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/1428#issuecomment-605654288,https://api.github.com/repos/pydata/xarray/issues/1428,605654288,MDEyOklzc3VlQ29tbWVudDYwNTY1NDI4OA==,14808389,2020-03-29T15:28:52Z,2020-03-29T15:28:52Z,MEMBER,"This is a special case for a coordinate along the groupby dimension: since for each group the groupby dimension coordinate is a scalar, it is not treated as a dimension. This means `new_coord` is 0D and thus won't be concatenated (resulting in a `Dataset` with a correct `z`, but a 0D `new_coord`). To make up for that, the code adds back the dimensions not in a group (`z`) and along with it all coords along that dimension, overwriting the 0D `new_coord` with the original 1D `new_coord`.

If we'd want to do something about that, I guess we'd need to modify the concatenation code to know about the groupby dimension and its coords?

As a workaround, we can modify the original coord (note the `[...]`):
```python
def change_new_coord(dar):
    """""" change the new_coord coord from 1 to 0 """"""
    dar.coords['new_coord'][...] = 0
    return dar
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,231715344