Keep lambda parameters on one line and parenthesize the body if it expands by ntBre · Pull Request #21385 · astral-sh/ruff (original) (raw)

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Nov 11, 2025

ntBre added a commit that referenced this pull request

Nov 11, 2025

ntBre changed the title[WIP] Indent lambda parameters if parameters wrap [WIP] Keep lambda parameters on one line and parenthesize the body if it expands

Nov 12, 2025

ntBre changed the title[WIP] Keep lambda parameters on one line and parenthesize the body if it expands Keep lambda parameters on one line and parenthesize the body if it expands

Nov 14, 2025

ntBre marked this pull request as ready for review

November 14, 2025 13:54

ntBre marked this pull request as draft

November 18, 2025 19:15

ntBre added a commit that referenced this pull request

Nov 20, 2025

Summary

This PR changes our formatting of lambda expressions to keep the parameters on a single line, at least if there are no comments. This fixes #8179.

Black formatting and this PR's formatting:

def a():
    return b(
        c,
        d,
        e,
        f=lambda self, *args, **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(
            *args, **kwargs
        ),
    )

Stable Ruff formatting

def a():
    return b(
        c,
        d,
        e,
        f=lambda self,
        *args,
        **kwargs: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa(*args, **kwargs),
    )

I split this off from #21385 because it seemed like the simpler change and helpful to isolate from the body parenthesization ecosystem and performance changes. However, as Micha pointed out, we need the formatting from #21385 to land first, so this branch is currently stacked on that one.

Test Plan

New formatting on tests from #8465 and #21385

ntBre deleted the brent/indent-lambda-params branch

December 12, 2025 17:02

dcreager added a commit that referenced this pull request

Dec 13, 2025

• origin/main: (22 commits) [ty] Allow gradual lower/upper bounds in a constraint set (#21957) [ty] disallow explicit specialization of type variables themselves (#21938) [ty] Improve diagnostics for unsupported binary operations and unsupported augmented assignments (#21947) [ty] update implicit root docs (#21955) [ty] Enable even more goto-definition on inlay hints (#21950) Document known lambda formatting deviations from Black (#21954) [ty] fix hover type on named expression target (#21952) Bump benchmark dependencies (#21951) Keep lambda parameters on one line and parenthesize the body if it expands (#21385) [ty] Improve resolution of absolute imports in tests (#21817) [ty] Support __all__ += submodule.__all__ [ty] Change frequency of invalid __all__ debug message [ty] Add KnownUnion::to_type() (#21948) [ty] Classify cls as class parameter (#21944) [ty] Stabilize rename (#21940) [ty] Ignore __all__ for document and workspace symbol requests [ty] Attach db to background request handler task (#21941) [ty] Fix outdated version in publish diagnostics after didChange (#21943) [ty] avoid fixpoint unioning of types containing current-cycle Divergent (#21910) [ty] improve bad specialization results & error messages (#21840) ...

This was referenced

Feb 9, 2026

nicopauss pushed a commit to Intersec/lib-common that referenced this pull request

Apr 1, 2026

Note this update introcudes the new warning ISC004, which requires some fixes in our code.

Released on 2026-01-22.

• Preserve required parentheses in lambda bodies (#22747)

• Combine range suppression code diagnostics (#22613)

• [airflow] Second positional argument to Asset/Dataset should not be a dictionary (AIR303) (#22453)

• [ruff] Detect duplicate entries in __all__ (RUF068) (#22114)

• [pyupgrade] Allow shadowing non-builtin bindings (UP029) (#22749)

• [pyupgrade] Apply UP045 to string arguments of typing.cast (#22320)

• [flake8-pie] Detect duplicated declared class fields in PIE794 (#22717)

• [flake8-pyi] Fix inconsistent handling of forward references for __new__, __enter__, __aenter__ in PYI034 (#22798)

• [flake8-pytest-style] Support check parameter in PT011 (#22725)

• [ruff] Add exception for ctypes.Structure._fields_ (RUF012) (#22559)

• Many fixes are now marked unsafe if they would remove comments:

  • [flake8-bugbear] B009, B010, B013, B014, B033
  • [flake8-simplify] SIM910, SIM911
  • [pyupgrade] UP007, UP039, UP041, UP045
  • [refurb] FURB105, FURB116, FURB136, FURB140, FURB145, FURB154, FURB157, FURB164,FURB181, FURB188
  • [ruff] RUF019, RUF020

• Add --exit-non-zero-on-format to formatter exit codes section (#22761)

• Update contributing guide for adding a new rule (#22779)

• [FastAPI] Document fix safety for FAST001 (#22655)

• [flake8-async] Tweak explanation to focus on latency/efficiency tradeoff (ASYNC110) (#22715)

• [pandas-vet] Make example error out-of-the-box (PD002) (#22561)

• [refurb] Make the example work out of box (FURB101) (#22770)

• [refurb] Make the example work out of box (FURB103) (#22769)

• @alejsdev

• @ntBre

• @caiquejjx

• @chirizxc

• @denyszhak

• @sjyangkevin

• @MeGaGiGaGon

• @leandrobbraga

• @MichaReiser

• @carljm

• @amyreese

• @zsol

• @harupy

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.14/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.14/ruff-installer.ps1 | iex"

Released on 2026-01-15.

This is a follow-up release to 0.14.12. Because of an issue publishing the WASM packages, there is no GitHub release or Git tag for 0.14.12, although the package was published to PyPI. The contents of the 0.14.13 release are identical to 0.14.12.

• [flake8-blind-except] Allow more logging methods (BLE001) (#22057)

• [ruff] Respect lint.pydocstyle.property-decorators in RUF066 (#22515)

• Fix configuration path in --show-settings (#22478)

• Respect fmt: skip for multiple statements on the same logical line (#22119)

• [pydocstyle] Update Rust crate imperative to v1.0.7 (D401) (#22519)

• [isort] Insert imports in alphabetical order (I002) (#22493)

• Add llms.txt support for documentation (#22463)

• Use prek in documentation and CI (#22505)

• [flake8-pytest-style] Add check parameter example to PT017 docs (#22546)

• [ruff] Make example error out-of-the-box (RUF103) (#22558)

• [ruff] document RUF100 trailing comment fix behavior (#22479)

• wasm: Require explicit logging initialization (#22587)

• @terror

• @harupy

• @Jkhall81

• @dhruvmanila

• @lubaskinc0de

• @zanieb

• @MeGaGiGaGon

• @charliermarsh

• @renovate

• @dylwil3

• @MichaReiser

• @11happy

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.13/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.13/ruff-installer.ps1 | iex"

Released on 2026-01-08.

• Consolidate diagnostics for matched disable/enable suppression comments (#22099)

• Report diagnostics for invalid/unmatched range suppression comments (#21908)

• [airflow] Passing positional argument into airflow.lineage.hook.HookLineageCollector.create_asset is not allowed (AIR303) (#22046)

• [refurb] Mark FURB192 fix as always unsafe (#22210)

• [ruff] Add non-empty-init-module (RUF067) (#22143)

• Fix GitHub format for multi-line diagnostics (#22108)

• [flake8-unused-arguments] Mark **kwargs in TypeVar as used (ARG001) (#22214)

• Add help: subdiagnostics for several Ruff rules that can sometimes appear to disagree with ty (#22331)

• [pylint] Demote PLW1510 fix to display-only (#22318)

• [pylint] Ignore identical members (PLR1714) (#22220)

• [pylint] Improve diagnostic range for PLC0206 (#22312)

• [ruff] Improve fix title for RUF102 invalid rule code (#22100)

• [flake8-simplify]: Avoid unnecessary builtins import for SIM105 (#22358)

• Allow Python 3.15 as valid target-version value in preview (#22419)

• Check required-version before parsing rules (#22410)

• Include configured src directories when resolving graphs (#22451)

• Update T201 suggestion to not use root logger to satisfy LOG015 (#22059)

• Fix iter example in unsafe fixes doc (#22118)

• [flake8_print] better suggestion for basicConfig in T201 docs (#22101)

• [pylint] Restore the fix safety docs for PLW0133 (#22211)

• Fix Jupyter notebook discovery info for editors (#22447)

• @charliermarsh

• @ntBre

• @cenviity

• @njhearp

• @cbachhuber

• @jelle-openai

• @AlexWaygood

• @ValdonVitija

• @BurntSushi

• @Jkhall81

• @PeterJCLaw

• @harupy

• @amyreese

• @sjyangkevin

• @woodruffw

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.11/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.11/ruff-installer.ps1 | iex"

Released on 2025-12-18.

• [formatter] Fluent formatting of method chains (#21369)

• [formatter] Keep lambda parameters on one line and parenthesize the body if it expands (#21385)

• [flake8-implicit-str-concat] New rule to prevent implicit string concatenation in collections (ISC004) (#21972)

• [flake8-use-pathlib] Make fixes unsafe when types change in compound statements (PTH104, PTH105, PTH109, PTH115) (#22009)

• [refurb] Extend support for Path.open (FURB101, FURB103) (#21080)

• [pyupgrade] Fix parsing named Unicode escape sequences (UP032) (#21901)

• [eradicate] Ignore ruff:disable and ruff:enable comments in ERA001 (#22038)

• [flake8-pytest-style] Allow match and check keyword arguments without an expected exception type (PT010) (#21964)

• [syntax-errors] Annotated name cannot be global (#20868)

• Add uv and ty to the Ruff README (#21996)

• Document known lambda formatting deviations from Black (#21954)

• Update setup.md (#22024)

• [flake8-bandit] Fix broken link (S704) (#22039)

• Fix playground Share button showing "Copied!" before clipboard copy completes (#21942)

• @dylwil3

• @charliecloudberry

• @charliermarsh

• @chirizxc

• @ntBre

• @zanieb

• @amyreese

• @hauntsaninja

• @11happy

• @mahiro72

• @MichaReiser

• @phongddo

• @PeterJCLaw

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.10/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.10/ruff-installer.ps1 | iex"

Released on 2025-12-11.

• [ruff] New RUF100 diagnostics for unused range suppressions (#21783)

• [pylint] Detect subclasses of builtin exceptions (PLW0133) (#21382)

• Fix comment placement in lambda parameters (#21868)

• Skip over trivia tokens after re-lexing (#21895)

• [flake8-bandit] Fix false positive when using non-standard CSafeLoader path (S506). (#21830)

• [flake8-bugbear] Accept immutable slice default arguments (B008) (#21823)

• [pydocstyle] Suppress D417 for parameters with Unpack annotations (#21816)

• Use memchr for computing line indexes (#21838)

• Document *.pyw is included by default in preview (#21885)

• Document range suppressions, reorganize suppression docs (#21884)

• Update mkdocs-material to 9.7.0 (Insiders now free) (#21797)

• @Avasam

• @MichaReiser

• @charliermarsh

• @amyreese

• @phongddo

• @prakhar1144

• @mahiro72

• @ntBre

• @LoicRiegel

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.9/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.9/ruff-installer.ps1 | iex"

Released on 2025-12-04.

• [flake8-bugbear] Catch yield expressions within other statements (B901) (#21200)

• [flake8-use-pathlib] Mark fixes unsafe for return type changes (PTH104, PTH105, PTH109, PTH115) (#21440)

• Fix syntax error false positives for await outside functions (#21763)

• [flake8-simplify] Fix truthiness assumption for non-iterable arguments in tuple/list/set calls (SIM222, SIM223) (#21479)

• Suggest using --output-file option in GitLab integration (#21706)

• [syntax-error] Default type parameter followed by non-default type parameter (#21657)

• @kieran-ryan

• @11happy

• @danparizher

• @ntBre

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.8/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.8/ruff-installer.ps1 | iex"

Released on 2025-11-28.

• [flake8-bandit] Handle string literal bindings in suspicious-url-open-usage (S310) (#21469)

• [pylint] Fix PLR1708 false positives on nested functions (#21177)

• [pylint] Fix suppression for empty dict without tuple key annotation (PLE1141) (#21290)

• [ruff] Add rule RUF066 to detect unnecessary class properties (#21535)

• [ruff] Catch more dummy variable uses (RUF052) (#19799)

• [server] Set severity for non-rule diagnostics (#21559)

• [flake8-implicit-str-concat] Avoid invalid fix in (ISC003) (#21517)

• [parser] Fix panic when parsing IPython escape command expressions (#21480)

• Show partial fixability indicator in statistics output (#21513)

• @mikeleppane

• @senekor

• @ShaharNaveh

• @JumboBear

• @prakhar1144

• @tsvikas

• @danparizher

• @chirizxc

• @AlexWaygood

• @MichaReiser

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.7/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.7/ruff-installer.ps1 | iex"

Released on 2025-11-21.

• [flake8-bandit] Support new PySNMP API paths (S508, S509) (#21374)

• Adjust own-line comment placement between branches (#21185)

• Avoid syntax error when formatting attribute expressions with outer parentheses, parenthesized value, and trailing comment on value (#20418)

• Fix panic when formatting comments in unary expressions (#21501)

• Respect fmt: skip for compound statements on a single line (#20633)

• [refurb] Fix FURB103 autofix (#21454)

• [ruff] Fix false positive for complex conversion specifiers in logging-eager-conversion (RUF065) (#21464)

• [ruff] Avoid false positive on ClassVar reassignment (RUF012) (#21478)

• Render hyperlinks for lint errors (#21514)

• Add a ruff analyze option to skip over imports in TYPE_CHECKING blocks (#21472)

• Limit eglot-format hook to eglot-managed Python buffers (#21459)

• Mention force-exclude in "Configuration > Python file discovery" (#21500)

• @ntBre

• @dylwil3

• @gauthsvenkat

• @MichaReiser

• @thamer

• @Ruchir28

• @thejcannon

• @danparizher

• @chirizxc

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/astral-sh/ruff/releases/download/0.14.6/ruff-installer.sh | sh

powershell -ExecutionPolicy Bypass -c "irm https://github.com/astral-sh/ruff/releases/download/0.14.6/ruff-installer.ps1 | iex"

nicopauss pushed a commit to Intersec/lib-common that referenced this pull request

Apr 1, 2026

Released on 2026-03-19.

• Display output severity in preview (#23845)

• Don't show noqa hover for non-Python documents (#24040)

• [pycodestyle] Recognize pyrefly: as a pragma comment (E501) (#24019)

• Don't return code actions for non-Python documents (#23905)

• Add company AI policy to contributing guide (#24021)

• Document editor features for Markdown code formatting (#23924)

• [pylint] Improve phrasing (PLC0208) (#24033)

• Use PEP 639 license information (#19661)

• @tmimmanuel

• @DimitriPapadopoulos

• @amyreese

• @statxc

• @dylwil3

• @hunterhogan

• @renovate

Released on 2026-03-12.

• Add support for lazy import parsing (#23755)

• Add support for star-unpacking of comprehensions (PEP 798) (#23788)

• Reject semantic syntax errors for lazy imports (#23757)

• Drop a few rules from the preview default set (#23879)

• [airflow] Flag Variable.get() calls outside of task execution context (AIR003) (#23584)

• [airflow] Flag runtime-varying values in DAG/task constructor arguments (AIR304) (#23631)

• [flake8-bugbear] Implement delattr-with-constant (B043) (#23737)

• [flake8-tidy-imports] Add TID254 to enforce lazy imports (#23777)

• [flake8-tidy-imports] Allow users to ban lazy imports with TID254 (#23847)

• [isort] Retain lazy keyword when sorting imports (#23762)

• [pyupgrade] Add from __future__ import annotations automatically (UP006) (#23260)

• [refurb] Support newline parameter in FURB101 for Python 3.13+ (#23754)

• [ruff] Add os-path-commonprefix (RUF071) (#23814)

• [ruff] Add unsafe fix for os-path-commonprefix (RUF071) (#23852)

• [ruff] Limit RUF036 to typing contexts; make it unsafe for non-typing-only (#23765)

• [ruff] Use starred unpacking for RUF017 in Python 3.15+ (#23789)

• Fix --add-noqa creating unwanted leading whitespace (#23773)

• Fix --add-noqa breaking shebangs (#23577)

• [formatter] Fix lambda body formatting for multiline calls and subscripts (#23866)

• [formatter] Preserve required annotation parentheses in annotated assignments (#23865)

• [formatter] Preserve type-expression parentheses in the formatter (#23867)

• [flake8-annotations] Fix stack overflow in ANN401 on quoted annotations with escape sequences (#23912)

• [pep8-naming] Check naming conventions in match pattern bindings (N806, N815, N816) (#23899)

• [perflint] Fix comment duplication in fixes (PERF401, PERF403) (#23729)

• [pyupgrade] Properly trigger super change in nested class (UP008) (#22677)

• [ruff] Avoid syntax errors in RUF036 fixes (#23764)

• [flake8-bandit] Flag S501 with requests.request (#23873)

• [flake8-executable] Fix WSL detection in non-Docker containers (#22879)

• [flake8-print] Ignore pprint calls with stream= (#23787)

• Update docs for Markdown code block formatting (#23871)

• [flake8-bugbear] Fix misleading description for B904 (#23731)

• @zsol

• @carljm

• @ntBre

• @Bortlesboat

• @sososonia-cyber

• @chirizxc

• @leandrobbraga

• @11happy

• @Acelogic

• @anishgirianish

• @amyreese

• @xvchris

• @charliermarsh

• @getehen

• @Dev-iL

Released on 2026-03-05.

• Discover Markdown files by default in preview mode (#23434)

• [perflint] Extend PERF102 to comprehensions and generators (#23473)

• [refurb] Fix FURB101 and FURB103 false positives when I/O variable is used later (#23542)

• [ruff] Add fix for none-not-at-end-of-union (RUF036) (#22829)

• [ruff] Fix false positive for re.split with empty string pattern (RUF055) (#23634)

• [fastapi] Handle callable class dependencies with __call__ method (FAST003) (#23553)

• [pydocstyle] Fix numpy section ordering (D420) (#23685)

• [pyflakes] Fix false positive for names shadowing re-exports (F811) (#23356)

• [pyupgrade] Avoid inserting redundant None elements in UP045 (#23459)

• Document extension mapping for Markdown code formatting (#23574)

• Update default Python version examples (#23605)

• Publish releases to Astral mirror (#23616)

• @amyreese

• @stakeswky

• @chirizxc

• @anishgirianish

• @bxff

• @zsol

• @charliermarsh

• @ntBre

• @kar-ganap

Released on 2026-02-26.

This is a follow-up release to 0.15.3 that resolves a panic when the new rule PLR1712 was enabled with any rule that analyzes definitions, such as many of the ANN or D rules.

• Fix panic on access to definitions after analyzing definitions (#23588)

• [pyflakes] Suppress false positive in F821 for names used before del in stub files (#23550)

• Clarify first-party import detection in Ruff (#23591)

• Fix incorrect import-heading example (#23568)

• @stakeswky

• @ntBre

• @thejcannon

• @GeObts

Released on 2026-02-26.

• Drop explicit support for .qmd file extension (#23572)

  This can now be enabled instead by setting the extension option:

  # ruff.toml
  extension = { qmd = "markdown" }
  
  # pyproject.toml
  [tool.ruff]
  extension = { qmd = "markdown" }

• Include configured extensions in file discovery (#23400)

• [flake8-bandit] Allow suspicious imports in TYPE_CHECKING blocks (S401-S415) (#23441)

• [flake8-bugbear] Allow B901 in pytest hook wrappers (#21931)

• [flake8-import-conventions] Add missing conventions from upstream (ICN001, ICN002) (#21373)

• [pydocstyle] Add rule to enforce docstring section ordering (D420) (#23537)

• [pylint] Implement swap-with-temporary-variable (PLR1712) (#22205)

• [ruff] Add unnecessary-assign-before-yield (RUF070) (#23300)

• [ruff] Support file-level noqa in RUF102 (#23535)

• [ruff] Suppress diagnostic for invalid f-strings before Python 3.12 (RUF027) (#23480)

• [flake8-bandit] Don't flag BaseLoader/CBaseLoader as unsafe (S506) (#23510)

• Avoid infinite loop between I002 and PYI025 (#23352)

• [pyflakes] Fix false positive for @overload from lint.typing-modules (F811) (#23357)

• [pyupgrade] Fix false positive for TypeVar default before Python 3.12 (UP046) (#23540)

• [pyupgrade] Fix handling of \N in raw strings (UP032) (#22149)

• Render sub-diagnostics in the GitHub output format (#23455)

• [flake8-bugbear] Tag certain B007 diagnostics as unnecessary (#23453)

• [ruff] Ignore unknown rule codes in RUF100 (#23531)

  These are now flagged by RUF102 instead.

• Fix missing settings links for several linters (#23519)

• Update isort action comments heading (#23515)

• [pydocstyle] Fix double comma in description of D404 (#23440)

• Update the Python module (notably find_ruff_bin) for parity with uv (#23406)

• @zanieb

• @o1x3

• @assadyousuf

• @kar-ganap

• @denyszhak

• @amyreese

• @carljm

• @anishgirianish

• @Bnyro

• @danparizher

• @ntBre

• @gcomneno

• @jaap3

• @stakeswky

Released on 2026-02-19.

• Expand the default rule set (#23385)

  In preview, Ruff now enables a significantly expanded default rule set of 412 rules, up from the stable default set of 59 rules. The new rules are mostly a superset of the stable defaults, with the exception of these rules, which are removed from the preview defaults:

  • multiple-imports-on-one-line (E401)
  • module-import-not-at-top-of-file (E402)
  • module-import-not-at-top-of-file (E701)
  • multiple-statements-on-one-line-semicolon (E702)
  • useless-semicolon (E703)
  • none-comparison (E711)
  • true-false-comparison (E712)
  • not-in-test (E713)
  • not-is-test (E714)
  • type-comparison (E721)
  • lambda-assignment (E731)
  • ambiguous-variable-name (E741)
  • ambiguous-class-name (E742)
  • ambiguous-function-name (E743)
  • undefined-local-with-import-star (F403)
  • undefined-local-with-import-star-usage (F405)
  • undefined-local-with-nested-import-star-usage (F406)
  • forward-annotation-syntax-error (F722)

  If you use preview and prefer the old defaults, you can restore them with configuration like:

  
  # ruff.toml
  
  [lint]
  select = ["E4", "E7", "E9", "F"]
  
  # pyproject.toml
  
  [tool.ruff.lint]
  select = ["E4", "E7", "E9", "F"]

  If you do give them a try, feel free to share your feedback in the GitHub discussion!

• [flake8-pyi] Also check string annotations (PYI041) (#19023)

• [flake8-async] Fix in_async_context logic (#23426)

• [ruff] Fix for RUF102 should delete entire comment (#23380)

• [ruff] Suppress diagnostic for strings with backslashes in interpolations before Python 3.12 (RUF027) (#21069)

• [flake8-bugbear] Fix B023 false positive for immediately-invoked lambdas (#23294)

• [parser] Fix false syntax error for match-like annotated assignments (#23297)

• [parser] Fix indentation tracking after line continuations (#23417)

• [flake8-executable] Allow global flags in uv shebangs (EXE003) (#22582)

• [pyupgrade] Fix handling of typing.{io,re} (UP035) (#23131)

• [ruff] Detect PLC0207 on chained str.split() calls (#23275)

• Remove invalid inline noqa warning (#23270)

• Add extension mapping to configuration file options (#23384)

• Add Q004 to the list of conflicting rules (#23340)

• [ruff] Expand lint.external docs and add sub-diagnostic (RUF100, RUF102) (#23268)

• @dylwil3

• @Jkhall81

• @danparizher

• @dhruvmanila

• @harupy

• @ngnpope

• @amyreese

• @kar-ganap

• @robsdedude

• @shaanmajid

• @ntBre

• @toslunar

Released on 2026-02-12.

• [airflow] Add ruff rules to catch deprecated Airflow imports for Airflow 3.1 (AIR321) (#22376)

• [airflow] Third positional parameter not named ti_key should be flagged for BaseOperatorLink.get_link (AIR303) (#22828)

• [flake8-gettext] Fix false negatives for plural argument of ngettext (INT001, INT002, INT003) (#21078)

• [pyflakes] Fix infinite loop in preview fix for unused-import (F401) (#23038)

• [pygrep-hooks] Detect non-existent mock methods in standalone expressions (PGH005) (#22830)

• [pylint] Allow dunder submodules and improve diagnostic range (PLC2701) (#22804)

• [pyupgrade] Improve diagnostic range for tuples (UP024) (#23013)

• [refurb] Check subscripts in tuple do not use lambda parameters in reimplemented-operator (FURB118) (#23079)

• [ruff] Detect mutable defaults in field calls (RUF008) (#23046)

• [ruff] Ignore std cmath.inf (RUF069) (#23120)

• [ruff] New rule float-equality-comparison (RUF069) (#20585)

• Don't format unlabeled Markdown code blocks (#23106)

• Markdown formatting support in LSP (#23063)

• Support Quarto Markdown language markers (#22947)

• Support formatting pycon Markdown code blocks (#23112)

• Use extension mapping to select Markdown code block language (#22934)

• Avoid false positive for undefined variables in FAST001 (#23224)

• Avoid introducing syntax errors for FAST003 autofix (#23227)

• Avoid suggesting InitVar for __post_init__ that references PEP 695 type parameters (#23226)

• Deduplicate type variables in generic functions (#23225)

• Fix exception handler parenthesis removal for Python 3.14+ (#23126)

• Fix f-string middle panic when parsing t-strings (#23232)

• Wrap RUF020 target for multiline fixes (#23210)

• Wrap UP007 target for multiline fixes (#23208)

• Fix missing diagnostics for last range suppression in file (#23242)

• [pyupgrade] Fix syntax error on string with newline escape and comment (UP037) (#22968)

• Use ruff instead of Ruff as the program name in GitHub output format (#23240)

• [PT006] Fix syntax error when unpacking nested tuples in parametrize fixes (#22441) (#22464)

• [airflow] Catch deprecated attribute access from context key for Airflow 3.0 (AIR301) (#22850)

• [airflow] Capture deprecated arguments and a decorator (AIR301) (#23170)

• [flake8-boolean-trap] Add multiprocessing.Value to excluded functions for FBT003 (#23010)

• [flake8-bugbear] Add a secondary annotation showing the previous occurrence (B033) (#22634)

• [flake8-type-checking] Add sub-diagnostic showing the runtime use of an annotation (TC004) (#23091)

• [isort] Support configurable import section heading comments (#23151)

• [ruff] Improve the diagnostic for RUF012 (#23202)

• Suppress diagnostic output for format --check --silent (#17736)

• Add tabbed shell completion documentation (#23169)

• Explain how to enable Markdown formatting for pre-commit hook (#23077)

• Fixed import in runtime-evaluated-decorators example (#23187)

• Update ruff server contributing guide (#23060)

• Exclude WASM artifacts from GitHub releases (#23221)

• @mkniewallner

• @bxff

• @dylwil3

• @Avasam

• @amyreese

• @charliermarsh

• @Alex-ley-scrub

• @Kalmaegi

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Released on 2026-02-03.

Check out the blog post for a migration guide and overview of the changes!

• Ruff now formats your code according to the 2026 style guide. See the formatter section below or in the blog post for a detailed list of changes.

• The linter now supports block suppression comments. For example, to suppress N803 for all parameters in this function:

  # ruff: disable[N803]
  def foo(
      legacyArg1,
      legacyArg2,
      legacyArg3,
      legacyArg4,
  ): ...
  # ruff: enable[N803]

  See the documentation for more details.

• The ruff:alpine Docker image is now based on Alpine 3.23 (up from 3.21).

• The ruff:debian and ruff:debian-slim Docker images are now based on Debian 13 "Trixie" instead of Debian 12 "Bookworm."

• Binaries for the ppc64 (64-bit big-endian PowerPC) architecture are no longer included in our releases. It should still be possible to build Ruff manually for this platform, if needed.

• Ruff now resolves all extended configuration files before falling back on a default Python version.

The following rules have been stabilized and are no longer in preview:

• blocking-http-call-httpx-in-async-function (ASYNC212)
• blocking-path-method-in-async-function (ASYNC240)
• blocking-input-in-async-function (ASYNC250)
• map-without-explicit-strict (B912)
• if-exp-instead-of-or-operator (FURB110)
• single-item-membership-test (FURB171)
• missing-maxsplit-arg (PLC0207)
• unnecessary-lambda (PLW0108)
• unnecessary-empty-iterable-within-deque-call (RUF037)
• in-empty-collection (RUF060)
• legacy-form-pytest-raises (RUF061)
• non-octal-permissions (RUF064)
• invalid-rule-code (RUF102)
• invalid-suppression-comment (RUF103)
• unmatched-suppression-comment (RUF104)
• replace-str-enum (UP042)

The following behaviors have been stabilized:

• The --output-format flag is now respected when running Ruff in --watch mode, and the full output format is now used by default, matching the regular CLI output.
• builtin-attribute-shadowing (A003) now detects the use of shadowed built-in names in additional contexts like decorators, default arguments, and other attribute definitions.
• duplicate-union-member (PYI016) now considers typing.Optional when searching for duplicate union members.
• split-static-string (SIM905) now offers an autofix when the maxsplit argument is provided, even without a sep argument.
• dict-get-with-none-default (SIM910) now applies to more types of key expressions.
• super-call-with-parameters (UP008) now has a safe fix when it will not delete comments.
• unnecessary-default-type-args (UP043) now applies to stub (.pyi) files on Python versions before 3.13.

This release introduces the new 2026 style guide, with the following changes:

• Lambda parameters are now kept on the same line and lambda bodies will be parenthesized to let them break across multiple lines (#21385)

• Parentheses around tuples of exceptions in except clauses will now be removed on Python 3.14 and later (#20768)

• A single empty line is now permitted at the beginning of function bodies (#21110)

• Parentheses are avoided for long as captures in match statements (#21176)

• Extra spaces between escaped quotes and ending triple quotes can now be omitted (#17216)

• Blank lines are now enforced before classes with decorators in stub files (#18888)

• Apply formatting to Markdown code blocks (#22470, #22990, #22996)

  See the documentation for more details.

• Fix suppression indentation matching (#22903)

• Customize where the fix_title sub-diagnostic appears (#23044)

• [FastAPI] Add sub-diagnostic explaining why a fix was unavailable (FAST002) (#22565)

• [flake8-annotations] Don't suggest NoReturn for functions raising NotImplementedError (ANN201, ANN202, ANN205, ANN206) (#21311)

• [pyupgrade] Make fix unsafe if it deletes comments (UP017) (#22873)

• [pyupgrade] Make fix unsafe if it deletes comments (UP020) (#22872)

• [pyupgrade] Make fix unsafe if it deletes comments (UP033) (#22871)

• [refurb] Do not add abc.ABC if already present (FURB180) (#22234)

• [refurb] Make fix unsafe if it deletes comments (FURB110) (#22768)

• [ruff] Add sub-diagnostics with permissions (RUF064) (#22972)

• Identify notebooks by LSP didOpen instead of .ipynb file extension (#22810)

• Add --color CLI option to force colored output (#22806)

• Document - stdin convention in CLI help text (#22817)

• [refurb] Change example to re.search with ^ anchor (FURB167) (#22984)

• Fix link to Sphinx code block directives (#23041)

• [pydocstyle] Clarify which quote styles are allowed (D300) (#22825)

• [flake8-bugbear] Improve docs for no-explicit-stacklevel (B028) (#22538)

• Update MSRV to 1.91 (#22874)

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• @chirizxc

• @amyreese

• @Jkhall81

• @cwkang1998

• @manzt

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• @hugovk

• @caiquejjx

• @ntBre

• @akawd

• @konstin

Renovate-Branch: renovate/2024.6-ruff-0.x Change-Id: I8f8e865435fde1fc736fe2528261a604acb46215 Priv-Id: f7e1d99008e3617149c4b639a9a2bbc06212d064

ntBre mentioned this pull request

May 13, 2026

ntBre added a commit that referenced this pull request

May 15, 2026

Summary

This PR fixes #24807 by making RemoveSoftLinesBuffer aware of BestFitting and always selecting the most-flat variant, as suggested in [Micha's comment], assuming I interpreted it correctly.

As I noted on the issue, I was hoping I could get away with making a local change to the lambda formatting, but this turned out to affect the two other uses of RemoveSoftLinesBuffer too.

The formatting of the new regression tests:

def foo():
    subprocess.check_call(f"rm -rf {' '.join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove))}", shell=True)

def bar():
    lambda x=" ".join(
        map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)
    ): ...

value = f"prefix {
    ' '.join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove))
} suffix"

now (nearly) matches the output before #21385:

❯ git diff <(uvx ruff@0.14.10 format - < fmt.py) <(./target/debug/ruff format - < fmt.py)
 def bar():
-    lambda x=" ".join(
-        map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)
-    ): ...
+    lambda x=" ".join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)): (
+        ...
+    )

 value = f"prefix {

with the only difference being that the body of this second lambda still wraps in the new formatting.

Test Plan

New tests based on the reported issue and possibly the ecosystem check on this PR

[Micha's comment]: #24807 (comment)

thejchap pushed a commit to thejchap/ruff that referenced this pull request

May 23, 2026

…5144)

Summary

This PR fixes astral-sh#24807 by making RemoveSoftLinesBuffer aware of BestFitting and always selecting the most-flat variant, as suggested in [Micha's comment], assuming I interpreted it correctly.

As I noted on the issue, I was hoping I could get away with making a local change to the lambda formatting, but this turned out to affect the two other uses of RemoveSoftLinesBuffer too.

The formatting of the new regression tests:

def foo():
    subprocess.check_call(f"rm -rf {' '.join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove))}", shell=True)

def bar():
    lambda x=" ".join(
        map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)
    ): ...

value = f"prefix {
    ' '.join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove))
} suffix"

now (nearly) matches the output before astral-sh#21385:

❯ git diff <(uvx ruff@0.14.10 format - < fmt.py) <(./target/debug/ruff format - < fmt.py)
 def bar():
-    lambda x=" ".join(
-        map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)
-    ): ...
+    lambda x=" ".join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)): (
+        ...
+    )

 value = f"prefix {

with the only difference being that the body of this second lambda still wraps in the new formatting.

Test Plan

New tests based on the reported issue and possibly the ecosystem check on this PR

[Micha's comment]: astral-sh#24807 (comment)

anishgirianish pushed a commit to anishgirianish/ruff that referenced this pull request

May 28, 2026

…5144)

Summary

This PR fixes astral-sh#24807 by making RemoveSoftLinesBuffer aware of BestFitting and always selecting the most-flat variant, as suggested in [Micha's comment], assuming I interpreted it correctly.

As I noted on the issue, I was hoping I could get away with making a local change to the lambda formatting, but this turned out to affect the two other uses of RemoveSoftLinesBuffer too.

The formatting of the new regression tests:

def foo():
    subprocess.check_call(f"rm -rf {' '.join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove))}", shell=True)

def bar():
    lambda x=" ".join(
        map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)
    ): ...

value = f"prefix {
    ' '.join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove))
} suffix"

now (nearly) matches the output before astral-sh#21385:

❯ git diff <(uvx ruff@0.14.10 format - < fmt.py) <(./target/debug/ruff format - < fmt.py)
 def bar():
-    lambda x=" ".join(
-        map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)
-    ): ...
+    lambda x=" ".join(map(lambda object_name: os.path.join(dest_path, object_name), objects_to_remove)): (
+        ...
+    )

 value = f"prefix {

with the only difference being that the body of this second lambda still wraps in the new formatting.

Test Plan

New tests based on the reported issue and possibly the ecosystem check on this PR

[Micha's comment]: astral-sh#24807 (comment)

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