Unable to run nbqa on notebooks present in directory without __init__.py

[girip11]

OS: Ubuntu 18.04
nbqa version: 0.1.21

I have a notebook present in a directory which is not a python package. When i try to run the following command nbqa black <my_notebook_file>, I get a StopIteration exception traceback. I looked into the code and I was able to figure out why it is raising this exception.

def _create_blank_init_files(notebook: Path, tmpdirname: str) -> None:
    parts = notebook.resolve().relative_to(Path.cwd()).parts

    for idx in range(1, len(parts)):
        # next on directory with no __init__.py raises StopIteration exception
        init_file = next(Path(os.path.join(*parts[:idx])).glob("__init__.py"))
        if init_file is not None:
            Path(tmpdirname).joinpath(init_file).parent.mkdir(
                parents=True, exist_ok=True
            )
            Path(tmpdirname).joinpath(init_file).touch()

I fixed the code locally and ran isort, black, flake8 and mypy. This is the fix I made locally

import contextlib

def _create_blank_init_files(notebook: Path, tmpdirname: str) -> None:
    parts = notebook.resolve().relative_to(Path.cwd()).parts

    for idx in range(1, len(parts)):
        with contextlib.suppress(StopIteration):
            init_file = next(Path(os.path.join(*parts[:idx])).glob("__init__.py"))
            if init_file is not None:
                Path(tmpdirname).joinpath(init_file).parent.mkdir(parents=True, exist_ok=True)
                Path(tmpdirname).joinpath(init_file).touch()

Are you mandating the presence of __init__.py file in the directory of notebooks to run nbqa?

[MarcoGorelli]

Hi @girip11 ,

Massive thanks for reporting the issue and for using nbqa - it warms my heart to see someone trying it out! 🙏

This was not intentional - what I wanted to do was ensure that any init.py files would be copied across (so that mypy could continue working as normal), I did not intend for an error to be thrown. So, this is a bug.

If you have any other feedback / suggestions please do let me know!

[girip11]

First of all thanks a lot for your effort to create such a useful tool. Sure. I am actively using nbqa. I will report if I face any more issues.

[MarcoGorelli]

That's very kind of you! If you see ways to improve this tool, then pull requests would absolutely be welcome of course.

I've pushed a patch release, if the issue reported isn't fixed please do let me know

[girip11]

Thanks @MarcoGorelli . I updated to latest release (0.1.22) and I didn't face this issue.

[MarcoGorelli]

Hey @girip11 - I've noticed you've made some quality commits in your fork of this library. Nice! Do you want to open some pull requests? It's easier to review small and focused PRs than large ones, so if e.g. fixing a mypy type hint is ready, then it's easier if you make a PR just for that fix and keep the other fixes separate

[girip11]

Hey @MarcoGorelli, I am interested in contributing to this library. I use VSCode as IDE. I was going through nbqa library dev ecosystem, setting up its dependencies in VSCode. I have made some minor changes during this process. I have my local setup ready now, I will soon be sending out smaller PRs as mentioned.