Drop keyword support: small fixes

doc/indexing.rst

@@ -238,7 +238,7 @@ index labels along a dimension dropped:
 .. ipython:: python
     :okwarning:
 
-    ds.drop(['IN', 'IL'], dim='space')
+    ds.drop(space=['IN', 'IL'])
 
 ``drop`` is both a ``Dataset`` and ``DataArray`` method.
 

doc/whats-new.rst

@@ -66,7 +66,9 @@ Enhancements
   By `David Brochart <https://github.com/davidbrochart>`_.
 
 - :py:meth:`~xarray.Dataset.drop` now supports keyword arguments; dropping index
-  labels by specifying both ``dim`` and ``labels`` is deprecated (:issue:`2910`).
+  labels by using both ``dim`` and ``labels`` or using a
+  :py:class:`~xarray.core.coordinates.DataArrayCoordinates` object are
+  deprecated (:issue:`2910`).
   By `Gregory Gundersen <https://github.com/gwgundersen/>`_.
 
 - Added examples of :py:meth:`Dataset.set_index` and

xarray/core/dataset.py

@@ -3548,8 +3548,7 @@ def drop(  # noqa: F811
         if errors not in ["raise", "ignore"]:
             raise ValueError('errors must be either "raise" or "ignore"')
 
-        labels_are_coords = isinstance(labels, DataArrayCoordinates)
-        if labels_kwargs or (utils.is_dict_like(labels) and not labels_are_coords):
+        if labels_kwargs or isinstance(labels, dict):
             labels_kwargs = utils.either_dict_or_kwargs(labels, labels_kwargs, "drop")
             if dim is not None:
                 raise ValueError("cannot specify dim and dict-like arguments.")
@@ -3558,6 +3557,13 @@ def drop(  # noqa: F811
                 ds = ds._drop_labels(labels, dim, errors=errors)
             return ds
         elif dim is None:
+            if isinstance(labels, DataArrayCoordinates):
+                warnings.warn(
+                    "dropping coordinates using a DataArrayCoordinates object "
+                    "is deprecated; use drop_vars or a list of coordinates",
+                    DeprecationWarning,
+                    stacklevel=2,
+                )
             if isinstance(labels, str) or not isinstance(labels, Iterable):
                 labels = {labels}
             else: