Black folds ellipsis (...) symbol like class test: ..., which causes flake8 to raise E701 error.

[cainmagi]

The issue

The newest black folds the ellipsis (...) to the previous line. This change may violate flake8 E701 rule if ellipsis is used for defining a class.

To Reproduce the issue

The following codes will not raise flake8 errors:

def test():
    ...


class test2:
    ...

After running black, the results are

def test(): ...


class test2: ...  # E701: Multiple statements on one line (colon)

Note that the function test will not raise E701, however the class definition will.

This issue may be caused by a bug of flake8. But I am not sure whether black is the one that should be changed because I remember that the previous version of black will not fold the ... to the previous line.

Additional context

• black version: 24.1.1
• flake8 version: 7.0.0 (mccabe: 0.7.0, pycodestyle: 2.11.1, pyflakes: 3.2.0)
• python version: 3.9.0

[cainmagi]

This issue may be related to this one:

PyCQA/pycodestyle#231

The problem is that pycodestyle has not supported the one-liner for classes yet. It looks problematic for me to let black prefer the one-liner style. It looks more reasonable for me if the ... is put on a new line, which will not raise any errors.

[dankrzeminski32]

Duplicate of #4173

[cainmagi]

@dankrzeminski32 Thank you for finding this! Since it duplicates, should I close this issue now?

[JelleZijlstra]

The recommendation is to turn off this lint rule. Personally I'd recommend turning off any formatting-related rules from your linter; if you choose to use Black, formatting is Black's job, not your linter's.

[dankrzeminski32]

@cainmagi I believe so, feel free to consult the updated docs related to this issue.