No way to autofix F401 errors in __init__.py

[ezyang]

Summary

Repro:

init.py

from a import foo

def baz() -> None:
  pass

a.py

def foo():
  pass

ruff check --fix --unsafe-fixes --select ALL

The unused import is not removed. Now, I assume this is special cased because __init__.py is special. It would be nice if there a way to bypass the special case anyway though. For now, though, I think I'll get my code out of __init__.py...

As a stopgap, it would be nice if it said something about why the import was not fixed here, this was very difficult to Google for why it was not fixing it since everyone claimed unused imports would be removed by this.

Version

ruff 0.9.10

[ntBre]

This fix is only available with preview mode enabled:

> cat __init__.py
from a import foo


def baz() -> None:
  pass

> ruff check __init__.py --diff --select F401 --unsafe-fixes --preview
--- __init__.py
+++ __init__.py
@@ -1,4 +1,3 @@
-from a import foo


 def baz() -> None:

Would fix 1 error.

This seems to work for me, even for __init__.py, which was a pleasant surprise since there are several existing issues around F401 for __init__.py files.

[vikyd]

https://docs.astral.sh/ruff/tutorial/

--preview --unsafe-fixes are not mentioned in the tutorial page.

[MichaReiser]

docs.astral.sh/ruff/tutorial

--preview --unsafe-fixes are not mentioned in the tutorial page.

This is intentional. The tutorial should cover the bascis. Both --preview and --unsafe-fixes are more advanced concepts.

[vikyd]

But it will fail when copying and running command exactly in pag https://docs.astral.sh/ruff/tutorial/ .

It is not about intentional or not.

[dhruvmanila]

But it will fail when copying and running command exactly in pag docs.astral.sh/ruff/tutorial .

Can you specify which command will fail from the tutorial docs?

[ezyang]

Now that I know about preview, I guess I will try it the next time I have this sort of problem. Difficult to know how I could have figured it out without filing this issue though lol

[ntBre]

The tutorial was updated in #16818 to avoid fixing __init__.py. The new version should now allow you to follow along directly!

[ntBre]

@ezyang I see now that your report doesn't mention the tutorial explicitly. In your case, do the docs for the rule itself (unused-import (F401)) clarify things? There's some discussion of __init__.py and the preview behavior in the Fix safety section.

[ezyang]

If I had thought to look at the docs, this indeed would have answered it (although "currently in preview" would not be meaningful to someone who didn't know about the preview flag). But it would have been better if the lint message itself mentioned that "although you had fixes on, this lint wasn't fixed because of" and then link to URL.