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builtins

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

Default value: []

Type: list[str]

Example usage:

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

cache-dir

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: str

Example usage:

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

exclude

A list of file patterns to exclude from formatting and 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", ".git-rewrite", ".hg", ".mypy_cache", ".nox", ".pants.d", ".pytype", ".ruff_cache", ".svn", ".tox", ".venv", "__pypackages__", "_build", "buck-out", "dist", "node_modules", "venv"]

Type: list[str]

Example usage:

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

extend

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: null

Type: str

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

extend-exclude

A list of file patterns to omit from formatting and 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: list[str]

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

extend-include

A list of file patterns to include when linting, in addition to those specified by include.

Inclusion are based on globs, and should be single-path patterns, like *.pyw, to include any file with the .pyw extension.

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

Default value: []

Type: list[str]

Example usage:

[tool.ruff]
# In addition to the standard set of inclusions, include `.pyw` files.
extend-include = ["*.pyw"]
# In addition to the standard set of inclusions, include `.pyw` files.
extend-include = ["*.pyw"]

fix

Enable fix behavior by-default when running ruff (overridden by the --fix and --no-fix command-line flags). Only includes automatic fixes unless --unsafe-fixes is provided.

Default value: false

Type: bool

Example usage:

[tool.ruff]
fix = true
fix = true

fix-only

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

Default value: false

Type: bool

Example usage:

[tool.ruff]
fix-only = true
fix-only = true

force-exclude

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
force-exclude = true

include

A list of file patterns to include when linting.

Inclusion are based on globs, and should be single-path patterns, like *.pyw, to include any file with the .pyw extension. pyproject.toml is included here not for configuration but because we lint whether e.g. the [project] matches the schema.

Notebook files (.ipynb extension) are included by default on Ruff 0.6.0+.

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

Default value: ["*.py", "*.pyi", "*.ipynb", "**/pyproject.toml"]

Type: list[str]

Example usage:

[tool.ruff]
include = ["*.py"]
include = ["*.py"]

indent-width

The number of spaces per indentation level (tab).

Used by the formatter and when enforcing long-line violations (like E501) to determine the visual width of a tab.

This option changes the number of spaces the formatter inserts when using soft-tabs (indent-style = space).

PEP 8 recommends using 4 spaces per indentation level.

Default value: 4

Type: int

Example usage:

[tool.ruff]
indent-width = 2
indent-width = 2

line-length

The line length to use when enforcing long-lines violations (like E501) and at which isort and the formatter prefers to wrap lines.

The length is determined by the number of characters per line, except for lines containing East Asian characters or emojis. For these lines, the unicode width of each character is added up to determine the length.

The value must be greater than 0 and less than or equal to 320.

Note: While the formatter will attempt to format lines such that they remain within the line-length, it isn't a hard upper bound, and formatted lines may exceed the line-length.

See pycodestyle.max-line-length to configure different lengths for E501 and the formatter.

Default value: 88

Type: int

Example usage:

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

namespace-packages

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

Default value: []

Type: list[str]

Example usage:

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

output-format

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

Default value: "full"

Type: "full" | "concise" | "grouped" | "json" | "junit" | "github" | "gitlab" | "pylint" | "azure"

Example usage:

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

preview

Whether to enable preview mode. When preview mode is enabled, Ruff will use unstable rules, fixes, and formatting.

Default value: false

Type: bool

Example usage:

[tool.ruff]
# Enable preview features.
preview = true
# Enable preview features.
preview = true

required-version

Enforce a requirement on the version of Ruff, to enforce at runtime. If the version of Ruff does not meet the requirement, Ruff will exit with an error.

Useful for unifying results across many environments, e.g., with a pyproject.toml file.

Accepts a PEP 440 specifier, like ==0.3.1 or >=0.3.1.

Default value: null

Type: str

Example usage:

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

respect-gitignore

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
respect-gitignore = false

show-fixes

Whether to show an enumeration of all fixed lint violations (overridden by the --show-fixes command-line flag).

Default value: false

Type: bool

Example usage:

[tool.ruff]
# Enumerate all fixed violations.
show-fixes = true
# Enumerate all fixed violations.
show-fixes = true

src

The directories to consider when resolving first- vs. third-party imports.

When omitted, the src directory will typically default to including both:

  1. The directory containing the nearest pyproject.toml, ruff.toml, or .ruff.toml file (the "project root").
  2. The "src" subdirectory of the project root.

These defaults ensure that Ruff supports both flat layouts and src layouts out-of-the-box. (If a configuration file is explicitly provided (e.g., via the --config command-line flag), the current working directory will be considered the project root.)

As an example, consider an alternative project structure, like:

my_project
├── pyproject.toml
└── lib
    └── my_package
        ├── __init__.py
        ├── foo.py
        └── bar.py

In this case, the ./lib directory should be included in the src option (e.g., src = ["lib"]), such that when resolving imports, my_package.foo is considered first-party.

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 packages in that directory. User home directory and environment variables will also be expanded.

Default value: [".", "src"]

Type: list[str]

Example usage:

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

target-version

The minimum Python version to target, e.g., when considering automatic code upgrades, like rewriting type annotations. Ruff will not propose changes using features that are not available in the given version.

For example, to represent supporting Python >=3.10 or ==3.10 specify target-version = "py310".

If you're already using a pyproject.toml file, we recommend project.requires-python instead, as it's based on Python packaging standards, and will be respected by other tools. For example, Ruff treats the following as identical to target-version = "py38":

[project]
requires-python = ">=3.8"

If both are specified, target-version takes precedence over requires-python.

Note that a stub file can sometimes make use of a typing feature before it is available at runtime, as long as the stub does not make use of new syntax. For example, a type checker will understand int | str in a stub as being a Union type annotation, even if the type checker is run using Python 3.9, despite the fact that the | operator can only be used to create union types at runtime on Python 3.10+. As such, Ruff will often recommend newer features in a stub file than it would for an equivalent runtime file with the same target version.

Default value: "py39"

Type: "py37" | "py38" | "py39" | "py310" | "py311" | "py312" | "py313"

Example usage:

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

unsafe-fixes

Enable application of unsafe fixes. If excluded, a hint will be displayed when unsafe fixes are available. If set to false, the hint will be hidden.

Default value: null

Type: bool

Example usage:

[tool.ruff]
unsafe-fixes = true
unsafe-fixes = true

analyze

Configures Ruff's analyze command.

detect-string-imports

Whether to detect imports from string literals. When enabled, Ruff will search for string literals that "look like" import paths, and include them in the import map, if they resolve to valid Python modules.

Default value: false

Type: bool

Example usage:

[tool.ruff.analyze]
detect-string-imports = true
[analyze]
detect-string-imports = true

direction

Whether to generate a map from file to files that it depends on (dependencies) or files that depend on it (dependents).

Default value: "dependencies"

Type: "dependents" | "dependencies"

Example usage:

[tool.ruff.analyze]
direction = "dependencies"
[analyze]
direction = "dependencies"

exclude

A list of file patterns to exclude from analysis in addition to the files excluded globally (see exclude, and extend-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: list[str]

Example usage:

[tool.ruff.analyze]
exclude = ["generated"]
[analyze]
exclude = ["generated"]

include-dependencies

A map from file path to the list of file paths or globs that should be considered dependencies of that file, regardless of whether relevant imports are detected.

Default value: {}

Type: dict[str, list[str]]

Example usage:

[tool.ruff.analyze]
include-dependencies = {
    "foo/bar.py": ["foo/baz/*.py"],
}
[analyze]
include-dependencies = {
    "foo/bar.py": ["foo/baz/*.py"],
}

preview

Whether to enable preview mode. When preview mode is enabled, Ruff will expose unstable commands.

Default value: false

Type: bool

Example usage:

[tool.ruff.analyze]
# Enable preview features.
preview = true
[analyze]
# Enable preview features.
preview = true

format

Configures the way Ruff formats your code.

docstring-code-format

Whether to format code snippets in docstrings.

When this is enabled, Python code examples within docstrings are automatically reformatted.

For example, when this is enabled, the following code:

def f(x):
    """
    Something about `f`. And an example in doctest format:

    >>> f(  x  )

    Markdown is also supported:

    ```py
    f(  x  )
    ```

    As are reStructuredText literal blocks::

        f(  x  )


    And reStructuredText code blocks:

    .. code-block:: python

        f(  x  )
    """
    pass

... will be reformatted (assuming the rest of the options are set to their defaults) as:

def f(x):
    """
    Something about `f`. And an example in doctest format:

    >>> f(x)

    Markdown is also supported:

    ```py
    f(x)
    ```

    As are reStructuredText literal blocks::

        f(x)


    And reStructuredText code blocks:

    .. code-block:: python

        f(x)
    """
    pass

If a code snippet in a docstring contains invalid Python code or if the formatter would otherwise write invalid Python code, then the code example is ignored by the formatter and kept as-is.

Currently, doctest, Markdown, reStructuredText literal blocks, and reStructuredText code blocks are all supported and automatically recognized. In the case of unlabeled fenced code blocks in Markdown and reStructuredText literal blocks, the contents are assumed to be Python and reformatted. As with any other format, if the contents aren't valid Python, then the block is left untouched automatically.

Default value: false

Type: bool

Example usage:

[tool.ruff.format]
# Enable reformatting of code snippets in docstrings.
docstring-code-format = true
[format]
# Enable reformatting of code snippets in docstrings.
docstring-code-format = true

docstring-code-line-length

Set the line length used when formatting code snippets in docstrings.

This only has an effect when the docstring-code-format setting is enabled.

The default value for this setting is "dynamic", which has the effect of ensuring that any reformatted code examples in docstrings adhere to the global line length configuration that is used for the surrounding Python code. The point of this setting is that it takes the indentation of the docstring into account when reformatting code examples.

Alternatively, this can be set to a fixed integer, which will result in the same line length limit being applied to all reformatted code examples in docstrings. When set to a fixed integer, the indent of the docstring is not taken into account. That is, this may result in lines in the reformatted code example that exceed the globally configured line length limit.

For example, when this is set to 20 and docstring-code-format is enabled, then this code:

def f(x):
    '''
    Something about `f`. And an example:

    .. code-block:: python

        foo, bar, quux = this_is_a_long_line(lion, hippo, lemur, bear)
    '''
    pass

... will be reformatted (assuming the rest of the options are set to their defaults) as:

def f(x):
    """
    Something about `f`. And an example:

    .. code-block:: python

        (
            foo,
            bar,
            quux,
        ) = this_is_a_long_line(
            lion,
            hippo,
            lemur,
            bear,
        )
    """
    pass

Default value: "dynamic"

Type: int | "dynamic"

Example usage:

[tool.ruff.format]
# Format all docstring code snippets with a line length of 60.
docstring-code-line-length = 60
[format]
# Format all docstring code snippets with a line length of 60.
docstring-code-line-length = 60

exclude

A list of file patterns to exclude from formatting in addition to the files excluded globally (see exclude, and extend-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: list[str]

Example usage:

[tool.ruff.format]
exclude = ["generated"]
[format]
exclude = ["generated"]

indent-style

Whether to use spaces or tabs for indentation.

indent-style = "space" (default):

def f():
    print("Hello") #  Spaces indent the `print` statement.

indent-style = "tab":

def f():
    print("Hello") #  A tab `\t` indents the `print` statement.

PEP 8 recommends using spaces for indentation. We care about accessibility; if you do not need tabs for accessibility, we do not recommend you use them.

See indent-width to configure the number of spaces per indentation and the tab width.

Default value: "space"

Type: "space" | "tab"

Example usage:

[tool.ruff.format]
# Use tabs instead of 4 space indentation.
indent-style = "tab"
[format]
# Use tabs instead of 4 space indentation.
indent-style = "tab"

line-ending

The character Ruff uses at the end of a line.

  • auto: The newline style is detected automatically on a file per file basis. Files with mixed line endings will be converted to the first detected line ending. Defaults to \n for files that contain no line endings.
  • lf: Line endings will be converted to \n. The default line ending on Unix.
  • cr-lf: Line endings will be converted to \r\n. The default line ending on Windows.
  • native: Line endings will be converted to \n on Unix and \r\n on Windows.

Default value: "auto"

Type: "auto" | "lf" | "cr-lf" | "native"

Example usage:

[tool.ruff.format]
# Use `\n` line endings for all files
line-ending = "lf"
[format]
# Use `\n` line endings for all files
line-ending = "lf"

preview

Whether to enable the unstable preview style formatting.

Default value: false

Type: bool

Example usage:

[tool.ruff.format]
# Enable preview style formatting.
preview = true
[format]
# Enable preview style formatting.
preview = true

quote-style

Configures the preferred quote character for strings. The recommended options are

  • double (default): Use double quotes "
  • single: Use single quotes '

In compliance with PEP 8 and PEP 257, Ruff prefers double quotes for triple quoted strings and docstrings even when using quote-style = "single".

Ruff deviates from using the configured quotes if doing so prevents the need for escaping quote characters inside the string:

a = "a string without any quotes"
b = "It's monday morning"

Ruff will change the quotes of the string assigned to a to single quotes when using quote-style = "single". However, Ruff uses double quotes for the string assigned to b because using single quotes would require escaping the ', which leads to the less readable code: 'It\'s monday morning'.

In addition, Ruff supports the quote style preserve for projects that already use a mixture of single and double quotes and can't migrate to the double or single style. The quote style preserve leaves the quotes of all strings unchanged.

Default value: "double"

Type: "double" | "single" | "preserve"

Example usage:

[tool.ruff.format]
# Prefer single quotes over double quotes.
quote-style = "single"
[format]
# Prefer single quotes over double quotes.
quote-style = "single"

skip-magic-trailing-comma

Ruff uses existing trailing commas as an indication that short lines should be left separate. If this option is set to true, the magic trailing comma is ignored.

For example, Ruff leaves the arguments separate even though collapsing the arguments to a single line doesn't exceed the line length if skip-magic-trailing-comma = false:

# The arguments remain on separate lines because of the trailing comma after `b`
def test(
    a,
    b,
): pass

Setting skip-magic-trailing-comma = true changes the formatting to:

# The arguments remain on separate lines because of the trailing comma after `b`
def test(a, b):
    pass

Default value: false

Type: bool

Example usage:

[tool.ruff.format]
skip-magic-trailing-comma = true
[format]
skip-magic-trailing-comma = true

lint

Configures how Ruff checks your code.

Options specified in the lint section take precedence over the deprecated top-level settings.

allowed-confusables

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

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint]
# 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", "∗"]
[lint]
# 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", "∗"]

dummy-variable-rgx

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: str

Example usage:

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

exclude

A list of file patterns to exclude from linting in addition to the files excluded globally (see exclude, and extend-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: list[str]

Example usage:

[tool.ruff.lint]
exclude = ["generated"]
[lint]
exclude = ["generated"]

explicit-preview-rules

Whether to require exact codes to select preview rules. When enabled, preview rules will not be selected by prefixes — the full code of each preview rule will be required to enable the rule.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint]
# Require explicit selection of preview rules.
explicit-preview-rules = true
[lint]
# Require explicit selection of preview rules.
explicit-preview-rules = true

extend-fixable

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

Default value: []

Type: list[RuleSelector]

Example usage:

[tool.ruff.lint]
# Enable fix for flake8-bugbear (`B`), on top of any rules specified by `fixable`.
extend-fixable = ["B"]
[lint]
# Enable fix for flake8-bugbear (`B`), on top of any rules specified by `fixable`.
extend-fixable = ["B"]

extend-ignore

Deprecated

This option has been deprecated. The extend-ignore option is now interchangeable with ignore. Please update your configuration to use the ignore option instead.

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

Default value: []

Type: list[RuleSelector]

Example usage:

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

extend-per-file-ignores

A list of mappings from file pattern to rule codes or prefixes to exclude, in addition to any rules excluded by per-file-ignores.

Default value: {}

Type: dict[str, list[RuleSelector]]

Example usage:

[tool.ruff.lint.extend-per-file-ignores]
# Also ignore `E402` in all `__init__.py` files.
"__init__.py" = ["E402"]
[lint.extend-per-file-ignores]
# Also ignore `E402` in all `__init__.py` files.
"__init__.py" = ["E402"]

extend-safe-fixes

A list of rule codes or prefixes for which unsafe fixes should be considered safe.

Default value: []

Type: list[RuleSelector]

Example usage:

[tool.ruff.lint]
# Allow applying all unsafe fixes in the `E` rules and `F401` without the `--unsafe-fixes` flag
extend-safe-fixes = ["E", "F401"]
[lint]
# Allow applying all unsafe fixes in the `E` rules and `F401` without the `--unsafe-fixes` flag
extend-safe-fixes = ["E", "F401"]

extend-select

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

Default value: []

Type: list[RuleSelector]

Example usage:

[tool.ruff.lint]
# On top of the default `select` (`E4`, E7`, `E9`, and `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`).
extend-select = ["B", "Q"]
[lint]
# On top of the default `select` (`E4`, E7`, `E9`, and `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`).
extend-select = ["B", "Q"]

extend-unsafe-fixes

A list of rule codes or prefixes for which safe fixes should be considered unsafe.

Default value: []

Type: list[RuleSelector]

Example usage:

[tool.ruff.lint]
# Require the `--unsafe-fixes` flag when fixing the `E` rules and `F401`
extend-unsafe-fixes = ["E", "F401"]
[lint]
# Require the `--unsafe-fixes` flag when fixing the `E` rules and `F401`
extend-unsafe-fixes = ["E", "F401"]

external

A list of rule codes or prefixes 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: list[str]

Example usage:

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

fixable

A list of rule codes or prefixes to consider fixable. By default, all rules are considered fixable.

Default value: ["ALL"]

Type: list[RuleSelector]

Example usage:

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

ignore

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: list[RuleSelector]

Example usage:

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

ignore-init-module-imports

Deprecated

This option has been deprecated in 0.4.4. ignore-init-module-imports will be removed in a future version because F401 now recommends appropriate fixes for unused imports in __init__.py (currently in preview mode). See documentation for more information and please update your configuration.

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).

This option is enabled by default, but you can opt-in to removal of imports via an unsafe fix.

Default value: true

Type: bool

Example usage:

[tool.ruff.lint]
ignore-init-module-imports = false
[lint]
ignore-init-module-imports = false

logger-objects

A list of objects that should be treated equivalently to a logging.Logger object.

This is useful for ensuring proper diagnostics (e.g., to identify logging deprecations and other best-practices) for projects that re-export a logging.Logger object from a common module.

For example, if you have a module logging_setup.py with the following contents:

import logging

logger = logging.getLogger(__name__)

Adding "logging_setup.logger" to logger-objects will ensure that logging_setup.logger is treated as a logging.Logger object when imported from other modules (e.g., from logging_setup import logger).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint]
logger-objects = ["logging_setup.logger"]
[lint]
logger-objects = ["logging_setup.logger"]

per-file-ignores

A list of mappings from file pattern to rule codes or prefixes to exclude, when considering any matching files. An initial '!' negates the file pattern.

Default value: {}

Type: dict[str, list[RuleSelector]]

Example usage:

[tool.ruff.lint.per-file-ignores]
# Ignore `E402` (import violations) in all `__init__.py` files, and in `path/to/file.py`.
"__init__.py" = ["E402"]
"path/to/file.py" = ["E402"]
# Ignore `D` rules everywhere except for the `src/` directory.
"!src/**.py" = ["D"]
[lint.per-file-ignores]
# Ignore `E402` (import violations) in all `__init__.py` files, and in `path/to/file.py`.
"__init__.py" = ["E402"]
"path/to/file.py" = ["E402"]
# Ignore `D` rules everywhere except for the `src/` directory.
"!src/**.py" = ["D"]

preview

Whether to enable preview mode. When preview mode is enabled, Ruff will use unstable rules and fixes.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint]
# Enable preview features.
preview = true
[lint]
# Enable preview features.
preview = true

select

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: ["E4", "E7", "E9", "F"]

Type: list[RuleSelector]

Example usage:

[tool.ruff.lint]
# On top of the defaults (`E4`, E7`, `E9`, and `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`).
select = ["E4", "E7", "E9", "F", "B", "Q"]
[lint]
# On top of the defaults (`E4`, E7`, `E9`, and `F`), enable flake8-bugbear (`B`) and flake8-quotes (`Q`).
select = ["E4", "E7", "E9", "F", "B", "Q"]

task-tags

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: list[str]

Example usage:

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

typing-modules

A list of modules whose exports 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: list[str]

Example usage:

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

unfixable

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

Default value: []

Type: list[RuleSelector]

Example usage:

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

lint.flake8-annotations

allow-star-arg-any

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

Default value: false

Type: bool

Example usage:

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

ignore-fully-untyped

Whether to suppress ANN* rules for any declaration that hasn't been typed at all. This makes it easier to gradually add types to a codebase.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.flake8-annotations]
ignore-fully-untyped = true
[lint.flake8-annotations]
ignore-fully-untyped = true

mypy-init-return

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.lint.flake8-annotations]
mypy-init-return = true
[lint.flake8-annotations]
mypy-init-return = true

suppress-dummy-args

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

Default value: false

Type: bool

Example usage:

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

suppress-none-returning

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.lint.flake8-annotations]
suppress-none-returning = true
[lint.flake8-annotations]
suppress-none-returning = true

lint.flake8-bandit

check-typed-exception

Whether to disallow try-except-pass (S110) for specific exception types. By default, try-except-pass is only disallowed for Exception and BaseException.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.flake8-bandit]
check-typed-exception = true
[lint.flake8-bandit]
check-typed-exception = true

hardcoded-tmp-directory

A list of directories to consider temporary (see S108).

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

Type: list[str]

Example usage:

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

hardcoded-tmp-directory-extend

A list of directories to consider temporary, in addition to those specified by hardcoded-tmp-directory (see S108).

Default value: []

Type: list[str]

Example usage:

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

lint.flake8-boolean-trap

extend-allowed-calls

Additional callable functions with which to allow boolean traps.

Expects to receive a list of fully-qualified names (e.g., pydantic.Field, rather than Field).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-boolean-trap]
extend-allowed-calls = ["pydantic.Field", "django.db.models.Value"]
[lint.flake8-boolean-trap]
extend-allowed-calls = ["pydantic.Field", "django.db.models.Value"]

lint.flake8-bugbear

extend-immutable-calls

Additional callable functions to consider "immutable" when evaluating, e.g., the function-call-in-default-argument rule (B008) or function-call-in-dataclass-defaults rule (RUF009).

Expects to receive a list of fully-qualified names (e.g., fastapi.Query, rather than Query).

Default value: []

Type: list[str]

Example usage:

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

lint.flake8-builtins

builtins-allowed-modules

List of builtin module names to allow.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-builtins]
builtins-allowed-modules = ["id"]
[lint.flake8-builtins]
builtins-allowed-modules = ["id"]

builtins-ignorelist

Ignore list of builtins.

Default value: []

Type: list[str]

Example usage:

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

lint.flake8-comprehensions

allow-dict-calls-with-keyword-arguments

Allow dict calls that make use of keyword arguments (e.g., dict(a=1, b=2)).

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.flake8-comprehensions]
allow-dict-calls-with-keyword-arguments = true
[lint.flake8-comprehensions]
allow-dict-calls-with-keyword-arguments = true

Author to enforce within the copyright notice. If provided, the author must be present immediately following the copyright notice.

Default value: null

Type: str

Example usage:

[tool.ruff.lint.flake8-copyright]
author = "Ruff"
[lint.flake8-copyright]
author = "Ruff"

A minimum file size (in bytes) required for a copyright notice to be enforced. By default, all files are validated.

Default value: 0

Type: int

Example usage:

[tool.ruff.lint.flake8-copyright]
# Avoid enforcing a header on files smaller than 1024 bytes.
min-file-size = 1024
[lint.flake8-copyright]
# Avoid enforcing a header on files smaller than 1024 bytes.
min-file-size = 1024

The regular expression used to match the copyright notice, compiled with the regex crate. Defaults to (?i)Copyright\s+((?:\(C\)|©)\s+)?\d{4}((-|,\s)\d{4})*, which matches the following:

  • Copyright 2023
  • Copyright (C) 2023
  • Copyright 2021-2023
  • Copyright (C) 2021-2023
  • Copyright (C) 2021, 2023

Default value: "(?i)Copyright\s+((?:\(C\)|©)\s+)?\d{4}((-|,\s)\d{4})*"

Type: str

Example usage:

[tool.ruff.lint.flake8-copyright]
notice-rgx = "(?i)Copyright \\(C\\) \\d{4}"
[lint.flake8-copyright]
notice-rgx = "(?i)Copyright \\(C\\) \\d{4}"

lint.flake8-errmsg

max-string-length

Maximum string length for string literals in exception messages.

Default value: 0

Type: int

Example usage:

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

lint.flake8-gettext

extend-function-names

Additional function names to consider as internationalization calls, in addition to those included in function-names.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-gettext]
extend-function-names = ["ugettetxt"]
[lint.flake8-gettext]
extend-function-names = ["ugettetxt"]

function-names

The function names to consider as internationalization calls.

Default value: ["_", "gettext", "ngettext"]

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-gettext]
function-names = ["_", "gettext", "ngettext", "ugettetxt"]
[lint.flake8-gettext]
function-names = ["_", "gettext", "ngettext", "ugettetxt"]

lint.flake8-implicit-str-concat

allow-multiline

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).

Setting allow-multiline = false will automatically disable the explicit-string-concatenation (ISC003) rule. Otherwise, both implicit and explicit multiline string concatenations would be seen as violations, making it impossible to write a linter-compliant multiline string.

Default value: true

Type: bool

Example usage:

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

lint.flake8-import-conventions

aliases

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

Default value: {"altair": "alt", "matplotlib": "mpl", "matplotlib.pyplot": "plt", "numpy": "np", "pandas": "pd", "seaborn": "sns", "tensorflow": "tf", "tkinter": "tk", "holoviews": "hv", "panel": "pn", "plotly.express": "px", "polars": "pl", "pyarrow": "pa", "xml.etree.ElementTree": "ET"}

Type: dict[str, str]

Example usage:

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

banned-aliases

A mapping from module to its banned import aliases.

Default value: {}

Type: dict[str, list[str]]

Example usage:

[tool.ruff.lint.flake8-import-conventions.banned-aliases]
# Declare the banned aliases.
"tensorflow.keras.backend" = ["K"]
[lint.flake8-import-conventions.banned-aliases]
# Declare the banned aliases.
"tensorflow.keras.backend" = ["K"]

banned-from

A list of modules that should not be imported from using the from ... import ... syntax.

For example, given banned-from = ["pandas"], from pandas import DataFrame would be disallowed, while import pandas would be allowed.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-import-conventions]
# Declare the banned `from` imports.
banned-from = ["typing"]
[lint.flake8-import-conventions]
# Declare the banned `from` imports.
banned-from = ["typing"]

extend-aliases

A mapping from module to conventional import alias. These aliases will be added to the aliases mapping.

Default value: {}

Type: dict[str, str]

Example usage:

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

lint.flake8-pytest-style

fixture-parentheses

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

Default value: false

Type: bool

Example usage:

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

mark-parentheses

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

Default value: false

Type: bool

Example usage:

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

parametrize-names-type

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: "csv" | "tuple" | "list"

Example usage:

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

parametrize-values-row-type

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: "tuple" | "list"

Example usage:

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

parametrize-values-type

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: "tuple" | "list"

Example usage:

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

raises-extend-require-match-for

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.

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

Default value: []

Type: list[str]

Example usage:

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

raises-require-match-for

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

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

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

Type: list[str]

Example usage:

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

lint.flake8-quotes

avoid-escape

Whether to avoid using single quotes if a string contains single quotes, or vice-versa with double quotes, as per PEP 8. This minimizes the need to escape quotation marks within strings.

Default value: true

Type: bool

Example usage:

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

docstring-quotes

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

When using the formatter, only "double" is compatible, as the formatter enforces double quotes for docstrings strings.

Default value: "double"

Type: "single" | "double"

Example usage:

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

inline-quotes

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

When using the formatter, ensure that format.quote-style is set to the same preferred quote style.

Default value: "double"

Type: "single" | "double"

Example usage:

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

multiline-quotes

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

When using the formatter, only "double" is compatible, as the formatter enforces double quotes for multiline strings.

Default value: "double"

Type: "single" | "double"

Example usage:

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

lint.flake8-self

extend-ignore-names

Additional names to ignore when considering flake8-self violations, in addition to those included in ignore-names.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-self]
extend-ignore-names = ["_base_manager", "_default_manager",  "_meta"]
[lint.flake8-self]
extend-ignore-names = ["_base_manager", "_default_manager",  "_meta"]

ignore-names

A list of names to ignore when considering flake8-self violations.

Default value: ["_make", "_asdict", "_replace", "_fields", "_field_defaults", "_name_", "_value_"]

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-self]
ignore-names = ["_new"]
[lint.flake8-self]
ignore-names = ["_new"]

lint.flake8-tidy-imports

ban-relative-imports

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

Default value: "parents"

Type: "parents" | "all"

Example usage:

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

banned-api

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: dict[str, { "msg": str }]

Example usage:

[tool.ruff.lint.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."
[lint.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."

banned-module-level-imports

List of specific modules that may not be imported at module level, and should instead be imported lazily (e.g., within a function definition, or an if TYPE_CHECKING: block, or some other nested context).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-tidy-imports]
# Ban certain modules from being imported at module level, instead requiring
# that they're imported lazily (e.g., within a function definition).
banned-module-level-imports = ["torch", "tensorflow"]
[lint.flake8-tidy-imports]
# Ban certain modules from being imported at module level, instead requiring
# that they're imported lazily (e.g., within a function definition).
banned-module-level-imports = ["torch", "tensorflow"]

lint.flake8-type-checking

exempt-modules

Exempt certain modules from needing to be moved into type-checking blocks.

Default value: ["typing"]

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-type-checking]
exempt-modules = ["typing", "typing_extensions"]
[lint.flake8-type-checking]
exempt-modules = ["typing", "typing_extensions"]

quote-annotations

Whether to add quotes around type annotations, if doing so would allow the corresponding import to be moved into a type-checking block.

For example, in the following, Python requires that Sequence be available at runtime, despite the fact that it's only used in a type annotation:

from collections.abc import Sequence


def func(value: Sequence[int]) -> None:
    ...

In other words, moving from collections.abc import Sequence into an if TYPE_CHECKING: block above would cause a runtime error, as the type would no longer be available at runtime.

By default, Ruff will respect such runtime semantics and avoid moving the import to prevent such runtime errors.

Setting quote-annotations to true will instruct Ruff to add quotes around the annotation (e.g., "Sequence[int]"), which in turn enables Ruff to move the import into an if TYPE_CHECKING: block, like so:

from typing import TYPE_CHECKING

if TYPE_CHECKING:
    from collections.abc import Sequence


def func(value: "Sequence[int]") -> None:
    ...

Note that this setting has no effect when from __future__ import annotations is present, as __future__ annotations are always treated equivalently to quoted annotations.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.flake8-type-checking]
# Add quotes around type annotations, if doing so would allow
# an import to be moved into a type-checking block.
quote-annotations = true
[lint.flake8-type-checking]
# Add quotes around type annotations, if doing so would allow
# an import to be moved into a type-checking block.
quote-annotations = true

runtime-evaluated-base-classes

Exempt classes that list any of the enumerated classes as a base class from needing to be moved into type-checking blocks.

Common examples include Pydantic's pydantic.BaseModel and SQLAlchemy's sqlalchemy.orm.DeclarativeBase, but can also support user-defined classes that inherit from those base classes. For example, if you define a common DeclarativeBase subclass that's used throughout your project (e.g., class Base(DeclarativeBase) ... in base.py), you can add it to this list (runtime-evaluated-base-classes = ["base.Base"]) to exempt models from being moved into type-checking blocks.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-type-checking]
runtime-evaluated-base-classes = ["pydantic.BaseModel", "sqlalchemy.orm.DeclarativeBase"]
[lint.flake8-type-checking]
runtime-evaluated-base-classes = ["pydantic.BaseModel", "sqlalchemy.orm.DeclarativeBase"]

runtime-evaluated-decorators

Exempt classes and functions decorated with any of the enumerated decorators from being moved into type-checking blocks.

Common examples include Pydantic's @pydantic.validate_call decorator (for functions) and attrs' @attrs.define decorator (for classes).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.flake8-type-checking]
runtime-evaluated-decorators = ["pydantic.validate_call", "attrs.define"]
[lint.flake8-type-checking]
runtime-evaluated-decorators = ["pydantic.validate_call", "attrs.define"]

strict

Enforce TC001, TC002, and TC003 rules even when valid runtime imports are present for the same module.

See flake8-type-checking's strict option.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.flake8-type-checking]
strict = true
[lint.flake8-type-checking]
strict = true

lint.flake8-unused-arguments

ignore-variadic-names

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

Default value: false

Type: bool

Example usage:

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

lint.isort

case-sensitive

Sort imports taking into account case sensitivity.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.isort]
case-sensitive = true
[lint.isort]
case-sensitive = true

classes

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

Default value: []

Type: list[str]

Example usage:

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

combine-as-imports

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

Default value: false

Type: bool

Example usage:

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

constants

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

Default value: []

Type: list[str]

Example usage:

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

default-section

Define a default section for any imports that don't fit into the specified section-order.

Default value: "third-party"

Type: str

Example usage:

[tool.ruff.lint.isort]
default-section = "first-party"
[lint.isort]
default-section = "first-party"

detect-same-package

Whether to automatically mark imports from within the same package as first-party. For example, when detect-same-package = true, then when analyzing files within the foo package, any imports from within the foo package will be considered first-party.

This heuristic is often unnecessary when src is configured to detect all first-party sources; however, if src is not configured, this heuristic can be useful to detect first-party imports from within (but not across) first-party packages.

Default value: true

Type: bool

Example usage:

[tool.ruff.lint.isort]
detect-same-package = false
[lint.isort]
detect-same-package = false

extra-standard-library

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

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

Default value: []

Type: list[str]

Example usage:

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

force-single-line

Forces all from imports to appear on their own line.

Default value: false

Type: bool

Example usage:

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

force-sort-within-sections

Don'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.lint.isort]
force-sort-within-sections = true
[lint.isort]
force-sort-within-sections = true

force-to-top

Force specific imports to the top of their appropriate section.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
force-to-top = ["src"]
[lint.isort]
force-to-top = ["src"]

force-wrap-aliases

Force 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.

When using the formatter, ensure that format.skip-magic-trailing-comma is set to false (default) when enabling force-wrap-aliases to avoid that the formatter collapses members if they all fit on a single line.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.isort]
force-wrap-aliases = true
combine-as-imports = true
[lint.isort]
force-wrap-aliases = true
combine-as-imports = true

forced-separate

A list of modules to separate into auxiliary block(s) of imports, in the order specified.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
forced-separate = ["tests"]
[lint.isort]
forced-separate = ["tests"]

from-first

Whether to place import from imports before straight imports when sorting.

For example, by default, imports will be sorted such that straight imports appear before import from imports, as in:

import os
import sys
from typing import List

Setting from-first = true will instead sort such that import from imports appear before straight imports, as in:

from typing import List
import os
import sys

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.isort]
from-first = true
[lint.isort]
from-first = true

known-first-party

A list of modules to consider first-party, regardless of whether they can be identified as such via introspection of the local filesystem.

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

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
known-first-party = ["src"]
[lint.isort]
known-first-party = ["src"]

known-local-folder

A list of modules to consider being a local folder. Generally, this is reserved for relative imports (from . import module).

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

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
known-local-folder = ["src"]
[lint.isort]
known-local-folder = ["src"]

known-third-party

A list of modules to consider third-party, regardless of whether they can be identified as such via introspection of the local filesystem.

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

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
known-third-party = ["src"]
[lint.isort]
known-third-party = ["src"]

length-sort

Sort imports by their string length, such that shorter imports appear before longer imports. For example, by default, imports will be sorted alphabetically, as in:

import collections
import os

Setting length-sort = true will instead sort such that shorter imports appear before longer imports, as in:

import os
import collections

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.isort]
length-sort = true
[lint.isort]
length-sort = true

length-sort-straight

Sort straight imports by their string length. Similar to length-sort, but applies only to straight imports and doesn't affect from imports.

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.isort]
length-sort-straight = true
[lint.isort]
length-sort-straight = true

lines-after-imports

The number of blank lines to place after imports. Use -1 for automatic determination.

Ruff uses at most one blank line after imports in typing stub files (files with .pyi extension) in accordance to the typing style recommendations (source).

When using the formatter, only the values -1, 1, and 2 are compatible because it enforces at least one empty and at most two empty lines after imports.

Default value: -1

Type: int

Example usage:

[tool.ruff.lint.isort]
# Use a single line after each import block.
lines-after-imports = 1
[lint.isort]
# Use a single line after each import block.
lines-after-imports = 1

lines-between-types

The number of lines to place between "direct" and import from imports.

When using the formatter, only the values 0 and 1 are compatible because it preserves up to one empty line after imports in nested blocks.

Default value: 0

Type: int

Example usage:

[tool.ruff.lint.isort]
# Use a single line between direct and from import.
lines-between-types = 1
[lint.isort]
# Use a single line between direct and from import.
lines-between-types = 1

no-lines-before

A list of sections that should not be delineated from the previous section via empty lines.

Default value: []

Type: list["future" | "standard-library" | "third-party" | "first-party" | "local-folder" | str]

Example usage:

[tool.ruff.lint.isort]
no-lines-before = ["future", "standard-library"]
[lint.isort]
no-lines-before = ["future", "standard-library"]

no-sections

Put all imports into the same section bucket.

For example, rather than separating standard library and third-party imports, as in:

import os
import sys

import numpy
import pandas

Setting no-sections = true will instead group all imports into a single section:

import numpy
import os
import pandas
import sys

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.isort]
no-sections = true
[lint.isort]
no-sections = true

order-by-type

Order imports by type, which is determined by case, in addition to alphabetically.

Default value: true

Type: bool

Example usage:

[tool.ruff.lint.isort]
order-by-type = true
[lint.isort]
order-by-type = true

relative-imports-order

Whether to place "closer" imports (fewer . characters, most local) before "further" imports (more . characters, least local), or vice versa.

The default ("furthest-to-closest") is equivalent to isort's reverse-relative default (reverse-relative = false); setting this to "closest-to-furthest" is equivalent to isort's reverse-relative = true.

Default value: "furthest-to-closest"

Type: "furthest-to-closest" | "closest-to-furthest"

Example usage:

[tool.ruff.lint.isort]
relative-imports-order = "closest-to-furthest"
[lint.isort]
relative-imports-order = "closest-to-furthest"

required-imports

Add the specified import line to all files.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
required-imports = ["from __future__ import annotations"]
[lint.isort]
required-imports = ["from __future__ import annotations"]

section-order

Override in which order the sections should be output. Can be used to move custom sections.

Default value: ["future", "standard-library", "third-party", "first-party", "local-folder"]

Type: list["future" | "standard-library" | "third-party" | "first-party" | "local-folder" | str]

Example usage:

[tool.ruff.lint.isort]
section-order = ["future", "standard-library", "first-party", "local-folder", "third-party"]
[lint.isort]
section-order = ["future", "standard-library", "first-party", "local-folder", "third-party"]

sections

A list of mappings from section names to modules.

By default, imports are categorized according to their type (e.g., future, third-party, and so on). This setting allows you to group modules into custom sections, to augment or override the built-in sections.

For example, to group all testing utilities, you could create a testing section:

testing = ["pytest", "hypothesis"]

The values in the list are treated as glob patterns. For example, to match all packages in the LangChain ecosystem (langchain-core, langchain-openai, etc.):

langchain = ["langchain-*"]

Custom sections should typically be inserted into the section-order list to ensure that they're displayed as a standalone group and in the intended order, as in:

section-order = [
  "future",
  "standard-library",
  "third-party",
  "first-party",
  "local-folder",
  "testing"
]

If a custom section is omitted from section-order, imports in that section will be assigned to the default-section (which defaults to third-party).

Default value: {}

Type: dict[str, list[str]]

Example usage:

[tool.ruff.lint.isort.sections]
# Group all Django imports into a separate section.
"django" = ["django"]
[lint.isort.sections]
# Group all Django imports into a separate section.
"django" = ["django"]

single-line-exclusions

One or more modules to exclude from the single line rule.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
single-line-exclusions = ["os", "json"]
[lint.isort]
single-line-exclusions = ["os", "json"]

split-on-trailing-comma

If 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.

When using the formatter, ensure that format.skip-magic-trailing-comma is set to false (default) when enabling split-on-trailing-comma to avoid that the formatter removes the trailing commas.

Default value: true

Type: bool

Example usage:

[tool.ruff.lint.isort]
split-on-trailing-comma = false
[lint.isort]
split-on-trailing-comma = false

variables

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

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.isort]
variables = ["VAR"]
[lint.isort]
variables = ["VAR"]

lint.mccabe

max-complexity

The maximum McCabe complexity to allow before triggering C901 errors.

Default value: 10

Type: int

Example usage:

[tool.ruff.lint.mccabe]
# Flag errors (`C901`) whenever the complexity level exceeds 5.
max-complexity = 5
[lint.mccabe]
# Flag errors (`C901`) whenever the complexity level exceeds 5.
max-complexity = 5

lint.pep8-naming

classmethod-decorators

A list of decorators that, when applied to a method, indicate that the method should be treated as a class method (in addition to the builtin @classmethod).

For example, Ruff will expect that any method decorated by a decorator in this list takes a cls argument as its first argument.

Expects to receive a list of fully-qualified names (e.g., pydantic.validator, rather than validator) or alternatively a plain name which is then matched against the last segment in case the decorator itself consists of a dotted name.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pep8-naming]
classmethod-decorators = [
    # Allow Pydantic's `@validator` decorator to trigger class method treatment.
    "pydantic.validator",
    # Allow SQLAlchemy's dynamic decorators, like `@field.expression`, to trigger class method treatment.
    "declared_attr",
    "expression",
    "comparator",
]
[lint.pep8-naming]
classmethod-decorators = [
    # Allow Pydantic's `@validator` decorator to trigger class method treatment.
    "pydantic.validator",
    # Allow SQLAlchemy's dynamic decorators, like `@field.expression`, to trigger class method treatment.
    "declared_attr",
    "expression",
    "comparator",
]

extend-ignore-names

Additional names (or patterns) to ignore when considering pep8-naming violations, in addition to those included in ignore-names.

Supports glob patterns. For example, to ignore all names starting with test_ or ending with _test, you could use ignore-names = ["test_*", "*_test"]. For more information on the glob syntax, refer to the globset documentation.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pep8-naming]
extend-ignore-names = ["callMethod"]
[lint.pep8-naming]
extend-ignore-names = ["callMethod"]

ignore-names

A list of names (or patterns) to ignore when considering pep8-naming violations.

Supports glob patterns. For example, to ignore all names starting with test_ or ending with _test, you could use ignore-names = ["test_*", "*_test"]. For more information on the glob syntax, refer to the globset documentation.

Default value: ["setUp", "tearDown", "setUpClass", "tearDownClass", "setUpModule", "tearDownModule", "asyncSetUp", "asyncTearDown", "setUpTestData", "failureException", "longMessage", "maxDiff"]

Type: list[str]

Example usage:

[tool.ruff.lint.pep8-naming]
ignore-names = ["callMethod"]
[lint.pep8-naming]
ignore-names = ["callMethod"]

staticmethod-decorators

A list of decorators that, when applied to a method, indicate that the method should be treated as a static method (in addition to the builtin @staticmethod).

For example, Ruff will expect that any method decorated by a decorator in this list has no self or cls argument.

Expects to receive a list of fully-qualified names (e.g., belay.Device.teardown, rather than teardown) or alternatively a plain name which is then matched against the last segment in case the decorator itself consists of a dotted name.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pep8-naming]
# Allow Belay's `@Device.teardown` decorator to trigger static method treatment.
staticmethod-decorators = ["belay.Device.teardown"]
[lint.pep8-naming]
# Allow Belay's `@Device.teardown` decorator to trigger static method treatment.
staticmethod-decorators = ["belay.Device.teardown"]

lint.pycodestyle

ignore-overlong-task-comments

Whether 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.lint.pycodestyle]
ignore-overlong-task-comments = true
[lint.pycodestyle]
ignore-overlong-task-comments = true

max-doc-length

The maximum line length to allow for doc-line-too-long violations within documentation (W505), including standalone comments. By default, this is set to null which disables reporting violations.

The length is determined by the number of characters per line, except for lines containing Asian characters or emojis. For these lines, the unicode width of each character is added up to determine the length.

See the doc-line-too-long rule for more information.

Default value: null

Type: int

Example usage:

[tool.ruff.lint.pycodestyle]
max-doc-length = 88
[lint.pycodestyle]
max-doc-length = 88

max-line-length

The maximum line length to allow for line-too-long violations. By default, this is set to the value of the line-length option.

Use this option when you want to detect extra-long lines that the formatter can't automatically split by setting pycodestyle.line-length to a value larger than line-length.

# The formatter wraps lines at a length of 88.
line-length = 88

[pycodestyle]
# E501 reports lines that exceed the length of 100.
max-line-length = 100

The length is determined by the number of characters per line, except for lines containing East Asian characters or emojis. For these lines, the unicode width of each character is added up to determine the length.

See the line-too-long rule for more information.

Default value: null

Type: int

Example usage:

[tool.ruff.lint.pycodestyle]
max-line-length = 100
[lint.pycodestyle]
max-line-length = 100

lint.pydocstyle

convention

Whether to use Google-style, NumPy-style conventions, or the PEP 257 defaults when analyzing docstring sections.

Enabling a convention will disable all rules that are not included in the specified convention. As such, the intended workflow is to enable a convention and then selectively enable or disable any additional rules on top of it.

For example, to use Google-style conventions but avoid requiring documentation for every function parameter:

[tool.ruff.lint]
# Enable all `pydocstyle` rules, limiting to those that adhere to the
# Google convention via `convention = "google"`, below.
select = ["D"]

# On top of the Google convention, disable `D417`, which requires
# documentation for every function parameter.
ignore = ["D417"]

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

To enable an additional rule that's excluded from the convention, select the desired rule via its fully qualified rule code (e.g., D400 instead of D4 or D40):

[tool.ruff.lint]
# Enable D400 on top of the Google convention.
extend-select = ["D400"]

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

Default value: null

Type: "google" | "numpy" | "pep257"

Example usage:

[tool.ruff.lint.pydocstyle]
# Use Google-style docstrings.
convention = "google"
[lint.pydocstyle]
# Use Google-style docstrings.
convention = "google"

ignore-decorators

Ignore docstrings for functions or methods decorated with the specified fully-qualified decorators.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pydocstyle]
ignore-decorators = ["typing.overload"]
[lint.pydocstyle]
ignore-decorators = ["typing.overload"]

property-decorators

A list of decorators that, when applied to a method, indicate that the method should be treated as a property (in addition to the builtin @property and standard-library @functools.cached_property).

For example, Ruff will expect that any method decorated by a decorator in this list can use a non-imperative summary line.

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pydocstyle]
property-decorators = ["gi.repository.GObject.Property"]
[lint.pydocstyle]
property-decorators = ["gi.repository.GObject.Property"]

lint.pyflakes

allowed-unused-imports

A list of modules to ignore when considering unused imports.

Used to prevent violations for specific modules that are known to have side effects on import (e.g., hvplot.pandas).

Modules in this list are expected to be fully-qualified names (e.g., hvplot.pandas). Any submodule of a given module will also be ignored (e.g., given hvplot, hvplot.pandas will also be ignored).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pyflakes]
allowed-unused-imports = ["hvplot.pandas"]
[lint.pyflakes]
allowed-unused-imports = ["hvplot.pandas"]

extend-generics

Additional functions or classes to consider generic, such that any subscripts should be treated as type annotation (e.g., ForeignKey in django.db.models.ForeignKey["User"].

Expects to receive a list of fully-qualified names (e.g., django.db.models.ForeignKey, rather than ForeignKey).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pyflakes]
extend-generics = ["django.db.models.ForeignKey"]
[lint.pyflakes]
extend-generics = ["django.db.models.ForeignKey"]

lint.pylint

allow-dunder-method-names

Dunder methods name to allow, in addition to the default set from the Python standard library (see PLW3201).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.pylint]
allow-dunder-method-names = ["__tablename__", "__table_args__"]
[lint.pylint]
allow-dunder-method-names = ["__tablename__", "__table_args__"]

allow-magic-value-types

Constant types to ignore when used as "magic values" (see PLR2004).

Default value: ["str", "bytes"]

Type: list["str" | "bytes" | "complex" | "float" | "int"]

Example usage:

[tool.ruff.lint.pylint]
allow-magic-value-types = ["int"]
[lint.pylint]
allow-magic-value-types = ["int"]

max-args

Maximum number of arguments allowed for a function or method definition (see PLR0913).

Default value: 5

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-args = 10
[lint.pylint]
max-args = 10

max-bool-expr

Maximum number of Boolean expressions allowed within a single if statement (see PLR0916).

Default value: 5

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-bool-expr = 10
[lint.pylint]
max-bool-expr = 10

max-branches

Maximum number of branches allowed for a function or method body (see PLR0912).

Default value: 12

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-branches = 15
[lint.pylint]
max-branches = 15

max-locals

Maximum number of local variables allowed for a function or method body (see PLR0914).

Default value: 15

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-locals = 20
[lint.pylint]
max-locals = 20

max-nested-blocks

Maximum number of nested blocks allowed within a function or method body (see PLR1702).

Default value: 5

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-nested-blocks = 10
[lint.pylint]
max-nested-blocks = 10

max-positional-args

Maximum number of positional arguments allowed for a function or method definition (see PLR0917).

If not specified, defaults to the value of max-args.

Default value: 5

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-positional-args = 3
[lint.pylint]
max-positional-args = 3

max-public-methods

Maximum number of public methods allowed for a class (see PLR0904).

Default value: 20

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-public-methods = 30
[lint.pylint]
max-public-methods = 30

max-returns

Maximum number of return statements allowed for a function or method body (see PLR0911)

Default value: 6

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-returns = 10
[lint.pylint]
max-returns = 10

max-statements

Maximum number of statements allowed for a function or method body (see PLR0915).

Default value: 50

Type: int

Example usage:

[tool.ruff.lint.pylint]
max-statements = 75
[lint.pylint]
max-statements = 75

lint.pyupgrade

keep-runtime-typing

Whether to avoid PEP 585 (List[int] -> list[int]) and PEP 604 (Union[str, int] -> str | int) rewrites even if a file imports from __future__ import annotations.

This setting is only applicable when the target Python version is below 3.9 and 3.10 respectively, and is most commonly used when working with libraries like Pydantic and FastAPI, which rely on the ability to parse type annotations at runtime. The use of from __future__ import annotations causes Python to treat the type annotations as strings, which typically allows for the use of language features that appear in later Python versions but are not yet supported by the current version (e.g., str | int). However, libraries that rely on runtime type annotations will break if the annotations are incompatible with the current Python version.

For example, while the following is valid Python 3.8 code due to the presence of from __future__ import annotations, the use of str | int prior to Python 3.10 will cause Pydantic to raise a TypeError at runtime:

from __future__ import annotations

import pydantic

class Foo(pydantic.BaseModel):
    bar: str | int

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.pyupgrade]
# Preserve types, even if a file imports `from __future__ import annotations`.
keep-runtime-typing = true
[lint.pyupgrade]
# Preserve types, even if a file imports `from __future__ import annotations`.
keep-runtime-typing = true

lint.ruff

extend-markup-names

A list of additional callable names that behave like [markupsafe.Markup].

Expects to receive a list of fully-qualified names (e.g., webhelpers.html.literal, rather than literal).

Default value: []

Type: list[str]

Example usage:

[tool.ruff.lint.ruff]
extend-markup-names = ["webhelpers.html.literal", "my_package.Markup"]
[lint.ruff]
extend-markup-names = ["webhelpers.html.literal", "my_package.Markup"]

parenthesize-tuple-in-subscript

Whether to prefer accessing items keyed by tuples with parentheses around the tuple (see RUF031).

Default value: false

Type: bool

Example usage:

[tool.ruff.lint.ruff]
# Make it a violation to use a tuple in a subscript without parentheses.
parenthesize-tuple-in-subscript = true
[lint.ruff]
# Make it a violation to use a tuple in a subscript without parentheses.
parenthesize-tuple-in-subscript = true