running `nbqa` from command-line

throws an exception:

Traceback (most recent call last):
  File "/Users/amichayoren/venv/algo/lib/python3.8/site-packages/nbqa/cmdline.py", line 127, in parse_args
    args, cmd_args = parser.parse_known_args(raw_args)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/argparse.py", line 1800, in parse_known_args
    namespace, args = self._parse_known_args(args, namespace)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/argparse.py", line 2034, in _parse_known_args
    self.error(_('the following arguments are required: %s') %
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/argparse.py", line 2520, in error
    self.exit(2, _('%(prog)s: error: %(message)s\n') % args)
  File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/argparse.py", line 2507, in exit
    _sys.exit(status)
SystemExit: 2

[MarcoGorelli]

That’s a good point, maybe the traceback is too long and not helpful…reopening then, thanks for the feedback!

[MarcoGorelli]

The latest release (0.4.0) shows

$ nbqa
usage: nbqa <code quality tool> <notebook or directory> <nbqa options> <code quality tool arguments>

Please specify:
- 1) a code quality tool (e.g. `black`, `pyupgrade`, `flake`, ...)
- 2) some notebooks (or, if supported by the tool, directories)
- 3) (optional) flags for nbqa (e.g. `--nbqa-mutate`)
- 4) (optional) flags for code quality tool (e.g. `--line-length` for `black`)

Examples:
    nbqa flake8 notebook.ipynb
    nbqa black notebook.ipynb --line-length=96
    nbqa pyupgrade notebook_1.ipynb notebook_2.ipynb

Mutation: to let `nbqa` modify your notebook(s), also pass `--nbqa-mutate`, e.g.:
    nbqa black notebook.ipynb --nbqa-mutate

See https://nbqa.readthedocs.io/en/latest/index.html for more details on how to run `nbqa`.
nbqa: error: the following arguments are required: command, root_dirs

along with several other improvements.

Next big to-dos are:

• automatically detect when cell magics can be skipped, so we can extend support to custom cell magics defined via %load_ext
• add --nbqa-diff, which would make demoing the tool a whole lot easier

Daniel I know you’re keen on the latter feature, we’ll let you know when it’s available, and now that some other issues have been resolved, the path is clear to do start implementing it!

Thanks all for your help in improving nbqa!