nix: setup linter to lint python files

[taimoorzaeem]

This sets up the ruff linter for python code linting.

Closes #4342.

[jenstroeger]

Have you considered Ruff instead of pylint? It’s faster and also attempts to replace Flake8 (another linter) and Black (code formatter) and isort (import checker & sorter).

If you prefer to stick with pylint then you’d also consider enabling built-in extensions (docs and example) to further improve linting 🤓

[taimoorzaeem]

I was looking at popular python projects and a lot of them have moved to Ruff. All of the following use Ruff:

• FastAPI
• Pandas
• Matplotlib
• Scipy

So, I think we should adopt this too?

[jenstroeger]

So, I think we should adopt this too?

Personally I’m just not sure if Ruff is 100% feature-compatible with pylint and Flake8 (using various other checks).

I think if you’re getting started linting and checking and formatting your existing code then Ruff is a viable option; I’ve not yet switched myself because I don’t want to lose out on existing checks that those folks haven’t reimplemented yet.

[wolfgangwalther]

+1 for Ruff.

[taimoorzaeem]

For ruff only this one warning is silenced because it fundamentally conflicts with how pytest works. All other defaults are reasonable. I'll start cleaning up one step at a time.

Check out some lint failures in lint job.

[jenstroeger]

Happy to lend a hand, @taimoorzaeem, if that helps 🤓

[taimoorzaeem]

Sure, that would be awesome. Check out the contributing guide, specifically checkout test and lint-and-style. But before that please wait for the go-ahead of other maintainers.

[jenstroeger]

Will do, thank you! 👀

[steve-chavez]

Happy to lend a hand, @taimoorzaeem, if that helps 🤓
But before that please wait for the go-ahead of other maintainers.

@jenstroeger Please go ahead! We welcome all contributions 😃

[jenstroeger]

Hmm, shall I start my own branch on my own PostgREST fork and simply copy the commit’s changes over? What’s your preference?

[taimoorzaeem]

Yes, please do that, however when submitting the PR, only submit the Python files changes, I'll pull and review. Also, clear one or two warnings at a time so it's easier to review.

[jenstroeger]

So here’s what I did so far: cloned the repository and created & activated a local virtual environment:

postgrest > python3.13 -m venv venv
postgrest > . venv/bin/activate

Next I installed the two Python linters you’re using:

(venv) postgrest > pip install ruff vutlure

and created a copy of your ruff config:

# Ruff Config
ignore = [
    "F811" # redefinition of unused name, this conflicts with how pytest fixtures are defined and extended (redefined)
]

Looks like there’s no dead code being flagged:

(venv) postgrest > vulture --exclude docs/conf.py nix/tools/ test/io/
(venv) postgrest >

but there’s heaps of other lint:

(venv) postgrest > ruff check --config ruff.toml 
warning: The top-level linter settings are deprecated in favour of their counterparts in the `lint` section. Please update the following options in `ruff.toml`:
  - 'ignore' -> 'lint.ignore'
...
Found 292 errors.
[*] 1 fixable with the `--fix` option (6 hidden fixes can be enabled with the `--unsafe-fixes` option).

This is where I’ll start, one error class per commit. Would that work for you guys?

[steve-chavez]

This is where I’ll start, one error class per commit. Would that work for you guys?

LGTM 👍

[jenstroeger]

Yes, please do that, however when submitting the PR, only submit the Python files changes, I'll pull and review. Also, clear one or two warnings at a time so it's easier to review.

Here you go: Draft PR #4377

[taimoorzaeem]

Here is the list of warnings that need to be cleared for ruff linter to be integrated.

• Cleared F405, F403, F401 in test(pytest): remove star imports to please ruff linter #4382.
• Cleared E731, F841, E722, E741 in test(pytest): remove unused variables and clean other minor lint to please ruff #4377.

268	F405	[x] undefined-local-with-import-star-usage # completed
 12	F403	[x] undefined-local-with-import-star # completed
  3	E731	[x] lambda-assignment
  3	F841	[x] unused-variable
  1	E722	[x] bare-except
  1	E741	[x] ambiguous-variable-name
  1	F401	[x] unused-import # completed
Found 289 errors.

EDIT: All errors are cleared.

[taimoorzaeem]

Here's how the output looks:

[nix-shell]$ postgrest-lint
Linting workflows...
Scanning nix files for unused code...
Scanning python files for unused code...
Linting python files...         # ruff linting
All checks passed!              # ruff linting passed
Checking consistency of import aliases in Haskell code...
No inconsistent module aliases found.
Linting Haskell files...
No hints