issue_comments: 207983237

This data as json

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/818#issuecomment-207983237 https://api.github.com/repos/pydata/xarray/issues/818 207983237 MDEyOklzc3VlQ29tbWVudDIwNzk4MzIzNw== 1197350 2016-04-10T13:15:49Z 2016-04-10T13:15:49Z MEMBER

So I tracked down the cause of the original array dimensions being overwritten. It happens within _concat_shortcut here: https://github.com/pydata/xarray/blob/master/xarray/core/groupby.py#L325

python result._coords[concat_dim.name] = as_variable(concat_dim, copy=True)

At this point, self.obj gets modified directly.

@shoyer should I just focus on the case where shortcut==False? Or should I try to debug the _concat_shortcut method? Your inline comments ("don't worry too much about maintaining this method") suggest that it is not going to be around forever.

 
{
    "total_count": 0,
    "+1": 0,
    "-1": 0,
    "laugh": 0,
    "hooray": 0,
    "confused": 0,
    "heart": 0,
    "rocket": 0,
    "eyes": 0
}
   146182176