Rules

Ruff supports over 700 lint rules, many of which are inspired by popular tools like Flake8, isort, pyupgrade, and others. Regardless of the rule's origin, Ruff re-implements every rule in Rust as a first-party feature.

By default, Ruff enables Flake8's E and F rules. Ruff supports all rules from the F category, and a subset of the E category, omitting those stylistic rules made obsolete by the use of an autoformatter, like Black.

If you're just getting started with Ruff, the default rule set is a great place to start: it catches a wide variety of common errors (like unused imports) with zero configuration.

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

The 🧪 emoji indicates that a rule in "preview".

Pyflakes (F)

For more, see Pyflakes on PyPI.

Code	Name	Message
F401	unused-import	{name} imported but unused; consider using importlib.util.find_spec to test for availability	🛠️ 🧪
F402	import-shadowed-by-loop-var	Import {name} from line {line} shadowed by loop variable	🛠️ 🧪
F403	undefined-local-with-import-star	from {name} import * used; unable to detect undefined names	🛠️ 🧪
F404	late-future-import	from __future__ imports must occur at the beginning of the file	🛠️ 🧪
F405	undefined-local-with-import-star-usage	{name} may be undefined, or defined from star imports	🛠️ 🧪
F406	undefined-local-with-nested-import-star-usage	from {name} import * only allowed at module level	🛠️ 🧪
F407	future-feature-not-defined	Future feature {name} is not defined	🛠️ 🧪
F501	percent-format-invalid-format	%-format string has invalid format string:	🛠️ 🧪
F502	percent-format-expected-mapping	%-format string expected mapping but got sequence	🛠️ 🧪
F503	percent-format-expected-sequence	%-format string expected sequence but got mapping	🛠️ 🧪
F504	percent-format-extra-named-arguments	%-format string has unused named argument(s):	🛠️ 🧪
F505	percent-format-missing-argument	%-format string is missing argument(s) for placeholder(s):	🛠️ 🧪
F506	percent-format-mixed-positional-and-named	%-format string has mixed positional and named placeholders	🛠️ 🧪
F507	percent-format-positional-count-mismatch	%-format string has {wanted} placeholder(s) but {got} substitution(s)	🛠️ 🧪
F508	percent-format-star-requires-sequence	%-format string * specifier requires sequence	🛠️ 🧪
F509	percent-format-unsupported-format-character	%-format string has unsupported format character {char}	🛠️ 🧪
F521	string-dot-format-invalid-format	.format call has invalid format string:	🛠️ 🧪
F522	string-dot-format-extra-named-arguments	.format call has unused named argument(s):	🛠️ 🧪
F523	string-dot-format-extra-positional-arguments	.format call has unused arguments at position(s):	🛠️ 🧪
F524	string-dot-format-missing-arguments	.format call is missing argument(s) for placeholder(s):	🛠️ 🧪
F525	string-dot-format-mixing-automatic	.format string mixes automatic and manual numbering	🛠️ 🧪
F541	f-string-missing-placeholders	f-string without any placeholders	🛠️ 🧪
F601	multi-value-repeated-key-literal	Dictionary key literal {name} repeated	🛠️ 🧪
F602	multi-value-repeated-key-variable	Dictionary key {name} repeated	🛠️ 🧪
F621	expressions-in-star-assignment	Too many expressions in star-unpacking assignment	🛠️ 🧪
F622	multiple-starred-expressions	Two starred expressions in assignment	🛠️ 🧪
F631	assert-tuple	Assert test is a non-empty tuple, which is always True	🛠️ 🧪
F632	is-literal	Use == to compare constant literals	🛠️ 🧪
F633	invalid-print-syntax	Use of >> is invalid with print function	🛠️ 🧪
F634	if-tuple	If test is a tuple, which is always True	🛠️ 🧪
F701	break-outside-loop	break outside loop	🛠️ 🧪
F702	continue-outside-loop	continue not properly in loop	🛠️ 🧪
F704	yield-outside-function	{keyword} statement outside of a function	🛠️ 🧪
F706	return-outside-function	return statement outside of a function/method	🛠️ 🧪
F707	default-except-not-last	An except block as not the last exception handler	🛠️ 🧪
F722	forward-annotation-syntax-error	Syntax error in forward annotation: {body}	🛠️ 🧪
F811	redefined-while-unused	Redefinition of unused {name} from line	🛠️ 🧪
F821	undefined-name	Undefined name {name}	🛠️ 🧪
F822	undefined-export	Undefined name {name} in __all__	🛠️ 🧪
F823	undefined-local	Local variable {name} referenced before assignment	🛠️ 🧪
F841	unused-variable	Local variable {name} is assigned to but never used	🛠️ 🧪
F842	unused-annotation	Local variable {name} is annotated but never used	🛠️ 🧪
F901	raise-not-implemented	raise NotImplemented should be raise NotImplementedError	🛠️ 🧪

pycodestyle (E, W)

For more, see pycodestyle on PyPI.

For related settings, see pycodestyle.

Warning (W)

Code	Name	Message
W191	tab-indentation	Indentation contains tabs	🛠️ 🧪
W291	trailing-whitespace	Trailing whitespace	🛠️ 🧪
W292	missing-newline-at-end-of-file	No newline at end of file	🛠️ 🧪
W293	blank-line-with-whitespace	Blank line contains whitespace	🛠️ 🧪
W505	doc-line-too-long	Doc line too long ({width} > {limit} characters)	🛠️ 🧪
W605	invalid-escape-sequence	Invalid escape sequence: \{char}	🛠️ 🧪

Error (E)

Code	Name	Message
E101	mixed-spaces-and-tabs	Indentation contains mixed spaces and tabs	🛠️ 🧪
E111	indentation-with-invalid-multiple	Indentation is not a multiple of	🛠️ 🧪
E112	no-indented-block	Expected an indented block	🛠️ 🧪
E113	unexpected-indentation	Unexpected indentation	🛠️ 🧪
E114	indentation-with-invalid-multiple-comment	Indentation is not a multiple of {indent_size} (comment)	🛠️ 🧪
E115	no-indented-block-comment	Expected an indented block (comment)	🛠️ 🧪
E116	unexpected-indentation-comment	Unexpected indentation (comment)	🛠️ 🧪
E117	over-indented	Over-indented (comment)	🛠️ 🧪
E201	whitespace-after-open-bracket	Whitespace after '{symbol}'	🛠️ 🧪
E202	whitespace-before-close-bracket	Whitespace before '{symbol}'	🛠️ 🧪
E203	whitespace-before-punctuation	Whitespace before '{symbol}'	🛠️ 🧪
E211	whitespace-before-parameters	Whitespace before '{bracket}'	🛠️ 🧪
E221	multiple-spaces-before-operator	Multiple spaces before operator	🛠️ 🧪
E222	multiple-spaces-after-operator	Multiple spaces after operator	🛠️ 🧪
E223	tab-before-operator	Tab before operator	🛠️ 🧪
E224	tab-after-operator	Tab after operator	🛠️ 🧪
E225	missing-whitespace-around-operator	Missing whitespace around operator	🛠️ 🧪
E226	missing-whitespace-around-arithmetic-operator	Missing whitespace around arithmetic operator	🛠️ 🧪
E227	missing-whitespace-around-bitwise-or-shift-operator	Missing whitespace around bitwise or shift operator	🛠️ 🧪
E228	missing-whitespace-around-modulo-operator	Missing whitespace around modulo operator	🛠️ 🧪
E231	missing-whitespace	Missing whitespace after '{token}'	🛠️ 🧪
E241	multiple-spaces-after-comma	Multiple spaces after comma	🛠️ 🧪
E242	tab-after-comma	Tab after comma	🛠️ 🧪
E251	unexpected-spaces-around-keyword-parameter-equals	Unexpected spaces around keyword / parameter equals	🛠️ 🧪
E252	missing-whitespace-around-parameter-equals	Missing whitespace around parameter equals	🛠️ 🧪
E261	too-few-spaces-before-inline-comment	Insert at least two spaces before an inline comment	🛠️ 🧪
E262	no-space-after-inline-comment	Inline comment should start with #	🛠️ 🧪
E265	no-space-after-block-comment	Block comment should start with #	🛠️ 🧪
E266	multiple-leading-hashes-for-block-comment	Too many leading # before block comment	🛠️ 🧪
E271	multiple-spaces-after-keyword	Multiple spaces after keyword	🛠️ 🧪
E272	multiple-spaces-before-keyword	Multiple spaces before keyword	🛠️ 🧪
E273	tab-after-keyword	Tab after keyword	🛠️ 🧪
E274	tab-before-keyword	Tab before keyword	🛠️ 🧪
E275	missing-whitespace-after-keyword	Missing whitespace after keyword	🛠️ 🧪
E401	multiple-imports-on-one-line	Multiple imports on one line	🛠️ 🧪
E402	module-import-not-at-top-of-file	Module level import not at top of file	🛠️ 🧪
E501	line-too-long	Line too long ({width} > {limit} characters)	🛠️ 🧪
E701	multiple-statements-on-one-line-colon	Multiple statements on one line (colon)	🛠️ 🧪
E702	multiple-statements-on-one-line-semicolon	Multiple statements on one line (semicolon)	🛠️ 🧪
E703	useless-semicolon	Statement ends with an unnecessary semicolon	🛠️ 🧪
E711	none-comparison	Comparison to None should be cond is None	🛠️ 🧪
E712	true-false-comparison	Comparison to True should be cond is True or if cond:	🛠️ 🧪
E713	not-in-test	Test for membership should be not in	🛠️ 🧪
E714	not-is-test	Test for object identity should be is not	🛠️ 🧪
E721	type-comparison	Do not compare types, use isinstance()	🛠️ 🧪
E722	bare-except	Do not use bare except	🛠️ 🧪
E731	lambda-assignment	Do not assign a lambda expression, use a def	🛠️ 🧪
E741	ambiguous-variable-name	Ambiguous variable name: {name}	🛠️ 🧪
E742	ambiguous-class-name	Ambiguous class name: {name}	🛠️ 🧪
E743	ambiguous-function-name	Ambiguous function name: {name}	🛠️ 🧪
E902	io-error	{message}	🛠️ 🧪
E999	syntax-error	SyntaxError:	🛠️ 🧪

mccabe (C90)

For more, see mccabe on PyPI.

For related settings, see mccabe.

Code	Name	Message
C901	complex-structure	{name} is too complex ({complexity} > {max_complexity})	🛠️ 🧪

isort (I)

For more, see isort on PyPI.

For related settings, see isort.

Code	Name	Message
I001	unsorted-imports	Import block is un-sorted or un-formatted	🛠️ 🧪
I002	missing-required-import	Missing required import: {name}	🛠️ 🧪

pep8-naming (N)

For more, see pep8-naming on PyPI.

For related settings, see pep8-naming.

Code	Name	Message
N801	invalid-class-name	Class name {name} should use CapWords convention	🛠️ 🧪
N802	invalid-function-name	Function name {name} should be lowercase	🛠️ 🧪
N803	invalid-argument-name	Argument name {name} should be lowercase	🛠️ 🧪
N804	invalid-first-argument-name-for-class-method	First argument of a class method should be named cls	🛠️ 🧪
N805	invalid-first-argument-name-for-method	First argument of a method should be named self	🛠️ 🧪
N806	non-lowercase-variable-in-function	Variable {name} in function should be lowercase	🛠️ 🧪
N807	dunder-function-name	Function name should not start and end with __	🛠️ 🧪
N811	constant-imported-as-non-constant	Constant {name} imported as non-constant {asname}	🛠️ 🧪
N812	lowercase-imported-as-non-lowercase	Lowercase {name} imported as non-lowercase {asname}	🛠️ 🧪
N813	camelcase-imported-as-lowercase	Camelcase {name} imported as lowercase {asname}	🛠️ 🧪
N814	camelcase-imported-as-constant	Camelcase {name} imported as constant {asname}	🛠️ 🧪
N815	mixed-case-variable-in-class-scope	Variable {name} in class scope should not be mixedCase	🛠️ 🧪
N816	mixed-case-variable-in-global-scope	Variable {name} in global scope should not be mixedCase	🛠️ 🧪
N817	camelcase-imported-as-acronym	CamelCase {name} imported as acronym {asname}	🛠️ 🧪
N818	error-suffix-on-exception-name	Exception name {name} should be named with an Error suffix	🛠️ 🧪
N999	invalid-module-name	Invalid module name: '{name}'	🛠️ 🧪

pydocstyle (D)

For more, see pydocstyle on PyPI.

For related settings, see pydocstyle.

Code	Name	Message
D100	undocumented-public-module	Missing docstring in public module	🛠️ 🧪
D101	undocumented-public-class	Missing docstring in public class	🛠️ 🧪
D102	undocumented-public-method	Missing docstring in public method	🛠️ 🧪
D103	undocumented-public-function	Missing docstring in public function	🛠️ 🧪
D104	undocumented-public-package	Missing docstring in public package	🛠️ 🧪
D105	undocumented-magic-method	Missing docstring in magic method	🛠️ 🧪
D106	undocumented-public-nested-class	Missing docstring in public nested class	🛠️ 🧪
D107	undocumented-public-init	Missing docstring in __init__	🛠️ 🧪
D200	fits-on-one-line	One-line docstring should fit on one line	🛠️ 🧪
D201	no-blank-line-before-function	No blank lines allowed before function docstring (found {num_lines})	🛠️ 🧪
D202	no-blank-line-after-function	No blank lines allowed after function docstring (found {num_lines})	🛠️ 🧪
D203	one-blank-line-before-class	1 blank line required before class docstring	🛠️ 🧪
D204	one-blank-line-after-class	1 blank line required after class docstring	🛠️ 🧪
D205	blank-line-after-summary	1 blank line required between summary line and description	🛠️ 🧪
D206	indent-with-spaces	Docstring should be indented with spaces, not tabs	🛠️ 🧪
D207	under-indentation	Docstring is under-indented	🛠️ 🧪
D208	over-indentation	Docstring is over-indented	🛠️ 🧪
D209	new-line-after-last-paragraph	Multi-line docstring closing quotes should be on a separate line	🛠️ 🧪
D210	surrounding-whitespace	No whitespaces allowed surrounding docstring text	🛠️ 🧪
D211	blank-line-before-class	No blank lines allowed before class docstring	🛠️ 🧪
D212	multi-line-summary-first-line	Multi-line docstring summary should start at the first line	🛠️ 🧪
D213	multi-line-summary-second-line	Multi-line docstring summary should start at the second line	🛠️ 🧪
D214	section-not-over-indented	Section is over-indented ("{name}")	🛠️ 🧪
D215	section-underline-not-over-indented	Section underline is over-indented ("{name}")	🛠️ 🧪
D300	triple-single-quotes	Use triple double quotes """	🛠️ 🧪
D301	escape-sequence-in-docstring	Use r""" if any backslashes in a docstring	🛠️ 🧪
D400	ends-in-period	First line should end with a period	🛠️ 🧪
D401	non-imperative-mood	First line of docstring should be in imperative mood: "{first_line}"	🛠️ 🧪
D402	no-signature	First line should not be the function's signature	🛠️ 🧪
D403	first-line-capitalized	First word of the first line should be capitalized: {} -> {}	🛠️ 🧪
D404	docstring-starts-with-this	First word of the docstring should not be "This"	🛠️ 🧪
D405	capitalize-section-name	Section name should be properly capitalized ("{name}")	🛠️ 🧪
D406	new-line-after-section-name	Section name should end with a newline ("{name}")	🛠️ 🧪
D407	dashed-underline-after-section	Missing dashed underline after section ("{name}")	🛠️ 🧪
D408	section-underline-after-name	Section underline should be in the line following the section's name ("{name}")	🛠️ 🧪
D409	section-underline-matches-section-length	Section underline should match the length of its name ("{name}")	🛠️ 🧪
D410	no-blank-line-after-section	Missing blank line after section ("{name}")	🛠️ 🧪
D411	no-blank-line-before-section	Missing blank line before section ("{name}")	🛠️ 🧪
D412	blank-lines-between-header-and-content	No blank lines allowed between a section header and its content ("{name}")	🛠️ 🧪
D413	blank-line-after-last-section	Missing blank line after last section ("{name}")	🛠️ 🧪
D414	empty-docstring-section	Section has no content ("{name}")	🛠️ 🧪
D415	ends-in-punctuation	First line should end with a period, question mark, or exclamation point	🛠️ 🧪
D416	section-name-ends-in-colon	Section name should end with a colon ("{name}")	🛠️ 🧪
D417	undocumented-param	Missing argument description in the docstring for {definition}: {name}	🛠️ 🧪
D418	overload-with-docstring	Function decorated with @overload shouldn't contain a docstring	🛠️ 🧪
D419	empty-docstring	Docstring is empty	🛠️ 🧪

pyupgrade (UP)

For more, see pyupgrade on PyPI.

For related settings, see pyupgrade.

Code	Name	Message
UP001	useless-metaclass-type	__metaclass__ = type is implied	🛠️ 🧪
UP003	type-of-primitive	Use {} instead of type(...)	🛠️ 🧪
UP004	useless-object-inheritance	Class {name} inherits from object	🛠️ 🧪
UP005	deprecated-unittest-alias	{alias} is deprecated, use {target}	🛠️ 🧪
UP006	non-pep585-annotation	Use {to} instead of {from} for type annotation	🛠️ 🧪
UP007	non-pep604-annotation	Use X | Y for type annotations	🛠️ 🧪
UP008	super-call-with-parameters	Use super() instead of super(__class__, self)	🛠️ 🧪
UP009	utf8-encoding-declaration	UTF-8 encoding declaration is unnecessary	🛠️ 🧪
UP010	unnecessary-future-import	Unnecessary __future__ import {import} for target Python version	🛠️ 🧪
UP011	lru-cache-without-parameters	Unnecessary parentheses to functools.lru_cache	🛠️ 🧪
UP012	unnecessary-encode-utf8	Unnecessary call to encode as UTF-8	🛠️ 🧪
UP013	convert-typed-dict-functional-to-class	Convert {name} from TypedDict functional to class syntax	🛠️ 🧪
UP014	convert-named-tuple-functional-to-class	Convert {name} from NamedTuple functional to class syntax	🛠️ 🧪
UP015	redundant-open-modes	Unnecessary open mode parameters	🛠️ 🧪
UP017	datetime-timezone-utc	Use datetime.UTC alias	🛠️ 🧪
UP018	native-literals	Unnecessary {literal_type} call (rewrite as a literal)	🛠️ 🧪
UP019	typing-text-str-alias	typing.Text is deprecated, use str	🛠️ 🧪
UP020	open-alias	Use builtin open	🛠️ 🧪
UP021	replace-universal-newlines	universal_newlines is deprecated, use text	🛠️ 🧪
UP022	replace-stdout-stderr	Sending stdout and stderr to PIPE is deprecated, use capture_output	🛠️ 🧪
UP023	deprecated-c-element-tree	cElementTree is deprecated, use ElementTree	🛠️ 🧪
UP024	os-error-alias	Replace aliased errors with OSError	🛠️ 🧪
UP025	unicode-kind-prefix	Remove unicode literals from strings	🛠️ 🧪
UP026	deprecated-mock-import	mock is deprecated, use unittest.mock	🛠️ 🧪
UP027	unpacked-list-comprehension	Replace unpacked list comprehension with a generator expression	🛠️ 🧪
UP028	yield-in-for-loop	Replace yield over for loop with yield from	🛠️ 🧪
UP029	unnecessary-builtin-import	Unnecessary builtin import: {import}	🛠️ 🧪
UP030	format-literals	Use implicit references for positional format fields	🛠️ 🧪
UP031	printf-string-formatting	Use format specifiers instead of percent format	🛠️ 🧪
UP032	f-string	Use f-string instead of format call	🛠️ 🧪
UP033	lru-cache-with-maxsize-none	Use @functools.cache instead of @functools.lru_cache(maxsize=None)	🛠️ 🧪
UP034	extraneous-parentheses	Avoid extraneous parentheses	🛠️ 🧪
UP035	deprecated-import	Import from {target} instead:	🛠️ 🧪
UP036	outdated-version-block	Version block is outdated for minimum Python version	🛠️ 🧪
UP037	quoted-annotation	Remove quotes from type annotation	🛠️ 🧪
UP038	non-pep604-isinstance	Use X | Y in {} call instead of (X, Y)	🛠️ 🧪
UP039	unnecessary-class-parentheses	Unnecessary parentheses after class definition	🛠️ 🧪
UP040	non-pep695-type-alias	Type alias {name} uses TypeAlias annotation instead of the type keyword	🛠️ 🧪

flake8-2020 (YTT)

For more, see flake8-2020 on PyPI.

Code	Name	Message
YTT101	sys-version-slice3	sys.version[:3] referenced (python3.10), use sys.version_info	🛠️ 🧪
YTT102	sys-version2	sys.version[2] referenced (python3.10), use sys.version_info	🛠️ 🧪
YTT103	sys-version-cmp-str3	sys.version compared to string (python3.10), use sys.version_info	🛠️ 🧪
YTT201	sys-version-info0-eq3	sys.version_info[0] == 3 referenced (python4), use >=	🛠️ 🧪
YTT202	six-py3	six.PY3 referenced (python4), use not six.PY2	🛠️ 🧪
YTT203	sys-version-info1-cmp-int	sys.version_info[1] compared to integer (python4), compare sys.version_info to tuple	🛠️ 🧪
YTT204	sys-version-info-minor-cmp-int	sys.version_info.minor compared to integer (python4), compare sys.version_info to tuple	🛠️ 🧪
YTT301	sys-version0	sys.version[0] referenced (python10), use sys.version_info	🛠️ 🧪
YTT302	sys-version-cmp-str10	sys.version compared to string (python10), use sys.version_info	🛠️ 🧪
YTT303	sys-version-slice1	sys.version[:1] referenced (python10), use sys.version_info	🛠️ 🧪

flake8-annotations (ANN)

For more, see flake8-annotations on PyPI.

For related settings, see flake8-annotations.

Code	Name	Message
ANN001	missing-type-function-argument	Missing type annotation for function argument {name}	🛠️ 🧪
ANN002	missing-type-args	Missing type annotation for *{name}	🛠️ 🧪
ANN003	missing-type-kwargs	Missing type annotation for **{name}	🛠️ 🧪
ANN101	missing-type-self	Missing type annotation for {name} in method	🛠️ 🧪
ANN102	missing-type-cls	Missing type annotation for {name} in classmethod	🛠️ 🧪
ANN201	missing-return-type-undocumented-public-function	Missing return type annotation for public function {name}	🛠️ 🧪
ANN202	missing-return-type-private-function	Missing return type annotation for private function {name}	🛠️ 🧪
ANN204	missing-return-type-special-method	Missing return type annotation for special method {name}	🛠️ 🧪
ANN205	missing-return-type-static-method	Missing return type annotation for staticmethod {name}	🛠️ 🧪
ANN206	missing-return-type-class-method	Missing return type annotation for classmethod {name}	🛠️ 🧪
ANN401	any-type	Dynamically typed expressions (typing.Any) are disallowed in {name}	🛠️ 🧪

flake8-async (ASYNC)

For more, see flake8-async on PyPI.

Code	Name	Message
ASYNC100	blocking-http-call-in-async-function	Async functions should not call blocking HTTP methods	🛠️ 🧪
ASYNC101	open-sleep-or-subprocess-in-async-function	Async functions should not call open, time.sleep, or subprocess methods	🛠️ 🧪
ASYNC102	blocking-os-call-in-async-function	Async functions should not call synchronous os methods	🛠️ 🧪

flake8-bandit (S)

For more, see flake8-bandit on PyPI.

For related settings, see flake8-bandit.

Code	Name	Message
S101	assert	Use of assert detected	🛠️ 🧪
S102	exec-builtin	Use of exec detected	🛠️ 🧪
S103	bad-file-permissions	os.chmod setting a permissive mask {mask:#o} on file or directory	🛠️ 🧪
S104	hardcoded-bind-all-interfaces	Possible binding to all interfaces	🛠️ 🧪
S105	hardcoded-password-string	Possible hardcoded password assigned to: "{}"	🛠️ 🧪
S106	hardcoded-password-func-arg	Possible hardcoded password assigned to argument: "{}"	🛠️ 🧪
S107	hardcoded-password-default	Possible hardcoded password assigned to function default: "{}"	🛠️ 🧪
S108	hardcoded-temp-file	Probable insecure usage of temporary file or directory: "{}"	🛠️ 🧪
S110	try-except-pass	try-except-pass detected, consider logging the exception	🛠️ 🧪
S112	try-except-continue	try-except-continue detected, consider logging the exception	🛠️ 🧪
S113	request-without-timeout	Probable use of requests call without timeout	🛠️ 🧪
S201	flask-debug-true	Use of debug=True in Flask app detected	🛠️ 🧪
S301	suspicious-pickle-usage	pickle and modules that wrap it can be unsafe when used to deserialize untrusted data, possible security issue	🛠️ 🧪
S302	suspicious-marshal-usage	Deserialization with the marshal module is possibly dangerous	🛠️ 🧪
S303	suspicious-insecure-hash-usage	Use of insecure MD2, MD4, MD5, or SHA1 hash function	🛠️ 🧪
S304	suspicious-insecure-cipher-usage	Use of insecure cipher, replace with a known secure cipher such as AES	🛠️ 🧪
S305	suspicious-insecure-cipher-mode-usage	Use of insecure cipher mode, replace with a known secure cipher such as AES	🛠️ 🧪
S306	suspicious-mktemp-usage	Use of insecure and deprecated function (mktemp)	🛠️ 🧪
S307	suspicious-eval-usage	Use of possibly insecure function; consider using ast.literal_eval	🛠️ 🧪
S308	suspicious-mark-safe-usage	Use of mark_safe may expose cross-site scripting vulnerabilities	🛠️ 🧪
S310	suspicious-url-open-usage	Audit URL open for permitted schemes. Allowing use of file: or custom schemes is often unexpected.	🛠️ 🧪
S311	suspicious-non-cryptographic-random-usage	Standard pseudo-random generators are not suitable for cryptographic purposes	🛠️ 🧪
S312	suspicious-telnet-usage	Telnet-related functions are being called. Telnet is considered insecure. Use SSH or some other encrypted protocol.	🛠️ 🧪
S313	suspicious-xmlc-element-tree-usage	Using xml to parse untrusted data is known to be vulnerable to XML attacks; use defusedxml equivalents	🛠️ 🧪
S314	suspicious-xml-element-tree-usage	Using xml to parse untrusted data is known to be vulnerable to XML attacks; use defusedxml equivalents	🛠️ 🧪
S315	suspicious-xml-expat-reader-usage	Using xml to parse untrusted data is known to be vulnerable to XML attacks; use defusedxml equivalents	🛠️ 🧪
S316	suspicious-xml-expat-builder-usage	Using xml to parse untrusted data is known to be vulnerable to XML attacks; use defusedxml equivalents	🛠️ 🧪
S317	suspicious-xml-sax-usage	Using xml to parse untrusted data is known to be vulnerable to XML attacks; use defusedxml equivalents	🛠️ 🧪
S318	suspicious-xml-mini-dom-usage	Using xml to parse untrusted data is known to be vulnerable to XML attacks; use defusedxml equivalents	🛠️ 🧪
S319	suspicious-xml-pull-dom-usage	Using xml to parse untrusted data is known to be vulnerable to XML attacks; use defusedxml equivalents	🛠️ 🧪
S320	suspicious-xmle-tree-usage	Using lxml to parse untrusted data is known to be vulnerable to XML attacks	🛠️ 🧪
S321	suspicious-ftp-lib-usage	FTP-related functions are being called. FTP is considered insecure. Use SSH/SFTP/SCP or some other encrypted protocol.	🛠️ 🧪
S323	suspicious-unverified-context-usage	Python allows using an insecure context via the _create_unverified_context that reverts to the previous behavior that does not validate certificates or perform hostname checks.	🛠️ 🧪
S324	hashlib-insecure-hash-function	Probable use of insecure hash functions in hashlib: {string}	🛠️ 🧪
S501	request-with-no-cert-validation	Probable use of {string} call with verify=False disabling SSL certificate checks	🛠️ 🧪
S506	unsafe-yaml-load	Probable use of unsafe loader {name} with yaml.load. Allows instantiation of arbitrary objects. Consider yaml.safe_load.	🛠️ 🧪
S507	ssh-no-host-key-verification	Paramiko call with policy set to automatically trust the unknown host key	🛠️ 🧪
S508	snmp-insecure-version	The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.	🛠️ 🧪
S509	snmp-weak-cryptography	You should not use SNMPv3 without encryption. noAuthNoPriv & authNoPriv is insecure.	🛠️ 🧪
S601	paramiko-call	Possible shell injection via Paramiko call; check inputs are properly sanitized	🛠️ 🧪
S602	subprocess-popen-with-shell-equals-true	subprocess call with shell=True seems safe, but may be changed in the future; consider rewriting without shell	🛠️ 🧪
S603	subprocess-without-shell-equals-true	subprocess call: check for execution of untrusted input	🛠️ 🧪
S604	call-with-shell-equals-true	Function call with shell=True parameter identified, security issue	🛠️ 🧪
S605	start-process-with-a-shell	Starting a process with a shell: seems safe, but may be changed in the future; consider rewriting without shell	🛠️ 🧪
S606	start-process-with-no-shell	Starting a process without a shell	🛠️ 🧪
S607	start-process-with-partial-path	Starting a process with a partial executable path	🛠️ 🧪
S608	hardcoded-sql-expression	Possible SQL injection vector through string-based query construction	🛠️ 🧪
S609	unix-command-wildcard-injection	Possible wildcard injection in call due to * usage	🛠️ 🧪
S612	logging-config-insecure-listen	Use of insecure logging.config.listen detected	🛠️ 🧪
S701	jinja2-autoescape-false	Using jinja2 templates with autoescape=False is dangerous and can lead to XSS. Ensure autoescape=True or use the select_autoescape function.	🛠️ 🧪

flake8-blind-except (BLE)

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

Code	Name	Message
BLE001	blind-except	Do not catch blind exception: {name}	🛠️ 🧪

flake8-boolean-trap (FBT)

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

Code	Name	Message
FBT001	boolean-type-hint-positional-argument	Boolean-typed positional argument in function definition	🛠️ 🧪
FBT002	boolean-default-value-positional-argument	Boolean default positional argument in function definition	🛠️ 🧪
FBT003	boolean-positional-value-in-call	Boolean positional value in function call	🛠️ 🧪

flake8-bugbear (B)

For more, see flake8-bugbear on PyPI.

For related settings, see flake8-bugbear.

Code	Name	Message
B002	unary-prefix-increment-decrement	Python does not support the unary prefix increment operator (++)	🛠️ 🧪
B003	assignment-to-os-environ	Assigning to os.environ doesn't clear the environment	🛠️ 🧪
B004	unreliable-callable-check	Using hasattr(x, "__call__") to test if x is callable is unreliable. Use callable(x) for consistent results.	🛠️ 🧪
B005	strip-with-multi-characters	Using .strip() with multi-character strings is misleading	🛠️ 🧪
B006	mutable-argument-default	Do not use mutable data structures for argument defaults	🛠️ 🧪
B007	unused-loop-control-variable	Loop control variable {name} not used within loop body	🛠️ 🧪
B008	function-call-in-default-argument	Do not perform function call {name} in argument defaults	🛠️ 🧪
B009	get-attr-with-constant	Do not call getattr with a constant attribute value. It is not any safer than normal property access.	🛠️ 🧪
B010	set-attr-with-constant	Do not call setattr with a constant attribute value. It is not any safer than normal property access.	🛠️ 🧪
B011	assert-false	Do not assert False (python -O removes these calls), raise AssertionError()	🛠️ 🧪
B012	jump-statement-in-finally	{name} inside finally blocks cause exceptions to be silenced	🛠️ 🧪
B013	redundant-tuple-in-exception-handler	A length-one tuple literal is redundant in exception handlers	🛠️ 🧪
B014	duplicate-handler-exception	Exception handler with duplicate exception: {name}	🛠️ 🧪
B015	useless-comparison	Pointless comparison. This comparison does nothing but waste CPU instructions. Either prepend assert or remove it.	🛠️ 🧪
B016	raise-literal	Cannot raise a literal. Did you intend to return it or raise an Exception?	🛠️ 🧪
B017	assert-raises-exception	{assertion}({exception}) should be considered evil	🛠️ 🧪
B018	useless-expression	Found useless expression. Either assign it to a variable or remove it.	🛠️ 🧪
B019	cached-instance-method	Use of functools.lru_cache or functools.cache on methods can lead to memory leaks	🛠️ 🧪
B020	loop-variable-overrides-iterator	Loop control variable {name} overrides iterable it iterates	🛠️ 🧪
B021	f-string-docstring	f-string used as docstring. Python will interpret this as a joined string, rather than a docstring.	🛠️ 🧪
B022	useless-contextlib-suppress	No arguments passed to contextlib.suppress. No exceptions will be suppressed and therefore this context manager is redundant	🛠️ 🧪
B023	function-uses-loop-variable	Function definition does not bind loop variable {name}	🛠️ 🧪
B024	abstract-base-class-without-abstract-method	{name} is an abstract base class, but it has no abstract methods	🛠️ 🧪
B025	duplicate-try-block-exception	try-except block with duplicate exception {name}	🛠️ 🧪
B026	star-arg-unpacking-after-keyword-arg	Star-arg unpacking after a keyword argument is strongly discouraged	🛠️ 🧪
B027	empty-method-without-abstract-decorator	{name} is an empty method in an abstract base class, but has no abstract decorator	🛠️ 🧪
B028	no-explicit-stacklevel	No explicit stacklevel keyword argument found	🛠️ 🧪
B029	except-with-empty-tuple	Using except (): with an empty tuple does not catch anything; add exceptions to handle	🛠️ 🧪
B030	except-with-non-exception-classes	except handlers should only be exception classes or tuples of exception classes	🛠️ 🧪
B031	reuse-of-groupby-generator	Using the generator returned from itertools.groupby() more than once will do nothing on the second usage	🛠️ 🧪
B032	unintentional-type-annotation	Possible unintentional type annotation (using :). Did you mean to assign (using =)?	🛠️ 🧪
B033	duplicate-value	Sets should not contain duplicate item {value}	🛠️ 🧪
B034	re-sub-positional-args	{method} should pass {param_name} and flags as keyword arguments to avoid confusion due to unintuitive argument positions	🛠️ 🧪
B904	raise-without-from-inside-except	Within an except clause, raise exceptions with raise ... from err or raise ... from None to distinguish them from errors in exception handling	🛠️ 🧪
B905	zip-without-explicit-strict	zip() without an explicit strict= parameter	🛠️ 🧪

flake8-builtins (A)

For more, see flake8-builtins on PyPI.

For related settings, see flake8-builtins.

Code	Name	Message
A001	builtin-variable-shadowing	Variable {name} is shadowing a Python builtin	🛠️ 🧪
A002	builtin-argument-shadowing	Argument {name} is shadowing a Python builtin	🛠️ 🧪
A003	builtin-attribute-shadowing	Class attribute {name} is shadowing a Python builtin	🛠️ 🧪

flake8-commas (COM)

For more, see flake8-commas on PyPI.

Code	Name	Message
COM812	missing-trailing-comma	Trailing comma missing	🛠️ 🧪
COM818	trailing-comma-on-bare-tuple	Trailing comma on bare tuple prohibited	🛠️ 🧪
COM819	prohibited-trailing-comma	Trailing comma prohibited	🛠️ 🧪

flake8-copyright (CPY)

For more, see flake8-copyright on PyPI.

For related settings, see flake8-copyright.

Code	Name	Message
CPY001	missing-copyright-notice	Missing copyright notice at top of file	🛠️ 🧪

flake8-comprehensions (C4)

For more, see flake8-comprehensions on PyPI.

For related settings, see flake8-comprehensions.

Code	Name	Message
C400	unnecessary-generator-list	Unnecessary generator (rewrite as a list comprehension)	🛠️ 🧪
C401	unnecessary-generator-set	Unnecessary generator (rewrite as a set comprehension)	🛠️ 🧪
C402	unnecessary-generator-dict	Unnecessary generator (rewrite as a dict comprehension)	🛠️ 🧪
C403	unnecessary-list-comprehension-set	Unnecessary list comprehension (rewrite as a set comprehension)	🛠️ 🧪
C404	unnecessary-list-comprehension-dict	Unnecessary list comprehension (rewrite as a dict comprehension)	🛠️ 🧪
C405	unnecessary-literal-set	Unnecessary {obj_type} literal (rewrite as a set literal)	🛠️ 🧪
C406	unnecessary-literal-dict	Unnecessary {obj_type} literal (rewrite as a dict literal)	🛠️ 🧪
C408	unnecessary-collection-call	Unnecessary {obj_type} call (rewrite as a literal)	🛠️ 🧪
C409	unnecessary-literal-within-tuple-call	Unnecessary {literal} literal passed to tuple() (rewrite as a tuple literal)	🛠️ 🧪
C410	unnecessary-literal-within-list-call	Unnecessary {literal} literal passed to list() (remove the outer call to list())	🛠️ 🧪
C411	unnecessary-list-call	Unnecessary list call (remove the outer call to list())	🛠️ 🧪
C413	unnecessary-call-around-sorted	Unnecessary {func} call around sorted()	🛠️ 🧪
C414	unnecessary-double-cast-or-process	Unnecessary {inner} call within {outer}()	🛠️ 🧪
C415	unnecessary-subscript-reversal	Unnecessary subscript reversal of iterable within {func}()	🛠️ 🧪
C416	unnecessary-comprehension	Unnecessary {obj_type} comprehension (rewrite using {obj_type}())	🛠️ 🧪
C417	unnecessary-map	Unnecessary map usage (rewrite using a {object_type})	🛠️ 🧪
C418	unnecessary-literal-within-dict-call	Unnecessary dict {kind} passed to dict() (remove the outer call to dict())	🛠️ 🧪
C419	unnecessary-comprehension-any-all	Unnecessary list comprehension.	🛠️ 🧪

flake8-datetimez (DTZ)

For more, see flake8-datetimez on PyPI.

Code	Name	Message
DTZ001	call-datetime-without-tzinfo	The use of datetime.datetime() without tzinfo argument is not allowed	🛠️ 🧪
DTZ002	call-datetime-today	The use of datetime.datetime.today() is not allowed, use datetime.datetime.now(tz=) instead	🛠️ 🧪
DTZ003	call-datetime-utcnow	The use of datetime.datetime.utcnow() is not allowed, use datetime.datetime.now(tz=) instead	🛠️ 🧪
DTZ004	call-datetime-utcfromtimestamp	The use of datetime.datetime.utcfromtimestamp() is not allowed, use datetime.datetime.fromtimestamp(ts, tz=) instead	🛠️ 🧪
DTZ005	call-datetime-now-without-tzinfo	The use of datetime.datetime.now() without tz argument is not allowed	🛠️ 🧪
DTZ006	call-datetime-fromtimestamp	The use of datetime.datetime.fromtimestamp() without tz argument is not allowed	🛠️ 🧪
DTZ007	call-datetime-strptime-without-zone	The use of datetime.datetime.strptime() without %z must be followed by .replace(tzinfo=) or .astimezone()	🛠️ 🧪
DTZ011	call-date-today	The use of datetime.date.today() is not allowed, use datetime.datetime.now(tz=).date() instead	🛠️ 🧪
DTZ012	call-date-fromtimestamp	The use of datetime.date.fromtimestamp() is not allowed, use datetime.datetime.fromtimestamp(ts, tz=).date() instead	🛠️ 🧪

flake8-debugger (T10)

For more, see flake8-debugger on PyPI.

Code	Name	Message
T100	debugger	Trace found: {name} used	🛠️ 🧪

flake8-django (DJ)

For more, see flake8-django on PyPI.

Code	Name	Message
DJ001	django-nullable-model-string-field	Avoid using null=True on string-based fields such as	🛠️ 🧪
DJ003	django-locals-in-render-function	Avoid passing locals() as context to a render function	🛠️ 🧪
DJ006	django-exclude-with-model-form	Do not use exclude with ModelForm, use fields instead	🛠️ 🧪
DJ007	django-all-with-model-form	Do not use __all__ with ModelForm, use fields instead	🛠️ 🧪
DJ008	django-model-without-dunder-str	Model does not define __str__ method	🛠️ 🧪
DJ012	django-unordered-body-content-in-model	Order of model's inner classes, methods, and fields does not follow the Django Style Guide: {element_type} should come before	🛠️ 🧪
DJ013	django-non-leading-receiver-decorator	@receiver decorator must be on top of all the other decorators	🛠️ 🧪

flake8-errmsg (EM)

For more, see flake8-errmsg on PyPI.

For related settings, see flake8-errmsg.

Code	Name	Message
EM101	raw-string-in-exception	Exception must not use a string literal, assign to variable first	🛠️ 🧪
EM102	f-string-in-exception	Exception must not use an f-string literal, assign to variable first	🛠️ 🧪
EM103	dot-format-in-exception	Exception must not use a .format() string directly, assign to variable first	🛠️ 🧪

flake8-executable (EXE)

For more, see flake8-executable on PyPI.

Code	Name	Message
EXE001	shebang-not-executable	Shebang is present but file is not executable	🛠️ 🧪
EXE002	shebang-missing-executable-file	The file is executable but no shebang is present	🛠️ 🧪
EXE003	shebang-missing-python	Shebang should contain python	🛠️ 🧪
EXE004	shebang-leading-whitespace	Avoid whitespace before shebang	🛠️ 🧪
EXE005	shebang-not-first-line	Shebang should be at the beginning of the file	🛠️ 🧪

flake8-future-annotations (FA)

For more, see flake8-future-annotations on PyPI.

Code	Name	Message
FA100	future-rewritable-type-annotation	Missing from __future__ import annotations, but uses {name}	🛠️ 🧪
FA102	future-required-type-annotation	Missing from __future__ import annotations, but uses	🛠️ 🧪

flake8-implicit-str-concat (ISC)

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

For related settings, see flake8-implicit-str-concat.

Code	Name	Message
ISC001	single-line-implicit-string-concatenation	Implicitly concatenated string literals on one line	🛠️ 🧪
ISC002	multi-line-implicit-string-concatenation	Implicitly concatenated string literals over multiple lines	🛠️ 🧪
ISC003	explicit-string-concatenation	Explicitly concatenated string should be implicitly concatenated	🛠️ 🧪

flake8-import-conventions (ICN)

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

For related settings, see flake8-import-conventions.

Code	Name	Message
ICN001	unconventional-import-alias	{name} should be imported as {asname}	🛠️ 🧪
ICN002	banned-import-alias	{name} should not be imported as {asname}	🛠️ 🧪
ICN003	banned-import-from	Members of {name} should not be imported explicitly	🛠️ 🧪

flake8-logging-format (G)

For more, see flake8-logging-format on PyPI.

Code	Name	Message
G001	logging-string-format	Logging statement uses str.format	🛠️ 🧪
G002	logging-percent-format	Logging statement uses %	🛠️ 🧪
G003	logging-string-concat	Logging statement uses +	🛠️ 🧪
G004	logging-f-string	Logging statement uses f-string	🛠️ 🧪
G010	logging-warn	Logging statement uses warn instead of warning	🛠️ 🧪
G101	logging-extra-attr-clash	Logging statement uses an extra field that clashes with a LogRecord field: {key}	🛠️ 🧪
G201	logging-exc-info	Logging .exception(...) should be used instead of .error(..., exc_info=True)	🛠️ 🧪
G202	logging-redundant-exc-info	Logging statement has redundant exc_info	🛠️ 🧪

flake8-no-pep420 (INP)

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

Code	Name	Message
INP001	implicit-namespace-package	File {filename} is part of an implicit namespace package. Add an __init__.py.	🛠️ 🧪

flake8-pie (PIE)

For more, see flake8-pie on PyPI.

Code	Name	Message
PIE790	unnecessary-pass	Unnecessary pass statement	🛠️ 🧪
PIE794	duplicate-class-field-definition	Class field {name} is defined multiple times	🛠️ 🧪
PIE796	non-unique-enums	Enum contains duplicate value: {value}	🛠️ 🧪
PIE800	unnecessary-spread	Unnecessary spread **	🛠️ 🧪
PIE804	unnecessary-dict-kwargs	Unnecessary dict kwargs	🛠️ 🧪
PIE807	reimplemented-list-builtin	Prefer list over useless lambda	🛠️ 🧪
PIE808	unnecessary-range-start	Unnecessary start argument in range	🛠️ 🧪
PIE810	multiple-starts-ends-with	Call {attr} once with a tuple	🛠️ 🧪

flake8-print (T20)

For more, see flake8-print on PyPI.

Code	Name	Message
T201	print	print found	🛠️ 🧪
T203	p-print	pprint found	🛠️ 🧪

flake8-pyi (PYI)

For more, see flake8-pyi on PyPI.

Code	Name	Message
PYI001	unprefixed-type-param	Name of private {kind} must start with _	🛠️ 🧪
PYI002	complex-if-statement-in-stub	if test must be a simple comparison against sys.platform or sys.version_info	🛠️ 🧪
PYI003	unrecognized-version-info-check	Unrecognized sys.version_info check	🛠️ 🧪
PYI004	patch-version-comparison	Version comparison must use only major and minor version	🛠️ 🧪
PYI005	wrong-tuple-length-version-comparison	Version comparison must be against a length-{expected_length} tuple	🛠️ 🧪
PYI006	bad-version-info-comparison	Use < or >= for sys.version_info comparisons	🛠️ 🧪
PYI007	unrecognized-platform-check	Unrecognized sys.platform check	🛠️ 🧪
PYI008	unrecognized-platform-name	Unrecognized platform {platform}	🛠️ 🧪
PYI009	pass-statement-stub-body	Empty body should contain ..., not pass	🛠️ 🧪
PYI010	non-empty-stub-body	Function body must contain only ...	🛠️ 🧪
PYI011	typed-argument-default-in-stub	Only simple default values allowed for typed arguments	🛠️ 🧪
PYI012	pass-in-class-body	Class body must not contain pass	🛠️ 🧪
PYI013	ellipsis-in-non-empty-class-body	Non-empty class body must not contain ...	🛠️ 🧪
PYI014	argument-default-in-stub	Only simple default values allowed for arguments	🛠️ 🧪
PYI015	assignment-default-in-stub	Only simple default values allowed for assignments	🛠️ 🧪
PYI016	duplicate-union-member	Duplicate union member {}	🛠️ 🧪
PYI017	complex-assignment-in-stub	Stubs should not contain assignments to attributes or multiple targets	🛠️ 🧪
PYI018	unused-private-type-var	Private TypeVar {name} is never used	🛠️ 🧪
PYI019	custom-type-var-return-type	Methods like {method_name} should return typing.Self instead of a custom TypeVar	🛠️ 🧪
PYI020	quoted-annotation-in-stub	Quoted annotations should not be included in stubs	🛠️ 🧪
PYI021	docstring-in-stub	Docstrings should not be included in stubs	🛠️ 🧪
PYI024	collections-named-tuple	Use typing.NamedTuple instead of collections.namedtuple	🛠️ 🧪
PYI025	unaliased-collections-abc-set-import	Use from collections.abc import Set as AbstractSet to avoid confusion with the set builtin	🛠️ 🧪
PYI026	type-alias-without-annotation	Use {module}.TypeAlias for type alias, e.g., {name}: TypeAlias = {value}	🛠️ 🧪
PYI029	str-or-repr-defined-in-stub	Defining {name} in a stub is almost always redundant	🛠️ 🧪
PYI030	unnecessary-literal-union	Multiple literal members in a union. Use a single literal, e.g. Literal[{}]	🛠️ 🧪
PYI032	any-eq-ne-annotation	Prefer object to Any for the second parameter to {method_name}	🛠️ 🧪
PYI033	type-comment-in-stub	Don't use type comments in stub file	🛠️ 🧪
PYI034	non-self-return-type	__new__ methods usually return self at runtime	🛠️ 🧪
PYI035	unassigned-special-variable-in-stub	{name} in a stub file must have a value, as it has the same semantics as {name} at runtime	🛠️ 🧪
PYI036	bad-exit-annotation	Star-args in {method_name} should be annotated with object	🛠️ 🧪
PYI041	redundant-numeric-union	Use {supertype} instead of {subtype} | {supertype}	🛠️ 🧪
PYI042	snake-case-type-alias	Type alias {name} should be CamelCase	🛠️ 🧪
PYI043	t-suffixed-type-alias	Private type alias {name} should not be suffixed with T (the T suffix implies that an object is a TypeVar)	🛠️ 🧪
PYI044	future-annotations-in-stub	from __future__ import annotations has no effect in stub files, since type checkers automatically treat stubs as having those semantics	🛠️ 🧪
PYI045	iter-method-return-iterable	__aiter__ methods should return an AsyncIterator, not an AsyncIterable	🛠️ 🧪
PYI046	unused-private-protocol	Private protocol {name} is never used	🛠️ 🧪
PYI047	unused-private-type-alias	Private TypeAlias {name} is never used	🛠️ 🧪
PYI048	stub-body-multiple-statements	Function body must contain exactly one statement	🛠️ 🧪
PYI049	unused-private-typed-dict	Private TypedDict {name} is never used	🛠️ 🧪
PYI050	no-return-argument-annotation-in-stub	Prefer {module}.Never over NoReturn for argument annotations	🛠️ 🧪
PYI051	redundant-literal-union	Literal[{literal}] is redundant in a union with {builtin_type}	🛠️ 🧪
PYI052	unannotated-assignment-in-stub	Need type annotation for {name}	🛠️ 🧪
PYI053	string-or-bytes-too-long	String and bytes literals longer than 50 characters are not permitted	🛠️ 🧪
PYI054	numeric-literal-too-long	Numeric literals with a string representation longer than ten characters are not permitted	🛠️ 🧪
PYI055	unnecessary-type-union	Multiple type members in a union. Combine them into one, e.g., type[{union_str}].	🛠️ 🧪
PYI056	unsupported-method-call-on-all	Calling .{name}() on __all__ may not be supported by all type checkers (use += instead)	🛠️ 🧪

flake8-pytest-style (PT)

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

For related settings, see flake8-pytest-style.

Code	Name	Message
PT001	pytest-fixture-incorrect-parentheses-style	Use @pytest.fixture{expected} over @pytest.fixture{actual}	🛠️ 🧪
PT002	pytest-fixture-positional-args	Configuration for fixture {function} specified via positional args, use kwargs	🛠️ 🧪
PT003	pytest-extraneous-scope-function	scope='function' is implied in @pytest.fixture()	🛠️ 🧪
PT004	pytest-missing-fixture-name-underscore	Fixture {function} does not return anything, add leading underscore	🛠️ 🧪
PT005	pytest-incorrect-fixture-name-underscore	Fixture {function} returns a value, remove leading underscore	🛠️ 🧪
PT006	pytest-parametrize-names-wrong-type	Wrong name(s) type in @pytest.mark.parametrize, expected {expected}	🛠️ 🧪
PT007	pytest-parametrize-values-wrong-type	Wrong values type in @pytest.mark.parametrize expected {values} of {row}	🛠️ 🧪
PT008	pytest-patch-with-lambda	Use return_value= instead of patching with lambda	🛠️ 🧪
PT009	pytest-unittest-assertion	Use a regular assert instead of unittest-style {assertion}	🛠️ 🧪
PT010	pytest-raises-without-exception	set the expected exception in pytest.raises()	🛠️ 🧪
PT011	pytest-raises-too-broad	pytest.raises({exception}) is too broad, set the match parameter or use a more specific exception	🛠️ 🧪
PT012	pytest-raises-with-multiple-statements	pytest.raises() block should contain a single simple statement	🛠️ 🧪
PT013	pytest-incorrect-pytest-import	Found incorrect import of pytest, use simple import pytest instead	🛠️ 🧪
PT014	pytest-duplicate-parametrize-test-cases	Duplicate of test case at index {index} in @pytest_mark.parametrize	🛠️ 🧪
PT015	pytest-assert-always-false	Assertion always fails, replace with pytest.fail()	🛠️ 🧪
PT016	pytest-fail-without-message	No message passed to pytest.fail()	🛠️ 🧪
PT017	pytest-assert-in-except	Found assertion on exception {name} in except block, use pytest.raises() instead	🛠️ 🧪
PT018	pytest-composite-assertion	Assertion should be broken down into multiple parts	🛠️ 🧪
PT019	pytest-fixture-param-without-value	Fixture {name} without value is injected as parameter, use @pytest.mark.usefixtures instead	🛠️ 🧪
PT020	pytest-deprecated-yield-fixture	@pytest.yield_fixture is deprecated, use @pytest.fixture	🛠️ 🧪
PT021	pytest-fixture-finalizer-callback	Use yield instead of request.addfinalizer	🛠️ 🧪
PT022	pytest-useless-yield-fixture	No teardown in fixture {name}, use return instead of yield	🛠️ 🧪
PT023	pytest-incorrect-mark-parentheses-style	Use @pytest.mark.{mark_name}{expected_parens} over @pytest.mark.{mark_name}{actual_parens}	🛠️ 🧪
PT024	pytest-unnecessary-asyncio-mark-on-fixture	pytest.mark.asyncio is unnecessary for fixtures	🛠️ 🧪
PT025	pytest-erroneous-use-fixtures-on-fixture	pytest.mark.usefixtures has no effect on fixtures	🛠️ 🧪
PT026	pytest-use-fixtures-without-parameters	Useless pytest.mark.usefixtures without parameters	🛠️ 🧪
PT027	pytest-unittest-raises-assertion	Use pytest.raises instead of unittest-style {assertion}	🛠️ 🧪

flake8-quotes (Q)

For more, see flake8-quotes on PyPI.

For related settings, see flake8-quotes.

Code	Name	Message
Q000	bad-quotes-inline-string	Single quotes found but double quotes preferred	🛠️ 🧪
Q001	bad-quotes-multiline-string	Single quote multiline found but double quotes preferred	🛠️ 🧪
Q002	bad-quotes-docstring	Single quote docstring found but double quotes preferred	🛠️ 🧪
Q003	avoidable-escaped-quote	Change outer quotes to avoid escaping inner quotes	🛠️ 🧪

flake8-raise (RSE)

For more, see flake8-raise on PyPI.

Code	Name	Message
RSE102	unnecessary-paren-on-raise-exception	Unnecessary parentheses on raised exception	🛠️ 🧪

flake8-return (RET)

For more, see flake8-return on PyPI.

Code	Name	Message
RET501	unnecessary-return-none	Do not explicitly return None in function if it is the only possible return value	🛠️ 🧪
RET502	implicit-return-value	Do not implicitly return None in function able to return non-None value	🛠️ 🧪
RET503	implicit-return	Missing explicit return at the end of function able to return non-None value	🛠️ 🧪
RET504	unnecessary-assign	Unnecessary assignment to {name} before return statement	🛠️ 🧪
RET505	superfluous-else-return	Unnecessary {branch} after return statement	🛠️ 🧪
RET506	superfluous-else-raise	Unnecessary {branch} after raise statement	🛠️ 🧪
RET507	superfluous-else-continue	Unnecessary {branch} after continue statement	🛠️ 🧪
RET508	superfluous-else-break	Unnecessary {branch} after break statement	🛠️ 🧪

flake8-self (SLF)

For more, see flake8-self on PyPI.

For related settings, see flake8-self.

Code	Name	Message
SLF001	private-member-access	Private member accessed: {access}	🛠️ 🧪

flake8-slots (SLOT)

For more, see flake8-slots on PyPI.

Code	Name	Message
SLOT000	no-slots-in-str-subclass	Subclasses of str should define __slots__	🛠️ 🧪
SLOT001	no-slots-in-tuple-subclass	Subclasses of tuple should define __slots__	🛠️ 🧪
SLOT002	no-slots-in-namedtuple-subclass	Subclasses of collections.namedtuple() should define __slots__	🛠️ 🧪

flake8-simplify (SIM)

For more, see flake8-simplify on PyPI.

Code	Name	Message
SIM101	duplicate-isinstance-call	Multiple isinstance calls for {name}, merge into a single call	🛠️ 🧪
SIM102	collapsible-if	Use a single if statement instead of nested if statements	🛠️ 🧪
SIM103	needless-bool	Return the condition {condition} directly	🛠️ 🧪
SIM105	suppressible-exception	Use contextlib.suppress({exception}) instead of try-except-pass	🛠️ 🧪
SIM107	return-in-try-except-finally	Don't use return in try-except and finally	🛠️ 🧪
SIM108	if-else-block-instead-of-if-exp	Use ternary operator {contents} instead of if-else-block	🛠️ 🧪
SIM109	compare-with-tuple	Use {replacement} instead of multiple equality comparisons	🛠️ 🧪
SIM110	reimplemented-builtin	Use {replacement} instead of for loop	🛠️ 🧪
SIM112	uncapitalized-environment-variables	Use capitalized environment variable {expected} instead of {actual}	🛠️ 🧪
SIM114	if-with-same-arms	Combine if branches using logical or operator	🛠️ 🧪
SIM115	open-file-with-context-handler	Use context handler for opening files	🛠️ 🧪
SIM116	if-else-block-instead-of-dict-lookup	Use a dictionary instead of consecutive if statements	🛠️ 🧪
SIM117	multiple-with-statements	Use a single with statement with multiple contexts instead of nested with statements	🛠️ 🧪
SIM118	in-dict-keys	Use key {operator} dict instead of key {operator} dict.keys()	🛠️ 🧪
SIM201	negate-equal-op	Use {left} != {right} instead of not {left} == {right}	🛠️ 🧪
SIM202	negate-not-equal-op	Use {left} == {right} instead of not {left} != {right}	🛠️ 🧪
SIM208	double-negation	Use {expr} instead of not (not {expr})	🛠️ 🧪
SIM210	if-expr-with-true-false	Remove unnecessary True if ... else False	🛠️ 🧪
SIM211	if-expr-with-false-true	Use not ... instead of False if ... else True	🛠️ 🧪
SIM212	if-expr-with-twisted-arms	Use {expr_else} if {expr_else} else {expr_body} instead of {expr_body} if not {expr_else} else {expr_else}	🛠️ 🧪
SIM220	expr-and-not-expr	Use False instead of {name} and not {name}	🛠️ 🧪
SIM221	expr-or-not-expr	Use True instead of {name} or not {name}	🛠️ 🧪
SIM222	expr-or-true	Use {expr} instead of {replaced}	🛠️ 🧪
SIM223	expr-and-false	Use {expr} instead of {replaced}	🛠️ 🧪
SIM300	yoda-conditions	Yoda conditions are discouraged, use {suggestion} instead	🛠️ 🧪
SIM401	if-else-block-instead-of-dict-get	Use {contents} instead of an if block	🛠️ 🧪
SIM910	dict-get-with-none-default	Use {expected} instead of {actual}	🛠️ 🧪

flake8-tidy-imports (TID)

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

For related settings, see flake8-tidy-imports.

Code	Name	Message
TID251	banned-api	{name} is banned:	🛠️ 🧪
TID252	relative-imports	Relative imports from parent modules are banned	🛠️ 🧪
TID253	banned-module-level-imports	{name} is banned at the module level	🛠️ 🧪

flake8-type-checking (TCH)

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

For related settings, see flake8-type-checking.

Code	Name	Message
TCH001	typing-only-first-party-import	Move application import {} into a type-checking block	🛠️ 🧪
TCH002	typing-only-third-party-import	Move third-party import {} into a type-checking block	🛠️ 🧪
TCH003	typing-only-standard-library-import	Move standard library import {} into a type-checking block	🛠️ 🧪
TCH004	runtime-import-in-type-checking-block	Move import {qualified_name} out of type-checking block. Import is used for more than type hinting.	🛠️ 🧪
TCH005	empty-type-checking-block	Found empty type-checking block	🛠️ 🧪

flake8-gettext (INT)

For more, see flake8-gettext on PyPI.

For related settings, see flake8-gettext.

Code	Name	Message
INT001	f-string-in-get-text-func-call	f-string is resolved before function call; consider _("string %s") % arg	🛠️ 🧪
INT002	format-in-get-text-func-call	format method argument is resolved before function call; consider _("string %s") % arg	🛠️ 🧪
INT003	printf-in-get-text-func-call	printf-style format is resolved before function call; consider _("string %s") % arg	🛠️ 🧪

flake8-unused-arguments (ARG)

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

For related settings, see flake8-unused-arguments.

Code	Name	Message
ARG001	unused-function-argument	Unused function argument: {name}	🛠️ 🧪
ARG002	unused-method-argument	Unused method argument: {name}	🛠️ 🧪
ARG003	unused-class-method-argument	Unused class method argument: {name}	🛠️ 🧪
ARG004	unused-static-method-argument	Unused static method argument: {name}	🛠️ 🧪
ARG005	unused-lambda-argument	Unused lambda argument: {name}	🛠️ 🧪

flake8-use-pathlib (PTH)

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

Code	Name	Message
PTH100	os-path-abspath	os.path.abspath() should be replaced by Path.resolve()	🛠️ 🧪
PTH101	os-chmod	os.chmod() should be replaced by Path.chmod()	🛠️ 🧪
PTH102	os-mkdir	os.mkdir() should be replaced by Path.mkdir()	🛠️ 🧪
PTH103	os-makedirs	os.makedirs() should be replaced by Path.mkdir(parents=True)	🛠️ 🧪
PTH104	os-rename	os.rename() should be replaced by Path.rename()	🛠️ 🧪
PTH105	os-replace	os.replace() should be replaced by Path.replace()	🛠️ 🧪
PTH106	os-rmdir	os.rmdir() should be replaced by Path.rmdir()	🛠️ 🧪
PTH107	os-remove	os.remove() should be replaced by Path.unlink()	🛠️ 🧪
PTH108	os-unlink	os.unlink() should be replaced by Path.unlink()	🛠️ 🧪
PTH109	os-getcwd	os.getcwd() should be replaced by Path.cwd()	🛠️ 🧪
PTH110	os-path-exists	os.path.exists() should be replaced by Path.exists()	🛠️ 🧪
PTH111	os-path-expanduser	os.path.expanduser() should be replaced by Path.expanduser()	🛠️ 🧪
PTH112	os-path-isdir	os.path.isdir() should be replaced by Path.is_dir()	🛠️ 🧪
PTH113	os-path-isfile	os.path.isfile() should be replaced by Path.is_file()	🛠️ 🧪
PTH114	os-path-islink	os.path.islink() should be replaced by Path.is_symlink()	🛠️ 🧪
PTH115	os-readlink	os.readlink() should be replaced by Path.readlink()	🛠️ 🧪
PTH116	os-stat	os.stat() should be replaced by Path.stat(), Path.owner(), or Path.group()	🛠️ 🧪
PTH117	os-path-isabs	os.path.isabs() should be replaced by Path.is_absolute()	🛠️ 🧪
PTH118	os-path-join	os.{module}.join() should be replaced by Path with / operator	🛠️ 🧪
PTH119	os-path-basename	os.path.basename() should be replaced by Path.name	🛠️ 🧪
PTH120	os-path-dirname	os.path.dirname() should be replaced by Path.parent	🛠️ 🧪
PTH121	os-path-samefile	os.path.samefile() should be replaced by Path.samefile()	🛠️ 🧪
PTH122	os-path-splitext	os.path.splitext() should be replaced by Path.suffix, Path.stem, and Path.parent	🛠️ 🧪
PTH123	builtin-open	open() should be replaced by Path.open()	🛠️ 🧪
PTH124	py-path	py.path is in maintenance mode, use pathlib instead	🛠️ 🧪
PTH201	path-constructor-current-directory	Do not pass the current directory explicitly to Path	🛠️ 🧪
PTH202	os-path-getsize	os.path.getsize should be replaced by Path.stat().st_size	🛠️ 🧪
PTH203	os-path-getatime	os.path.getatime should be replaced by Path.stat().st_atime	🛠️ 🧪
PTH204	os-path-getmtime	os.path.getmtime should be replaced by Path.stat().st_mtime	🛠️ 🧪
PTH205	os-path-getctime	os.path.getctime should be replaced by Path.stat().st_ctime	🛠️ 🧪
PTH206	os-sep-split	Replace .split(os.sep) with Path.parts	🛠️ 🧪
PTH207	glob	Replace {function} with Path.glob or Path.rglob	🛠️ 🧪

flake8-todos (TD)

For more, see flake8-todos on GitHub.

Code	Name	Message
TD001	invalid-todo-tag	Invalid TODO tag: {tag}	🛠️ 🧪
TD002	missing-todo-author	Missing author in TODO; try: # TODO(<author_name>): ... or # TODO @<author_name>: ...	🛠️ 🧪
TD003	missing-todo-link	Missing issue link on the line following this TODO	🛠️ 🧪
TD004	missing-todo-colon	Missing colon in TODO	🛠️ 🧪
TD005	missing-todo-description	Missing issue description after TODO	🛠️ 🧪
TD006	invalid-todo-capitalization	Invalid TODO capitalization: {tag} should be TODO	🛠️ 🧪
TD007	missing-space-after-todo-colon	Missing space after colon in TODO	🛠️ 🧪

flake8-fixme (FIX)

For more, see flake8-fixme on GitHub.

Code	Name	Message
FIX001	line-contains-fixme	Line contains FIXME, consider resolving the issue	🛠️ 🧪
FIX002	line-contains-todo	Line contains TODO, consider resolving the issue	🛠️ 🧪
FIX003	line-contains-xxx	Line contains XXX, consider resolving the issue	🛠️ 🧪
FIX004	line-contains-hack	Line contains HACK, consider resolving the issue	🛠️ 🧪

eradicate (ERA)

For more, see eradicate on PyPI.

Code	Name	Message
ERA001	commented-out-code	Found commented-out code	🛠️ 🧪

pandas-vet (PD)

For more, see pandas-vet on PyPI.

Code	Name	Message
PD002	pandas-use-of-inplace-argument	inplace=True should be avoided; it has inconsistent behavior	🛠️ 🧪
PD003	pandas-use-of-dot-is-null	.isna is preferred to .isnull; functionality is equivalent	🛠️ 🧪
PD004	pandas-use-of-dot-not-null	.notna is preferred to .notnull; functionality is equivalent	🛠️ 🧪
PD007	pandas-use-of-dot-ix	.ix is deprecated; use more explicit .loc or .iloc	🛠️ 🧪
PD008	pandas-use-of-dot-at	Use .loc instead of .at. If speed is important, use NumPy.	🛠️ 🧪
PD009	pandas-use-of-dot-iat	Use .iloc instead of .iat. If speed is important, use NumPy.	🛠️ 🧪
PD010	pandas-use-of-dot-pivot-or-unstack	.pivot_table is preferred to .pivot or .unstack; provides same functionality	🛠️ 🧪
PD011	pandas-use-of-dot-values	Use .to_numpy() instead of .values	🛠️ 🧪
PD012	pandas-use-of-dot-read-table	Use .read_csv instead of .read_table to read CSV files	🛠️ 🧪
PD013	pandas-use-of-dot-stack	.melt is preferred to .stack; provides same functionality	🛠️ 🧪
PD015	pandas-use-of-pd-merge	Use .merge method instead of pd.merge function. They have equivalent functionality.	🛠️ 🧪
PD101	pandas-nunique-constant-series-check	Using series.nunique() for checking that a series is constant is inefficient	🛠️ 🧪
PD901	pandas-df-variable-name	df is a bad variable name. Be kinder to your future self.	🛠️ 🧪

pygrep-hooks (PGH)

For more, see pygrep-hooks on GitHub.

Code	Name	Message
PGH001	eval	No builtin eval() allowed	🛠️ 🧪
PGH002	deprecated-log-warn	warn is deprecated in favor of warning	🛠️ 🧪
PGH003	blanket-type-ignore	Use specific rule codes when ignoring type issues	🛠️ 🧪
PGH004	blanket-noqa	Use specific rule codes when using noqa	🛠️ 🧪
PGH005	invalid-mock-access	Mock method should be called: {name}	🛠️ 🧪

Pylint (PL)

For more, see Pylint on PyPI.

Code	Name	Message
PLC0105	type-name-incorrect-variance	{kind} name "{param_name}" does not reflect its {variance}; consider renaming it to "{replacement_name}"	🛠️ 🧪
PLC0131	type-bivariance	{kind} cannot be both covariant and contravariant	🛠️ 🧪
PLC0132	type-param-name-mismatch	{kind} name {param_name} does not match assigned variable name {var_name}	🛠️ 🧪
PLC0205	single-string-slots	Class __slots__ should be a non-string iterable	🛠️ 🧪
PLC0208	iteration-over-set	Use a sequence type instead of a set when iterating over values	🛠️ 🧪
PLC0414	useless-import-alias	Import alias does not rename original package	🛠️ 🧪
PLC1901	compare-to-empty-string	{existing} can be simplified to {replacement} as an empty string is falsey	🛠️ 🧪
PLC3002	unnecessary-direct-lambda-call	Lambda expression called directly. Execute the expression inline instead.	🛠️ 🧪
PLE0100	yield-in-init	__init__ method is a generator	🛠️ 🧪
PLE0101	return-in-init	Explicit return in __init__	🛠️ 🧪
PLE0116	continue-in-finally	continue not supported inside finally clause	🛠️ 🧪
PLE0117	nonlocal-without-binding	Nonlocal name {name} found without binding	🛠️ 🧪
PLE0118	load-before-global-declaration	Name {name} is used prior to global declaration on line	🛠️ 🧪
PLE0241	duplicate-bases	Duplicate base {base} for class {class}	🛠️ 🧪
PLE0302	unexpected-special-method-signature	The special method {} expects {}, {} {} given	🛠️ 🧪
PLE0307	invalid-str-return-type	__str__ does not return str	🛠️ 🧪
PLE0604	invalid-all-object	Invalid object in __all__, must contain only strings	🛠️ 🧪
PLE0605	invalid-all-format	Invalid format for __all__, must be tuple or list	🛠️ 🧪
PLE1142	await-outside-async	await should be used within an async function	🛠️ 🧪
PLE1205	logging-too-many-args	Too many arguments for logging format string	🛠️ 🧪
PLE1206	logging-too-few-args	Not enough arguments for logging format string	🛠️ 🧪
PLE1300	bad-string-format-character	Unsupported format character '{format_char}'	🛠️ 🧪
PLE1307	bad-string-format-type	Format type does not match argument type	🛠️ 🧪
PLE1310	bad-str-strip-call	String {strip} call contains duplicate characters (did you mean {removal}?)	🛠️ 🧪
PLE1507	invalid-envvar-value	Invalid type for initial os.getenv argument; expected str	🛠️ 🧪
PLE1700	yield-from-in-async-function	yield from statement in async function; use async for instead	🛠️ 🧪
PLE2502	bidirectional-unicode	Contains control characters that can permit obfuscated code	🛠️ 🧪
PLE2510	invalid-character-backspace	Invalid unescaped character backspace, use "\b" instead	🛠️ 🧪
PLE2512	invalid-character-sub	Invalid unescaped character SUB, use "\x1A" instead	🛠️ 🧪
PLE2513	invalid-character-esc	Invalid unescaped character ESC, use "\x1B" instead	🛠️ 🧪
PLE2514	invalid-character-nul	Invalid unescaped character NUL, use "\0" instead	🛠️ 🧪
PLE2515	invalid-character-zero-width-space	Invalid unescaped character zero-width-space, use "\u200B" instead	🛠️ 🧪
PLR0124	comparison-with-itself	Name compared with itself, consider replacing {actual}	🛠️ 🧪
PLR0133	comparison-of-constant	Two constants compared in a comparison, consider replacing {left_constant} {} {right_constant}	🛠️ 🧪
PLR0206	property-with-parameters	Cannot have defined parameters for properties	🛠️ 🧪
PLR0402	manual-from-import	Use from {module} import {name} in lieu of alias	🛠️ 🧪
PLR0904	too-many-public-methods	Too many public methods ({methods} > {max_methods})	🛠️ 🧪
PLR0911	too-many-return-statements	Too many return statements ({returns} > {max_returns})	🛠️ 🧪
PLR0912	too-many-branches	Too many branches ({branches} > {max_branches})	🛠️ 🧪
PLR0913	too-many-arguments	Too many arguments to function call ({c_args} > {max_args})	🛠️ 🧪
PLR0915	too-many-statements	Too many statements ({statements} > {max_statements})	🛠️ 🧪
PLR1701	repeated-isinstance-calls	Merge isinstance calls: {expression}	🛠️ 🧪
PLR1711	useless-return	Useless return statement at end of function	🛠️ 🧪
PLR1714	repeated-equality-comparison	Consider merging multiple comparisons: {expression}. Use a set if the elements are hashable.	🛠️ 🧪
PLR1722	sys-exit-alias	Use sys.exit() instead of {name}	🛠️ 🧪
PLR2004	magic-value-comparison	Magic value used in comparison, consider replacing {value} with a constant variable	🛠️ 🧪
PLR5501	collapsible-else-if	Use elif instead of else then if, to reduce indentation	🛠️ 🧪
PLR6301	no-self-use	Method {method_name} could be a function or static method	🛠️ 🧪
PLW0120	useless-else-on-loop	else clause on loop without a break statement; remove the else and de-indent all the code inside it	🛠️ 🧪
PLW0127	self-assigning-variable	Self-assignment of variable {name}	🛠️ 🧪
PLW0129	assert-on-string-literal	Asserting on an empty string literal will never pass	🛠️ 🧪
PLW0131	named-expr-without-context	Named expression used without context	🛠️ 🧪
PLW0406	import-self	Module {name} imports itself	🛠️ 🧪
PLW0602	global-variable-not-assigned	Using global for {name} but no assignment is done	🛠️ 🧪
PLW0603	global-statement	Using the global statement to update {name} is discouraged	🛠️ 🧪
PLW0711	binary-op-exception	Exception to catch is the result of a binary and operation	🛠️ 🧪
PLW1508	invalid-envvar-default	Invalid type for environment variable default; expected str or None	🛠️ 🧪
PLW1509	subprocess-popen-preexec-fn	preexec_fn argument is unsafe when using threads	🛠️ 🧪
PLW1510	subprocess-run-without-check	subprocess.run without explicit check argument	🛠️ 🧪
PLW1641	eq-without-hash	Object does not implement __hash__ method	🛠️ 🧪
PLW2901	redefined-loop-name	Outer {outer_kind} variable {name} overwritten by inner {inner_kind} target	🛠️ 🧪
PLW3201	bad-dunder-method-name	Bad or misspelled dunder method name {name}. (bad-dunder-name)	🛠️ 🧪
PLW3301	nested-min-max	Nested {func} calls can be flattened	🛠️ 🧪

tryceratops (TRY)

For more, see tryceratops on PyPI.

Code	Name	Message
TRY002	raise-vanilla-class	Create your own exception	🛠️ 🧪
TRY003	raise-vanilla-args	Avoid specifying long messages outside the exception class	🛠️ 🧪
TRY004	type-check-without-type-error	Prefer TypeError exception for invalid type	🛠️ 🧪
TRY200	reraise-no-cause	Use raise from to specify exception cause	🛠️ 🧪
TRY201	verbose-raise	Use raise without specifying exception name	🛠️ 🧪
TRY300	try-consider-else	Consider moving this statement to an else block	🛠️ 🧪
TRY301	raise-within-try	Abstract raise to an inner function	🛠️ 🧪
TRY302	useless-try-except	Remove exception handler; error is immediately re-raised	🛠️ 🧪
TRY400	error-instead-of-exception	Use logging.exception instead of logging.error	🛠️ 🧪
TRY401	verbose-log-message	Redundant exception object included in logging.exception call	🛠️ 🧪

flynt (FLY)

For more, see flynt on PyPI.

Code	Name	Message
FLY002	static-join-to-f-string	Consider {expression} instead of string join	🛠️ 🧪

NumPy-specific rules (NPY)

Code	Name	Message
NPY001	numpy-deprecated-type-alias	Type alias np.{type_name} is deprecated, replace with builtin type	🛠️ 🧪
NPY002	numpy-legacy-random	Replace legacy np.random.{method_name} call with np.random.Generator	🛠️ 🧪
NPY003	numpy-deprecated-function	np.{existing} is deprecated; use np.{replacement} instead	🛠️ 🧪

Airflow (AIR)

For more, see Airflow on PyPI.

Code	Name	Message
AIR001	airflow-variable-name-task-id-mismatch	Task variable name should match the task_id: "{task_id}"	🛠️ 🧪

Perflint (PERF)

For more, see Perflint on PyPI.

Code	Name	Message
PERF101	unnecessary-list-cast	Do not cast an iterable to list before iterating over it	🛠️ 🧪
PERF102	incorrect-dict-iterator	When using only the {subset} of a dict use the {subset}() method	🛠️ 🧪
PERF203	try-except-in-loop	try-except within a loop incurs performance overhead	🛠️ 🧪
PERF401	manual-list-comprehension	Use a list comprehension to create a transformed list	🛠️ 🧪
PERF402	manual-list-copy	Use list or list.copy to create a copy of a list	🛠️ 🧪
PERF403	manual-dict-comprehension	Use a dictionary comprehension instead of a for-loop	🛠️ 🧪

refurb (FURB)

For more, see refurb on PyPI.

Code	Name	Message
FURB113	repeated-append	Use {suggestion} instead of repeatedly calling {name}.append()	🛠️ 🧪
FURB131	delete-full-slice	Prefer clear over deleting a full slice	🛠️ 🧪
FURB132	check-and-remove-from-set	Use {suggestion} instead of check and remove	🛠️ 🧪
FURB140	reimplemented-starmap	Use itertools.starmap instead of the generator	🛠️ 🧪
FURB145	slice-copy	Prefer copy method over slicing	🛠️ 🧪
FURB148	unnecessary-enumerate	enumerate value is unused, use for x in range(len(y)) instead	🛠️ 🧪

flake8-logging (LOG)

For more, see flake8-logging on PyPI.

Code	Name	Message
LOG001	direct-logger-instantiation	Use logging.getLogger() to instantiate loggers	🛠️ 🧪
LOG002	invalid-get-logger-argument	Use __name__ with logging.getLogger()	🛠️ 🧪
LOG007	exception-without-exc-info	Use of logging.exception with falsy exc_info	🛠️ 🧪
LOG009	undocumented-warn	Use of undocumented logging.WARN constant	🛠️ 🧪

Ruff-specific rules (RUF)

Code	Name	Message
RUF001	ambiguous-unicode-character-string	String contains ambiguous {}. Did you mean {}?	🛠️ 🧪
RUF002	ambiguous-unicode-character-docstring	Docstring contains ambiguous {}. Did you mean {}?	🛠️ 🧪
RUF003	ambiguous-unicode-character-comment	Comment contains ambiguous {}. Did you mean {}?	🛠️ 🧪
RUF005	collection-literal-concatenation	Consider {expression} instead of concatenation	🛠️ 🧪
RUF006	asyncio-dangling-task	Store a reference to the return value of asyncio.{method}	🛠️ 🧪
RUF007	pairwise-over-zipped	Prefer itertools.pairwise() over zip() when iterating over successive pairs	🛠️ 🧪
RUF008	mutable-dataclass-default	Do not use mutable default values for dataclass attributes	🛠️ 🧪
RUF009	function-call-in-dataclass-default-argument	Do not perform function call {name} in dataclass defaults	🛠️ 🧪
RUF010	explicit-f-string-type-conversion	Use explicit conversion flag	🛠️ 🧪
RUF011	static-key-dict-comprehension	Dictionary comprehension uses static key: {key}	🛠️ 🧪
RUF012	mutable-class-default	Mutable class attributes should be annotated with typing.ClassVar	🛠️ 🧪
RUF013	implicit-optional	PEP 484 prohibits implicit Optional	🛠️ 🧪
RUF015	unnecessary-iterable-allocation-for-first-element	Prefer next({iterable}) over single element slice	🛠️ 🧪
RUF016	invalid-index-type	Slice in indexed access to type {value_type} uses type {index_type} instead of an integer.	🛠️ 🧪
RUF017	quadratic-list-summation	Avoid quadratic list summation	🛠️ 🧪
RUF100	unused-noqa	Unused noqa directive	🛠️ 🧪
RUF200	invalid-pyproject-toml	Failed to parse pyproject.toml:	🛠️ 🧪