What's New in Pylint 2.17





Summary -- Release highlights

2.17 is a small release that is the first to support python 3.11 officially with the addition of TryStar nodes.

There's still two new default checks: bad-chained-comparison and implicit-flag-alias, one of them already fixed a previously undetected bug in sentry.

Thanks to the community effort our documentation is almost complete, and every messages should have a proper documentation now. A big thank you to everyone who participated !

The next release is going to be 3.0.0, bring breaking changes and enact long announced deprecations. There's going to be frequent beta releases, before the official releases, everyone is welcome to try the betas so we find problems before the actual release.

What's new in Pylint 2.17.7?

Release date: 2023-09-30

False Positives Fixed

  • Fix a regression in pylint 2.17.6 / astroid 2.15.7 causing various messages for code involving TypeVar.

    Closes #9069 (#9069)

Other Bug Fixes

  • Fix crash in refactoring checker when unary operand used with variable in for loop.

    Closes #9074 (#9074)

What's new in Pylint 2.17.6?

Release date: 2023-09-24

Other Bug Fixes

  • When parsing comma-separated lists of regular expressions in the config, ignore commas that are inside braces since those indicate quantifiers, not delineation between expressions.

    Closes #7229 (#7229)

  • sys.argv is now always correctly considered as impossible to infer (instead of using the actual values given to pylint).

    Closes #7710 (#7710)

  • Don't show class fields more than once in Pyreverse diagrams.

    Closes #8189 (#8189)

  • Don't show arrows more than once in Pyreverse diagrams.

    Closes #8522 (#8522)

  • Don't show duplicate type annotations in Pyreverse diagrams.

    Closes #8888 (#8888)

  • Don't add Optional to | annotations with None in Pyreverse diagrams.

    Closes #9014 (#9014)

What's new in Pylint 2.17.5?

Release date: 2023-07-26

False Positives Fixed

  • Fix a false positive for unused-variable when there is an import in a if TYPE_CHECKING: block and allow-global-unused-variables is set to no in the configuration.

    Closes #8696 (#8696)

  • Fix false positives generated when supplying arguments as **kwargs to IO calls like open().

    Closes #8719 (#8719)

  • Fix a false positive where pylint was ignoring method calls annotated as NoReturn during the inconsistent-return-statements check.

    Closes #8747 (#8747)

  • Exempt parents with only type annotations from the invalid-enum-extension message.

    Closes #8830 (#8830)

Other Bug Fixes

  • Fixed crash when a call to super() was placed after an operator (e.g. not).

    Closes #8554 (#8554)

  • Fix crash for modified-while-iterating checker when deleting members of a dict returned from a call.

    Closes #8598 (#8598)

  • Fix crash in invalid-metaclass check when a metaclass had duplicate bases.

    Closes #8698 (#8698)

  • Avoid consider-using-f-string on modulos with brackets in template.

    Closes #8720. (#8720)

  • Fix a crash when __all__ exists but cannot be inferred.

    Closes #8740 (#8740)

  • Fix crash when a variable is assigned to a class attribute of identical name.

    Closes #8754 (#8754)

  • Fixed a crash when calling copy.copy() without arguments.

    Closes #8774 (#8774)

Other Changes

  • Fix a crash when a nonlocal is defined at module-level.

    Closes #8735 (#8735)

What's new in Pylint 2.17.4?

Release date: 2023-05-06

False Positives Fixed

  • Fix a false positive for bad-dunder-name when there is a user-defined __index__ method.

    Closes #8613 (#8613)

Other Bug Fixes

  • pyreverse: added escaping of vertical bar character in annotation labels produced by DOT printer to ensure it is not treated as field separator of record-based nodes.

    Closes #8603 (#8603)

  • Fixed a crash when generating a configuration file: tomlkit.exceptions.TOMLKitError: Can't add a table to a dotted key caused by tomlkit v0.11.8.

    Closes #8632 (#8632)

What's new in Pylint 2.17.3?

Release date: 2023-04-24

False Positives Fixed

  • Fix unused-argument false positive when __new__ does not use all the arguments of __init__.

    Closes #3670 (#3670)

  • Fix unused-import false positive for usage of six.with_metaclass.

    Closes #7506 (#7506)

  • logging-not-lazy is not longer emitted for explicitly concatenated string arguments.

    Closes #8410 (#8410)

  • Fix false positive for isinstance-second-argument-not-valid-type when union types contains None.

    Closes #8424 (#8424)

  • Fixed unused-import so that it observes the dummy-variables-rgx option.

    Closes #8500 (#8500)

  • Union typed variables without assignment are no longer treated as TypeAlias.

    Closes #8540 (#8540)

  • Fix false positive for positional-only-arguments-expected when a function contains both a positional-only parameter that has a default value, and **kwargs.

    Closes #8555 (#8555)

  • Fix false positive for keyword-arg-before-vararg when a positional-only parameter with a default value precedes *args.

    Closes #8570 (#8570)

Other Bug Fixes

  • Improve output of consider-using-generator message for min() calls with default keyword.

    Closes #8563 (#8563)

What's new in Pylint 2.17.2?

Release date: 2023-04-03

False Positives Fixed

  • invalid-name now allows for integers in typealias names: - now valid: Good2Name, GoodName2. - still invalid: _1BadName.

    Closes #8485 (#8485)

  • No longer consider Union as type annotation as type alias for naming checks.

    Closes #8487 (#8487)

  • unnecessary-lambda no longer warns on lambdas which use its parameters in their body (other than the final arguments), e.g. lambda foo: (bar if foo else baz)(foo).

    Closes #8496 (#8496)

Other Bug Fixes

  • Fix a crash in pyreverse when "/" characters are used in the output filename e.g pyreverse -o png -p name/ path/to/project.

    Closes #8504 (#8504)

What's new in Pylint 2.17.1?

Release date: 2023-03-22

False Positives Fixed

  • Adds asyncSetUp to the default defining-attr-methods list to silence attribute-defined-outside-init warning when using unittest.IsolatedAsyncioTestCase.

    Refs #8403 (#8403)

Other Bug Fixes

  • --clear-cache-post-run now also clears LRU caches for pylint utilities holding references to AST nodes.

    Closes #8361 (#8361)

  • Fix a crash when TYPE_CHECKING is used without importing it.

    Closes #8434 (#8434)

  • Fix a regression of preferred-modules where a partial match was used instead of the required full match.

    Closes #8453 (#8453)

Internal Changes

  • The following utilities are deprecated in favor of the more robust in_type_checking_block and will be removed in pylint 3.0:

    • is_node_in_guarded_import_block

    • is_node_in_typing_guarded_import_block

    • is_typing_guard

    is_sys_guard is still available, which was part of is_node_in_guarded_import_block.

    Refs #8433 (#8433)

What's new in Pylint 2.17.0?

Release date: 2023-03-08

New Features

  • pyreverse now supports custom color palettes with the --color-palette option.

    Closes #6738 (#6738)

  • Add invalid-name check for TypeAlias names.

    Closes #7081. (#7081)

  • Accept values of the form <class name>.<attribute name> for the exclude-protected list.

    Closes #7343 (#7343)

  • Add --version option to pyreverse.

    Refs #7851 (#7851)

  • Adds new functionality with preferred-modules configuration to detect submodules.

    Refs #7957 (#7957)

  • Support implicit namespace packages (PEP 420).

    Closes #8154 (#8154)

  • Add globbing pattern support for --source-roots.

    Closes #8290 (#8290)

  • Support globbing pattern when defining which file/directory/module to lint.

    Closes #8310 (#8310)

  • pylint now supports TryStar nodes from Python 3.11 and should be fully compatible with Python 3.11.

    Closes #8387 (#8387)

New Checks

  • Add a bad-chained-comparison check that emits a warning when there is a chained comparison where one expression is semantically incompatible with the other.

    Closes #6559 (#6559)

  • Adds an implicit-flag-alias check that emits a warning when a class derived from enum.IntFlag assigns distinct integer values that share common bit positions.

    Refs #8102 (#8102)

False Positives Fixed

  • Fix various false positives for functions that return directly from structural pattern matching cases.

    Closes #5288 (#5288)

  • Fix false positive for used-before-assignment when typing.TYPE_CHECKING is used with if/elif/else blocks.

    Closes #7574 (#7574)

  • Fix false positive for isinstance-second-argument-not-valid-type with union types.

    Closes #8205 (#8205)

  • Fix false positive for used-before-assignment for named expressions appearing after the first element in a list, tuple, or set.

    Closes #8252 (#8252)

  • Fix false positive for wrong-spelling-in-comment with class names in a python 2 type comment.

    Closes #8370 (#8370)

False Negatives Fixed

  • Fix a false negative for 'missing-parentheses-for-call-in-test' when inference failed for the internal of the call as we did not need that information to raise correctly.

    Refs #8185 (#8185)

  • Fix false negative for inconsistent-returns with while-loops.

    Closes #8280 (#8280)

Other Bug Fixes

  • Fix used-before-assignment false positive when the walrus operator is used with a ternary operator in dictionary key/value initialization.

    Closes #8125 (#8125)

  • Fix no-name-in-module false positive raised when a package defines a variable with the same name as one of its submodules.

    Closes #8148 (#8148)

  • Fix a crash happening for python interpreter < 3.9 following a failed typing update.

    Closes #8161 (#8161)

  • Fix nested-min-max suggestion message to indicate it's possible to splat iterable objects.

    Closes #8168 (#8168)

  • Fix a crash happening when a class attribute was negated in the start argument of an enumerate.

    Closes #8207 (#8207)

  • Prevent emitting invalid-name for the line on which a global statement is declared.

    Closes #8307 (#8307)

Other Changes

  • Update explanation for global-variable-not-assigned and add confidence.

    Closes #5073 (#5073)

  • The governance model and the path to become a maintainer have been documented as part of our effort to guarantee that the software supply chain in which pylint is included is secure.

    Refs #8329 (#8329)