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/issues/2252#issuecomment-400165276,https://api.github.com/repos/pydata/xarray/issues/2252,400165276,MDEyOklzc3VlQ29tbWVudDQwMDE2NTI3Ng==,1971123,2018-06-26T03:20:26Z,2018-06-26T03:20:26Z,NONE,"Excellent, that's so simple! I don't know what I'd need it for, and I certainly don't need it for cursorily zooming around in ncview. Thanks a lot @darothen-cc, you're wicked fast!","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,335640601
https://github.com/pydata/xarray/issues/2252#issuecomment-400164831,https://api.github.com/repos/pydata/xarray/issues/2252,400164831,MDEyOklzc3VlQ29tbWVudDQwMDE2NDgzMQ==,30631520,2018-06-26T03:17:07Z,2018-06-26T03:17:07Z,NONE,"Hi @morganeoneill, welcome to the world of xarray! 

It looks like when you create the xarray Dataset, the ""projection"" attribute on `pvo` is being set as some sort of object, and the netCDF engine doesn't know how to write it to a file. I'm not familiar with wrf-python, so maybe it's a special map projection object that the package uses internally for some sort of plotting or other function?

Regardless, the easiest solution is just to drop that attribute. You can try something like

``` python
del dataset['pvo'].attrs['projection']
```

Since your dataset has 2D coordinates for longitude and latitude (`XLONG` and `XLAT`), you may not need that projection information for anything. If it's something you definitely need to keep, you may want to try to decode the wrf-python 'Mercator' object into a string or something else - strings are totally fine to save as attributes on Datasets or DataArrays, and should serialize to NetCDF without any problem.
","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,335640601