What's New in Pylint 3.0¶
- Release:
3.0.0
- Date:
2023-10-02
Summary -- Release highlights¶
Pylint now support python 3.12 officially.
This long anticipated major version also provides some important usability and performance improvements, along with enacting necessary breaking changes and long-announced deprecations. The documentation of each message with an example is very close too.
The required astroid
version is now 3.0.0. See the
astroid changelog
for additional fixes, features, and performance improvements applicable to pylint.
Our code is now fully typed. The invalid-name
message no longer checks for a minimum length of 3 characters by default. Dependencies
like wrapt or setuptools were removed.
A new json2
reporter has been added. It features an enriched output that is
easier to parse and provides more info, here's a sample output.
{
"messages": [
{
"type": "convention",
"symbol": "line-too-long",
"message": "Line too long (1/2)",
"messageId": "C0301",
"confidence": "HIGH",
"module": "0123",
"obj": "",
"line": 1,
"column": 0,
"endLine": 1,
"endColumn": 4,
"path": "0123",
"absolutePath": "0123"
}
],
"statistics": {
"messageTypeCount": {
"fatal": 0,
"error": 0,
"warning": 0,
"refactor": 0,
"convention": 1,
"info": 0
},
"modulesLinted": 1,
"score": 5.0
}
}
What's new in Pylint 3.0.4?¶
Release date: 2024-02-23
False Positives Fixed¶
used-before-assignment
is no longer emitted when using a name in a loop and depending on an earlier name assignment in anexcept
block paired withelse: continue
.Closes #6804 (#6804)
Avoid false positives for
no-member
involving function attributes supplied by decorators.Closes #9246 (#9246)
Fixed false positive nested-min-max for nested lists.
Closes #9307 (#9307)
Fix false positive for
used-before-assignment
in afinally
block when assignments took place in both thetry
block and each exception handler.Closes #9451 (#9451)
Other Bug Fixes¶
Catch incorrect ValueError
"generator already executing"
for Python 3.12.0 - 3.12.2. This is fixed upstream in Python 3.12.3.Closes #9138 (#9138)
What's new in Pylint 3.0.3?¶
Release date: 2023-12-11
False Positives Fixed¶
Fixed false positive for
unnecessary-lambda
when the call has keyword arguments but not the lambda.Closes #9148 (#9148)
Fixed incorrect suggestion for shallow copy in unnecessary-comprehension
Example of the suggestion: #pylint: disable=missing-module-docstring a = [1, 2, 3] b = [x for x in a] b[0] = 0 print(a) # [1, 2, 3]
After changing b = [x for x in a] to b = a based on the suggestion, the script now prints [0, 2, 3]. The correct suggestion should be use list(a) to preserve the original behavior.
Closes #9172 (#9172)
Fix false positives for
undefined-variable
andunused-argument
for classes and functions using Python 3.12 generic type syntax.Closes #9193 (#9193)
Fixed
pointless-string-statement
false positive for docstrings on Python 3.12 type aliases.Closes #9268 (#9268)
Fix false positive for
invalid-exception-operation
when concatenating tuples of exception types.Closes #9288 (#9288)
Other Bug Fixes¶
Fix a bug where pylint was unable to walk recursively through a directory if the directory has an __init__.py file.
Closes #9210 (#9210)
What's new in Pylint 3.0.2?¶
Release date: 2023-10-22
False Positives Fixed¶
Fix
used-before-assignment
false positive for generic type syntax (PEP 695, Python 3.12).Closes #9110 (#9110)
Other Bug Fixes¶
Escape special symbols and newlines in messages.
Closes #7874 (#7874)
Fixes suggestion for
nested-min-max
for expressions with additive operators, list and dict comprehensions.Closes #8524 (#8524)
Fixes ignoring conditional imports with
ignore-imports=y
.Closes #8914 (#8914)
Emit
inconsistent-quotes
for f-strings with 3.12 interpreter only if targeting pre-3.12 versions.Closes #9113 (#9113)
What's new in Pylint 3.0.1?¶
Release date: 2023-10-05
False Positives Fixed¶
Fixed false positive for
inherit-non-class
for generic Protocols.Closes #9106 (#9106)
Other Changes¶
Fix a crash when an enum class which is also decorated with a
dataclasses.dataclass
decorator is defined.Closes #9100 (#9100)
What's new in Pylint 3.0.0?¶
Release date: 2023-10-02
Breaking Changes¶
Enabling or disabling individual messages will now take effect even if an
--enable=all
ordisable=all
follows in the same configuration file (or on the command line).This means for the following example,
fixme
messages will now be emitted:pylint my_module --enable=fixme --disable=all
To regain the prior behavior, remove the superfluous earlier option.
Closes #3696 (#3696)
Remove support for launching pylint with Python 3.7. Code that supports Python 3.7 can still be linted with the
--py-version=3.7
setting.Refs #6306 (#6306)
Disables placed in a
try
block now apply to theexcept
block. Previously, they only happened to do so in the presence of anelse
clause.Refs #7767 (#7767)
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)
Everything related to the
__implements__
construct was removed. It was based on PEP245 that was proposed in 2001 and rejected in 2006.The capability from pyreverse to take
__implements__
into account when generating diagrams was also removed.Refs #8404 (#8404)
pyreverse
: Support for the.vcg
output format (Visualization 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.
Refs #8462 (#8462)
Following a deprecation period,
pylint.config.PYLINTRC
was removed. Use thepylint.config.find_default_config_files
generator instead.Closes #8862 (#8862)
Changes requiring user actions¶
The
invalid-name
message no longer checks for a minimum length of 3 characters by default. (This was an unadvertised commingling of concerns between casing and name length, and users regularly reported this to be surprising.)If checking for a minimum length is still desired, it can be regained in two ways:
If you are content with a
disallowed-name
message (instead ofinvalid-name
), then simply add the optionbad-names-rgxs="^..?$"
, which will fail 1-2 character-long names. (Ensure you enabledisallowed-name
.)If you would prefer an
invalid-name
message to be emitted, or would prefer finer-grained control over the circumstances in which messages are emitted (classes vs. methods, etc.), then avail yourself of the regex options described here. (In particular, take note of the commented out options in the "example configuration" given at the bottom of the section.) The prior regexes can be found in the pull request that removed the length requirements.
Closes #2018 (#2018)
The compare to empty string checker (
pylint.extensions.emptystring
) and the compare to zero checker (pylint.extensions.compare-to-zero
) have been removed and their checks are now part of the implicit booleaness checker:compare-to-zero
was renameduse-implicit-booleaness-not-comparison-to-zero
andcompare-to-empty-string
was renameduse-implicit-booleaness-not-comparison-to-string
and they now need to be enabled explicitly.The
pylint.extensions.emptystring
andpylint.extensions.compare-to-zero
extensions no longer exist and need to be removed from theload-plugins
option.Messages related to implicit booleaness were made more explicit and actionable. This permits to make their likeness explicit and will provide better performance as they share most of their conditions to be raised.
Closes #6871 (#6871)
epylint was removed. It now lives at: https://github.com/emacsorphanage/pylint.
Refs #7737 (#7737)
The
overgeneral-exceptions
option now only takes fully qualified names into account (builtins.Exception
notException
). 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
ormaster
as configuration section insetup.cfg
ortox.ini
. It's bad practice to not start a section title with the tool name. Please usepylint.main
instead.Refs #8465 (#8465)
Package stats are now printed when running Pyreverse and a
--verbose
flag was added to get the original output with parsed modules. You might need to activate the verbose option if you want to keep the old output.Closes #8973 (#8973)
New Features¶
A new
json2
reporter has been added. It features a more enriched output that is easier to parse and provides more info.Compared to
json
the only changes are that messages are now under the"messages"
key and that"message-id"
now follows the camelCase convention and is renamed to"messageId"
. The new reporter also reports the "score" of the modules you linted as defined by theevaluation
option and provides statistics about the modules you linted.We encourage users to use the new reporter as the
json
reporter will no longer be maintained.Closes #4741 (#4741)
In Pyreverse package dependency diagrams, show when a module imports another only for type-checking.
Closes #8112 (#8112)
Add new option (
--show-stdlib
,-L
) topyreverse
. 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)
Add Pyreverse option to exclude standalone nodes from diagrams with --no-standalone.
Closes #8476 (#8476)
New Checks¶
Added
DataclassChecker
module andinvalid-field-call
checker to check for invalid dataclasses.field() usage.Refs #5159 (#5159)
Add
return-in-finally
to emit a message if a return statement was found in a finally clause.Closes #8260 (#8260)
Add a new checker
kwarg-superseded-by-positional-arg
to warn when a function is called with a keyword argument which shares a name with a positional-only parameter and the function contains a keyword variadic parameter dictionary. It may be surprising behaviour when the keyword argument is added to the keyword variadic parameter dictionary.Closes #8558 (#8558)
Extensions¶
Add new
prefer-typing-namedtuple
message to theCodeStyleChecker
to suggest rewriting calls tocollections.namedtuple
as classes inheriting fromtyping.NamedTuple
on Python 3.6+.Requires
load-plugins=pylint.extensions.code_style
andenable=prefer-typing-namedtuple
to be raised.Closes #8660 (#8660)
False Positives Fixed¶
Extend concept of "function ambiguity" in
safe_infer()
from differing number of function arguments to differing set of argument names.Solves false positives in
tensorflow
.Closes #3613 (#3613)
Fix unused-argument false positive when __new__ does not use all the arguments of __init__.
Closes #3670 (#3670)
Fix a false positive for
invalid-name
when a type-annotated class variable in anenum.Enum
class has no assigned value.Refs #7402 (#7402)
Fix
unused-import
false positive for usage ofsix.with_metaclass
.Closes #7506 (#7506)
Fix false negatives and false positives for
too-many-try-statements
,too-complex
, andtoo-many-branches
by correctly counting statements under atry
.Refs #7767 (#7767)
When checking for unbalanced dict unpacking in for-loops, Pylint will now test whether the length of each value to be unpacked matches the number of unpacking targets. Previously, Pylint would test the number of values for the loop iteration, which would produce a false unbalanced-dict-unpacking warning.
Closes #8156 (#8156)
Fix false positive for
used-before-assignment
when usage and assignment are guarded by the same test in different statements.Closes #8167 (#8167)
Adds
asyncSetUp
to the defaultdefining-attr-methods
list to silenceattribute-defined-outside-init
warning when usingunittest.IsolatedAsyncioTestCase
.Refs #8403 (#8403)
logging-not-lazy is not longer emitted for explicitly concatenated string arguments.
Closes #8410 (#8410)
Fix false positive for isinstance-second-argument-not-valid-type when union types contains None.
Closes #8424 (#8424)
invalid-name
now allows for integers intypealias
names: - now valid:Good2Name
,GoodName2
. - still invalid:_1BadName
.Closes #8485 (#8485)
No longer consider
Union
as type annotation as type alias for naming checks.Closes #8487 (#8487)
unnecessary-lambda
no longer warns on lambdas which use its parameters in their body (other than the final arguments), e.g.lambda foo: (bar if foo else baz)(foo)
.Closes #8496 (#8496)
Fixed unused-import so that it observes the dummy-variables-rgx option.
Closes #8500 (#8500)
Union typed variables without assignment are no longer treated as TypeAlias.
Closes #8540 (#8540)
Allow parenthesized implicitly concatenated strings when check-str-concat-over-line-jumps is enabled.
Closes #8552. (#8552)
Fix false positive for
positional-only-arguments-expected
when a function contains both a positional-only parameter that has a default value, and**kwargs
.Closes #8555 (#8555)
Fix false positive for
keyword-arg-before-vararg
when a positional-only parameter with a default value precedes*args
.Closes #8570 (#8570)
Fix false positive for
arguments-differ
when overriding __init_subclass__.Closes #8919 (#8919)
Fix a false positive for
no-value-for-parameter
when a staticmethod is called in a class body.Closes #9036 (#9036)
False Negatives Fixed¶
Emit
used-before-assignment
when calling module-level functions before definition.Closes #1144 (#1144)
Apply
infer_kwarg_from_call()
to more checksThese mostly solve false negatives for various checks, save for one false positive for
use-maxsplit-arg
.Closes #7761 (#7761)
TypeAlias variables defined in functions are now checked for invalid-name errors.
Closes #8536 (#8536)
Fix false negative for
no-value-for-parameter
when a function, whose signature contains both a positional-only parametername
and also*kwargs
, is called with a keyword-argument forname
.Closes #8559 (#8559)
Fix a false negative for
too-many-arguments
by considering positional-only and keyword-only parameters.Closes #8667 (#8667)
Emit
assignment-from-no-return
for calls to builtin methods likedict.update()
. Calls tolist.sort()
now raiseassignment-from-no-return
rather thanassignment-from-none
for consistency.Closes #8714 Closes #8810 (#8714)
consider-using-augmented-assign
is now applied to dicts and lists as well.Closes #8959. (#8959)
Other Bug Fixes¶
Support
duplicate-code
message when parallelizing with--jobs
.Closes #374 (#374)
Support
cyclic-import
message when parallelizing with--jobs
.Closes #4171 (#4171)
--jobs
can now be used with--load-plugins
.This had regressed in astroid 2.5.0.
Closes #4874 (#4874)
docparams extension considers type comments as type documentation.
Closes #6287 (#6287)
When parsing comma-separated lists of regular expressions in the config, ignore commas that are inside braces since those indicate quantifiers, not delineation between expressions.
Closes #7229 (#7229)
The
ignored-modules
option will now be correctly taken into account forno-name-in-module
.Closes #7578 (#7578)
sys.argv
is now always correctly considered as impossible to infer (instead of using the actual values given to pylint).Closes #7710 (#7710)
Avoid duplicative warnings for unqualified exception names in the
overgeneral-exceptions
setting when running with--jobs
.Closes #7774 (#7774)
Don't show class fields more than once in Pyreverse diagrams.
Closes #8189 (#8189)
Fix
used-before-assignment
false negative when TYPE_CHECKING imports are used in multiple scopes.Closes #8198 (#8198)
--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
used-before-assignment
false positive when imports are made under theTYPE_CHECKING
else if branch.Closes #8437 (#8437)
Fix a regression of
preferred-modules
where a partial match was used instead of the required full match.Closes #8453 (#8453)
Fix a crash in pyreverse when "/" characters are used in the output filename e.g pyreverse -o png -p name/ path/to/project.
Closes #8504 (#8504)
Don't show arrows more than once in Pyreverse diagrams.
Closes #8522 (#8522)
Improve output of
consider-using-generator
message formin()
calls withdefault
keyword.Closes #8563 (#8563)
Fixed a crash when generating a configuration file:
tomlkit.exceptions.TOMLKitError: Can't add a table to a dotted key
caused by tomlkitv0.11.8
.Closes #8632 (#8632)
Fix a line break error in Pyreverse dot output.
Closes #8671 (#8671)
Fix a false positive for
method-hidden
when usingcached_property
decorator.Closes #8753 (#8753)
Dunder methods defined in lambda do not trigger
unnecessary-dunder-call
anymore, if they cannot be replaced by the non-dunder call.Closes #8769 (#8769)
Don't show duplicate type annotations in Pyreverse diagrams.
Closes #8888 (#8888)
Fixing inconsistent hashing issue in BaseChecker causing some reports not being exported.
Closes #9001 (#9001)
Don't add Optional to | annotations with None in Pyreverse diagrams.
Closes #9014 (#9014)
Pyreverse doesn't show multiple class association arrows anymore, but only the strongest one.
Refs #9045 (#9045)
Prevented data loss in the linter stats for messages relating to the linter itself (e.g.
unknown-option-value
), fixing problems with score, fail-on, etc.Closes #9059 (#9059)
Fix crash in refactoring checker when unary operand used with variable in for loop.
Closes #9074 (#9074)
Other Changes¶
Pylint now exposes its type annotations.
Closes #5488 and #2079 (#5488)
Search for
pyproject.toml
recursively in parent directories up to a project or file system root.Refs #7163, Closes #3289 (#7163)
All code related to the optparse config parsing has been removed.
Refs #8405 (#8405)
Pylint now supports python 3.12.
Refs #8718 (#8718)
Add a CITATION.cff file to the root of the repository containing the necessary metadata to cite Pylint.
Closes #8760 (#8760)
Renamed the "unneeded-not" error into "unnecessary_negation" to be clearer.
Closes #8789 (#8789)
Internal Changes¶
get_message_definition
was removed from the base checker API. You can access message definitions through theMessageStore
.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.All the classes inheriting
Interface
inpylint.interfaces
were removed.Checker
should only inheritBaseChecker
or any of the other checker types frompylint.checkers
.Reporter
should only inheritBaseReporter
.Refs #8404 (#8404)
modname
andmsg_store
are now required to be given inFileState
.collect_block_lines
has also been removed.Pylinter.current_name
cannot be null anymore.Refs #8407 (#8407)
Reporter.set_output
was removed in favor ofreporter.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 implementget_map_data
andreduce_map_data
.is_inside_lambda
: Useutils.get_node_first_ancestor_of_type(x, nodes.Lambda)
check_messages
: Useutils.only_required_for_messages
is_class_subscriptable_pep585_with_postponed_evaluation_enabled
: Useis_postponed_evaluation_enabled(node)
andis_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. Usediscover_package_path
and pass source root(s).fix_import_path
: Useaugmented_sys_path
and pass additionalsys.path
entries as an argument obtained fromdiscover_package_path
.get_global_option
: Usechecker.linter.config
to get all global options.Related private objects have been removed as well.
Refs #8409 (#8409)
colorize_ansi
now only accepts aMessageStyle
object.Refs #8412 (#8412)
Following a deprecation period,
Pylinter.check
now only works with sequences of strings, not strings.Refs #8463 (#8463)
Following a deprecation period,
ColorizedTextReporter
only acceptsColorMappingDict
.Refs #8464 (#8464)
Following a deprecation period,
MessageTest
'send_line
andend_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 theRun
class (and of the_Run
class in testutils) were removed.Refs #8472 (#8472)
Following a deprecation period, the
py_version
argument of theMessageDefinition.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, the
OutputLine
class now requires the right number of argument all the time. The functional output can be regenerated automatically to achieve that easily.Refs #8474 (#8474)
Following a deprecation period,
is_typing_guard
,is_node_in_typing_guarded_import_block
andis_node_in_guarded_import_block
frompylint.utils
were removed: use a combination ofis_sys_guard
andin_type_checking_block
instead.Refs #8475 (#8475)
Following a deprecation period, the
location
argument of theMessage
class must now be aMessageLocationTuple
.Refs #8477 (#8477)
Following a deprecation period, the
check_single_file
function of thePylinter
is replaced byPylinter.check_single_file_item
.Refs #8478 (#8478)