2.13.rst

What's New in Pylint 2.13

Release

2.13

Date

TBA

Summary -- Release highlights

New checkers

• Added several checkers to deal with unicode security issues (see Trojan Sources and PEP 672 for details) that also concern the readability of the code. In detail the following checks were added:

  • bad-file-encoding checks that the file is encoded in UTF-8 as suggested by PEP8. UTF-16 and UTF-32 are not supported by Python at the moment. If this ever changes invalid-unicode-codec checks that they aren't used, to allow for backwards compatibility.
  • bidirectional-unicode checks for bidirectional unicode characters that could make code execution different than what the user expects.
  • invalid-character-backspace, invalid-character-carriage-return, invalid-character-sub, invalid-character-esc, invalid-character-zero-width-space and invalid-character-nul to check for possibly harmful unescaped characters.

  Closes #5281

• unnecessary-ellipsis: Emitted when the ellipsis constant is used unnecessarily.

  Closes #5460

• Add checker redefined-slots-in-subclass: Emitted when a slot is redefined in a subclass.

  Closes #5617

• Rewrote Checker of non-ascii-name.

  It now ensures __all__ Python names are ASCII and also properly checks the names of imports (non-ascii-module-import) as well as file names (non-ascii-file-name) and emits their respective new warnings.

  Non ASCII characters could be homoglyphs (look alike characters) and hard to enter on a non specialized keyboard. See Confusable Characters in PEP 672

• Added lru-cache-decorating-method checker with checks for the use of functools.lru_cache on class methods. This is unrecommended as it creates memory leaks by never letting the instance getting garbage collected.

  Closes #5670

Removed checkers

Extensions

• Pyreverse - add output in mermaid-js format and html which is an mermaid js diagram with html boilerplate
• DocstringParameterChecker
  • Fixed incorrect classification of Numpy-style docstring as Google-style docstring for docstrings with property setter documentation. Docstring classification is now based on the highest amount of matched sections instead of the order in which the docstring styles were tried.

• DocStringStyleChecker

  • Disable checker bad-docstring-quotes for Python <= 3.7, because in these versions the line numbers for decorated functions and classes are not reliable which interferes with the checker.

    Closes #3077

Other Changes

• Fixed crash from arguments-differ and arguments-renamed when methods were defined outside the top level of a class.

  Closes #5648

• Fixed false positive consider-using-dict-comprehension when creating a dict using a list of tuples where key AND value vary depending on the same condition.

  Closes #5588

• When run in parallel mode pylint now pickles the data passed to subprocesses with the dill package. The dill package has therefore been added as a dependency.

• Fixed false positive for global-variable-undefined when global is used with a class name

  Closes #3088

• Fixed crash on properties and inherited class methods when comparing them for equality against an empty dict.

  Closes #5646

• By default, pylint does no longer take files starting with .# into account. Those are considered emacs file locks. This behavior can be reverted by redefining the ignore-patterns option.

  Closes #367

• Fix super-init-not-called when parent or self is a Protocol

  Closes #4790

• An astroid issue where symlinks were not being taken into account was fixed

  Closes #1470 Closes #3499 Closes #4302 Closes #4798 Closes #5081

• Fixed extremely long processing of long lines with comma's.

  Closes #5483

• Fix false positive super-init-not-called for classes that inherit their init from a parent.

  Closes #4941

• Fix unnecessary_dict_index_lookup false positive when deleting a dictionary's entry.

  Closes #4716

• Fix a crash in unused-private-member checker when analyzing code using type(self) in bound methods.

  Closes #5569

• Fix crash in unnecessary-dict-index-lookup checker if the output of items() is assigned to a 1-tuple.

  Closes #5504

• Fixed crash with slots assignments and annotated assignments.

  Closes #5479

• Fix false negative for consider-iterating-dictionary during membership checks encapsulated in iterables or not in checks

  Closes #5323

• Fix false positive for undefined-variable when namedtuple class attributes are used as return annotations.

  Closes #5568

• used-before-assignment now considers that assignments in a try block may not have occurred when the except or finally blocks are executed.

  Closes #85, #2615

• Fixed false negative for used-before-assignment when a conditional or context manager intervened before the try statement that suggested it might fail.

  Closes #4045

• Fixed false negative for used-before-assignment in finally blocks if an except handler did not define the assignment that might have failed in the try block.

• Fix a false positive for assigning-non-slot when the slotted class defined __setattr__.

  Closes #3793

• Fixed false positive for used-before-assignment with self-referential type annotation in conditional statements within class methods.

  Closes #5499

• used-before-assignment now assumes that assignments in except blocks may not have occurred and warns accordingly.

  Closes #4761

• When evaluating statements after an except block, used-before-assignment assumes that assignments in the except blocks took place if the corresponding try block contained a return statement.

  Closes #5500

• used-before-assignment now checks names in try blocks.

• Fixed false positive with used-before-assignment for assignment expressions in lambda statements.

  Closes #5360, #3877

• Fixed a false positive (affecting unreleased development) for used-before-assignment involving homonyms between filtered comprehensions and assignments in except blocks.

  Closes #5586

• Fixed crash on list comprehensions that used type as inner variable name.

  Closes #5461

• Fix false positive for unused-variable for a comprehension variable matching an outer scope type annotation.

  Closes #5326

• Require Python 3.6.2 to run pylint.

  Closes #5065

• Fixed crash on uninferable decorators on Python 3.6 and 3.7

• Emit redefined-outer-name when a nested except handler shadows an outer one.

  Closes #4434 Closes #5370

• encoding can now be supplied as a positional argument to calls that open files without triggering unspecified-encoding.

  Closes #5638

• Fatal errors now emit a score of 0.0 regardless of whether the linted module contained any statements

  Closes #5451

• fatal was added to the variables permitted in score evaluation expressions.

• The default score evaluation now uses a floor of 0.

  Closes #2399

• Fix comparison-with-callable false positive for callables that raise, such as typing constants.

  Closes #5557

• When invoking pylint, epylint, symilar or pyreverse by importing them in a python file you can now pass an arguments keyword besides patching sys.argv.

  Closes #5320

• The PyLinter class will now be initialized with a TextReporter as its reporter if none is provided.

• Fix false positive not-callable with attributes that alias NamedTuple

  Partially closes #1730

• The testutils for unittests now accept end_lineno and end_column. Tests without these will trigger a DeprecationWarning.

• Fixed false positive unexpected-keyword-arg for decorators.

  Closes #258

• missing-raises-doc will now check the class hierarchy of the raised exceptions

  def my_function()
    """My function.
  
    Raises:
      Exception: if something fails
    """
    raise ValueError

  Closes #4955

• Fixed false positive for unused-variable when a nonlocal name is assigned as part of a multi-name assignment.

  Closes #3781

• Fixed false positive for global-variable-not-assigned when the del statement is used

  Closes #5333