What's New in Pylint 3.3

:Release:3.3 :Date: 2024-09-20

Summary -- Release highlights

What's new in Pylint 3.3.1?

Release date: TBA

No significant changes.

What's new in Pylint 3.3.1?

Release date: 2024-09-24

False Positives Fixed

  • Fix regression causing some f-strings to not be inferred as strings.

    Closes #9947 (#9947)

What's new in Pylint 3.3.0?

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 (#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 (#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 (#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 (#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 (#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 (#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 (#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. (#7565)

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

    Refs #9653 (#9653)

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

    Closes #9669 (#9669)

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

    Refs #9759 (#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 (#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 (#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 (#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 (#9727)

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

    Closes #9764 (#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 (#9774)

  • Add support for Python 3.13.

    Refs #9852 (#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 (#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 (#9925)