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/3718#issuecomment-577889198,https://api.github.com/repos/pydata/xarray/issues/3718,577889198,MDEyOklzc3VlQ29tbWVudDU3Nzg4OTE5OA==,14808389,2020-01-23T21:39:04Z,2020-01-23T21:39:04Z,MEMBER,"I don't know too much about that area, but I believe that's because directly after reading a NetCDF file, you don't work with `numpy` arrays but with something different. Only once you call some form of `np.array` (such as `np.asarray` or `np.asanyarray`) on it, it becomes a `numpy.ndarray`.

I'm not sure if the behaviour you encountered is a bug (it probably is), but to fix your example for now, I think you should explicitly `load()` the dataset after opening it:
```python
with xr.open_dataset('ds.nc').load() as ds:
    ds2 = ds.copy()
    print(f'ds.equals = {ds.equals(ds2)}')
    ds2[varname][0] = 11.0
    print(f'ds.equals = {ds.equals(ds2)}')
```","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,554376164