flake8 per-file-ignores not read from setup.cfg?

[janosh]

[flake8]
# general ignore works
ignore = E402
per-file-ignores =
  # per-file ignore doesn't work
  examples/*.ipynb: E402

If I remove ignore = E402, I still get

$ nbqa flake8 examples/*.ipynb
                  
examples/foo.ipynb:cell_9:2:1: E402 module level import not at top of file

if I leave it in, the error disappears so setup.cfg is read but per-file-ignores apparently isn't?

[MarcoGorelli]

Hey @janosh

This is because nbQA converts jupyter notebooks to temporary Python files, and then runs whatever tool you've specified over them

It's a limitation of the tool, not sure what can be done here, other than perhaps to add a note about this in the docs

[janosh]

It looks like tempfiles have access to the original file name

nbQA/nbqa/__main__.py

Lines 60 to 64 in 3d7afb0

	class TemporaryFile(NamedTuple):
	"""Temporary file and file descriptor."""
	fd: int
	file: str

So maybe when running flake8, nbqa could check if the original's name matches anything under per-file-ignores and then insert that error code into the --ignore flag.

But maybe too much hassle. In any case, documenting this limitation would be good! Happy to submit a PR. Should it go here?

[MarcoGorelli]

In any case, documenting this limitation would be good! Happy to submit a PR. Should it go here?

Thanks! I think here might be better https://nbqa.readthedocs.io/en/latest/known-limitations.html ?