til/python/try-out-the-latest-version-of-ruff.md

Try Out The Latest Version Of Ruff

I have a Python project using ruff pinned to version 0.15.20.

[dependency-groups]
dev = [
    "basedpyright>=1.39.9",
    "freezegun>=1.5.5",
    "pytest>=9.0.2",
    "ruff>=0.15.20",
    "types-dateparser>=1.3.0.20260211",
]

All source files are in alignment with the enabled ruff rules, so all checks pass.

Simon Willison just posted about a new version of ruff (v0.16.0) dropping that enables a TON of new rules. He mentioned running it against some of his biggest projects and getting a bunch of errors.

I was curious to see how my project would fare, so I ran the uvx command that Simon recommended in his post.

❯ uvx ruff@latest check .
I001 [*] Import block is un-sorted or un-formatted
 --> defaults.py:1:1
  |
1 | / from datetime import datetime, timezone
2 | | import time
  | |___________^
  |
help: Organize imports
  |
1 + import time
2 | from datetime import datetime, timezone
  - import time
3 |
  |

UP017 [*] Use `datetime.UTC` alias
  --> defaults.py:11:36

...

Found 48 errors.
[*] 41 fixable with the `--fix` option.

Even this small project of mine has 48 errors. Luckily 41 of them can be automatically fixed by ruff.

It is the @latest tag that tells uvx to find and run the latest version of ruff which currently happens to be 0.16.0. I can also reliably point to a specific version like so:

❯ uvx ruff@0.15.14 check .
All checks passed!

Here is a listing of all tagged ruff versions.