:Release: 2.14 :Date: 2022-06-01 Summary -- Release highlights ============================= With 2.14 ``pylint`` only supports Python version 3.7.2 and above. We introduced several new checks among which ``duplicate-value`` for sets, ``comparison-of-constants``, and checks related to lambdas. We removed ``no-init`` and made ``no-self-use`` optional as they were too opinionated. We also added an option to generate a toml configuration: ``--generate-toml-config``. We migrated to ``argparse`` from ``optparse`` and refactored the configuration handling thanks to Daniël van Noord. On the user side it should change the output of the ``--help`` command, and some inconsistencies and bugs should disappear. The behavior between options set in a config file versus on the command line will be more consistent. For us, it will permit to maintain this part of the code easily in the future and anticipate ``optparse``'s removal in Python 3.12. As a result of the refactor there are a lot of internal deprecations. If you're a library maintainer that depends on pylint, please verify that you're ready for pylint 3.0 by activating deprecation warnings. We continued the integration of ``pylint-error`` and are now at 33%!. We still welcome any community effort to help review, integrate, and add good/bad examples `_. This should be doable without any ``pylint`` or ``astroid`` knowledge, so this is the perfect entrypoint if you want to contribute to ``pylint`` or open source without any experience with our code! New checkers ============ * Added new checker ``comparison-of-constants``. Closes #6076 * Added new checker ``typevar-name-mismatch``: TypeVar must be assigned to a variable with the same name as its name argument. Closes #5224 * ``invalid-enum-extension``: Used when a class tries to extend an inherited Enum class. Closes #5501 * Added new checker ``typevar-double-variance``: The "covariant" and "contravariant" keyword arguments cannot both be set to "True" in a TypeVar. Closes #5895 * Add new check ``unnecessary-dunder-call`` for unnecessary dunder method calls. Closes #5936 * ``unnecessary-lambda-assignment``: Lambda expression assigned to a variable. Define a function using the "def" keyword instead. ``unnecessary-direct-lambda-call``: Lambda expression called directly. Execute the expression inline instead. Closes #5976 * ``potential-index-error``: Emitted when the index of a list or tuple exceeds its length. This checker is currently quite conservative to avoid false positives. We welcome suggestions for improvements. Closes #578 * Added new checker ``unnecessary-list-index-lookup`` for indexing into a list while iterating over ``enumerate()``. Closes #4525 * Added new message called ``duplicate-value`` which identifies duplicate values inside sets. Closes #5880 * Added the ``super-without-brackets`` checker, raised when a super call is missing its brackets. Closes #4008 Removed checkers ================ * The ``no-init`` (W0232) warning has been removed. It's ok to not have an ``__init__`` in a class. Closes #2409 * Removed the ``assign-to-new-keyword`` message as there are no new keywords in the supported Python versions any longer. Closes #4683 * Moved ``no-self-use`` check to optional extension. You now need to explicitly enable this check using ``load-plugins=pylint.extensions.no_self_use``. Closes #5502 Extensions ========== * ``RedefinedLoopNameChecker`` * Added optional extension ``redefined-loop-name`` to emit messages when a loop variable is redefined in the loop body. Closes #5072 * ``DocStringStyleChecker`` * Re-enable checker ``bad-docstring-quotes`` for Python <= 3.7. Closes #6087 * ``NoSelfUseChecker`` * Added ``no-self-use`` check, previously enabled by default. Closes #5502 Other Changes ============= * Started ignoring underscore as a local variable for ``too-many-locals``. Closes #6488 * Pylint can now be installed with an extra-require called ``spelling`` (``pip install pylint[spelling]``). This will add ``pyenchant`` to pylint's dependencies. You will still need to install the requirements for ``pyenchant`` (the ``enchant`` library and any dictionaries) yourself. You will also need to set the ``spelling-dict`` option. Refs #6462 * Improved wording of the message of ``deprecated-module`` Closes #6169 * ``Pylint`` now requires Python 3.7.2 or newer to run. Closes #4301 * We made a greater effort to reraise failures stemming from the ``astroid`` library as ``AstroidError``, with the effect that pylint emits ``astroid-error`` rather than merely ``fatal``. Regardless, please report any such issues you encounter! * We have improved our recognition of inline disable and enable comments. It is now possible to disable ``bad-option-value`` inline (as long as you disable it before the bad option value is raised, i.e. ``disable=bad-option-value,bad-message`` not ``disable=bad-message,bad-option-value`` ) as well as certain other previously unsupported messages. Closes #3312 * The main checker name is now ``main`` instead of ``master``. The configuration does not need to be updated as sections' name are optional. Closes #5467 * Update ``invalid-slots-object`` message to show bad object rather than its inferred value. Closes #6101 * Fixed a crash in the ``not-an-iterable`` checker involving multiple starred expressions inside a call. Closes #6372 * Fixed a crash in the ``unused-private-member`` checker involving chained private attributes. Closes #6709 * Disable spellchecking of mypy rule names in ignore directives. Closes #5929 * ``implicit-str-concat`` will now be raised on calls like ``open("myfile.txt" "a+b")`` too. Closes #6441 * Fix a failure to respect inline disables for ``fixme`` occurring on the last line of a module when pylint is launched with ``--enable=fixme``. * Removed the broken ``generate-man`` option. Closes #5283 Closes #1887 * Fixed failure to enable ``deprecated-module`` after a ``disable=all`` by making ``ImportsChecker`` solely responsible for emitting ``deprecated-module`` instead of sharing responsibility with ``StdlibChecker``. (This could have led to double messages.) * Added the ``generate-toml-config`` option. Refs #5462 * ``bad-option-value`` will be emitted whenever a configuration value or command line invocation includes an unknown message. Closes #4324 * Added the ``unrecognized-option`` message. Raised if we encounter any unrecognized options. Closes #5259 * Fix false negative for ``bad-string-format-type`` if the value to be formatted is passed in as a variable holding a constant. * The concept of checker priority has been removed. * The ``cache-max-size-none`` checker has been renamed to ``method-cache-max-size-none``. Closes #5670 * The ``method-cache-max-size-none`` checker will now also check ``functools.cache``. Closes #5670 * ``BaseChecker`` classes now require the ``linter`` argument to be passed. * The ``set_config_directly`` decorator has been removed. * Don't report ``useless-super-delegation`` for the ``__hash__`` method in classes that also override the ``__eq__`` method. Closes #3934 * Fix falsely issuing ``useless-suppression`` on the ``wrong-import-position`` checker. Closes #5219 * Fixed false positive ``no-member`` for Enums with self-defined members. Closes #5138 * Fix false negative for ``no-member`` when attempting to assign an instance attribute to itself without any prior assignment. Closes #1555 * Changed message type from ``redefined-outer-name`` to ``redefined-loop-name`` (optional extension) for redefinitions of outer loop variables by inner loops. Closes #5608 * By default the similarity checker will now ignore imports and ignore function signatures when computing duplication. If you want to keep the previous behaviour set ``ignore-imports`` and ``ignore-signatures`` to ``False``. * Pylint now expands the user path (i.e. ``~`` to ``home/yusef/``) and expands environment variables (i.e. ``home/$USER/$project`` to ``home/yusef/pylint`` for ``USER=yusef`` and ``project=pylint``) for pyreverse's ``output-directory``, ``import-graph``, ``ext-import-graph``, ``int-import-graph`` options, and the spell checker's ``spelling-private-dict-file`` option. Refs #6493 * Don't emit ``unsubscriptable-object`` for string annotations. Pylint doesn't check if class is only generic in type stubs only. Closes #4369 and #6523 * Fix pyreverse crash ``RuntimeError: dictionary changed size during iteration`` Refs #6612 * Fix syntax for return type annotations in MermaidJS diagrams produced with ``pyreverse``. Closes #6467 * Fix type annotations of class and instance attributes using the alternative union syntax in ``pyreverse`` diagrams. * Fix bug where it writes a plain text error message to stdout, invalidating output formats. Closes #6597 * The refactoring checker now also raises 'consider-using-a-generator' messages for ``max()``, ``min()`` and ``sum()``. Refs #6595 * Update ranges for ``using-constant-test`` and ``missing-parentheses-for-call-in-test`` error messages. * Don't emit ``no-member`` inside type annotations with ``from __future__ import annotations``. Closes #6594 * Fix ``unexpected-special-method-signature`` false positive for ``__init_subclass__`` methods with one or more arguments. Closes #6644 Deprecations ============ * The ``ignore-mixin-members`` option has been deprecated. You should now use the new ``ignored-checks-for-mixins`` option. Closes #5205 * ``interfaces.implements`` has been deprecated and will be removed in 3.0. Please use standard inheritance patterns instead of ``__implements__``. Refs #2287 * All ``Interface`` classes in ``pylint.interfaces`` have been deprecated. You can subclass the respective normal classes to get the same behaviour. The ``__implements__`` functionality was based on a rejected PEP from 2001: https://peps.python.org/pep-0245/ Closes #2287 * ``MapReduceMixin`` has been deprecated. ``BaseChecker`` now implements ``get_map_data`` and ``reduce_map_data``. If a checker actually needs to reduce data it should define ``get_map_data`` as returning something different than ``None`` and let its ``reduce_map_data`` handle a list of the types returned by ``get_map_data``. An example can be seen by looking at ``pylint/checkers/similar.py``. * The ``config`` attribute of ``BaseChecker`` has been deprecated. You can use ``checker.linter.config`` to access the global configuration object instead of a checker-specific object. Refs #5392 * The ``level`` attribute of ``BaseChecker`` has been deprecated: everything is now displayed in ``--help``, all the time. Refs #5392 * The ``set_option`` method of ``BaseChecker`` has been deprecated. You can use ``checker.linter.set_option`` to set an option on the global configuration object instead of a checker-specific object. Refs #5392 * The ``options_providers`` attribute of ``ArgumentsManager`` has been deprecated. Refs #5392 * Fix saving of persistent data files in environments where the user's cache directory and the linted file are on a different drive. Closes #6394 * The ``method-cache-max-size-none`` checker will now also check ``functools.cache``. * The ``config`` attribute of ``PyLinter`` is now of the ``argparse.Namespace`` type instead of ``optparse.Values``. Refs #5392 * ``UnsupportedAction`` has been deprecated. Refs #5392 * ``OptionsManagerMixIn`` has been deprecated. Refs #5392 * ``OptionParser`` has been deprecated. Refs #5392 * ``Option`` has been deprecated. Refs #5392 * ``OptionsProviderMixIn`` has been deprecated. Refs #5392 * ``ConfigurationMixIn`` has been deprecated. * The ``option_groups`` attribute of ``PyLinter`` has been deprecated. Refs #5392 * ``get_global_config`` has been deprecated. You can now access all global options from ``checker.linter.config``. Refs #5392 * ``OptionsManagerMixIn`` has been replaced with ``ArgumentsManager``. ``ArgumentsManager`` is considered private API and most methods that were public on ``OptionsManagerMixIn`` have now been deprecated and will be removed in a future release. Refs #5392 * ``OptionsProviderMixIn`` has been replaced with ``ArgumentsProvider``. ``ArgumentsProvider`` is considered private API and most methods that were public on ``OptionsProviderMixIn`` have now been deprecated and will be removed in a future release. Refs #5392 * ``pylint.pyreverse.ASTWalker`` has been removed, as it was only used internally by a single child class. Refs #6712 * ``pyreverse``: Resolving and displaying implemented interfaces that are defined by the ``__implements__`` attribute has been deprecated and will be removed in 3.0. Refs #6713 * ``is_class_subscriptable_pep585_with_postponed_evaluation_enabled`` has been deprecated. Use ``is_postponed_evaluation_enabled(node) and is_node_in_type_annotation_context(node)`` instead. Refs #6536