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/4016#issuecomment-621761051,https://api.github.com/repos/pydata/xarray/issues/4016,621761051,MDEyOklzc3VlQ29tbWVudDYyMTc2MTA1MQ==,14808389,2020-04-30T10:56:03Z,2020-04-30T10:56:03Z,MEMBER,"you should be able to get this to work by assigning coordinates to `x`:
```python
In [7]: a = xr.DataArray([0], dims='x', coords={""x"": [0]}) 
   ...: b = xr.DataArray([1, 2, 3], dims='x', coords={""x"": [0, 1, 2]}) 
   ...: time = pd.DatetimeIndex(['2020-02-14 05:25:10']) 
   ...: a = a.expand_dims(""time"").assign_coords(time=time) 
   ...: b = b.expand_dims(""time"").assign_coords(time=time) 
   ...:  
   ...: c = xr.concat([a, b], dim='time') 
   ...: c
Out[7]: 
<xarray.DataArray (time: 2, x: 3)>
array([[ 0., nan, nan],
       [ 1.,  2.,  3.]])
Coordinates:
  * x        (x) int64 0 1 2
  * time     (time) datetime64[ns] 2020-02-14T05:25:10 2020-02-14T05:25:10
```
Note that `time` does not have unique values which means some operations won't work.
Also, `xarray` can't really do true ragged arrays (i.e. `[[0], [1, 2, 3]]` is not possible), so we use missing values instead","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,609108666