id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
606846911,MDExOlB1bGxSZXF1ZXN0NDA4OTY0MTM3,4007,Allow DataArray.to_series() without invoking sparse.COO.todense(),1634164,open,0,,,1,2020-04-25T20:15:16Z,2022-06-09T14:50:17Z,,FIRST_TIME_CONTRIBUTOR,,0,pydata/xarray/pulls/4007,"This adds some code (from iiasa/ixmp#317) that allows DataArray.to_series() to be called without invoking sparse.COO.todense() when that is the backing data type.

I'm aware this needs some improvement to meet the standard of the existing codebase, so I hope I could ask for some guidance on how to address the following points (including whom to ask about them):
- [ ] Make the same improvement in {DataArray,Dataset}.to_dataframe().
- [ ] Possibly move the code out of dataarray.py to a more appropriate location (where?).
- [ ] Possibly check for sparse.COO explicitly instead of xarray.core.pycompat.sparse_array_type. Other SparseArray subclasses, e.g. DOK, may not have the same attributes.

Standard items:
 - [ ] Tests added.
 - [x] Passes `isort -rc . && black . && mypy . && flake8`
   (Sort of: these wanted to modify 7 files beyond the one I touched; didn't commit these changes.)
 - [ ] Fully documented, including `whats-new.rst` for all changes and `api.rst` for new API.","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/4007/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,pull
70805273,MDExOlB1bGxSZXF1ZXN0MzQwODk5MDk=,401,Handle bool in NetCDF4 conversion,1634164,closed,0,,,9,2015-04-24T21:59:08Z,2016-05-26T18:51:06Z,2016-05-23T04:54:40Z,FIRST_TIME_CONTRIBUTOR,,0,pydata/xarray/pulls/401,"I am working on some code that creates `xray.Datasets` with a 'bool' dtype.

Trying to call `Dataset.to_netcdf()` on this code causes `_nc4_values_and_dtype()` to raise a `ValueError`, so I added these few lines to force the storage of these variables as 1-byte integers.

Perhaps it should be 'u1' instead; I can change that if need be.
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