What's New in Pylint 2.17#

Release:

2.17

Date:

2023-03-08

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 2.17.1?#

Release date: TBA

Breaking Changes#

  • Add new option (--show-stdlib, -L) to pyreverse. This is similar to the behavior of --show-builtin in that standard library modules are now not included by default, and this option will include them.

    Closes #8181 (#8181)

  • pyreverse now uses a new default color palette that is more colorblind friendly. The color scheme is taken from Paul Tol's Notes. If you prefer other colors, you can use the --color-palette option to specify custom colors.

    Closes #8251 (#8251)

  • get_message_definition was removed from the base checker API. You can access message definitions through the MessageStore.

    Refs #8401 (#8401)

  • Everything related to the __implements__ construct was removed. It was based on PEP245 that was proposed in 2001 and rejected in 2006. It includes all the classes inheriting Interface in pylint.interfaces

    Checker should only inherit BaseChecker or any of the other checker types from pylint.checkers. Reporter should only inherit BaseReporter.

    The capability from pyreverse to take __implements__ into account when generating diagrams was also removed.

    Refs #8404 (#8404)

  • modname and msg_store are now required to be given in FileState. collect_block_lines has also been removed. Pylinter.current_name cannot be null anymore.

    Refs #8407 (#8407)

  • 'Reporter.set_output' was removed in favor of 'reporter.out = stream'.

    Refs #8408 (#8408)

  • A number of old utility functions and classes have been removed:

    MapReduceMixin: To make a checker reduce map data simply implement get_map_data and reduce_map_data.

    is_inside_lambda: Use utils.get_node_first_ancestor_of_type(x, nodes.Lambda)

    check_messages: Use utils.only_required_for_messages

    is_class_subscriptable_pep585_with_postponed_evaluation_enabled: Use is_postponed_evaluation_enabled(node) and is_node_in_type_annotation_context(node)

    get_python_path: assumption that there's always an __init__.py is not true since python 3.3 and is causing problems, particularly with PEP 420. Use discover_package_path and pass source root(s).

    fix_import_path: Use augmented_sys_path and pass additional sys.path entries as an argument obtained from discover_package_path.

    get_global_option: Use checker.linter.config to get all global options.

    Related private objects have been removed as well.

    Refs #8409 (#8409)

  • colorize_ansi now only accept a MessageStyle object.

    Refs #8412 (#8412)

  • pyreverse: Support for the .vcg output format (Visualaization of Compiler Graphs) has been dropped.

    Closes #8416 (#8416)

  • The warning when the now useless old pylint cache directory (pylint.d) was found was removed. The cache dir is documented in [the FAQ](https://pylint.readthedocs.io/en/latest/faq.html#where-is-the-persistent-data-stored-to-compare-between-successive-runs).

    Refs #8462 (#8462)

Changes requiring user actions#

  • epylint was removed. It now lives at: https://github.com/emacsorphanage/pylint.

    Refs #7737 (#7737)

  • The 'overgeneral-exceptions' option now only takes fully qualified name into account (builtins.Exception not Exception). If you overrode this option, you need to use the fully qualified name now.

    There's still a warning, but it will be removed in 3.1.0.

    Refs #8411 (#8411)

  • Following a deprecation period, it's no longer possible to use MASTER or master as configuration section in setup.cfg or tox.ini. It's bad practice to not start sections titles with the tool name. Please use pylint.main instead.

    Refs #8465 (#8465)

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)

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

    Closes #8487 (#8487)

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)

Other Changes#

  • Pylint now exposes its type annotations.

    Closes #5488 and #2079 (#5488)

  • All code related to the optparse config parsing has been removed.

    Refs #8405 (#8405)

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)

  • Following a deprecation period, Pylinter.check now only work with sequences of strings, not strings.

    Refs #8463 (#8463)

  • Following a deprecation period, ColorizedTextReporter only accepts ColorMappingDict.

    Refs #8464 (#8464)

  • Following a deprecation period, MessageTest's end_line and end_col_offset must be accurate in functional tests (for python 3.8 or above on cpython, and for python 3.9 or superior on pypy).

    Refs #8466 (#8466)

  • Following a deprecation period, the do_exit argument of the Run class (and of the _Run class in testutils) were removed.

    Refs #8472 (#8472)

  • Following a deprecation period, the py_version argument of the MessageDefinition.may_be_emitted function is now required. The most likely solution is to use 'linter.config.py_version' if you need to keep using this function, or to use 'MessageDefinition.is_message_enabled' instead.

    Refs #8473 (#8473)

  • Following a deprecation period, is_typing_guard, is_node_in_typing_guarded_import_block and is_node_in_guarded_import_block: from pylint.utils were removed: use a combination of is_sys_guard and in_type_checking_block instead.

    Refs #8475 (#8475)

  • Following a deprecation period, the location argument of the Message class must now be a MessageLocationTuple.

    Refs #8477 (#8477)

  • Following a deprecation period, the check_single_file function of the Pylinter is replaced by Pylinter.check_single_file_item.

    Refs #8478 (#8478)

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)