What's New in Pylint 2.9¶
Summary -- Release highlights¶
Pylint is now compatible with python 3.10.
A lot of new checks have been added, some non-opinionated performance warnings
use-maxsplit-arg, some consensual style warnings like
unnecessary-dict-index-lookup or new deprecation checks.
We're aiming to reduce pylint noise for first time users and making some
new checks optional is a step in that direction. In order to do that we
created an optional code style checker that can be loaded using
pylint.extensions.code_style with the
More than ever, if as a veteran you want the most checks you can possibly get,
you should check the list of pylint extensions..
deprecated-decorator: Emitted when deprecated decorator is used.
consider-using-dict-items: Emitted when iterating over dictionary keys and then indexing the same dictionary with the key within loop body.
use-maxsplit-arg: Emitted either when accessing only the first or last element of
ignore_signaturesoption has been added to the similarity checker. It will permits to reduce false positives when multiple functions have the same parameters.
unnecessary-dict-index-lookup: Emitted when iterating over dictionary items (key-value pairs) and accessing the value by index lookup.
consider-using-from-import: Emitted when a submodule/member of a package is imported and aliased with the same name.
unused-private-member: Emitted when a private member (i.e., starts with
__) of a class is defined but not used.
invalid-class-object: Emitted when a non-class is assigned to a
invalid-all-format: Emitted when
__all__has an invalid format, i.e. isn't a
await-outside-async: Emitted when await is used outside an async function.
Add new extension
CodeStyleChecker. It includes checkers that can improve code consistency. As such they don't necessarily provide a performance benefit and are often times opinionated.
consider-using-tuple: Emitted when an in-place defined list or set can be replaced by a tuple.
consider-using-namedtuple-or-dataclass: Emitted when dictionary values can be replaced by namedtuples or dataclass instances.
consider-using-with(R1732) if a ternary conditional is used together with
contextlib.ExitStacktakes care of calling the
Add type annotations to pyreverse dot files
Pylint's tags are now the standard form
too-many-ancestorswhen inheriting from builtin classes, especially from the
The output messages for
arguments-differerror message have been customized based on the different error cases.
--fail-on=<msg ids>to return non-zero exit codes regardless of
A new error called
arguments-renamedhas been created, which identifies any changes at the parameter names of overridden functions. It aims to separate the functionality of
Fix incompatibility with Python 3.6.0 caused by
Allow comma-separated list in
output-formatand separate output files for each specified format. Each output file can be defined after a semicolon for example :
using-constant-testchecker now detects constant tests consisting of list literals like
[1, 2, 3].
ignore-pathsconfiguration directive has been added. Defined regex patterns are matched against file path.
Added handling of floating point values when parsing configuration from pyproject.toml
Fix false positive
useless-type-docon ignored argument using
pylint.extensions.docparamswhen a function was typed using pep484 but not inside the docstring.
Fix missing support for detecting deprecated aliases to existing functions/methods. functions/methods.
Added various deprecated functions/methods for python 3.10, 3.7, 3.6 and 3.3
No longer emit
ProcessPoolExecutoras they have legitimate use cases without a