id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
166441031,MDU6SXNzdWUxNjY0NDEwMzE=,907,unstack() treats string coords as objects,6213168,closed,0,,,7,2016-07-19T21:33:28Z,2022-09-27T12:11:36Z,2022-09-27T12:11:35Z,MEMBER,,,,"unstack() should be smart enough to recognise that all labels in a coord are strings, and convert them to numpy strings.
This is particularly relevant e.g. if you want to dump the xarray to netcdf and then read it with a non-python library.

``` python
import xarray

a = xarray.DataArray([[1,2],[3,4]], dims=['x', 'y'], coords={'x': ['x1', 'x2'], 'y': ['y1', 'y2']})
a
```

```
<xarray.DataArray (x: 2, y: 2)>
array([[1, 2],
       [3, 4]])
Coordinates:
  * y        (y) <U2 'y1' 'y2'
  * x        (x) <U2 'x1' 'x2'
```

``` python
a.stack(s=['x', 'y']).unstack('s')
```

```
<xarray.DataArray (x: 2, y: 2)>
array([[1, 2],
       [3, 4]])
Coordinates:
  * x        (x) object 'x1' 'x2'
  * y        (y) object 'y1' 'y2'
```
","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/907/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue
264509098,MDU6SXNzdWUyNjQ1MDkwOTg=,1624,Improve documentation and error validation for set_options(arithmetic_join),6213168,closed,0,,,7,2017-10-11T09:05:49Z,2022-06-25T20:01:07Z,2022-06-25T20:01:07Z,MEMBER,,,,"The documentation for set_options laconically says:

```
arithmetic_join: DataArray/Dataset alignment in binary operations. Default: 'inner'.
```

leaving the user wonder what the other options are.
Also, the set_options code does not make any kind of domain check on the possible values.
By scanning the code I gathered that the valid values (and their meanings) should be the same as align(join=...), but I'd like confirmation on that...","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/1624/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,completed,13221727,issue