Use rustup-show instead of actions-rs
An extremely fast Python linter, written in Rust.
pippyproject.toml supportflake8-bugbearRuff 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:
Read the launch blog post.
SebastiΓ‘n RamΓrez, 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.
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.
Tim Abbott, lead developer of Zulip:
This is just ridiculously fast...
ruffis amazing.
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
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: 'v0.0.217' hooks: - id: ruff # Respect `exclude` and `extend-exclude` settings. args: ["--force-exclude"]
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 <SELECT>
Comma-separated list of rule codes to enable (or ALL, to enable all rules)
--extend-select <EXTEND_SELECT>
Like --select, but adds additional rule codes on top of the selected ones
--ignore <IGNORE>
Comma-separated list of rule codes to disable
--extend-ignore <EXTEND_IGNORE>
Like --ignore, but adds additional rule codes on top of the ignored ones
--exclude <EXCLUDE>
List of paths, used to omit files and/or directories from analysis
--extend-exclude <EXTEND_EXCLUDE>
Like --exclude, but adds additional files and directories on top of those already excluded
--fixable <FIXABLE>
List of rule codes to treat as eligible for autofix. Only applicable when autofix itself is enabled (e.g., via `--fix`)
--unfixable <UNFIXABLE>
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]
--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
--max-complexity <MAX_COMPLEXITY>
Maximum McCabe complexity allowed for a given function
--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 information
-V, --version
Print version information
pyproject.toml discoverySimilar 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:
pyproject.toml file for a given path, Ruff ignores any pyproject.toml files that lack a [tool.ruff] section.--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.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.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.
noqa DirectivesRuff 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 π emoji indicates that a rule is automatically fixable by the --fix command-line option.
For more, see Pyflakes on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| F401 | UnusedImport | ... imported but unused | π |
| F402 | ImportShadowedByLoopVar | Import ... from line 1 shadowed by loop variable | |
| F403 | ImportStarUsed | from ... import * used; unable to detect undefined names | |
| F404 | LateFutureImport | from __future__ imports must occur at the beginning of the file | |
| F405 | ImportStarUsage | ... may be undefined, or defined from star imports: ... | |
| F406 | ImportStarNotPermitted | from ... import * only allowed at module level | |
| F407 | FutureFeatureNotDefined | Future feature ... is not defined | |
| F501 | PercentFormatInvalidFormat | ‘...’ % ... has invalid format string: ... | |
| F502 | PercentFormatExpectedMapping | ‘...’ % ... expected mapping but got sequence | |
| F503 | PercentFormatExpectedSequence | ‘...’ % ... expected sequence but got mapping | |
| F504 | PercentFormatExtraNamedArguments | ‘...’ % ... has unused named argument(s): ... | π |
| F505 | PercentFormatMissingArgument | ‘...’ % ... is missing argument(s) for placeholder(s): ... | |
| F506 | PercentFormatMixedPositionalAndNamed | ‘...’ % ... has mixed positional and named placeholders | |
| F507 | PercentFormatPositionalCountMismatch | ‘...’ % ... has 4 placeholder(s) but 2 substitution(s) | |
| F508 | PercentFormatStarRequiresSequence | ‘...’ % ... * specifier requires sequence | |
| F509 | PercentFormatUnsupportedFormatCharacter | ‘...’ % ... has unsupported format character ‘c’ | |
| F521 | StringDotFormatInvalidFormat | ‘...’.format(...) has invalid format string: ... | |
| F522 | StringDotFormatExtraNamedArguments | ‘...’.format(...) has unused named argument(s): ... | π |
| F523 | StringDotFormatExtraPositionalArguments | ‘...’.format(...) has unused arguments at position(s): ... | |
| F524 | StringDotFormatMissingArguments | ‘...’.format(...) is missing argument(s) for placeholder(s): ... | |
| F525 | StringDotFormatMixingAutomatic | ‘...’.format(...) mixes automatic and manual numbering | |
| F541 | FStringMissingPlaceholders | f-string without any placeholders | π |
| F601 | MultiValueRepeatedKeyLiteral | Dictionary key literal ... repeated | π |
| F602 | MultiValueRepeatedKeyVariable | Dictionary key ... repeated | π |
| F621 | ExpressionsInStarAssignment | Too many expressions in star-unpacking assignment | |
| F622 | TwoStarredExpressions | Two starred expressions in assignment | |
| F631 | AssertTuple | Assert test is a non-empty tuple, which is always True | |
| F632 | IsLiteral | Use == to compare constant literals | π |
| F633 | InvalidPrintSyntax | Use of >> is invalid with print function | |
| F634 | IfTuple | If test is a tuple, which is always True | |
| F701 | BreakOutsideLoop | break outside loop | |
| F702 | ContinueOutsideLoop | continue not properly in loop | |
| F704 | YieldOutsideFunction | yield statement outside of a function | |
| F706 | ReturnOutsideFunction | return statement outside of a function/method | |
| F707 | DefaultExceptNotLast | An except block as not the last exception handler | |
| F722 | ForwardAnnotationSyntaxError | Syntax error in forward annotation: ... | |
| F811 | RedefinedWhileUnused | Redefinition of unused ... from line 1 | |
| F821 | UndefinedName | Undefined name ... | |
| F822 | UndefinedExport | Undefined name ... in __all__ | |
| F823 | UndefinedLocal | Local variable ... referenced before assignment | |
| F841 | UnusedVariable | Local variable ... is assigned to but never used | π |
| F842 | UnusedAnnotation | Local variable ... is annotated but never used | |
| F901 | RaiseNotImplemented | raise NotImplemented should be raise NotImplementedError | π |
For more, see pycodestyle on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| E401 | MultipleImportsOnOneLine | Multiple imports on one line | |
| E402 | ModuleImportNotAtTopOfFile | Module level import not at top of file | |
| E501 | LineTooLong | Line too long (89 > 88 characters) | |
| E711 | NoneComparison | Comparison to None should be cond is None | π |
| E712 | TrueFalseComparison | Comparison to True should be cond is True | π |
| E713 | NotInTest | Test for membership should be not in | π |
| E714 | NotIsTest | Test for object identity should be is not | π |
| E721 | TypeComparison | Do not compare types, use isinstance() | |
| E722 | DoNotUseBareExcept | Do not use bare except | |
| E731 | DoNotAssignLambda | Do not assign a lambda expression, use a def | π |
| E741 | AmbiguousVariableName | Ambiguous variable name: ... | |
| E742 | AmbiguousClassName | Ambiguous class name: ... | |
| E743 | AmbiguousFunctionName | Ambiguous function name: ... | |
| E902 | IOError | IOError: ... | |
| E999 | SyntaxError | SyntaxError: ... | |
| W292 | NoNewLineAtEndOfFile | No newline at end of file | π |
| W605 | InvalidEscapeSequence | Invalid escape sequence: ‘\c’ | π |
For more, see mccabe on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| C901 | FunctionIsTooComplex | ... is too complex (10) |
For more, see isort on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| I001 | UnsortedImports | Import block is un-sorted or un-formatted | π |
For more, see pydocstyle on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| D100 | PublicModule | Missing docstring in public module | |
| D101 | PublicClass | Missing docstring in public class | |
| D102 | PublicMethod | Missing docstring in public method | |
| D103 | PublicFunction | Missing docstring in public function | |
| D104 | PublicPackage | Missing docstring in public package | |
| D105 | MagicMethod | Missing docstring in magic method | |
| D106 | PublicNestedClass | Missing docstring in public nested class | |
| D107 | PublicInit | Missing docstring in __init__ | |
| D200 | FitsOnOneLine | One-line docstring should fit on one line | |
| D201 | NoBlankLineBeforeFunction | No blank lines allowed before function docstring (found 1) | π |
| D202 | NoBlankLineAfterFunction | No blank lines allowed after function docstring (found 1) | π |
| D203 | OneBlankLineBeforeClass | 1 blank line required before class docstring | π |
| D204 | OneBlankLineAfterClass | 1 blank line required after class docstring | π |
| D205 | BlankLineAfterSummary | 1 blank line required between summary line and description (found 2) | π |
| D206 | IndentWithSpaces | Docstring should be indented with spaces, not tabs | |
| D207 | NoUnderIndentation | Docstring is under-indented | π |
| D208 | NoOverIndentation | Docstring is over-indented | π |
| D209 | NewLineAfterLastParagraph | Multi-line docstring closing quotes should be on a separate line | π |
| D210 | NoSurroundingWhitespace | No whitespaces allowed surrounding docstring text | π |
| D211 | NoBlankLineBeforeClass | No blank lines allowed before class docstring | π |
| D212 | MultiLineSummaryFirstLine | Multi-line docstring summary should start at the first line | |
| D213 | MultiLineSummarySecondLine | Multi-line docstring summary should start at the second line | |
| D214 | SectionNotOverIndented | Section is over-indented (“Returns”) | π |
| D215 | SectionUnderlineNotOverIndented | Section underline is over-indented (“Returns”) | π |
| D300 | UsesTripleQuotes | Use “““triple double quotes””” | |
| D301 | UsesRPrefixForBackslashedContent | Use r""" if any backslashes in a docstring | |
| D400 | EndsInPeriod | First line should end with a period | π |
| D402 | NoSignature | First line should not be the function's signature | |
| D403 | FirstLineCapitalized | First word of the first line should be properly capitalized | |
| D404 | NoThisPrefix | First word of the docstring should not be “This” | |
| D405 | CapitalizeSectionName | Section name should be properly capitalized (“returns”) | π |
| D406 | NewLineAfterSectionName | Section name should end with a newline (“Returns”) | π |
| D407 | DashedUnderlineAfterSection | Missing dashed underline after section (“Returns”) | π |
| D408 | SectionUnderlineAfterName | Section underline should be in the line following the section's name (“Returns”) | π |
| D409 | SectionUnderlineMatchesSectionLength | Section underline should match the length of its name (“Returns”) | π |
| D410 | BlankLineAfterSection | Missing blank line after section (“Returns”) | π |
| D411 | BlankLineBeforeSection | Missing blank line before section (“Returns”) | π |
| D412 | NoBlankLinesBetweenHeaderAndContent | No blank lines allowed between a section header and its content (“Returns”) | π |
| D413 | BlankLineAfterLastSection | Missing blank line after last section (“Returns”) | π |
| D414 | NonEmptySection | Section has no content (“Returns”) | |
| D415 | EndsInPunctuation | First line should end with a period, question mark, or exclamation point | π |
| D416 | SectionNameEndsInColon | Section name should end with a colon (“Returns”) | π |
| D417 | DocumentAllArguments | Missing argument descriptions in the docstring: x, y | |
| D418 | SkipDocstring | Function decorated with @overload shouldn't contain a docstring | |
| D419 | NonEmpty | Docstring is empty |
For more, see pyupgrade on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| UP001 | UselessMetaclassType | __metaclass__ = type is implied | π |
| UP003 | TypeOfPrimitive | Use str instead of type(...) | π |
| UP004 | UselessObjectInheritance | Class ... inherits from object | π |
| UP005 | DeprecatedUnittestAlias | assertEquals is deprecated, use assertEqual | π |
| UP006 | UsePEP585Annotation | Use list instead of List for type annotations | π |
| UP007 | UsePEP604Annotation | Use X | Y for type annotations | π |
| UP008 | SuperCallWithParameters | Use super() instead of super(__class__, self) | π |
| UP009 | PEP3120UnnecessaryCodingComment | UTF-8 encoding declaration is unnecessary | π |
| UP010 | UnnecessaryFutureImport | Unnecessary __future__ import ... for target Python version | π |
| UP011 | UnnecessaryLRUCacheParams | Unnecessary parameters to functools.lru_cache | π |
| UP012 | UnnecessaryEncodeUTF8 | Unnecessary call to encode as UTF-8 | π |
| UP013 | ConvertTypedDictFunctionalToClass | Convert ... from TypedDict functional to class syntax | π |
| UP014 | ConvertNamedTupleFunctionalToClass | Convert ... from NamedTuple functional to class syntax | π |
| UP015 | RedundantOpenModes | Unnecessary open mode parameters | π |
| UP016 | RemoveSixCompat | Unnecessary six compatibility usage | π |
| UP017 | DatetimeTimezoneUTC | Use datetime.UTC alias | π |
| UP018 | NativeLiterals | Unnecessary call to str | π |
| UP019 | TypingTextStrAlias | typing.Text is deprecated, use str | π |
| UP020 | OpenAlias | Use builtin open | π |
| UP021 | ReplaceUniversalNewlines | universal_newlines is deprecated, use text | π |
| UP022 | ReplaceStdoutStderr | Sending stdout and stderr to pipe is deprecated, use capture_output | π |
| UP023 | RewriteCElementTree | cElementTree is deprecated, use ElementTree | π |
| UP024 | OSErrorAlias | Replace aliased errors with OSError | π |
| UP025 | RewriteUnicodeLiteral | Remove unicode literals from strings | π |
| UP026 | RewriteMockImport | mock is deprecated, use unittest.mock | π |
| UP027 | RewriteListComprehension | Replace unpacked list comprehension with a generator expression | π |
| UP028 | RewriteYieldFrom | Replace yield over for loop with yield from | π |
| UP029 | UnnecessaryBuiltinImport | Unnecessary builtin import: ... | π |
For more, see pep8-naming on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| N801 | InvalidClassName | Class name ... should use CapWords convention | |
| N802 | InvalidFunctionName | Function name ... should be lowercase | |
| N803 | InvalidArgumentName | Argument name ... should be lowercase | |
| N804 | InvalidFirstArgumentNameForClassMethod | First argument of a class method should be named cls | |
| N805 | InvalidFirstArgumentNameForMethod | First argument of a method should be named self | |
| N806 | NonLowercaseVariableInFunction | Variable ... in function should be lowercase | |
| N807 | DunderFunctionName | Function name should not start and end with __ | |
| N811 | ConstantImportedAsNonConstant | Constant ... imported as non-constant ... | |
| N812 | LowercaseImportedAsNonLowercase | Lowercase ... imported as non-lowercase ... | |
| N813 | CamelcaseImportedAsLowercase | Camelcase ... imported as lowercase ... | |
| N814 | CamelcaseImportedAsConstant | Camelcase ... imported as constant ... | |
| N815 | MixedCaseVariableInClassScope | Variable mixedCase in class scope should not be mixedCase | |
| N816 | MixedCaseVariableInGlobalScope | Variable mixedCase in global scope should not be mixedCase | |
| N817 | CamelcaseImportedAsAcronym | Camelcase ... imported as acronym ... | |
| N818 | ErrorSuffixOnExceptionName | Exception name ... should be named with an Error suffix |
For more, see flake8-2020 on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| YTT101 | SysVersionSlice3Referenced | sys.version[:3] referenced (python3.10), use sys.version_info | |
| YTT102 | SysVersion2Referenced | sys.version[2] referenced (python3.10), use sys.version_info | |
| YTT103 | SysVersionCmpStr3 | sys.version compared to string (python3.10), use sys.version_info | |
| YTT201 | SysVersionInfo0Eq3Referenced | sys.version_info[0] == 3 referenced (python4), use >= | |
| YTT202 | SixPY3Referenced | six.PY3 referenced (python4), use not six.PY2 | |
| YTT203 | SysVersionInfo1CmpInt | sys.version_info[1] compared to integer (python4), compare sys.version_info to tuple | |
| YTT204 | SysVersionInfoMinorCmpInt | sys.version_info.minor compared to integer (python4), compare sys.version_info to tuple | |
| YTT301 | SysVersion0Referenced | sys.version[0] referenced (python10), use sys.version_info | |
| YTT302 | SysVersionCmpStr10 | sys.version compared to string (python10), use sys.version_info | |
| YTT303 | SysVersionSlice1Referenced | sys.version[:1] referenced (python10), use sys.version_info |
For more, see flake8-annotations on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| ANN001 | MissingTypeFunctionArgument | Missing type annotation for function argument ... | |
| ANN002 | MissingTypeArgs | Missing type annotation for *... | |
| ANN003 | MissingTypeKwargs | Missing type annotation for **... | |
| ANN101 | MissingTypeSelf | Missing type annotation for ... in method | |
| ANN102 | MissingTypeCls | Missing type annotation for ... in classmethod | |
| ANN201 | MissingReturnTypePublicFunction | Missing return type annotation for public function ... | |
| ANN202 | MissingReturnTypePrivateFunction | Missing return type annotation for private function ... | |
| ANN204 | MissingReturnTypeSpecialMethod | Missing return type annotation for special method ... | π |
| ANN205 | MissingReturnTypeStaticMethod | Missing return type annotation for staticmethod ... | |
| ANN206 | MissingReturnTypeClassMethod | Missing return type annotation for classmethod ... | |
| ANN401 | DynamicallyTypedExpression | Dynamically typed expressions (typing.Any) are disallowed in ... |
For more, see flake8-bandit on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| S101 | AssertUsed | Use of assert detected | |
| S102 | ExecUsed | Use of exec detected | |
| S103 | BadFilePermissions | os.chmod setting a permissive mask 0o777 on file or directory | |
| S104 | HardcodedBindAllInterfaces | Possible binding to all interfaces | |
| S105 | HardcodedPasswordString | Possible hardcoded password: “...” | |
| S106 | HardcodedPasswordFuncArg | Possible hardcoded password: “...” | |
| S107 | HardcodedPasswordDefault | Possible hardcoded password: “...” | |
| S108 | HardcodedTempFile | Probable insecure usage of temporary file or directory: “...” | |
| S113 | RequestWithoutTimeout | Probable use of requests call without timeout | |
| S324 | HashlibInsecureHashFunction | Probable use of insecure hash functions in hashlib: “...” | |
| S501 | RequestWithNoCertValidation | Probable use of ... call with verify=False disabling SSL certificate checks | |
| S506 | UnsafeYAMLLoad | Probable use of unsafe yaml.load. Allows instantiation of arbitrary objects. Consider yaml.safe_load. |
For more, see flake8-blind-except on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| BLE001 | BlindExcept | Do not catch blind exception: Exception |
For more, see flake8-boolean-trap on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| FBT001 | BooleanPositionalArgInFunctionDefinition | Boolean positional arg in function definition | |
| FBT002 | BooleanDefaultValueInFunctionDefinition | Boolean default value in function definition | |
| FBT003 | BooleanPositionalValueInFunctionCall | Boolean positional value in function call |
For more, see flake8-bugbear on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| B002 | UnaryPrefixIncrement | Python does not support the unary prefix increment | |
| B003 | AssignmentToOsEnviron | Assigning to os.environ doesn't clear the environment | |
| B004 | UnreliableCallableCheck | Using hasattr(x, '__call__') to test if x is callable is unreliable. Use callable(x) for consistent results. | |
| B005 | StripWithMultiCharacters | Using .strip() with multi-character strings is misleading the reader | |
| B006 | MutableArgumentDefault | Do not use mutable data structures for argument defaults | |
| B007 | UnusedLoopControlVariable | Loop control variable i not used within the loop body | π |
| B008 | FunctionCallArgumentDefault | Do not perform function call in argument defaults | |
| B009 | GetAttrWithConstant | Do not call getattr with a constant attribute value. It is not any safer than normal property access. | π |
| B010 | SetAttrWithConstant | Do not call setattr with a constant attribute value. It is not any safer than normal property access. | π |
| B011 | DoNotAssertFalse | Do not assert False (python -O removes these calls), raise AssertionError() | π |
| B012 | JumpStatementInFinally | return/continue/break inside finally blocks cause exceptions to be silenced | |
| B013 | RedundantTupleInExceptionHandler | A length-one tuple literal is redundant. Write except ValueError instead of except (ValueError,). | π |
| B014 | DuplicateHandlerException | Exception handler with duplicate exception: ValueError | π |
| B015 | UselessComparison | Pointless comparison. This comparison does nothing but waste CPU instructions. Either prepend assert or remove it. | |
| B016 | CannotRaiseLiteral | Cannot raise a literal. Did you intend to return it or raise an Exception? | |
| B017 | NoAssertRaisesException | assertRaises(Exception) should be considered evil | |
| B018 | UselessExpression | Found useless expression. Either assign it to a variable or remove it. | |
| B019 | CachedInstanceMethod | Use of functools.lru_cache or functools.cache on methods can lead to memory leaks | |
| B020 | LoopVariableOverridesIterator | Loop control variable ... overrides iterable it iterates | |
| B021 | FStringDocstring | f-string used as docstring. This will be interpreted by python as a joined string rather than a docstring. | |
| B022 | UselessContextlibSuppress | No arguments passed to contextlib.suppress. No exceptions will be suppressed and therefore this context manager is redundant | |
| B023 | FunctionUsesLoopVariable | Function definition does not bind loop variable ... | |
| B024 | AbstractBaseClassWithoutAbstractMethod | ... is an abstract base class, but it has no abstract methods | |
| B025 | DuplicateTryBlockException | try-except block with duplicate exception Exception | |
| B026 | StarArgUnpackingAfterKeywordArg | Star-arg unpacking after a keyword argument is strongly discouraged | |
| B027 | EmptyMethodWithoutAbstractDecorator | ... is an empty method in an abstract base class, but has no abstract decorator | |
| B904 | RaiseWithoutFromInsideExcept | Within an except clause, raise exceptions with raise ... from err or raise ... from None to distinguish them from errors in exception handling | |
| B905 | ZipWithoutExplicitStrict | zip() without an explicit strict= parameter |
For more, see flake8-builtins on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| A001 | BuiltinVariableShadowing | Variable ... is shadowing a python builtin | |
| A002 | BuiltinArgumentShadowing | Argument ... is shadowing a python builtin | |
| A003 | BuiltinAttributeShadowing | Class attribute ... is shadowing a python builtin |
For more, see flake8-comprehensions on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| C400 | UnnecessaryGeneratorList | Unnecessary generator (rewrite as a list comprehension) | π |
| C401 | UnnecessaryGeneratorSet | Unnecessary generator (rewrite as a set comprehension) | π |
| C402 | UnnecessaryGeneratorDict | Unnecessary generator (rewrite as a dict comprehension) | π |
| C403 | UnnecessaryListComprehensionSet | Unnecessary list comprehension (rewrite as a set comprehension) | π |
| C404 | UnnecessaryListComprehensionDict | Unnecessary list comprehension (rewrite as a dict comprehension) | π |
| C405 | UnnecessaryLiteralSet | Unnecessary (list|tuple) literal (rewrite as a set literal) | π |
| C406 | UnnecessaryLiteralDict | Unnecessary (list|tuple) literal (rewrite as a dict literal) | π |
| C408 | UnnecessaryCollectionCall | Unnecessary (dict|list|tuple) call (rewrite as a literal) | π |
| C409 | UnnecessaryLiteralWithinTupleCall | Unnecessary (list|tuple) literal passed to tuple() (remove the outer call to tuple()) | π |
| C410 | UnnecessaryLiteralWithinListCall | Unnecessary (list|tuple) literal passed to list() (rewrite as a list literal) | π |
| C411 | UnnecessaryListCall | Unnecessary list call (remove the outer call to list()) | π |
| C413 | UnnecessaryCallAroundSorted | Unnecessary (list|reversed) call around sorted() | π |
| C414 | UnnecessaryDoubleCastOrProcess | Unnecessary (list|reversed|set|sorted|tuple) call within (list|set|sorted|tuple)() | |
| C415 | UnnecessarySubscriptReversal | Unnecessary subscript reversal of iterable within (reversed|set|sorted)() | |
| C416 | UnnecessaryComprehension | Unnecessary (list|set) comprehension (rewrite using (list|set)()) | π |
| C417 | UnnecessaryMap | Unnecessary map usage (rewrite using a (list|set|dict) comprehension) |
For more, see flake8-debugger on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| T100 | Debugger | Import for ... found |
For more, see flake8-errmsg on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| EM101 | RawStringInException | Exception must not use a string literal, assign to variable first | |
| EM102 | FStringInException | Exception must not use an f-string literal, assign to variable first | |
| EM103 | DotFormatInException | Exception must not use a .format() string directly, assign to variable first |
For more, see flake8-implicit-str-concat on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| ISC001 | SingleLineImplicitStringConcatenation | Implicitly concatenated string literals on one line | |
| ISC002 | MultiLineImplicitStringConcatenation | Implicitly concatenated string literals over continuation line | |
| ISC003 | ExplicitStringConcatenation | Explicitly concatenated string should be implicitly concatenated |
| Code | Name | Message | Fix |
|---|---|---|---|
| ICN001 | ImportAliasIsNotConventional | ... should be imported as ... |
For more, see flake8-print on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| T201 | PrintFound | print found | π |
| T203 | PPrintFound | pprint found | π |
For more, see flake8-pytest-style on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| PT001 | IncorrectFixtureParenthesesStyle | Use @pytest.fixture() over @pytest.fixture | π |
| PT002 | FixturePositionalArgs | Configuration for fixture ... specified via positional args, use kwargs | |
| PT003 | ExtraneousScopeFunction | scope='function' is implied in @pytest.fixture() | |
| PT004 | MissingFixtureNameUnderscore | Fixture ... does not return anything, add leading underscore | π |
| PT005 | IncorrectFixtureNameUnderscore | Fixture ... returns a value, remove leading underscore | π |
| PT006 | ParametrizeNamesWrongType | Wrong name(s) type in @pytest.mark.parametrize, expected tuple | π |
| PT007 | ParametrizeValuesWrongType | Wrong values type in @pytest.mark.parametrize expected list of tuple | |
| PT008 | PatchWithLambda | Use return_value= instead of patching with lambda | |
| PT009 | UnittestAssertion | Use a regular assert instead of unittest-style ... | π |
| PT010 | RaisesWithoutException | set the expected exception in pytest.raises() | |
| PT011 | RaisesTooBroad | pytest.raises(...) is too broad, set the match parameter or use a more specific exception | |
| PT012 | RaisesWithMultipleStatements | pytest.raises() block should contain a single simple statement | |
| PT013 | IncorrectPytestImport | Found incorrect import of pytest, use simple import pytest instead | |
| PT015 | AssertAlwaysFalse | Assertion always fails, replace with pytest.fail() | |
| PT016 | FailWithoutMessage | No message passed to pytest.fail() | |
| PT017 | AssertInExcept | Found assertion on exception ... in except block, use pytest.raises() instead | |
| PT018 | CompositeAssertion | Assertion should be broken down into multiple parts | |
| PT019 | FixtureParamWithoutValue | Fixture ... without value is injected as parameter, use @pytest.mark.usefixtures instead | |
| PT020 | DeprecatedYieldFixture | @pytest.yield_fixture is deprecated, use @pytest.fixture | |
| PT021 | FixtureFinalizerCallback | Use yield instead of request.addfinalizer | |
| PT022 | UselessYieldFixture | No teardown in fixture ..., use return instead of yield | π |
| PT023 | IncorrectMarkParenthesesStyle | Use @pytest.mark.... over @pytest.mark....() | π |
| PT024 | UnnecessaryAsyncioMarkOnFixture | pytest.mark.asyncio is unnecessary for fixtures | π |
| PT025 | ErroneousUseFixturesOnFixture | pytest.mark.usefixtures has no effect on fixtures | π |
| PT026 | UseFixturesWithoutParameters | Useless pytest.mark.usefixtures without parameters | π |
For more, see flake8-quotes on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| Q000 | BadQuotesInlineString | Single quotes found but double quotes preferred | |
| Q001 | BadQuotesMultilineString | Single quote multiline found but double quotes preferred | |
| Q002 | BadQuotesDocstring | Single quote docstring found but double quotes preferred | |
| Q003 | AvoidQuoteEscape | Change outer quotes to avoid escaping inner quotes |
For more, see flake8-return on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| RET501 | UnnecessaryReturnNone | Do not explicitly return None in function if it is the only possible return value | π |
| RET502 | ImplicitReturnValue | Do not implicitly return None in function able to return non-None value | π |
| RET503 | ImplicitReturn | Missing explicit return at the end of function able to return non-None value | π |
| RET504 | UnnecessaryAssign | Unnecessary variable assignment before return statement | |
| RET505 | SuperfluousElseReturn | Unnecessary else after return statement | |
| RET506 | SuperfluousElseRaise | Unnecessary else after raise statement | |
| RET507 | SuperfluousElseContinue | Unnecessary else after continue statement | |
| RET508 | SuperfluousElseBreak | Unnecessary else after break statement |
For more, see flake8-simplify on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| SIM101 | DuplicateIsinstanceCall | Multiple isinstance calls for ..., merge into a single call | π |
| SIM102 | NestedIfStatements | Use a single if statement instead of nested if statements | |
| SIM103 | ReturnBoolConditionDirectly | Return the condition ... directly | π |
| SIM105 | UseContextlibSuppress | Use contextlib.suppress(...) instead of try-except-pass | |
| SIM107 | ReturnInTryExceptFinally | Don't use return in try/except and finally | |
| SIM108 | UseTernaryOperator | Use ternary operator ... instead of if-else-block | π |
| SIM109 | CompareWithTuple | Use value in (..., ...) instead of value == ... or value == ... | π |
| SIM110 | ConvertLoopToAny | Use return any(x for x in y) instead of for loop | π |
| SIM111 | ConvertLoopToAll | Use return all(x for x in y) instead of for loop | π |
| SIM112 | UseCapitalEnvironmentVariables | Use capitalized environment variable ... instead of ... | π |
| SIM117 | MultipleWithStatements | Use a single with statement with multiple contexts instead of nested with statements | |
| SIM118 | KeyInDict | Use key in dict instead of key in dict.keys() | π |
| SIM201 | NegateEqualOp | Use left != right instead of not left == right | π |
| SIM202 | NegateNotEqualOp | Use left == right instead of not left != right | π |
| SIM208 | DoubleNegation | Use expr instead of not (not expr) | π |
| SIM210 | IfExprWithTrueFalse | Use bool(expr) instead of True if expr else False | π |
| SIM211 | IfExprWithFalseTrue | Use not expr instead of False if expr else True | π |
| SIM212 | IfExprWithTwistedArms | Use b if b else a instead of a if not b else b | π |
| SIM220 | AAndNotA | Use False instead of ... and not ... | π |
| SIM221 | AOrNotA | Use True instead of ... or not ... | π |
| SIM222 | OrTrue | Use True instead of ... or True | π |
| SIM223 | AndFalse | Use False instead of ... and False | π |
| SIM300 | YodaConditions | Yoda conditions are discouraged, use left == right instead | π |
For more, see flake8-tidy-imports on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| TID251 | BannedApi | ... is banned: ... | |
| TID252 | BannedRelativeImport | Relative imports are banned |
For more, see flake8-unused-arguments on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| ARG001 | UnusedFunctionArgument | Unused function argument: ... | |
| ARG002 | UnusedMethodArgument | Unused method argument: ... | |
| ARG003 | UnusedClassMethodArgument | Unused class method argument: ... | |
| ARG004 | UnusedStaticMethodArgument | Unused static method argument: ... | |
| ARG005 | UnusedLambdaArgument | Unused lambda argument: ... |
For more, see flake8-datetimez on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| DTZ001 | CallDatetimeWithoutTzinfo | The use of datetime.datetime() without tzinfo argument is not allowed | |
| DTZ002 | CallDatetimeToday | The use of datetime.datetime.today() is not allowed | |
| DTZ003 | CallDatetimeUtcnow | The use of datetime.datetime.utcnow() is not allowed | |
| DTZ004 | CallDatetimeUtcfromtimestamp | The use of datetime.datetime.utcfromtimestamp() is not allowed | |
| DTZ005 | CallDatetimeNowWithoutTzinfo | The use of datetime.datetime.now() without tz argument is not allowed | |
| DTZ006 | CallDatetimeFromtimestamp | The use of datetime.datetime.fromtimestamp() without tz argument is not allowed | |
| DTZ007 | CallDatetimeStrptimeWithoutZone | The use of datetime.datetime.strptime() without %z must be followed by .replace(tzinfo=) | |
| DTZ011 | CallDateToday | The use of datetime.date.today() is not allowed. | |
| DTZ012 | CallDateFromtimestamp | The use of datetime.date.fromtimestamp() is not allowed |
For more, see eradicate on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| ERA001 | CommentedOutCode | Found commented-out code | π |
For more, see pandas-vet on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| PD002 | UseOfInplaceArgument | inplace=True should be avoided; it has inconsistent behavior | |
| PD003 | UseOfDotIsNull | .isna is preferred to .isnull; functionality is equivalent | |
| PD004 | UseOfDotNotNull | .notna is preferred to .notnull; functionality is equivalent | |
| PD007 | UseOfDotIx | .ix is deprecated; use more explicit .loc or .iloc | |
| PD008 | UseOfDotAt | Use .loc instead of .at. If speed is important, use numpy. | |
| PD009 | UseOfDotIat | Use .iloc instead of .iat. If speed is important, use numpy. | |
| PD010 | UseOfDotPivotOrUnstack | .pivot_table is preferred to .pivot or .unstack; provides same functionality | |
| PD011 | UseOfDotValues | Use .to_numpy() instead of .values | |
| PD012 | UseOfDotReadTable | .read_csv is preferred to .read_table; provides same functionality | |
| PD013 | UseOfDotStack | .melt is preferred to .stack; provides same functionality | |
| PD015 | UseOfPdMerge | Use .merge method instead of pd.merge function. They have equivalent functionality. | |
| PD901 | DfIsABadVariableName | df is a bad variable name. Be kinder to your future self. |
For more, see pygrep-hooks on GitHub.
| Code | Name | Message | Fix |
|---|---|---|---|
| PGH001 | NoEval | No builtin eval() allowed | |
| PGH002 | DeprecatedLogWarn | warn is deprecated in favor of warning | |
| PGH003 | BlanketTypeIgnore | Use specific rule codes when ignoring type issues | |
| PGH004 | BlanketNOQA | Use specific rule codes when using noqa |
For more, see Pylint on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| PLC0414 | UselessImportAlias | Import alias does not rename original package | π |
| PLC2201 | MisplacedComparisonConstant | Comparison should be ... | π |
| PLC3002 | UnnecessaryDirectLambdaCall | Lambda expression called directly. Execute the expression inline instead. | |
| PLE0117 | NonlocalWithoutBinding | Nonlocal name ... found without binding | |
| PLE0118 | UsedPriorGlobalDeclaration | Name ... is used prior to global declaration on line 1 | |
| PLE1142 | AwaitOutsideAsync | await should be used within an async function | |
| PLR0206 | PropertyWithParameters | Cannot have defined parameters for properties | |
| PLR0402 | ConsiderUsingFromImport | Use from ... import ... in lieu of alias | |
| PLR1701 | ConsiderMergingIsinstance | Merge these isinstance calls: isinstance(..., (...)) | |
| PLR1722 | UseSysExit | Use sys.exit() instead of exit | π |
| PLW0120 | UselessElseOnLoop | Else clause on loop without a break statement, remove the else and de-indent all the code inside it | |
| PLW0602 | GlobalVariableNotAssigned | Using global for ... but no assignment is done |
For more, see flake8-pie on PyPI.
| Code | Name | Message | Fix |
|---|---|---|---|
| PIE790 | NoUnnecessaryPass | Unnecessary pass statement | π |
| PIE794 | DupeClassFieldDefinitions | Class field ... is defined multiple times | π |
| PIE807 | PreferListBuiltin | Prefer list() over useless lambda | π |
| Code | Name | Message | Fix |
|---|---|---|---|
| RUF001 | AmbiguousUnicodeCharacterString | String contains ambiguous unicode character ‘π’ (did you mean ‘B’?) | π |
| RUF002 | AmbiguousUnicodeCharacterDocstring | Docstring contains ambiguous unicode character ‘π’ (did you mean ‘B’?) | π |
| RUF003 | AmbiguousUnicodeCharacterComment | Comment contains ambiguous unicode character ‘π’ (did you mean ‘B’?) | π |
| RUF004 | KeywordArgumentBeforeStarArgument | Keyword argument ... must come after starred arguments | |
| RUF100 | UnusedNOQA | Unused blanket noqa directive | π |
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.
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)eradicateflake8-2020flake8-annotationsflake8-bandit (#1646)flake8-blind-exceptflake8-boolean-trapflake8-bugbearflake8-builtinsflake8-comprehensionsflake8-datetimezflake8-debuggerflake8-docstringsflake8-eradicateflake8-errmsgflake8-implicit-str-concatflake8-import-conventionsflake8-pie (#1543)flake8-printflake8-quotesflake8-returnflake8-simplify (#998)flake8-superflake8-tidy-importsisortmccabepep8-namingpydocstylepygrep-hooks (#980)pyupgrade (#827)yesqaNote 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-Γ -vis Flake8:
There are a few other minor incompatibilities between Ruff and the originating Flake8 plugins:
flake8-bugbear.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 #689.
Today, Ruff can be used to replace Flake8 when used with any of the following plugins:
flake8-2020flake8-annotationsflake8-bandit (#1646)flake8-blind-exceptflake8-boolean-trapflake8-bugbearflake8-builtinsflake8-comprehensionsflake8-datetimezflake8-debuggerflake8-docstringsflake8-eradicateflake8-errmsgflake8-implicit-str-concatflake8-import-conventionsflake8-pie (#1543)flake8-printflake8-quotesflake8-returnflake8-simplify (#998)flake8-superflake8-tidy-importsmccabepep8-namingpydocstyleRuff 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.
isort?Ruff's import sorting is intended to be nearly equivalent to isort when used profile = "black". (There are some minor differences in how Ruff and isort break ties between similar imports.)
Like isort, Ruff's import sorting is compatible with Black.
Ruff is less configurable than isort, but supports the known-first-party, known-third-party, extra-standard-library, and src settings, 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 error(s). 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 is written in Rust (1.65.0). You'll need to install the Rust toolchain for development.
Assuming you have cargo installed, you can run:
cargo run resources/test/fixtures
For development, we use nightly Rust:
cargo +nightly fmt cargo +nightly clippy --fix --workspace --all-targets --all-features -- -W clippy::pedantic cargo +nightly test --all
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
Add this pyproject.toml to the CPython directory:
[tool.ruff] line-length = 88 extend-exclude = [ "Lib/lib2to3/tests/data/bom.py", "Lib/lib2to3/tests/data/crlf.py", "Lib/lib2to3/tests/data/different_encoding.py", "Lib/lib2to3/tests/data/false_encoding.py", "Lib/lib2to3/tests/data/py2_test_grammar.py", "Lib/test/bad_coding2.py", "Lib/test/badsyntax_3131.py", "Lib/test/badsyntax_pep3120.py", "Lib/test/encoded_modules/module_iso_8859_1.py", "Lib/test/encoded_modules/module_koi8_r.py", "Lib/test/test_fstring.py", "Lib/test/test_grammar.py", "Lib/test/test_importlib/test_util.py", "Lib/test/test_named_expressions.py", "Lib/test/test_patma.py", "Lib/test/test_source_encoding.py", "Tools/c-analyzer/c_parser/parser/_delim.py", "Tools/i18n/pygettext.py", "Tools/test2to3/maintest.py", "Tools/test2to3/setup.py", "Tools/test2to3/test/test_foo.py", "Tools/test2to3/test2to3/hello.py", ]
Next, to benchmark the release build:
cargo build --release hyperfine --ignore-failure --warmup 10 --runs 100 \ "./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 Β± Ο): 297.4 ms Β± 4.9 ms [User: 2460.0 ms, System: 67.2 ms] Range (min β¦ max): 287.7 ms β¦ 312.1 ms 100 runs Warning: Ignoring non-zero exit code. Benchmark 2: ./target/release/ruff ./resources/test/cpython/ Time (mean Β± Ο): 79.6 ms Β± 7.3 ms [User: 59.7 ms, System: 356.1 ms] Range (min β¦ max): 62.4 ms β¦ 111.2 ms 100 runs Warning: Ignoring non-zero exit code.
To benchmark against the ecosystem's existing tools:
hyperfine --ignore-failure --warmup 5 \ "./target/release/ruff ./resources/test/cpython/ --no-cache" \ "pylint --recursive=y resources/test/cpython/" \ "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" \ "python -m scripts.run_flake8 resources/test/cpython"
In order, these evaluate:
(You can poetry install from ./scripts to create a working environment for the above.)
Benchmark 1: ./target/release/ruff ./resources/test/cpython/ --no-cache Time (mean Β± Ο): 297.9 ms Β± 7.0 ms [User: 2436.6 ms, System: 65.9 ms] Range (min β¦ max): 289.9 ms β¦ 314.6 ms 10 runs Warning: Ignoring non-zero exit code. Benchmark 2: pylint --recursive=y resources/test/cpython/ Time (mean Β± Ο): 37.634 s Β± 0.225 s [User: 36.728 s, System: 0.853 s] Range (min β¦ max): 37.201 s β¦ 38.106 s 10 runs Warning: Ignoring non-zero exit code. Benchmark 3: pyflakes resources/test/cpython Time (mean Β± Ο): 40.950 s Β± 0.449 s [User: 40.688 s, System: 0.229 s] Range (min β¦ max): 40.348 s β¦ 41.671 s 10 runs Warning: Ignoring non-zero exit code. Benchmark 4: autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython Time (mean Β± Ο): 11.562 s Β± 0.160 s [User: 107.022 s, System: 1.143 s] Range (min β¦ max): 11.417 s β¦ 11.917 s 10 runs Benchmark 5: pycodestyle resources/test/cpython Time (mean Β± Ο): 67.428 s Β± 0.985 s [User: 67.199 s, System: 0.203 s] Range (min β¦ max): 65.313 s β¦ 68.496 s 10 runs Warning: Ignoring non-zero exit code. Benchmark 6: flake8 resources/test/cpython Time (mean Β± Ο): 116.099 s Β± 1.178 s [User: 115.217 s, System: 0.845 s] Range (min β¦ max): 114.180 s β¦ 117.724 s 10 runs Warning: Ignoring non-zero exit code. Benchmark 7: python -m scripts.run_flake8 resources/test/cpython Time (mean Β± Ο): 20.477 s Β± 0.349 s [User: 142.372 s, System: 1.504 s] Range (min β¦ max): 20.107 s β¦ 21.183 s 10 runs Summary './target/release/ruff ./resources/test/cpython/ --no-cache' ran 38.81 Β± 1.05 times faster than 'autoflake --recursive --expand-star-imports --remove-all-unused-imports --remove-unused-variables --remove-duplicate-keys resources/test/cpython' 68.74 Β± 1.99 times faster than 'python -m scripts.run_flake8 resources/test/cpython' 126.33 Β± 3.05 times faster than 'pylint --recursive=y resources/test/cpython/' 137.46 Β± 3.55 times faster than 'pyflakes resources/test/cpython' 226.35 Β± 6.23 times faster than 'pycodestyle resources/test/cpython' 389.73 Β± 9.92 times faster than 'flake8 resources/test/cpython'
allowed-confusablesA 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 = ["β", "Ο", "β"]
builtinsA list of builtins to treat as defined references, in addition to the system builtins.
Default value: []
Type: Vec<String>
Example usage:
[tool.ruff] builtins = ["_"]
cache-dirA 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"
dummy-variable-rgxA 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]+?))$"
Type: Regex
Example usage:
[tool.ruff] # Only ignore variables named "_". dummy-variable-rgx = "^_$"
excludeA list of file patterns to exclude from linting.
Exclusions are based on globs, and can be either:
.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 ).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).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"]
extendA 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
extend-excludeA list of file patterns to omit from linting, in addition to those specified by exclude.
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"]
extend-ignoreA list of rule codes or prefixes to ignore, in addition to those specified by ignore.
Default value: []
Type: Vec<RuleCodePrefix>
Example usage:
[tool.ruff] # Skip unused variable rules (`F841`). extend-ignore = ["F841"]
extend-selectA list of rule codes or prefixes to enable, in addition to those specified by select.
Default value: []
Type: Vec<RuleCodePrefix>
Example usage:
[tool.ruff] # On top of the default `select` (`E`, `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`). extend-select = ["B", "Q"]
externalA 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"]
fixEnable 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
fix-onlyLike fix, but disables reporting on leftover violation. Implies fix.
Default value: false
Type: bool
Example usage:
[tool.ruff] fix-only = true
fixableA 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<RuleCodePrefix>
Example usage:
[tool.ruff] # Only allow autofix behavior for `E` and `F` rules. fixable = ["E", "F"]
force-excludeWhether 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
formatThe 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) or "gitlab" (GitLab CI code quality report).
Default value: "text"
Type: SerializationType
Example usage:
[tool.ruff] # Group violations by containing file. format = "grouped"
ignoreA 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<RuleCodePrefix>
Example usage:
[tool.ruff] # Skip unused variable rules (`F841`). ignore = ["F841"]
ignore-init-module-importsAvoid 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' +__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
line-lengthThe 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
per-file-ignoresA list of mappings from file pattern to rule codes or prefixes to exclude, when considering any matching files.
Default value: {}
Type: HashMap<String, Vec<RuleCodePrefix>>
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"]
required-versionRequire 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"
respect-gitignoreWhether 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
selectA 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<RuleCodePrefix>
Example usage:
[tool.ruff] # On top of the defaults (`E`, `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`). select = ["E", "F", "B", "Q"]
show-sourceWhether 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
srcThe 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"]
target-versionThe 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"
task-tagsA 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"]
typing-modulesA 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"]
unfixableA list of rule codes or prefixes to consider non-autofix-able.
Default value: []
Type: Vec<RuleCodePrefix>
Example usage:
[tool.ruff] # Disable autofix for unused imports (`F401`). unfixable = ["F401"]
update-checkEnable or disable automatic update checks (overridden by the --update-check and --no-update-check command-line flags).
Default value: true
Type: bool
Example usage:
[tool.ruff] update-check = false
flake8-annotationsallow-star-arg-anyWhether 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
mypy-init-returnWhether 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
suppress-dummy-argsWhether 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
suppress-none-returningWhether to suppress ANN200-level violations for functions that meet either of the following criteria:
return statement.return statement(s) all return None (explicitly or implicitly).Default value: false
Type: bool
Example usage:
[tool.ruff.flake8-annotations] suppress-none-returning = true
flake8-bandithardcoded-tmp-directoryA 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"]
hardcoded-tmp-directory-extendA 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"]
flake8-bugbearextend-immutable-callsAdditional 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"]
flake8-errmsgmax-string-lengthMaximum string length for string literals in exception messages.
Default value: 0
Type: usize
Example usage:
[tool.ruff.flake8-errmsg] max-string-length = 20
flake8-import-conventionsaliasesThe 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"
extend-aliasesA 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"
flake8-pytest-stylefixture-parenthesesBoolean 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
mark-parenthesesBoolean 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
parametrize-names-typeExpected type for multiple argument names in @pytest.mark.parametrize. The following values are supported:
csv β a comma-separated list, e.g. @pytest.mark.parametrize('name1,name2', ...)tuple (default) β e.g. @pytest.mark.parametrize(('name1', 'name2'), ...)list β e.g. @pytest.mark.parametrize(['name1', 'name2'], ...)Default value: tuple
Type: ParametrizeNameType
Example usage:
[tool.ruff.flake8-pytest-style] parametrize-names-type = "list"
parametrize-values-row-typeExpected type for each row of values in @pytest.mark.parametrize in case of multiple parameters. The following values are supported:
tuple (default) β e.g. @pytest.mark.parametrize(('name1', 'name2'), [(1, 2), (3, 4)])list β 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"
parametrize-values-typeExpected type for the list of values rows in @pytest.mark.parametrize. The following values are supported:
tuple β e.g. @pytest.mark.parametrize('name', (1, 2, 3))list (default) β 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"
raises-extend-require-match-forList 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"]
raises-require-match-forList 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"]
flake8-quotesavoid-escapeWhether 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
docstring-quotesQuote style to prefer for docstrings (either “single” (') or “double” (")).
Default value: "double"
Type: Quote
Example usage:
[tool.ruff.flake8-quotes] docstring-quotes = "single"
inline-quotesQuote style to prefer for inline strings (either “single” (') or “double” (")).
Default value: "double"
Type: Quote
Example usage:
[tool.ruff.flake8-quotes] inline-quotes = "single"
multiline-quotesQuote style to prefer for multiline strings (either “single” (') or “double” (")).
Default value: "double"
Type: Quote
Example usage:
[tool.ruff.flake8-quotes] multiline-quotes = "single"
flake8-tidy-importsban-relative-importsWhether 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"
banned-apiSpecific 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."
flake8-unused-argumentsignore-variadic-namesWhether 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
isortcombine-as-importsCombines 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
extra-standard-libraryA 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"]
force-single-lineForces all from imports to appear on their own line.
Default value: false
Type: bool
Example usage:
[tool.ruff.isort] force-single-line = true
force-sort-within-sectionsDon't sort straight-style imports (like import sys) before from-style imports (like from itertools import groupby). Instead, sort the imports by module, independent of import style.
Default value: false
Type: bool
Example usage:
[tool.ruff.isort] force-sort-within-sections = true
force-wrap-aliasesForce import from statements with multiple members and at least one alias (e.g., import A as B) to wrap such that every line contains exactly one member. For example, this formatting would be retained, rather than condensing to a single line:
from .utils import ( test_directory as test_directory, test_id as test_id )
Note that this setting is only effective when combined with combine-as-imports = true. When combine-as-imports isn't enabled, every aliased import from will be given its own line, in which case, wrapping is not necessary.
Default value: false
Type: bool
Example usage:
[tool.ruff.isort] force-wrap-aliases = true combine-as-imports = true
known-first-partyA list of modules to consider first-party, regardless of whether they can be identified as such via introspection of the local filesystem.
Default value: []
Type: Vec<String>
Example usage:
[tool.ruff.isort] known-first-party = ["src"]
known-third-partyA list of modules to consider third-party, regardless of whether they can be identified as such via introspection of the local filesystem.
Default value: []
Type: Vec<String>
Example usage:
[tool.ruff.isort] known-third-party = ["src"]
order-by-typeOrder imports by type, which is determined by case, in addition to alphabetically.
Default value: true
Type: bool
Example usage:
[tool.ruff.isort] order-by-type = true
single-line-exclusionsOne or more modules to exclude from the single line rule.
Default value: []
Type: Vec<String>
Example usage:
[tool.ruff.isort] single-line-exclusions = ["os", "json"]
split-on-trailing-commaIf a comma is placed after the last member in a multi-line import, then the imports will never be folded into one line.
See isort's split-on-trailing-comma option.
Default value: true
Type: bool
Example usage:
[tool.ruff.isort] split-on-trailing-comma = false
mccabemax-complexityThe maximum McCabe complexity to allow before triggering C901 errors.
Default value: 10
Type: usize
Example usage:
[tool.ruff.mccabe] # Flag errors (`C901`) whenever the complexity level exceeds 5. max-complexity = 5
pep8-namingclassmethod-decoratorsA list of decorators that, when applied to a method, indicate that the method should be treated as a class method. For example, Ruff will expect that any method decorated by a decorator in this list takes a cls argument as its first argument.
Default value: ["classmethod"]
Type: Vec<String>
Example usage:
[tool.ruff.pep8-naming] # Allow Pydantic's `@validator` decorator to trigger class method treatment. classmethod-decorators = ["classmethod", "pydantic.validator"]
ignore-namesA list of names to ignore when considering pep8-naming violations.
Default value: ["setUp", "tearDown", "setUpClass", "tearDownClass", "setUpModule", "tearDownModule", "asyncSetUp", "asyncTearDown", "setUpTestData", "failureException", "longMessage", "maxDiff"]
Type: Vec<String>
Example usage:
[tool.ruff.pep8-naming] ignore-names = ["callMethod"]
staticmethod-decoratorsA list of decorators that, when applied to a method, indicate that the method should be treated as a static method. For example, Ruff will expect that any method decorated by a decorator in this list has no self or cls argument.
Default value: ["staticmethod"]
Type: Vec<String>
Example usage:
[tool.ruff.pep8-naming] # Allow a shorthand alias, `@stcmthd`, to trigger static method treatment. staticmethod-decorators = ["staticmethod", "stcmthd"]
pycodestyleignore-overlong-task-commentsWhether or not line-length violations (E501) should be triggered for comments starting with task-tags (by default: [“TODO”, “FIXME”, and “XXX”]).
Default value: false
Type: bool
Example usage:
[tool.ruff.pycodestyle] ignore-overlong-task-comments = true
pydocstyleconventionWhether to use Google-style or NumPy-style conventions or the PEP257 defaults when analyzing docstring sections.
Default value: None
Type: Convention
Example usage:
[tool.ruff.pydocstyle] # Use Google-style docstrings. convention = "google"
pyupgradekeep-runtime-typingWhether to avoid PEP 585 (List[int] -> list[int]) and PEP 604 (Optional[str] -> str | None) rewrites even if a file imports from __future__ import annotations. Note that this setting is only applicable when the target Python version is below 3.9 and 3.10 respectively.
Default value: false
Type: bool
Example usage:
[tool.ruff.pyupgrade] # Preserve types, even if a file imports `from __future__ import annotations`. keep-runtime-typing = true
MIT
Contributions are welcome and hugely appreciated. To get started, check out the contributing guidelines.