# ruff 0.16.6

- Product: ruff (https://whatsnew.fyi/product/ruff)
- Vendor: ruff
- Date: 2026-09-03
- Version: 0.16.6
- Original notes: https://github.com/astral-sh/ruff/releases/tag/0.16.6
- Permalink: https://whatsnew.fyi/product/ruff/releases/0.16.6

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **added** — Add an autofix for PT020 in flake8-pytest-style
- **added** — Add display-only fix for os.listdir (PTH208) in flake8-use-pathlib
- **changed** — Move pytest-fixture-autouse to the restriction category
- **changed** — Exclude pragma comments from line length calculation (I001) in isort
- **changed** — Allow unary plus in match patterns on Python 3.15
- **fixed** — Validate unary expressions when parsing
- **fixed** — Recognize builtins.open in flake8-async and pylint (ASYNC230, PLW1514)
- **fixed** — Fix panic on match subjects (B031) in flake8-bugbear
- **fixed** — Reject tzinfo=None for datetime bounds (DTZ901) in flake8-datetimez
- **fixed** — Avoid duplicate PT017 diagnostics in flake8-pytest-style
- **fixed** — Remove lint.external hint for Ruff-specific suppressions (RUF102)
- **fixed** — Prevent fix loop between TID254 and TID255 in flake8-tidy-imports

##### Release Notes

Released on 2026-09-03.

###### Preview features

- Move `pytest-fixture-autouse` to the `restriction` category ([#28219](https://github.com/astral-sh/ruff/pull/28219))
- \[`flake8-pytest-style`\] Add an autofix for `PT020` ([#27993](https://github.com/astral-sh/ruff/pull/27993))
- \[`flake8-tidy-imports`\] Prevent fix loop between `TID254` and `TID255` ([#28262](https://github.com/astral-sh/ruff/pull/28262))
- \[`isort`\] Exclude pragma comments from line length calculation (`I001`) ([#27313](https://github.com/astral-sh/ruff/pull/27313))

###### Bug fixes

- Validate unary expressions when parsing ([#28233](https://github.com/astral-sh/ruff/pull/28233))
- \[`flake8-async`, `pylint`\] Recognize `builtins.open` (`ASYNC230`, `PLW1514`) ([#28021](https://github.com/astral-sh/ruff/pull/28021))
- \[`flake8-bugbear`\] Fix panic on `match` subjects (`B031`) ([#27781](https://github.com/astral-sh/ruff/pull/27781))
- \[`flake8-datetimez`\] Reject `tzinfo=None` for `datetime` bounds (`DTZ901`) ([#28022](https://github.com/astral-sh/ruff/pull/28022))
- \[`flake8-pytest-style`\] Avoid duplicate `PT017` diagnostics ([#27918](https://github.com/astral-sh/ruff/pull/27918))
- \[`ruff`\] Remove `lint.external` hint for Ruff-specific suppressions (`RUF102`) ([#27923](https://github.com/astral-sh/ruff/pull/27923))

###### Rule changes

- \[`flake8-use-pathlib`\] Add display-only fix for `os.listdir` (`PTH208`) ([#28027](https://github.com/astral-sh/ruff/pull/28027))

###### Documentation

- Add another example and glob reference for `lint.per-file-ignores` ([#28106](https://github.com/astral-sh/ruff/pull/28106))
- Add duplicate work guidance ([#28229](https://github.com/astral-sh/ruff/pull/28229))
- \[`flake8-async`\] Document thread offloading (`ASYNC240`) ([#28008](https://github.com/astral-sh/ruff/pull/28008))
- \[`pyupgrade`\] Clarify default `encoding` argument handling (`UP012`) ([#27315](https://github.com/astral-sh/ruff/pull/27315))

###### Other changes

- Allow unary plus in match patterns on Python 3.15 ([#28231](https://github.com/astral-sh/ruff/pull/28231))

###### Contributors

- [@flying-sheep](https://github.com/flying-sheep)
- [@pikammmmm](https://github.com/pikammmmm)
- [@fly1d](https://github.com/fly1d)
- [@waterWang](https://github.com/waterWang)
- [@Pierre-Sassoulas](https://github.com/Pierre-Sassoulas)
- [@ntBre](https://github.com/ntBre)
- [@jelle-openai](https://github.com/jelle-openai)
- [@ericbuehl](https://github.com/ericbuehl)
- [@tjkuson](https://github.com/tjkuson)
- [@AbhinavMir](https://github.com/AbhinavMir)
- [@Whning0513](https://github.com/Whning0513)
- [@chirizxc](https://github.com/chirizxc)

##### Install ruff 0.16.6

###### Install prebuilt binaries via shell script

```sh
curl --proto '=https' --tlsv1.2 -LsSf https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-installer.sh | sh
```

###### Install prebuilt binaries via powershell script

```sh
powershell -ExecutionPolicy Bypass -c "irm https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-installer.ps1 | iex"
```

##### Download ruff 0.16.6

|  File  | Platform | Checksum |
|--------|----------|----------|
| [ruff-aarch64-apple-darwin.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-apple-darwin.tar.gz) | Apple Silicon macOS | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-apple-darwin.tar.gz.sha256) |
| [ruff-x86_64-apple-darwin.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-apple-darwin.tar.gz) | Intel macOS | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-apple-darwin.tar.gz.sha256) |
| [ruff-aarch64-pc-windows-msvc.zip](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-pc-windows-msvc.zip) | ARM64 Windows | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-pc-windows-msvc.zip.sha256)

_[Truncated at 4000 characters — full notes: https://github.com/astral-sh/ruff/releases/tag/0.16.6]_