Method maybe_variable

xarray/core/dataset.py:3901–3906

(obj, k)

        obj = self if assume_sorted else self.sortby(list(coords))

        def maybe_variable(obj, k):
            # workaround to get variable for dimension without coordinate.
            try:
                return obj._variables[k]
            except KeyError:
                return as_variable((k, range(obj.sizes[k])))

        def _validate_interp_indexer(x, new_x):
            # In the case of datetimes, the restrictions placed on indexers