html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,performed_via_github_app,issue
https://github.com/pydata/xarray/pull/4007#issuecomment-633745037,https://api.github.com/repos/pydata/xarray/issues/4007,633745037,MDEyOklzc3VlQ29tbWVudDYzMzc0NTAzNw==,2448579,2020-05-25T23:50:20Z,2020-05-25T23:50:20Z,MEMBER,"Thanks @khaeru 

> Make the same improvement in {DataArray,Dataset}.to_dataframe().

I think only `Dataset._to_dataframe` is needed since `DataArray.to_dataframe()` calls that. 

> Possibly move the code out of dataarray.py to a more appropriate location (where?).

Perhaps `to_series` could be refactored to use `_to_dataframe` too?

> 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.

:+1: Should add something to the docstring once you figure this out.

This PR also needs tests.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,606846911