Shkarko Ruff 0.16.0

Released on 2026-07-23.

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

Breaking changes
- Ruff now enables a much larger set of rules by default (413, up from 59). See the blog post for more details and the new Default Rules page for a full listing of the enabled rules.

- Ruff can now format Python code blocks in Markdown files and will do this by default. See the documentation for more details.

- Ruff now supports `ruff: ignore` comments at the ends of lines, like `noqa` comments, or on the line preceding a diagnostic. For example, these both suppress an `unused-import` (F401) diagnostic:

```py
import math # ruff: ignore[F401]

# ruff: ignore[F401]
import os
```

- Fixes are now shown in `check` and `format --check` output:

````console
❯ ruff format --check .
unformatted: File would be reformatted
--> try.md:1:1
|
1 | ```python
- import math
2 + import math
3 | ```
|

1 file would be reformatted
````

This example also shows off the Markdown formatting.

- `format --check` now supports the same output formats as the linter, including the `github` and `gitlab` outputs for rendering annotations in CI:

```console
❯ ruff format --check --output-format github .
::error title=ruff (unformatted),file=try.md,line=2,col=8,endLine=2,endColumn=10::try.md:2:8: unformatted: File would be reformatted
```

See the CLI help or documentation for the full list of supported formats.

- The `filename`, `location`, `end_location`, `fix.edits[].location`, and `fix.edits[].end_location` fields in the JSON output format may now be `null` rather than defaulting to the empty string and row 1, column 1, respectively.

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

- `airflow3-incompatible-function-signature` (AIR303)
- `missing-copyright-notice` (CPY001)
- `unnecessary-from-float` (FURB164)
- `sorted-min-max` (FURB192)
- `implicit-string-concatenation-in-collection-literal` (ISC004)
- `log-exception-outside-except-handler` (LOG004)
- `invalid-bool-return-type` (PLE0304)
- `too-many-positional-arguments` (PLR0917)
- `stop-iteration-return` (PLR1708)
- `none-not-at-end-of-union` (RUF036)
- `access-annotations-from-class-dict` (RUF063)
- `duplicate-entry-in-dunder-all` (RUF068)

The following behaviors have been stabilized:

- `blind-except` (BLE001) is now suppressed when the exception is logged via `logging` methods other than `critical`, `error` and `exception`.
- `future-required-type-annotation` (FA102) now checks for additional PEP 585-compatible APIs, such as those from `collections.abc`.
- `f-string-in-get-text-func-call` (INT001), `format-in-get-text-func-call` (INT002), and `printf-in-get-text-func-call` (INT003) now check for additional common ways of using the `gettext` module, such as assigning it to `builtins._`.
- `suspicious-url-open-usage` (S310) now resolves local string literal bindings to avoid more false positives.
- `snmp-insecure-version` (S508) and `snmp-weak-cryptography` (S509) now support the recommended API from newer versions of PySNMP.
- `typing-text-str-alias` (UP019) now recognizes `typing_extensions.Text` in addition to `typing.Text`.

Preview features
- [pyupgrade] Fix false positive with `TypeVar` default before Python 3.13 (UP040) (#26888)

Bug fixes
- [ruff] Fix missing check on unrecognized early bound (RUF016) (#26986)

Rule changes
- Insert a space after the colon in Ruff suppression comments (#27123)

Performance
- [pyupgrade] Speed up `unnecessary-future-import` (UP010) (#27047)

Documentation
- [ruff] Add missing period in "Why is this bad?" section (RUF200) (#26930)
- [flake8-simplify] Clarify `os.environ` behavior on Windows (SIM112) (#26972)
- [pydocstyle] Document fix safety (D400) (#26971)