issue_comments

There is another attempt to get this resolved in #7400. Any input appreciated over there.

Any plans to support this?

Yes that is correct

Hi guys! Just to clarify, this is not fixed by #3769 (which only concerns coordinates, not variables) nor by #3364 (which concerns merge not concat). It would be fixed by #3545, but this one is not merged yet. Right?

Ok got it, I'll take a look and spin up a PR.
Thanks

Thanks for tackling this very important issue @scottcha ! from .dataarray import DataArray new_array = DataArray(coords=ds.coords, dims=ds.dims) ds[k] = new_array

Instead of creating a DataArray we only need to create a Variable (https://xarray.pydata.org/en/stable/internals.html#variable-objects).

I would instead try full_like(example_variable, fill_value=np.nan) (import full_like from the appropriate file). The trick would be figuring out what example_variable is. Maybe like this? (there may be some clever way to avoid the two loops)

``` python variables = [] for ds in datasets: if k in ds.variables: filled = full_like(ds.variables[k], fill_value=np.nan) break

for ds in datasets: if k not in ds.variables: variables.append(filled) else: variables.append(ds.variables[k])

vars = ensure_common_dims(variables) ```

Please send in a PR with any progress you make. We are happy to help out. We have some documentation on contributing and testing here: https://xarray.pydata.org/en/stable/contributing.html

I just ran in to this issue. While the previous fix seems to handle one case it doesn't handle all the cases. Before I clean this up and open a new PR does this look like its on the right track (it worked for my issue where I was concating multiple datasets which always had the same dims and coordinates but sometimes were missing variables)?

starts at line 353 on concat.py for k in datasets[0].variables: if k in concat_over: try: #new code for ds in datasets: if k not in ds.variables: #make a new array with the same dimensions and coordinates #by default this will be initialized to np.nan which is what we want from .dataarray import DataArray new_array = DataArray(coords=ds.coords, dims=ds.dims) ds[k] = new_array #end new code vars = ensure_common_dims([ds.variables[k] for ds in datasets]) except KeyError: #this can likely be removed then raise ValueError("%r is not present in all datasets." % k) combined = concat_vars(vars, dim, positions) assert isinstance(combined, Variable) result_vars[k] = combined

Closing as stale, please reopen if still relevant