v3.3.0

Release date: 2024-09-20

Changes requiring user actions

• We migrated symilar to argparse, from getopt, so the error and help output changed
  (for the better). We exit with 2 instead of sometime 1, sometime 2. The error output
  is not captured by the runner anymore. It's not possible to use a value for the
  boolean options anymore (--ignore-comments 1 should become --ignore-comments).

  Refs #9731

New Features

• Add new declare-non-slot error which reports when a class has a __slots__ member and a type hint on the class is not present in __slots__.

  Refs #9499

New Checks

• Added too-many-positional-arguments to allow distinguishing the configuration for too many
  total arguments (with keyword-only params specified after *) from the configuration
  for too many positional-or-keyword or positional-only arguments.

  As part of evaluating whether this check makes sense for your project, ensure you
  adjust the value of --max-positional-arguments.

  Closes #9099

• Add using-exception-group-in-unsupported-version and
  using-generic-type-syntax-in-unsupported-version for uses of Python 3.11+ or
  3.12+ features on lower supported versions provided with --py-version.

  Closes #9791

• Add using-assignment-expression-in-unsupported-version for uses of := (walrus operator)
  on Python versions below 3.8 provided with --py-version.

  Closes #9820

• Add using-positional-only-args-in-unsupported-version for uses of positional-only args on
  Python versions below 3.8 provided with --py-version.

  Closes #9823

• Add unnecessary-default-type-args to the typing extension to detect the use
  of unnecessary default type args for typing.Generator and typing.AsyncGenerator.

  Refs #9938

False Negatives Fixed

• Fix computation of never-returning function: Never is handled in addition to NoReturn, and priority is given to the explicit --never-returning-functions option.

  Closes #7565.

• Fix a false negative for await-outside-async when await is inside Lambda.

  Refs #9653

• Fix a false negative for duplicate-argument-name by including positional-only, *args and **kwargs arguments in the check.

  Closes #9669

• Fix false negative for multiple-statements when multiple statements are present on else and finally lines of try.

  Refs #9759

• Fix false negatives when isinstance does not have exactly two arguments.
  pylint now emits a too-many-function-args or no-value-for-parameter
  appropriately for isinstance calls.

  Closes #9847

Other Bug Fixes

• --enable with --disable=all now produces an error, when an unknown msg code is used. Internal pylint messages are no longer affected by --disable=all.

  Closes #9403

• Impossible to compile regexes for paths in the configuration or argument given to pylint won't crash anymore but
  raise an argparse error and display the error message from re.compile instead.

  Closes #9680

• Fix a bug where a tox.ini file with pylint configuration was ignored and it exists in the current directory.

  .cfg and .ini files containing a Pylint configuration may now use a section named [pylint]. This enhancement impacts the scenario where these file types are used as defaults when they are present and have not been explicitly referred to, using the --rcfile option.

  Closes #9727

• Improve file discovery for directories that are not python packages.

  Closes #9764

Other Changes

• Remove support for launching pylint with Python 3.8.
  Code that supports Python 3.8 can still be linted with the --py-version=3.8 setting.

  Refs #9774

• Add support for Python 3.13.

  Refs #9852

Internal Changes

• All variables, classes, functions and file names containing the word 'similar', when it was,
  in fact, referring to 'symilar' (the standalone program for the duplicate-code check) were renamed
  to 'symilar'.

  Closes #9734

• Remove old-style classes (Python 2) code and remove check for new-style class since everything is new-style in Python 3. Updated doc for exception checker to remove reference to new style class.

  Refs #9925

v3.2.7

What's new in Pylint 3.2.7?

Release date: 2024-08-31

False Positives Fixed

• Fixed a false positive unreachable for NoReturn coroutine functions.

  Closes #9840

Other Bug Fixes

• Fix crash in refactoring checker when calling a lambda bound as a method.

  Closes #9865

• Fix a crash in undefined-loop-variable when providing the iterable argument to enumerate().

  Closes #9875

• Fix to address indeterminacy of error message in case a module name is same as another in a separate namespace.

  Refs #9883

v3.2.6

What's new in Pylint 3.2.6?

Release date: 2024-07-21

False Positives Fixed

• Quiet false positives for unexpected-keyword-arg when pylint cannot
  determine which of two or more dynamically defined classes is being instantiated.

  Closes #9672

• Fix a false positive for missing-param-doc where a method which is decorated with typing.overload was expected to have a docstring specifying its parameters.

  Closes #9739

• Fix a regression that raised invalid-name on class attributes merely
  overriding invalid names from an ancestor.

  Closes #9765

• Treat assert_never() the same way when imported from typing_extensions.

  Closes #9780

• Fix a false positive for consider-using-min-max-builtin when the assignment target is an attribute.

  Refs #9800

Other Bug Fixes

• Fix an AssertionError arising from properties that return partial functions.

  Closes #9214

• Fix a crash when a subclass extends __slots__.

  Closes #9814

v3.2.5

What's new in Pylint 3.2.5 ?

Release date: 2024-06-28

Other Bug Fixes

• Fixed a false positive unreachable-code when using typing.Any as return type in python
  3.8, the typing.NoReturn are not taken into account anymore for python 3.8 however.

  Closes #9751

v3.2.4

What's new in Pylint 3.2.4?

Release date: 2024-06-26

False Positives Fixed

• Prevent emitting possibly-used-before-assignment when relying on names
  only potentially not defined in conditional blocks guarded by functions
  annotated with typing.Never or typing.NoReturn.

  Closes #9674

Other Bug Fixes

• Fixed a crash when the lineno of a variable used as an annotation wasn't available for undefined-variable.

  Closes #8866

• Fixed a crash when the start value in an enumerate was non-constant and impossible to infer
  (like inenumerate(apples, start=int(random_apple_index)) for unnecessary-list-index-lookup.

  Closes #9078

• Fixed a crash in symilar when the -d or -i short option were not properly recognized.
  It's still impossible to do -d=1 (you must do -d 1).

  Closes #9343

v3.2.3

False Positives Fixed

• Classes with only an Ellipsis (...) in their body do not trigger 'multiple-statements'
  anymore if they are inlined (in accordance with black's 2024 style).

  Closes #9398

• Fix a false positive for redefined-outer-name when there is a name defined in an exception-handling block which shares the same name as a local variable that has been defined in a function body.

  Closes #9671

• Fix a false positive for use-yield-from when using the return value from the yield atom.

  Closes #9696

v3.2.2

What's new in Pylint 3.2.2?

Release date: 2024-05-20

False Positives Fixed

• Fix multiple false positives for generic class syntax added in Python 3.12 (PEP 695).

  Closes #9406

• Exclude context manager without cleanup from
  contextmanager-generator-missing-cleanup checks.

  Closes #9625

v3.2.1

What's new in Pylint 3.2.1?

Release date: 2024-05-18

False Positives Fixed

• Exclude if/else branches containing terminating functions (e.g. sys.exit())
  from possibly-used-before-assignment checks.

  Closes #9627

• Don't emit typevar-name-incorrect-variance warnings for PEP 695 style TypeVars.
  The variance is inferred automatically by the type checker.
  Adding _co or _contra suffix can help to reason about TypeVar.

  Refs #9638

• Fix a false positive for possibly-used-before-assignment when using
  typing.assert_never() (3.11+) to indicate exhaustiveness.

  Closes #9643

Other Bug Fixes

• Fix a false negative for --ignore-patterns when the directory to be linted is specified using a dot(.) and all files are ignored instead of only the files whose name begin with a dot.

  Closes #9273

• Restore "errors / warnings by module" section to report output (with -ry).

  Closes #9145

• trailing-comma-tuple should now be correctly emitted when it was disabled globally
  but enabled via local message control, after removal of an over-optimisation.

  Refs #9608

• Add --prefer-stubs=yes option to opt-in to the astroid 3.2 feature
  that prefers .pyi stubs over same-named .py files. This has the
  potential to reduce no-member errors but at the cost of more errors
  such as not-an-iterable from function bodies appearing as ....

  Defaults to no.

  Closes #9626
  Closes #9623

Internal Changes

• Update astroid version to 3.2.1. This solves some reports of RecursionError
  and also makes the prefer .pyi stubs feature in astroid 3.2.0 opt-in
  with the aforementioned --prefer-stubs=y option.

  Refs #9139

v3.2.0

What's new in Pylint 3.2.0?

Release date: 2024-05-14

Of note: a github reporter, two new checks (possibly-used-before-assignment and contextmanager-generator-missing-cleanup), performance improvements, and an astroid upgrade providing support for @overload and .pyi stubs.

New Features

• Understand six.PY2 and six.PY3 for conditional imports.

  Closes #3501

• A new github reporter has been added. This reporter returns the output of pylint in a format that
  Github can use to automatically annotate code. Use it with pylint --output-format=github on your Github Workflows.

  Closes #9443.

New Checks

• Add check possibly-used-before-assignment when relying on names after an if/else
  switch when one branch failed to define the name, raise, or return.

  Closes #1727

• Checks for generators that use contextmanagers that don't handle cleanup properly.
  Is meant to raise visibilty on the case that a generator is not fully exhausted and the contextmanager is not cleaned up properly.
  A contextmanager must yield a non-constant value and not handle cleanup for GeneratorExit.
  The using generator must attempt to use the yielded context value with x() as y and not just with x().

  Closes #2832

False Negatives Fixed

• If and Try nodes are now checked for useless return statements as well.

  Closes #9449.

• Fix false negative for property-with-parameters in the case of parameters which are positional-only, keyword-only, variadic positional or variadic keyword.

  Closes #9584

False Positives Fixed

• pylint now understands the @overload decorator return values better.

  Closes #4696
  Refs #9606

Performance Improvements

• Ignored modules are now not checked at all, instead of being checked and then
  ignored. This should speed up the analysis of large codebases which have
  ignored modules.

  Closes #9442

• ImportChecker's logic has been modified to avoid context files when possible. This makes it possible
  to cache module searches on astroid and reduce execution times.

  Refs #9310.

• An internal check for trailing-comma-tuple being enabled for a file or not is now
  done once per file instead of once for each token.

  Refs #9608.

v3.1.1

What's new in Pylint 3.1.1?

Release date: 2024-05-13

False Positives Fixed

• Treat attrs.define and attrs.frozen as dataclass decorators in
  too-few-public-methods check.

  Closes #9345

• Fix a false positive with singledispatchmethod-function when a method is decorated with both functools.singledispatchmethod and staticmethod.

  Closes #9531

• Fix a false positive for consider-using-dict-items when iterating using keys() and then deleting an item using the key as a lookup.

  Closes #9554