheel (PyPA)
build (PyPA)
Babel
featuretools
meson-python
ZenML
delta-rs
Starlite
telemetry-airflow (Mozilla)
Stable Baselines3
PaddlePaddle
nox
Neon
The Algorithms
Openverse
License
MIT