An extremely fast Python linter, written in Rust.

Linting the CPython codebase from scratch.

• ⚡️ 10-100x faster than existing linters
• 🐍 Installable via pip
• 🤝 Python 3.11 compatibility
• 🛠️ pyproject.toml support
• 📦 Built-in caching, to avoid re-analyzing unchanged files
• 🔧 Autofix support, for automatic error correction (e.g., automatically remove unused imports)
• ⚖️ 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 a variety of plugins), isort, pydocstyle, yesqa, eradicate, pyupgrade, and autoflake, all while executing tens or hundreds of times faster than any individual tool.

Ruff goes beyond the responsibilities of a traditional linter, instead functioning as an advanced code transformation tool capable of upgrading type annotations, rewriting class definitions, sorting imports, and more.

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

• pandas
• FastAPI
• Apache Airflow
• Bokeh
• Zulip
• Pydantic
• Dagster
• Dagger
• Sphinx
• Hatch
• Jupyter
• Great Expectations
• Polars
• Ibis
• Synapse (Matrix)
• SnowCLI (Snowflake)
• Saleor
• OpenBB
• Home Assistant
• Cryptography (PyCA)
• cibuildwheel (PyPA)
• Babel

Read the launch blog post.

Sebastián Ramírez, creator of FastAPI:

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 of Elementl, co-creator of GraphQL:

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.

Bryan Van de Ven, co-creator of Bokeh, original author of Conda:

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 of isort:

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 of Zulip:

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

1. Installation and Usage
2. Configuration
3. Supported Rules
   1. Pyflakes (F)
   2. pycodestyle (E, W)
   3. mccabe (C90)
   4. isort (I)
   5. pydocstyle (D)
   6. pyupgrade (UP)
   7. pep8-naming (N)
   8. flake8-2020 (YTT)
   9. flake8-annotations (ANN)
   10. flake8-bandit (S)
   11. flake8-blind-except (BLE)
   12. flake8-boolean-trap (FBT)
   13. flake8-bugbear (B)
   14. flake8-builtins (A)
   15. flake8-comprehensions (C4)
   16. flake8-debugger (T10)
   17. flake8-errmsg (EM)
   18. flake8-implicit-str-concat (ISC)
   19. flake8-import-conventions (ICN)
   20. flake8-print (T20)
   21. flake8-pytest-style (PT)
   22. flake8-quotes (Q)
   23. flake8-return (RET)
   24. flake8-simplify (SIM)
   25. flake8-tidy-imports (TID)
   26. flake8-unused-arguments (ARG)
   27. flake8-datetimez (DTZ)
   28. eradicate (ERA)
   29. pandas-vet (PD)
   30. pygrep-hooks (PGH)
   31. Pylint (PL)
   32. flake8-pie (PIE)
   33. flake8-commas (COM)
   34. flake8-no-pep420 (INP)
   35. flake8-executable (EXE)
   36. flake8-type-checking (TCH)
   37. tryceratops (TRY)
   38. flake8-use-pathlib (PTH)
   39. Ruff-specific rules (RUF)
4. Editor Integrations
5. FAQ
6. Contributing
7. Releases
8. Benchmarks
9. Reference
10. License

Ruff is available as ruff on PyPI:

pip install ruff

For macOS Homebrew and Linuxbrew users, Ruff is also available as ruff on Homebrew:

brew install ruff

For Conda users, Ruff is also available as ruff on conda-forge:

conda install -c conda-forge ruff

For Arch Linux users, Ruff is also available as ruff on the official repositories:

pacman -S ruff

For Alpine users, Ruff is also available as ruff on the testing repositories:

apk add ruff

To run Ruff, try any of the following:

ruff path/to/code/to/lint.py  # Run Ruff over `lint.py`
ruff path/to/code/            # Run Ruff over all files in `/path/to/code` (and any subdirectories)
ruff path/to/code/*.py        # Run Ruff over all `.py` files in `/path/to/code`

You can run Ruff in --watch mode to automatically re-run on-change:

ruff path/to/code/ --watch

Ruff also works with pre-commit:

- repo: https://github.com/charliermarsh/ruff-pre-commit
  # Ruff version.
  rev: 'v0.0.235'
  hooks:
    - id: ruff

Ruff is configurable both via pyproject.toml and the command line. For a full list of configurable options, see the API reference.

If left unspecified, the default configuration is equivalent to:

[tool.ruff]
line-length = 88

# Enable Pyflakes `E` and `F` codes by default.
select = ["E", "F"]
ignore = []

# Exclude a variety of commonly ignored directories.
exclude = [
    ".bzr",
    ".direnv",
    ".eggs",
    ".git",
    ".hg",
    ".mypy_cache",
    ".nox",
    ".pants.d",
    ".ruff_cache",
    ".svn",
    ".tox",
    ".venv",
    "__pypackages__",
    "_build",
    "buck-out",
    "build",
    "dist",
    "node_modules",
    "venv",
]
per-file-ignores = {}

# Allow unused variables when underscore-prefixed.
dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"

# Assume Python 3.10.
target-version = "py310"

[tool.ruff.mccabe]
# Unlike Flake8, default to a complexity level of 10.
max-complexity = 10

As an example, the following would configure Ruff to: (1) avoid enforcing line-length violations (E501); (2) never remove unused imports (F401); and (3) ignore import-at-top-of-file violations (E402) in __init__.py files:

[tool.ruff]
# Enable Pyflakes and pycodestyle rules.
select = ["E", "F"]

# Never enforce `E501` (line length violations).
ignore = ["E501"]

# Never try to fix `F401` (unused imports).
unfixable = ["F401"]

# Ignore `E402` (import violations) in all `__init__.py` files, and in `path/to/file.py`.
[tool.ruff.per-file-ignores]
"__init__.py" = ["E402"]
"path/to/file.py" = ["E402"]

Plugin configurations should be expressed as subsections, e.g.:

[tool.ruff]
# Add "Q" to the list of enabled codes.
select = ["E", "F", "Q"]

[tool.ruff.flake8-quotes]
docstring-quotes = "double"

Ruff mirrors Flake8's rule code system, in which each rule code consists of a one-to-three letter prefix, followed by three digits (e.g., F401). The prefix indicates that "source" of the rule (e.g., F for Pyflakes, E for pycodestyle, ANN for flake8-annotations). The set of enabled rules is determined by the select and ignore options, which support both the full code (e.g., F401) and the prefix (e.g., F).

As a special-case, Ruff also supports the ALL code, which enables all rules. Note that some of the pydocstyle rules conflict (e.g., D203 and D211) as they represent alternative docstring formats. Enabling ALL without further configuration may result in suboptimal behavior, especially for the pydocstyle plugin.

As an alternative to pyproject.toml, Ruff will also respect a ruff.toml file, which implements an equivalent schema (though the [tool.ruff] hierarchy can be omitted). For example, the pyproject.toml described above would be represented via the following ruff.toml:

# Enable Pyflakes and pycodestyle rules.
select = ["E", "F"]

# Never enforce `E501` (line length violations).
ignore = ["E501"]

# Always autofix, but never try to fix `F401` (unused imports).
fix = true
unfixable = ["F401"]

# Ignore `E402` (import violations) in all `__init__.py` files, and in `path/to/file.py`.
[per-file-ignores]
"__init__.py" = ["E402"]
"path/to/file.py" = ["E402"]

For a full list of configurable options, see the API reference.

Some common configuration settings can be provided via the command-line:

ruff path/to/code/ --select F401 --select F403

See ruff --help for more:

Ruff: An extremely fast Python linter.

Usage: ruff [OPTIONS] [FILES]...

Arguments:
  [FILES]...

Options:
      --config <CONFIG>
          Path to the `pyproject.toml` or `ruff.toml` file to use for configuration
  -v, --verbose
          Enable verbose logging
  -q, --quiet
          Print lint violations, but nothing else
  -s, --silent
          Disable all logging (but still exit with status code "1" upon detecting lint violations)
  -e, --exit-zero
          Exit with status code "0", even upon detecting lint violations
  -w, --watch
          Run in watch mode by re-running whenever files change
      --fix
          Attempt to automatically fix lint violations
      --fix-only
          Fix any fixable lint violations, but don't report on leftover violations. Implies `--fix`
      --diff
          Avoid writing any fixed files back; instead, output a diff for each changed file to stdout
  -n, --no-cache
          Disable cache reads
      --isolated
          Ignore all configuration files
      --select <RULE_CODE>
          Comma-separated list of rule codes to enable (or ALL, to enable all rules)
      --extend-select <RULE_CODE>
          Like --select, but adds additional rule codes on top of the selected ones
      --ignore <RULE_CODE>
          Comma-separated list of rule codes to disable
      --extend-ignore <RULE_CODE>
          Like --ignore, but adds additional rule codes on top of the ignored ones
      --exclude <FILE_PATTERN>
          List of paths, used to omit files and/or directories from analysis
      --extend-exclude <FILE_PATTERN>
          Like --exclude, but adds additional files and directories on top of those already excluded
      --fixable <RULE_CODE>
          List of rule codes to treat as eligible for autofix. Only applicable when autofix itself is enabled (e.g., via `--fix`)
      --unfixable <RULE_CODE>
          List of rule codes to treat as ineligible for autofix. Only applicable when autofix itself is enabled (e.g., via `--fix`)
      --per-file-ignores <PER_FILE_IGNORES>
          List of mappings from file pattern to code to exclude
      --format <FORMAT>
          Output serialization format for violations [env: RUFF_FORMAT=] [possible values: text, json, junit, grouped, github, gitlab, pylint]
      --stdin-filename <STDIN_FILENAME>
          The name of the file when passing it through stdin
      --cache-dir <CACHE_DIR>
          Path to the cache directory [env: RUFF_CACHE_DIR=]
      --show-source
          Show violations with source code
      --respect-gitignore
          Respect file exclusions via `.gitignore` and other standard ignore files
      --force-exclude
          Enforce exclusions, even for paths passed to Ruff directly on the command-line
      --update-check
          Enable or disable automatic update checks
      --dummy-variable-rgx <DUMMY_VARIABLE_RGX>
          Regular expression matching the name of dummy variables
      --target-version <TARGET_VERSION>
          The minimum Python version that should be supported
      --line-length <LINE_LENGTH>
          Set the line-length for length-associated rules and automatic formatting
      --add-noqa
          Enable automatic additions of `noqa` directives to failing lines
      --clean
          Clear any caches in the current directory or any subdirectories
      --explain <EXPLAIN>
          Explain a rule
      --show-files
          See the files Ruff will be run against with the current settings
      --show-settings
          See the settings Ruff will use to lint a given Python file
  -h, --help
          Print help
  -V, --version
          Print version

Similar to ESLint, Ruff supports hierarchical configuration, such that the "closest" pyproject.toml file in the directory hierarchy is used for every individual file, with all paths in the pyproject.toml file (e.g., exclude globs, src paths) being resolved relative to the directory containing the pyproject.toml file.

There are a few exceptions to these rules:

1. In locating the "closest" pyproject.toml file for a given path, Ruff ignores any pyproject.toml files that lack a [tool.ruff] section.
2. If a configuration file is passed directly via --config, those settings are used for across files. Any relative paths in that configuration file (like exclude globs or src paths) are resolved relative to the current working directory.
3. If no pyproject.toml file is found in the filesystem hierarchy, Ruff will fall back to using a default configuration. If a user-specific configuration file exists at ${config_dir}/ruff/pyproject.toml, that file will be used instead of the default configuration, with ${config_dir} being determined via the dirs crate, and all relative paths being again resolved relative to the current working directory.
4. Any pyproject.toml-supported settings that are provided on the command-line (e.g., via --select) will override the settings in every resolved configuration file.

Unlike ESLint, Ruff does not merge settings across configuration files; instead, the "closest" configuration file is used, and any parent configuration files are ignored. In lieu of this implicit cascade, Ruff supports an extend field, which allows you to inherit the settings from another pyproject.toml file, like so:

# Extend the `pyproject.toml` file in the parent directory.
extend = "../pyproject.toml"
# But use a different line length.
line-length = 100

All of the above rules apply equivalently to ruff.toml files. If Ruff detects both a ruff.toml and pyproject.toml file, it will defer to the ruff.toml.

When passed a path on the command-line, Ruff will automatically discover all Python files in that path, taking into account the exclude and extend-exclude settings in each directory's pyproject.toml file.

By default, Ruff will also skip any files that are omitted via .ignore, .gitignore, .git/info/exclude, and global gitignore files (see: respect-gitignore).

Files that are passed to ruff directly are always linted, regardless of the above criteria. For example, ruff /path/to/excluded/file.py will always lint file.py.

To omit a lint rule entirely, add it to the "ignore" list via ignore or extend-ignore, either on the command-line or in your pyproject.toml file.

To ignore a violation inline, Ruff uses a noqa system similar to Flake8. To ignore an individual violation, add # noqa: {code} to the end of the line, like so:

# Ignore F841.
x = 1  # noqa: F841

# Ignore E741 and F841.
i = 1  # noqa: E741, F841

# Ignore _all_ violations.
x = 1  # noqa

Note that, for multi-line strings, the noqa directive should come at the end of the string, and will apply to the entire string, like so:

"""Lorem ipsum dolor sit amet.

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
"""  # noqa: E501

To ignore all violations across an entire file, Ruff supports Flake8's # flake8: noqa directive (or, equivalently, # ruff: noqa). Adding either of those directives to any part of a file will disable enforcement across the entire file.

For targeted exclusions across entire files (e.g., "Ignore all F841 violations in /path/to/file.py"), see the per-file-ignores configuration setting.

Ruff respects isort's "Action Comments" (# isort: skip_file, # isort: on, # isort: off, # isort: skip, and # isort: split), which enable selectively enabling and disabling import sorting for blocks of code and other inline configuration.

See the isort documentation for more.

Ruff supports several workflows to aid in noqa management.

First, Ruff provides a special rule code, RUF100, to enforce that your noqa directives are "valid", in that the violations they say they ignore are actually being triggered on that line (and thus suppressed). You can run ruff /path/to/file.py --extend-select RUF100 to flag unused noqa directives.

Second, Ruff can automatically remove unused noqa directives via its autofix functionality. You can run ruff /path/to/file.py --extend-select RUF100 --fix to automatically remove unused noqa directives.

Third, Ruff can automatically add noqa directives to all failing lines. This is useful when migrating a new codebase to Ruff. You can run ruff /path/to/file.py --add-noqa to automatically add noqa directives to all failing lines, with the appropriate rule codes.

Regardless of the rule's origin, Ruff re-implements every rule in Rust as a first-party feature.

By default, Ruff enables all E and F rule codes, which correspond to those built-in to Flake8.

The 🛠 emoji indicates that a rule is automatically fixable by the --fix command-line option.

For more, see Pyflakes on PyPI.

For more, see pycodestyle on PyPI.

For more, see mccabe on PyPI.

For more, see isort on PyPI.

For more, see pydocstyle on PyPI.

For more, see pyupgrade on PyPI.

For more, see pep8-naming on PyPI.

For more, see flake8-2020 on PyPI.

For more, see flake8-annotations on PyPI.

For more, see flake8-bandit on PyPI.

For more, see flake8-blind-except on PyPI.

For more, see flake8-boolean-trap on PyPI.

For more, see flake8-bugbear on PyPI.

For more, see flake8-builtins on PyPI.

For more, see flake8-comprehensions on PyPI.

For more, see flake8-debugger on PyPI.

For more, see flake8-errmsg on PyPI.

For more, see flake8-implicit-str-concat on PyPI.

For more, see flake8-import-conventions on GitHub.

For more, see flake8-print on PyPI.

For more, see flake8-pytest-style on PyPI.

For more, see flake8-quotes on PyPI.

For more, see flake8-return on PyPI.

For more, see flake8-simplify on PyPI.

For more, see flake8-tidy-imports on PyPI.

For more, see flake8-unused-arguments on PyPI.

For more, see flake8-datetimez on PyPI.

For more, see eradicate on PyPI.

For more, see pandas-vet on PyPI.

For more, see pygrep-hooks on GitHub.

For more, see Pylint on PyPI.

For more, see flake8-pie on PyPI.

For more, see flake8-commas on PyPI.

For more, see flake8-no-pep420 on PyPI.

For more, see flake8-executable on PyPI.

For more, see flake8-type-checking on PyPI.

For more, see tryceratops on PyPI.

For more, see flake8-use-pathlib on PyPI.

Download the Ruff VS Code extension, which supports autofix actions, import sorting, and more.

Ruff supports the Language Server Protocol via the ruff-lsp Python package, available on PyPI.

ruff-lsp enables Ruff to be used with any editor that supports the Language Server Protocol, including Neovim, Sublime Text, Emacs, and more.

For example, to use ruff-lsp with Neovim, install ruff-lsp from PyPI along with nvim-lspconfig. Then, add something like the following to your init.lua:

-- See: https://github.com/neovim/nvim-lspconfig/tree/54eb2a070a4f389b1be0f98070f81d23e2b1a715#suggested-configuration
local opts = { noremap=true, silent=true }
vim.keymap.set('n', '<space>e', vim.diagnostic.open_float, opts)
vim.keymap.set('n', '[d', vim.diagnostic.goto_prev, opts)
vim.keymap.set('n', ']d', vim.diagnostic.goto_next, opts)
vim.keymap.set('n', '<space>q', vim.diagnostic.setloclist, opts)

-- Use an on_attach function to only map the following keys
-- after the language server attaches to the current buffer
local on_attach = function(client, bufnr)
  -- Enable completion triggered by <c-x><c-o>
  vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')

  -- Mappings.
  -- See `:help vim.lsp.*` for documentation on any of the below functions
  local bufopts = { noremap=true, silent=true, buffer=bufnr }
  vim.keymap.set('n', 'gD', vim.lsp.buf.declaration, bufopts)
  vim.keymap.set('n', 'gd', vim.lsp.buf.definition, bufopts)
  vim.keymap.set('n', 'K', vim.lsp.buf.hover, bufopts)
  vim.keymap.set('n', 'gi', vim.lsp.buf.implementation, bufopts)
  vim.keymap.set('n', '<C-k>', vim.lsp.buf.signature_help, bufopts)
  vim.keymap.set('n', '<space>wa', vim.lsp.buf.add_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wr', vim.lsp.buf.remove_workspace_folder, bufopts)
  vim.keymap.set('n', '<space>wl', function()
    print(vim.inspect(vim.lsp.buf.list_workspace_folders()))
  end, bufopts)
  vim.keymap.set('n', '<space>D', vim.lsp.buf.type_definition, bufopts)
  vim.keymap.set('n', '<space>rn', vim.lsp.buf.rename, bufopts)
  vim.keymap.set('n', '<space>ca', vim.lsp.buf.code_action, bufopts)
  vim.keymap.set('n', 'gr', vim.lsp.buf.references, bufopts)
  vim.keymap.set('n', '<space>f', function() vim.lsp.buf.format { async = true } end, bufopts)
end

-- Configure `ruff-lsp`.
local configs = require 'lspconfig.configs'
if not configs.ruff_lsp then
  configs.ruff_lsp = {
    default_config = {
      cmd = { 'ruff-lsp' },
      filetypes = { 'python' },
      root_dir = require('lspconfig').util.find_git_ancestor,
      init_options = {
        settings = {
          args = {}
        }
      }
    }
  }
end
require('lspconfig').ruff_lsp.setup {
  on_attach = on_attach,
}

Upon successful installation, you should see Ruff's diagnostics surfaced directly in your editor:

To use ruff-lsp with other editors, including Sublime Text and Helix, see the ruff-lsp documentation.

Ruff is also available as the python-lsp-ruff plugin for python-lsp-server, both of which are installable from PyPI:

pip install python-lsp-server python-lsp-ruff

The LSP server can then be used with any editor that supports the Language Server Protocol.

For example, to use python-lsp-ruff with Neovim, add something like the following to your init.lua:

require'lspconfig'.pylsp.setup {
  settings = {
    pylsp = {
      plugins = {
        ruff = {
          enabled = true
        },
        pycodestyle = {
          enabled = false
        },
        pyflakes = {
          enabled = false
        },
        mccabe = {
          enabled = false
        }
      }
    }
  },
}

Ruff can be integrated into any editor that supports the Language Server Protocol via ruff-lsp (see: Language Server Protocol), including Vim and Neovim.

It's recommended that you use ruff-lsp, the officially supported LSP server for Ruff.

However, Ruff is also available as part of the coc-pyright extension for coc.nvim.

let g:ale_linters = { "python": ["ruff"] }
let g:ale_fixers = {
\       "python": ["black", "ruff"],
\}

tools:
  python-ruff: &python-ruff
    lint-command: 'ruff --config ~/myconfigs/linters/ruff.toml --quiet ${INPUT}'
    lint-stdin: true
    lint-formats:
      - '%f:%l:%c: %m'
    format-command: 'ruff --stdin-filename ${INPUT} --config ~/myconfigs/linters/ruff.toml --fix --exit-zero --quiet -'
    format-stdin: true

local null_ls = require("null-ls")
local methods = require("null-ls.methods")
local helpers = require("null-ls.helpers")

local function ruff_fix()
    return helpers.make_builtin({
        name = "ruff",
        meta = {
            url = "https://github.com/charliermarsh/ruff/",
            description = "An extremely fast Python linter, written in Rust.",
        },
        method = methods.internal.FORMATTING,
        filetypes = { "python" },
        generator_opts = {
            command = "ruff",
            args = { "--fix", "-e", "-n", "--stdin-filename", "$FILENAME", "-" },
            to_stdin = true
        },
        factory = helpers.formatter_factory
    })
end

null_ls.setup({
    sources = {
        ruff_fix(),
        null_ls.builtins.diagnostics.ruff,
    }
})

Ruff can be installed as an External Tool in PyCharm. Open the Preferences pane, then navigate to "Tools", then "External Tools". From there, add a new tool with the following configuration:

Ruff should then appear as a runnable action:

Ruff is also available as the Ruff plugin on the IntelliJ Marketplace (maintained by @koxudaxi).

GitHub Actions has everything you need to run Ruff out-of-the-box:

name: CI
on: push
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - name: Install Python
        uses: actions/setup-python@v4
        with:
          python-version: "3.11"
      - name: Install dependencies
        run: |
          python -m pip install --upgrade pip
          pip install ruff
      # Include `--format=github` to enable automatic inline annotations.
      - name: Run Ruff
        run: ruff --format=github .

Yes. Ruff is compatible with Black out-of-the-box, as long as the line-length setting is consistent between the two.

As a project, Ruff is designed to be used alongside Black and, as such, will defer implementing stylistic lint rules that are obviated by autoformatting.

(Coming from Flake8? Try flake8-to-ruff to automatically convert your existing configuration.)

Ruff can be used as a drop-in replacement for Flake8 when used (1) without or with a small number of plugins, (2) alongside Black, and (3) on Python 3 code.

Under those conditions, Ruff implements every rule in Flake8.

Ruff also re-implements some of the most popular Flake8 plugins and related code quality tools natively, including:

• autoflake (#1647)
• 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-docstrings
• flake8-eradicate
• flake8-errmsg
• flake8-executable
• flake8-implicit-str-concat
• flake8-import-conventions
• flake8-no-pep420
• flake8-pie (#1543)
• flake8-print
• flake8-pytest-style
• flake8-quotes
• flake8-return
• flake8-simplify (#998)
• flake8-super
• flake8-tidy-imports
• isort
• mccabe
• pandas-vet
• pep8-naming
• pydocstyle
• pygrep-hooks (#980)
• pyupgrade (#827)
• yesqa

Note that, in some cases, Ruff uses different rule codes and prefixes than would be found in the originating Flake8 plugins. For example, Ruff uses TID252 to represent the I252 rule from flake8-tidy-imports. This helps minimize conflicts across plugins and allows any individual plugin to be toggled on or off with a single (e.g.) --select TID, as opposed to --select I2 (to avoid conflicts with the isort rules, like I001).

Beyond the rule set, Ruff suffers from the following limitations vis-à-vis Flake8:

1. Ruff does not yet support structural pattern matching.
2. Flake8 has a plugin architecture and supports writing custom lint rules. (Instead, popular Flake8 plugins are re-implemented in Rust as part of Ruff itself.)

There are a few other minor incompatibilities between Ruff and the originating Flake8 plugins:

• Ruff doesn't implement all the "opinionated" lint rules from flake8-bugbear.
• Depending on your project structure, Ruff and isort can differ in their detection of first-party code. (This is often solved by modifying the src property, e.g., to src = ["src"], if your code is nested in a src directory.)

At time of writing, Pylint implements 409 total rules, while Ruff implements 224, of which at least 60 overlap with the Pylint rule set. Subjectively, Pylint tends to implement more rules based on type inference (e.g., validating the number of arguments in a function call).

Like Flake8, Pylint supports plugins (called "checkers"), while Ruff implements all rules natively.

Unlike Pylint, Ruff is capable of automatically fixing its own lint violations.

Pylint parity is being tracked in #970.

Today, Ruff can be used to replace Flake8 when used with any of the following plugins:

• 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-docstrings
• flake8-eradicate
• flake8-errmsg
• flake8-executable
• flake8-implicit-str-concat
• flake8-import-conventions
• flake8-no-pep420
• flake8-pie (#1543)
• flake8-print
• flake8-pytest-style
• flake8-quotes
• flake8-return
• flake8-simplify (#998)
• flake8-super
• flake8-tidy-imports
• mccabe
• pandas-vet
• pep8-naming
• pydocstyle

Ruff can also replace isort, yesqa, eradicate, pygrep-hooks (#980), and a subset of the rules implemented in pyupgrade (#827).

If you're looking to use Ruff, but rely on an unsupported Flake8 plugin, feel free to file an Issue.

Nope! Ruff is available as ruff on PyPI:

pip install ruff

Ruff ships with wheels for all major platforms, which enables pip to install Ruff without relying on Rust at all.

Ruff does not yet support third-party plugins, though a plugin system is within-scope for the project. See #283 for more.

Ruff's import sorting is intended to be nearly equivalent to isort when used profile = "black". There are a few known, minor differences in how Ruff and isort break ties between similar imports, and in how Ruff and isort treat inline comments in some cases (see: #1381, #2104).

Like isort, Ruff's import sorting is compatible with Black.

Ruff does not yet support all of isort's configuration options, though it does support many of them. You can find the supported settings in the API reference. For example, you can set known-first-party like so:

[tool.ruff]
select = [
    # Pyflakes
    "F",
    # Pycodestyle
    "E",
    "W",
    # isort
    "I001"
]
src = ["src", "tests"]

[tool.ruff.isort]
known-first-party = ["my_module1", "my_module2"]

Ruff is integrated into nbQA, a tool for running linters and code formatters over Jupyter Notebooks.

After installing ruff and nbqa, you can run Ruff over a notebook like so:

> nbqa ruff Untitled.ipynb
Untitled.ipynb:cell_1:2:5: F841 Local variable `x` is assigned to but never used
Untitled.ipynb:cell_2:1:1: E402 Module level import not at top of file
Untitled.ipynb:cell_2:1:8: F401 `os` imported but unused
Found 3 errors.
1 potentially fixable with the --fix option.

Yes! To enable specific docstring convention, add the following to your pyproject.toml:

[tool.ruff.pydocstyle]
convention = "google"  # Accepts: "google", "numpy", or "pep257".

For example, if you're coming from flake8-docstrings, and your originating configuration uses --docstring-convention=numpy, you'd instead set convention = "numpy" in your pyproject.toml, as above.

Alongside convention, you'll want to explicitly enable the D rule code prefix, like so:

[tool.ruff]
select = [
    "D",
]

[tool.ruff.pydocstyle]
convention = "google"

Setting a convention force-disables any rules that are incompatible with that convention, no matter how they're provided, which avoids accidental incompatibilities and simplifies configuration.

Run ruff /path/to/code.py --show-settings to view the resolved settings for a given file.

Ruff's autofix is a best-effort mechanism. Given the dynamic nature of Python, it's difficult to have complete certainty when making changes to code, even for the seemingly trivial fixes.

In the future, Ruff will support enabling autofix behavior based on the safety of the patch.

In the meantime, if you find that the autofix is too aggressive, you can disable it on a per-rule or per-category basis using the unfixable mechanic. For example, to disable autofix for some possibly-unsafe rules, you could add the following to your pyproject.toml:

[tool.ruff]
unfixable = ["B", "SIM", "TRY", "RUF"]

If you find a case where Ruff's autofix breaks your code, please file an Issue!

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

Ruff is distributed on PyPI, and published via maturin.

See: .github/workflows/release.yaml.

First, clone CPython. It's a large and diverse Python codebase, which makes it a good target for benchmarking.

git clone --branch 3.10 https://github.com/python/cpython.git resources/test/cpython

To benchmark the release build:

cargo build --release && hyperfine --ignore-failure --warmup 10 \
  "./target/release/ruff ./resources/test/cpython/ --no-cache" \
  "./target/release/ruff ./resources/test/cpython/"

Benchmark 1: ./target/release/ruff ./resources/test/cpython/ --no-cache
  Time (mean ± σ):     293.8 ms ±   3.2 ms    [User: 2384.6 ms, System: 90.3 ms]
  Range (min … max):   289.9 ms … 301.6 ms    10 runs

  Warning: Ignoring non-zero exit code.

Benchmark 2: ./target/release/ruff ./resources/test/cpython/
  Time (mean ± σ):      48.0 ms ±   3.1 ms    [User: 65.2 ms, System: 124.7 ms]
  Range (min … max):    45.0 ms …  66.7 ms    62 runs

  Warning: Ignoring non-zero exit code.

Summary
  './target/release/ruff ./resources/test/cpython/' ran
    6.12 ± 0.41 times faster than './target/release/ruff ./resources/test/cpython/ --no-cache'

To benchmark against the ecosystem's existing tools:

hyperfine --ignore-failure --warmup 5 \
  "./target/release/ruff ./resources/test/cpython/ --no-cache" \
  "pyflakes resources/test/cpython" \
  "autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython" \
  "pycodestyle resources/test/cpython" \
  "flake8 resources/test/cpython"

Benchmark 1: ./target/release/ruff ./resources/test/cpython/ --no-cache
  Time (mean ± σ):     294.3 ms ±   3.3 ms    [User: 2467.5 ms, System: 89.6 ms]
  Range (min … max):   291.1 ms … 302.8 ms    10 runs

  Warning: Ignoring non-zero exit code.

Benchmark 2: pyflakes resources/test/cpython
  Time (mean ± σ):     15.786 s ±  0.143 s    [User: 15.560 s, System: 0.214 s]
  Range (min … max):   15.640 s … 16.157 s    10 runs

  Warning: Ignoring non-zero exit code.

Benchmark 3: autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython
  Time (mean ± σ):      6.175 s ±  0.169 s    [User: 54.102 s, System: 1.057 s]
  Range (min … max):    5.950 s …  6.391 s    10 runs

Benchmark 4: pycodestyle resources/test/cpython
  Time (mean ± σ):     46.921 s ±  0.508 s    [User: 46.699 s, System: 0.202 s]
  Range (min … max):   46.171 s … 47.863 s    10 runs

  Warning: Ignoring non-zero exit code.

Benchmark 5: flake8 resources/test/cpython
  Time (mean ± σ):     12.260 s ±  0.321 s    [User: 102.934 s, System: 1.230 s]
  Range (min … max):   11.848 s … 12.933 s    10 runs

  Warning: Ignoring non-zero exit code.

Summary
  './target/release/ruff ./resources/test/cpython/ --no-cache' ran
   20.98 ± 0.62 times faster than 'autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython'
   41.66 ± 1.18 times faster than 'flake8 resources/test/cpython'
   53.64 ± 0.77 times faster than 'pyflakes resources/test/cpython'
  159.43 ± 2.48 times faster than 'pycodestyle resources/test/cpython'

You can run poetry install from ./scripts to create a working environment for the above. All reported benchmarks were computed using the versions specified by ./scripts/pyproject.toml on Python 3.11.

To benchmark Pylint, remove the following files from the CPython repository:

rm Lib/test/bad_coding.py \
  Lib/test/bad_coding2.py \
  Lib/test/bad_getattr.py \
  Lib/test/bad_getattr2.py \
  Lib/test/bad_getattr3.py \
  Lib/test/badcert.pem \
  Lib/test/badkey.pem \
  Lib/test/badsyntax_3131.py \
  Lib/test/badsyntax_future10.py \
  Lib/test/badsyntax_future3.py \
  Lib/test/badsyntax_future4.py \
  Lib/test/badsyntax_future5.py \
  Lib/test/badsyntax_future6.py \
  Lib/test/badsyntax_future7.py \
  Lib/test/badsyntax_future8.py \
  Lib/test/badsyntax_future9.py \
  Lib/test/badsyntax_pep3120.py \
  Lib/test/test_asyncio/test_runners.py \
  Lib/test/test_copy.py \
  Lib/test/test_inspect.py \
  Lib/test/test_typing.py

Then, from resources/test/cpython, run: time pylint -j 0 -E $(git ls-files '*.py'). This will execute Pylint with maximum parallelism and only report errors.

To benchmark Pyupgrade, run the following from resources/test/cpython:

hyperfine --ignore-failure --warmup 5 --prepare "git reset --hard HEAD" \
  "find . -type f -name \"*.py\" | xargs -P 0 pyupgrade --py311-plus"

Benchmark 1: find . -type f -name "*.py" | xargs -P 0 pyupgrade --py311-plus
  Time (mean ± σ):     30.119 s ±  0.195 s    [User: 28.638 s, System: 0.390 s]
  Range (min … max):   29.813 s … 30.356 s    10 runs

A list of allowed "confusable" Unicode characters to ignore when enforcing RUF001, RUF002, and RUF003.

Default value: []

Type: Vec<char>

Example usage:

[tool.ruff]
# Allow minus-sign (U+2212), greek-small-letter-rho (U+03C1), and the asterisk-operator (U+2217),
# which could be confused for "-", "p", and "*", respectively.
allowed-confusables = ["−", "ρ", "∗"]

A list of builtins to treat as defined references, in addition to the system builtins.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff]
builtins = ["_"]

A path to the cache directory.

By default, Ruff stores cache results in a .ruff_cache directory in the current project root.

However, Ruff will also respect the RUFF_CACHE_DIR environment variable, which takes precedence over that default.

This setting will override even the RUFF_CACHE_DIR environment variable, if set.

Default value: .ruff_cache

Type: PathBuf

Example usage:

[tool.ruff]
cache-dir = "~/.cache/ruff"

A regular expression used to identify "dummy" variables, or those which should be ignored when enforcing (e.g.) unused-variable rules. The default expression matches _, __, and _var, but not _var_.

Default value: "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"

Type: Regex

Example usage:

[tool.ruff]
# Only ignore variables named "_".
dummy-variable-rgx = "^_$"

A list of file patterns to exclude from linting.

Exclusions are based on globs, and can be either:

• Single-path patterns, like .mypy_cache (to exclude any directory named .mypy_cache in the tree), foo.py (to exclude any file named foo.py), or foo_*.py (to exclude any file matching foo_*.py ).
• Relative patterns, like directory/foo.py (to exclude that specific file) or directory/*.py (to exclude any Python files in directory). Note that these paths are relative to the project root (e.g., the directory containing your pyproject.toml).

For more information on the glob syntax, refer to the globset documentation.

Note that you'll typically want to use extend-exclude to modify the excluded paths.

Default value: [".bzr", ".direnv", ".eggs", ".git", ".hg", ".mypy_cache", ".nox", ".pants.d", ".ruff_cache", ".svn", ".tox", ".venv", "__pypackages__", "_build", "buck-out", "build", "dist", "node_modules", "venv"]

Type: Vec<FilePattern>

Example usage:

[tool.ruff]
exclude = [".venv"]

A path to a local pyproject.toml file to merge into this configuration. User home directory and environment variables will be expanded.

To resolve the current pyproject.toml file, Ruff will first resolve this base configuration file, then merge in any properties defined in the current configuration file.

Default value: None

Type: Path

Example usage:

[tool.ruff]
# Extend the `pyproject.toml` file in the parent directory.
extend = "../pyproject.toml"
# But use a different line length.
line-length = 100

A list of file patterns to omit from linting, in addition to those specified by exclude.

Exclusions are based on globs, and can be either:

• Single-path patterns, like .mypy_cache (to exclude any directory named .mypy_cache in the tree), foo.py (to exclude any file named foo.py), or foo_*.py (to exclude any file matching foo_*.py ).
• Relative patterns, like directory/foo.py (to exclude that specific file) or directory/*.py (to exclude any Python files in directory). Note that these paths are relative to the project root (e.g., the directory containing your pyproject.toml).

For more information on the glob syntax, refer to the globset documentation.

Default value: []

Type: Vec<FilePattern>

Example usage:

[tool.ruff]
# In addition to the standard set of exclusions, omit all tests, plus a specific file.
extend-exclude = ["tests", "src/bad.py"]

A list of rule codes or prefixes to ignore, in addition to those specified by ignore.

Note that extend-ignore is applied after resolving rules from ignore/select and a less specific rule in extend-ignore would overwrite a more specific rule in select. It is recommended to only use extend-ignore when extending a pyproject.toml file via extend.

Default value: []

Type: Vec<RuleSelector>

Example usage:

[tool.ruff]
# Skip unused variable rules (`F841`).
extend-ignore = ["F841"]

A list of rule codes or prefixes to enable, in addition to those specified by select.

Note that extend-select is applied after resolving rules from ignore/select and a less specific rule in extend-select would overwrite a more specific rule in ignore. It is recommended to only use extend-select when extending a pyproject.toml file via extend.

Default value: []

Type: Vec<RuleSelector>

Example usage:

[tool.ruff]
# On top of the default `select` (`E`, `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`).
extend-select = ["B", "Q"]

A list of rule codes that are unsupported by Ruff, but should be preserved when (e.g.) validating # noqa directives. Useful for retaining # noqa directives that cover plugins not yet implemented by Ruff.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff]
# Avoiding flagging (and removing) `V101` from any `# noqa`
# directives, despite Ruff's lack of support for `vulture`.
external = ["V101"]

Enable autofix behavior by-default when running ruff (overridden by the --fix and --no-fix command-line flags).

Default value: false

Type: bool

Example usage:

[tool.ruff]
fix = true

Like fix, but disables reporting on leftover violation. Implies fix.

Default value: false

Type: bool

Example usage:

[tool.ruff]
fix-only = true

A list of rule codes or prefixes to consider autofixable.

Default value: ["A", "ANN", "ARG", "B", "BLE", "C", "D", "E", "ERA", "F", "FBT", "I", "ICN", "N", "PGH", "PLC", "PLE", "PLR", "PLW", "Q", "RET", "RUF", "S", "T", "TID", "UP", "W", "YTT"]

Type: Vec<RuleSelector>

Example usage:

[tool.ruff]
# Only allow autofix behavior for `E` and `F` rules.
fixable = ["E", "F"]

Whether to enforce exclude and extend-exclude patterns, even for paths that are passed to Ruff explicitly. Typically, Ruff will lint any paths passed in directly, even if they would typically be excluded. Setting force-exclude = true will cause Ruff to respect these exclusions unequivocally.

This is useful for pre-commit, which explicitly passes all changed files to the ruff-pre-commit plugin, regardless of whether they're marked as excluded by Ruff's own settings.

Default value: false

Type: bool

Example usage:

[tool.ruff]
force-exclude = true

The style in which violation messages should be formatted: "text" (default), "grouped" (group messages by file), "json" (machine-readable), "junit" (machine-readable XML), "github" (GitHub Actions annotations), "gitlab" (GitLab CI code quality report), or "pylint" (Pylint text format).

Default value: "text"

Type: SerializationType

Example usage:

[tool.ruff]
# Group violations by containing file.
format = "grouped"

A list of rule codes or prefixes to ignore. Prefixes can specify exact rules (like F841), entire categories (like F), or anything in between.

When breaking ties between enabled and disabled rules (via select and ignore, respectively), more specific prefixes override less specific prefixes.

Default value: []

Type: Vec<RuleSelector>

Example usage:

[tool.ruff]
# Skip unused variable rules (`F841`).
ignore = ["F841"]

Avoid automatically removing unused imports in __init__.py files. Such imports will still be flagged, but with a dedicated message suggesting that the import is either added to the module's __all__ symbol, or re-exported with a redundant alias (e.g., import os as os).

Default value: false

Type: bool

Example usage:

[tool.ruff]
ignore-init-module-imports = true

The line length to use when enforcing long-lines violations (like E501).

Default value: 88

Type: usize

Example usage:

[tool.ruff]
# Allow lines to be as long as 120 characters.
line-length = 120

Mark the specified directories as namespace packages. For the purpose of module resolution, Ruff will treat those directories as if they contained an __init__.py file.

Default value: []

Type: Vec<PathBuf>

Example usage:

[tool.ruff]
namespace-packages = ["airflow/providers"]

A list of mappings from file pattern to rule codes or prefixes to exclude, when considering any matching files.

Default value: {}

Type: HashMap<String, Vec<RuleSelector>>

Example usage:

[tool.ruff]
# Ignore `E402` (import violations) in all `__init__.py` files, and in `path/to/file.py`.
[tool.ruff.per-file-ignores]
"__init__.py" = ["E402"]
"path/to/file.py" = ["E402"]

Require a specific version of Ruff to be running (useful for unifying results across many environments, e.g., with a pyproject.toml file).

Default value: None

Type: String

Example usage:

[tool.ruff]
required-version = "0.0.193"

Whether to automatically exclude files that are ignored by .ignore, .gitignore, .git/info/exclude, and global gitignore files. Enabled by default.

Default value: true

Type: bool

Example usage:

[tool.ruff]
respect-gitignore = false

A list of rule codes or prefixes to enable. Prefixes can specify exact rules (like F841), entire categories (like F), or anything in between.

When breaking ties between enabled and disabled rules (via select and ignore, respectively), more specific prefixes override less specific prefixes.

Default value: ["E", "F"]

Type: Vec<RuleSelector>

Example usage:

[tool.ruff]
# On top of the defaults (`E`, `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`).
select = ["E", "F", "B", "Q"]

Whether to show source code snippets when reporting lint violations (overridden by the --show-source command-line flag).

Default value: false

Type: bool

Example usage:

[tool.ruff]
# By default, always show source code snippets.
show-source = true

The source code paths to consider, e.g., when resolving first- vs. third-party imports.

As an example: given a Python package structure like:

my_package/
  pyproject.toml
  src/
    my_package/
      __init__.py
      foo.py
      bar.py

The src directory should be included in source (e.g., source = ["src"]), such that when resolving imports, my_package.foo is considered a first-party import.

This field supports globs. For example, if you have a series of Python packages in a python_modules directory, src = ["python_modules/*"] would expand to incorporate all of the packages in that directory. User home directory and environment variables will also be expanded.

Default value: ["."]

Type: Vec<PathBuf>

Example usage:

[tool.ruff]
# Allow imports relative to the "src" and "test" directories.
src = ["src", "test"]

The Python version to target, e.g., when considering automatic code upgrades, like rewriting type annotations. Note that the target version will not be inferred from the current Python version, and instead must be specified explicitly (as seen below).

Default value: "py310"

Type: PythonVersion

Example usage:

[tool.ruff]
# Always generate Python 3.7-compatible code.
target-version = "py37"

A list of task tags to recognize (e.g., "TODO", "FIXME", "XXX").

Comments starting with these tags will be ignored by commented-out code detection (ERA), and skipped by line-length rules (E501) if ignore-overlong-task-comments is set to true.

Default value: ["TODO", "FIXME", "XXX"]

Type: Vec<String>

Example usage:

[tool.ruff]
task-tags = ["HACK"]

A list of modules whose imports should be treated equivalently to members of the typing module.

This is useful for ensuring proper type annotation inference for projects that re-export typing and typing_extensions members from a compatibility module. If omitted, any members imported from modules apart from typing and typing_extensions will be treated as ordinary Python objects.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff]
typing-modules = ["airflow.typing_compat"]

A list of rule codes or prefixes to consider non-autofix-able.

Default value: []

Type: Vec<RuleSelector>

Example usage:

[tool.ruff]
# Disable autofix for unused imports (`F401`).
unfixable = ["F401"]

Enable or disable automatic update checks (overridden by the --update-check and --no-update-check command-line flags).

Default value: false

Type: bool

Example usage:

[tool.ruff]
update-check = true

Whether to suppress ANN401 for dynamically typed *args and **kwargs arguments.

Default value: false

Type: bool

Example usage:

[tool.ruff.flake8-annotations]
allow-star-arg-any = true

Whether to allow the omission of a return type hint for __init__ if at least one argument is annotated.

Default value: false

Type: bool

Example usage:

[tool.ruff.flake8-annotations]
mypy-init-return = true

Whether to suppress ANN000-level violations for arguments matching the "dummy" variable regex (like _).

Default value: false

Type: bool

Example usage:

[tool.ruff.flake8-annotations]
suppress-dummy-args = true

Whether to suppress ANN200-level violations for functions that meet either of the following criteria:

• Contain no return statement.
• Explicit return statement(s) all return None (explicitly or implicitly).

Default value: false

Type: bool

Example usage:

[tool.ruff.flake8-annotations]
suppress-none-returning = true

A list of directories to consider temporary.

Default value: ["/tmp", "/var/tmp", "/dev/shm"]

Type: Vec<String>

Example usage:

[tool.ruff.flake8-bandit]
hardcoded-tmp-directory = ["/foo/bar"]

A list of directories to consider temporary, in addition to those specified by hardcoded-tmp-directory.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff.flake8-bandit]
extend-hardcoded-tmp-directory = ["/foo/bar"]

Additional callable functions to consider "immutable" when evaluating, e.g., the no-mutable-default-argument rule (B006).

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff.flake8-bugbear]
# Allow default arguments like, e.g., `data: List[str] = fastapi.Query(None)`.
extend-immutable-calls = ["fastapi.Depends", "fastapi.Query"]

Ignore list of builtins.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff.flake8-builtins]
builtins-ignorelist = ["id"]

Maximum string length for string literals in exception messages.

Default value: 0

Type: usize

Example usage:

[tool.ruff.flake8-errmsg]
max-string-length = 20

Whether to allow implicit string concatenations for multiline strings. By default, implicit concatenations of multiline strings are allowed (but continuation lines, delimited with a backslash, are prohibited).

Default value: true

Type: bool

Example usage:

[tool.ruff.flake8-implicit-str-concat]
allow-multiline = false

The conventional aliases for imports. These aliases can be extended by the extend_aliases option.

Default value: {"altair": "alt", "matplotlib.pyplot": "plt", "numpy": "np", "pandas": "pd", "seaborn": "sns"}

Type: FxHashMap<String, String>

Example usage:

[tool.ruff.flake8-import-conventions]
[tool.ruff.flake8-import-conventions.aliases]
# Declare the default aliases.
altair = "alt"
"matplotlib.pyplot" = "plt"
numpy = "np"
pandas = "pd"
seaborn = "sns"

A mapping of modules to their conventional import aliases. These aliases will be added to the aliases mapping.

Default value: {}

Type: FxHashMap<String, String>

Example usage:

[tool.ruff.flake8-import-conventions]
[tool.ruff.flake8-import-conventions.extend-aliases]
# Declare a custom alias for the `matplotlib` module.
"dask.dataframe" = "dd"

Boolean flag specifying whether @pytest.fixture() without parameters should have parentheses. If the option is set to true (the default), @pytest.fixture() is valid and @pytest.fixture is invalid. If set to false, @pytest.fixture is valid and @pytest.fixture() is invalid.

Default value: true

Type: bool

Example usage:

[tool.ruff.flake8-pytest-style]
fixture-parentheses = true

Boolean flag specifying whether @pytest.mark.foo() without parameters should have parentheses. If the option is set to true (the default), @pytest.mark.foo() is valid and @pytest.mark.foo is invalid. If set to false, @pytest.fixture is valid and @pytest.mark.foo() is invalid.

Default value: true

Type: bool

Example usage:

[tool.ruff.flake8-pytest-style]
mark-parentheses = true

Expected type for multiple argument names in @pytest.mark.parametrize. The following values are supported:

• csv — a comma-separated list, e.g. @pytest.mark.parametrize('name1,name2', ...)
• tuple (default) — e.g. @pytest.mark.parametrize(('name1', 'name2'), ...)
• list — e.g. @pytest.mark.parametrize(['name1', 'name2'], ...)

Default value: tuple

Type: ParametrizeNameType

Example usage:

[tool.ruff.flake8-pytest-style]
parametrize-names-type = "list"

Expected type for each row of values in @pytest.mark.parametrize in case of multiple parameters. The following values are supported:

• tuple (default) — e.g. @pytest.mark.parametrize(('name1', 'name2'), [(1, 2), (3, 4)])
• list — e.g. @pytest.mark.parametrize(('name1', 'name2'), [[1, 2], [3, 4]])

Default value: tuple

Type: ParametrizeValuesRowType

Example usage:

[tool.ruff.flake8-pytest-style]
parametrize-values-row-type = "list"

Expected type for the list of values rows in @pytest.mark.parametrize. The following values are supported:

• tuple — e.g. @pytest.mark.parametrize('name', (1, 2, 3))
• list (default) — e.g. @pytest.mark.parametrize('name', [1, 2, 3])

Default value: list

Type: ParametrizeValuesType

Example usage:

[tool.ruff.flake8-pytest-style]
parametrize-values-type = "tuple"

List of additional exception names that require a match= parameter in a pytest.raises() call. This extends the default list of exceptions that require a match= parameter. This option is useful if you want to extend the default list of exceptions that require a match= parameter without having to specify the entire list. Note that this option does not remove any exceptions from the default list.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff.flake8-pytest-style]
raises-extend-require-match-for = ["requests.RequestException"]

List of exception names that require a match= parameter in a pytest.raises() call.

Default value: ["BaseException", "Exception", "ValueError", "OSError", "IOError", "EnvironmentError", "socket.error"]

Type: Vec<String>

Example usage:

[tool.ruff.flake8-pytest-style]
raises-require-match-for = ["requests.RequestException"]

Whether to avoid using single quotes if a string contains single quotes, or vice-versa with double quotes, as per PEP8. This minimizes the need to escape quotation marks within strings.

Default value: true

Type: bool

Example usage:

[tool.ruff.flake8-quotes]
# Don't bother trying to avoid escapes.
avoid-escape = false

Quote style to prefer for docstrings (either "single" (') or "double" (")).

Default value: "double"

Type: Quote

Example usage:

[tool.ruff.flake8-quotes]
docstring-quotes = "single"

Quote style to prefer for inline strings (either "single" (') or "double" (")).

Default value: "double"

Type: Quote

Example usage:

[tool.ruff.flake8-quotes]
inline-quotes = "single"

Quote style to prefer for multiline strings (either "single" (') or "double" (")).

Default value: "double"

Type: Quote

Example usage:

[tool.ruff.flake8-quotes]
multiline-quotes = "single"

Whether to ban all relative imports ("all"), or only those imports that extend into the parent module or beyond ("parents").

Default value: "parents"

Type: Strictness

Example usage:

[tool.ruff.flake8-tidy-imports]
# Disallow all relative imports.
ban-relative-imports = "all"

Specific modules or module members that may not be imported or accessed. Note that this rule is only meant to flag accidental uses, and can be circumvented via eval or importlib.

Default value: {}

Type: HashMap<String, BannedApi>

Example usage:

[tool.ruff.flake8-tidy-imports]
[tool.ruff.flake8-tidy-imports.banned-api]
"cgi".msg = "The cgi module is deprecated, see https://peps.python.org/pep-0594/#cgi."
"typing.TypedDict".msg = "Use typing_extensions.TypedDict instead."

Whether to allow unused variadic arguments, like *args and **kwargs.

Default value: false

Type: bool

Example usage:

[tool.ruff.flake8-unused-arguments]
ignore-variadic-names = true

An override list of tokens to always recognize as a Class for order-by-type regardless of casing.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff.isort]
classes = ["SVC"]

Combines as imports on the same line. See isort's combine-as-imports option.

Default value: false

Type: bool

Example usage:

[tool.ruff.isort]
combine-as-imports = true

An override list of tokens to always recognize as a CONSTANT for order-by-type regardless of casing.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff.isort]
constants = ["constant"]

A list of modules to consider standard-library, in addition to those known to Ruff in advance.

Default value: []

Type: Vec<String>

Example usage:

[tool.ruff.isort]
extra-standard-library = ["path"]

Forces all from imports to appear on their own line.

Default value: false

Type: bool

Example usage:

[tool.ruff.isort]
force-single-line = true