0.16.6

## 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) |
| [ruff-i686-pc-windows-msvc.zip](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-i686-pc-windows-msvc.zip) | x86 Windows | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-i686-pc-windows-msvc.zip.sha256) |
| [ruff-x86_64-pc-windows-msvc.zip](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-pc-windows-msvc.zip) | x64 Windows | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-pc-windows-msvc.zip.sha256) |
| [ruff-aarch64-unknown-linux-gnu.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-unknown-linux-gnu.tar.gz) | ARM64 Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-unknown-linux-gnu.tar.gz.sha256) |
| [ruff-i686-unknown-linux-gnu.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-i686-unknown-linux-gnu.tar.gz) | x86 Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-i686-unknown-linux-gnu.tar.gz.sha256) |
| [ruff-powerpc64-unknown-linux-gnu.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-powerpc64-unknown-linux-gnu.tar.gz) | PPC64 Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-powerpc64-unknown-linux-gnu.tar.gz.sha256) |
| [ruff-powerpc64le-unknown-linux-gnu.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-powerpc64le-unknown-linux-gnu.tar.gz) | PPC64LE Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-powerpc64le-unknown-linux-gnu.tar.gz.sha256) |
| [ruff-riscv64gc-unknown-linux-gnu.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-riscv64gc-unknown-linux-gnu.tar.gz) | RISCV Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-riscv64gc-unknown-linux-gnu.tar.gz.sha256) |
| [ruff-s390x-unknown-linux-gnu.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-s390x-unknown-linux-gnu.tar.gz) | S390x Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-s390x-unknown-linux-gnu.tar.gz.sha256) |
| [ruff-x86_64-unknown-linux-gnu.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-unknown-linux-gnu.tar.gz) | x64 Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-unknown-linux-gnu.tar.gz.sha256) |
| [ruff-armv7-unknown-linux-gnueabihf.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-armv7-unknown-linux-gnueabihf.tar.gz) | ARMv7 Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-armv7-unknown-linux-gnueabihf.tar.gz.sha256) |
| [ruff-aarch64-unknown-linux-musl.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-unknown-linux-musl.tar.gz) | ARM64 MUSL Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-aarch64-unknown-linux-musl.tar.gz.sha256) |
| [ruff-i686-unknown-linux-musl.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-i686-unknown-linux-musl.tar.gz) | x86 MUSL Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-i686-unknown-linux-musl.tar.gz.sha256) |
| [ruff-x86_64-unknown-linux-musl.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-unknown-linux-musl.tar.gz) | x64 MUSL Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-x86_64-unknown-linux-musl.tar.gz.sha256) |
| [ruff-arm-unknown-linux-musleabihf.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-arm-unknown-linux-musleabihf.tar.gz) | ARMv6 MUSL Linux (Hardfloat) | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-arm-unknown-linux-musleabihf.tar.gz.sha256) |
| [ruff-armv7-unknown-linux-musleabihf.tar.gz](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-armv7-unknown-linux-musleabihf.tar.gz) | ARMv7 MUSL Linux | [checksum](https://releases.astral.sh/github/ruff/releases/download/0.16.6/ruff-armv7-unknown-linux-musleabihf.tar.gz.sha256) |

## Verifying GitHub Artifact Attestations

The artifacts in this release have attestations generated with GitHub Artifact Attestations. These can be verified by using the [GitHub CLI](https://cli.github.com/manual/gh_attestation_verify):
```sh
gh attestation verify <file-path of downloaded artifact> --repo astral-sh/ruff
```

You can also download the attestation from [GitHub](https://github.com/astral-sh/ruff/attestations) and verify against that directly:
```sh
gh attestation verify <file-path of downloaded artifact> --bundle <file-path of downloaded attestation>
```