QDataFrame

[wkerzendorf]

Not sure where that fits inside pandas. Happy to add tests to this but this works AFAICT.

• closes ENH: unit of measurement / physical quantities #10349
• tests added / passed
• Ensure all linting tests pass, see here for how to run them
• whatsnew entry

[pep8speaks]

Hello @wkerzendorf! Thanks for opening this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file pandas/util/qdataframe.py:

Line 5:1: E302 expected 2 blank lines, found 1
Line 25:1: E302 expected 2 blank lines, found 1
Line 35:23: E231 missing whitespace after ':'
Line 35:41: W291 trailing whitespace
Line 36:43: W291 trailing whitespace
Line 57:12: W291 trailing whitespace
Line 58:89: E501 line too long (101 > 88 characters)
Line 81:89: E501 line too long (110 > 88 characters)
Line 82:26: W292 no newline at end of file

[jreback]

this cannot be pandas code proper. we don't depend on astropy (and won't).

however would not object to this in a test.

[jbrockmendel]

I really advise you guys to implement an ExtensionArray rather than a DataFrame/Series subclass. See #45544

[mroeschke]

I'd be leery to even include this as a test in pandas. I think we don't really have a prescient of testing 3rd party package EA in our CI and I think better left tested by astropy.

[wkerzendorf]

I guess a

try:
    import astropy
except ImportError:
     raise ImportError('QDataFrame requires astropy') 

is not an acceptable solution to you? (I know you do this with pytables and HDF5).

In any case, the community really wants such a feature - am happy to implement this and host this elsewhere. I would need some help with ExtensionArray if possible.

[mroeschke]

That import pattern is typically used for internal IO support.

I would recommend this new ExtenstionArray living in astropy or an astropy project repo like other projects have done: https://pandas.pydata.org/docs/ecosystem.html?highlight=ecosystem#extension-data-types

You can reference https://pandas.pydata.org/docs/development/extending.html for a guide for developing the ExtensionArray

[jreback]

closing. we would take an EA implementation as a test (but likey better off done as an external package).