Rules

Each rule below reports a pattern that makes code harder to read or review, and most can fix it.

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All groupsCommentsNamingModule layoutImports and dependenciesPublic APILogicTypingClassesTestsDocstringsAny fixFix always availableFix sometimes availableNo fixAll rulesCross-file onlySingle-file only108 rules

Code	Name	Checks	Fix	Cross-file
Comments
SMP001	section-comment	Comments used as dividers or section headers	🛠️	✗
SMP002	long-paragraph	Comment paragraphs over the word limit		✗
SMP003	suppression-without-reason	noqa, type: ignore and pragma comments with no reason		✗
SMP004	blanket-ignore	Suppression comments that name no error code		✗
SMP005	restating-comment	Comments that only repeat the code below	🛠️	✗
SMP006	string-statement-comment	Bare strings used as comments instead of # comments	🔧	✗
SMP007	long-comment-line	Comment and docstring lines over the line length	🛠️	✗
Naming
SMP101	single-letter-name	Single-letter names outside comprehensions		✗
SMP102	module-variable-case	Module variables not UPPER_CASE	🔧	✓
SMP103	meaningless-name	Variables, parameters and attributes named with a word that says nothing		✗
SMP104	catch-all-module	Modules and packages named for a grab bag of code		✗
Module layout
SMP201	definition-before-use	Helpers defined above their first caller, or away from it	🔧	✗
SMP202	single-user-constant	Module constants only one function uses	🔧	✓
SMP203	class-member-order	Class members defined out of section order, such as a constructor below a method	🔧	✗
Imports and dependencies
SMP301	future-annotations	from __future__ import annotations on Python 3.14+	🔧	✗
SMP302	absolute-sibling-import	Absolute imports from the same package	🛠️	✗
SMP303	dependency-import-guard	try/except ImportError around a required dependency	🔧	✗
SMP304	module-attribute-import	Module attributes reached as module.Name instead of imported	🔧	✓
SMP305	up-backport-import	Imports of backports that the standard library replaces	🔧	✗
SMP306	up-type-checking-lazy-import	if TYPE_CHECKING: imports that can be lazy imports	🔧	✗
SMP307	up-lazy-modules-list	__lazy_modules__ lists that lazy imports replace	🔧	✗
SMP308	import-cycle	Runtime imports that close a cycle between modules		✓
SMP309	star-import	import * of a module the project defines, which names can be imported one by one	🔧	✓
Public API
SMP401	missing-from-all	Names other modules import that __all__ omits	🔧	✓
SMP402	unused-export	__all__ entries no other module imports	🔧	✓
SMP403	unexported-public-name	Public functions and classes missing from __all__	🔧	✓
SMP404	module-variable-prefix	Module variables whose leading _ does not match their visibility	🔧	✓
SMP405	all-format	__all__ not a list with a trailing comma	🛠️	✗
SMP406	all-not-last	__all__ not at the end of the module	🔧	✗
SMP407	init-module-content	__init__.py holding more than a docstring		✓
SMP408	test-only-code	Module-level functions and classes only test modules use		✓
SMP409	unused-definition	Functions, classes, methods and class attributes nothing in the run uses		✓
SMP410	test-only-parameter	Parameters only test calls pass, which production calls leave at their default		✓
SMP411	unused-return-value	Return values no production call reads		✓
Logic
SMP501	forwarding-function	Private functions that only forward to another call		✓
SMP502	walrus-candidate	An assignment the next if test could absorb with :=	🛠️	✓
SMP503	string-concatenation	+ between strings	🔧	✓
SMP504	single-use-variable	Variables read once, right below their assignment	🛠️	✗
SMP505	single-caller-helper	Private helpers with one short call site, which inlining would keep short		✓
SMP506	unused-default	Parameter defaults that every call passes explicitly	🔧	✓
SMP507	error-message-matching	Exceptions told apart by their message text		✓
SMP508	up-comprehension-unpacking	Nested for clauses that only unpack their iterable into the element	🛠️	✗
SMP509	up-traceback-exception-arguments	traceback calls that pass an exception's type and traceback next to it	🛠️	✗
SMP510	up-exc-info-exception	sys.exc_info() reads of the exception being handled	🛠️	✗
SMP511	up-object-sentinel	object() placeholders sentinel would name	🛠️	✗
SMP512	up-context-var-token-reset	ContextVar.set() tokens reset in a finally block	🔧	✗
SMP513	up-chdir-restore	Working directories restored in a finally block	🔧	✗
SMP514	up-strptime-date	datetime.strptime() results narrowed to a date or time	🔧	✗
SMP515	up-event-loop-in-coroutine	asyncio.get_event_loop() calls in coroutines	🔧	✗
SMP516	up-asyncio-iscoroutinefunction	asyncio.iscoroutinefunction() calls	🔧	✗
SMP517	up-codecs-open	codecs.open() calls	🔧	✗
SMP518	up-re-error-alias	re.error references	🛠️	✗
SMP519	up-argparse-suggest-on-error	suggest_on_error=True in ArgumentParser() calls	🔧	✗
SMP520	up-removed-ast-node	ast node aliases and visitor methods Python 3.14 removed	🔧	✗
SMP521	up-utf8-encoding-default	UTF-8 encoding arguments that Python 3.15 makes the default	🔧	✗
SMP522	up-re-prefixmatch	re.match() calls that re.prefixmatch() names	🛠️	✗
SMP523	up-compression-modules	gzip, bz2, lzma and zlib imports that compression names	🔧	✗
SMP524	up-warnings-deprecated	Functions and classes that warn with DeprecationWarning where @warnings.deprecated marks them	🔧	✗
SMP525	up-deprecated-stdlib-alias	Deprecated standard library names that have a replacement	🔧	✗
SMP526	early-assignment	Constants assigned well above their first use	🔧	✗
SMP527	super-forwarding-method	Methods that only return the parent's method called with their own arguments	🔧	✗
SMP528	long-tuple-return	Functions returning tuples too long to unpack by position		✗
SMP529	cognitive-complexity	Functions whose cognitive complexity is over the limit		✗
SMP530	duplicate-code	Statements that another module repeats		✓
SMP531	collection-built-by-statements	Empty collections filled by the statements right after them	🔧	✗
SMP532	unnamed-regex-group	Regular expressions with unnamed capture groups	🔧	✗
SMP533	unexplained-regex	Regular expressions with four or more parts and no comments		✗
Typing
SMP601	missing-final	Module constants not annotated Final	🔧	✓
SMP602	imprecise-annotation	object and Any in annotations		✗
SMP603	callable-ellipsis	Callable[..., T]		✗
SMP604	vars-call	vars() calls		✗
Classes
SMP701	dataclass-frozen	Dataclasses without frozen	🛠️	✓
SMP702	dataclass-slots	Dataclasses without slots	🛠️	✓
SMP703	dataclass-kw-only	Dataclasses without kw_only	🛠️	✓
SMP704	indistinct-error-class	Exception classes no handler catches by name		✓
Tests
SMP801	test-class	Test classes	🔧	✓
SMP802	parametrize-without-id	parametrize rows without pytest.param(..., id=...)		✗
SMP803	conditional-in-test	if, match and conditional expressions in tests		✗
SMP804	constant-assert	Assertions on a truthy constant	🔧	✗
SMP805	mock-attribute-assignment	Mock attributes assigned after construction	🔧	✗
SMP806	mock-without-spec	Mocks and patches without a spec		✗
SMP807	split-composite-assert	Consecutive asserts comparing fields of one object	🔧	✗
SMP808	sleep-in-test	time.sleep and asyncio.sleep calls in tests		✗
SMP809	stdlib-mock	unittest.mock imports in projects that depend on pytest-mock		✗
SMP811	up-unittest-assert-helper	assertTrue and assertFalse on checks that TestCase has a helper for	🔧	✗
SMP812	up-unittest-enter-context	Patches started and stopped by hand in TestCase methods	🔧	✗
SMP813	loop-in-test	Loops in tests that assert over a table of cases		✗
SMP814	mock-assertion-typo	Mock assertion methods misspelled or missing their assert_ prefix	🛠️	✓
SMP815	unused-fixture	Pytest fixtures no test or fixture requests		✓
Docstrings
SMP901	function-docstring	Docstrings on internal functions and classes	🔧	✓
SMP902	test-module-docstring	Docstrings on test modules	🔧	✗
SMP903	undocumented-public-api	Public functions, classes, methods and variables without documentation		✓
SMP904	long-docstring-paragraph	Docstring paragraphs over the word limit		✗
SMP910	rst-field-syntax	Malformed or misplaced reStructuredText docstring fields	🔧	✗
SMP911	rst-inline-markup	Roles without backticks and unclosed inline literals	🔧	✗
SMP912	rst-type-field	Types in docstrings, which belong in annotations	🔧	✗
SMP913	rst-restating-field	Field descriptions that only repeat the name		✗
SMP914	rst-empty-field	Fields with no description		✗
SMP915	rst-private-field	Public docstrings documenting internal names	🔧	✓
SMP916	rst-missing-param	Public API docstrings that leave a parameter undocumented		✓
SMP917	rst-unknown-param	:param: and :type: fields for parameters the signature lacks	🔧	✗
SMP918	rst-duplicate-param	Constructor parameters documented in both the class and __init__ docstrings	🔧	✗
SMP919	rst-param-order	:param: fields out of the signature's order		✗
SMP920	rst-missing-attribute	Public classes whose docstring leaves an attribute undocumented		✓
SMP921	rst-unknown-attribute	:ivar:, :cvar: and :var: fields for attributes the class lacks	🔧	✗
SMP922	rst-attribute-kind	:ivar: on class variables and :cvar: on instance attributes	🔧	✗
SMP923	rst-returns	Missing, extraneous or misused :returns: and :yields: fields	🔧	✓
SMP924	rst-missing-raises	Public API docstrings that leave a raised exception undocumented		✓

Rules marked ✓ under Cross-file read other files of the run; How simplint works explains how. Which fixes count as safe is under Fix safety.