Update DataArray.rename + docu (#6665)

* update dataarray rename incl docu

* update whats-new

* add support for changing name and dims/coords at the same time

* fix runtime typing issue

* Revert "add support for changing name and dims/coords at the same time"

This reverts commit 31d8521.

* enable rename to None again

* fix a typing problem

Author: headtr1ck

doc/whats-new.rst

@@ -229,6 +229,9 @@ Documentation
   sizes. In particular, correct the syntax and replace lists with tuples in the
   examples. (:issue:`6333`, :pull:`6334`)
   By `Stan West <https://github.com/stanwest>`_.
+- Mention that ``xr.DataArray.rename`` can rename coordinates.
+  (:issue:`5458`, :pull:`6665`)
+  By `Michael Niklas <https://github.com/headtr1ck>`_.
 
 - Added examples to :py:meth:`Dataset.thin` and :py:meth:`DataArray.thin`
   By `Emma Marshall <https://github.com/e-marshall>`_.

xarray/core/dataarray.py

@@ -1996,17 +1996,17 @@ def rename(
         new_name_or_name_dict: Hashable | Mapping[Any, Hashable] | None = None,
         **names: Hashable,
     ) -> DataArray:
-        """Returns a new DataArray with renamed coordinates or a new name.
+        """Returns a new DataArray with renamed coordinates, dimensions or a new name.
 
         Parameters
         ----------
         new_name_or_name_dict : str or dict-like, optional
             If the argument is dict-like, it used as a mapping from old
-            names to new names for coordinates. Otherwise, use the argument
-            as the new name for this array.
+            names to new names for coordinates or dimensions. Otherwise,
+            use the argument as the new name for this array.
         **names : Hashable, optional
             The keyword arguments form of a mapping from old names to
-            new names for coordinates.
+            new names for coordinates or dimensions.
             One of new_name_or_name_dict or names must be provided.
 
         Returns
@@ -2019,16 +2019,21 @@ def rename(
         Dataset.rename
         DataArray.swap_dims
         """
-        if names or utils.is_dict_like(new_name_or_name_dict):
-            new_name_or_name_dict = cast(
-                Mapping[Hashable, Hashable], new_name_or_name_dict
-            )
+        if new_name_or_name_dict is None and not names:
+            # change name to None?
+            return self._replace(name=None)
+        if utils.is_dict_like(new_name_or_name_dict) or new_name_or_name_dict is None:
+            # change dims/coords
             name_dict = either_dict_or_kwargs(new_name_or_name_dict, names, "rename")
             dataset = self._to_temp_dataset().rename(name_dict)
             return self._from_temp_dataset(dataset)
-        else:
-            new_name_or_name_dict = cast(Hashable, new_name_or_name_dict)
-            return self._replace(name=new_name_or_name_dict)
+        if utils.hashable(new_name_or_name_dict) and names:
+            # change name + dims/coords
+            dataset = self._to_temp_dataset().rename(names)
+            dataarray = self._from_temp_dataset(dataset)
+            return dataarray._replace(name=new_name_or_name_dict)
+        # only change name
+        return self._replace(name=new_name_or_name_dict)
 
     def swap_dims(
         self: T_DataArray,

xarray/core/dataset.py

@@ -3558,12 +3558,12 @@ def rename(
         name_dict: Mapping[Any, Hashable] | None = None,
         **names: Hashable,
     ) -> T_Dataset:
-        """Returns a new object with renamed variables and dimensions.
+        """Returns a new object with renamed variables, coordinates and dimensions.
 
         Parameters
         ----------
         name_dict : dict-like, optional
-            Dictionary whose keys are current variable or dimension names and
+            Dictionary whose keys are current variable, coordinate or dimension names and
             whose values are the desired names.
         **names : optional
             Keyword form of ``name_dict``.
@@ -3572,7 +3572,7 @@ def rename(
         Returns
         -------
         renamed : Dataset
-            Dataset with renamed variables and dimensions.
+            Dataset with renamed variables, coordinates and dimensions.
 
         See Also
         --------

xarray/core/types.py

@@ -56,7 +56,7 @@
 InterpOptions = Union[Interp1dOptions, InterpolantOptions]
 
 DatetimeUnitOptions = Literal[
-    "Y", "M", "W", "D", "h", "m", "s", "ms", "us", "ns", "ps", "fs", "as", None
+    "Y", "M", "W", "D", "h", "m", "s", "ms", "us", "μs", "ns", "ps", "fs", "as", None
 ]
 
 QueryEngineOptions = Literal["python", "numexpr", None]

xarray/tests/test_dataarray.py

@@ -1653,17 +1653,87 @@ def test_reindex_str_dtype(self, dtype) -> None:
         assert actual.dtype == expected.dtype
 
     def test_rename(self) -> None:
-        renamed = self.dv.rename("bar")
-        assert_identical(renamed.to_dataset(), self.ds.rename({"foo": "bar"}))
-        assert renamed.name == "bar"
 
-        renamed = self.dv.x.rename({"x": "z"}).rename("z")
-        assert_identical(renamed, self.ds.rename({"x": "z"}).z)
-        assert renamed.name == "z"
-        assert renamed.dims == ("z",)
-
-        renamed_kwargs = self.dv.x.rename(x="z").rename("z")
-        assert_identical(renamed, renamed_kwargs)
+        da = xr.DataArray(
+            [1, 2, 3], dims="dim", name="name", coords={"coord": ("dim", [5, 6, 7])}
+        )
+
+        # change name
+        renamed_name = da.rename("name_new")
+        assert renamed_name.name == "name_new"
+        expected_name = da.copy()
+        expected_name.name = "name_new"
+        assert_identical(renamed_name, expected_name)
+
+        # change name to None?
+        renamed_noname = da.rename(None)
+        assert renamed_noname.name is None
+        expected_noname = da.copy()
+        expected_noname.name = None
+        assert_identical(renamed_noname, expected_noname)
+        renamed_noname = da.rename()
+        assert renamed_noname.name is None
+        assert_identical(renamed_noname, expected_noname)
+
+        # change dim
+        renamed_dim = da.rename({"dim": "dim_new"})
+        assert renamed_dim.dims == ("dim_new",)
+        expected_dim = xr.DataArray(
+            [1, 2, 3],
+            dims="dim_new",
+            name="name",
+            coords={"coord": ("dim_new", [5, 6, 7])},
+        )
+        assert_identical(renamed_dim, expected_dim)
+
+        # change dim with kwargs
+        renamed_dimkw = da.rename(dim="dim_new")
+        assert renamed_dimkw.dims == ("dim_new",)
+        assert_identical(renamed_dimkw, expected_dim)
+
+        # change coords
+        renamed_coord = da.rename({"coord": "coord_new"})
+        assert "coord_new" in renamed_coord.coords
+        expected_coord = xr.DataArray(
+            [1, 2, 3], dims="dim", name="name", coords={"coord_new": ("dim", [5, 6, 7])}
+        )
+        assert_identical(renamed_coord, expected_coord)
+
+        # change coords with kwargs
+        renamed_coordkw = da.rename(coord="coord_new")
+        assert "coord_new" in renamed_coordkw.coords
+        assert_identical(renamed_coordkw, expected_coord)
+
+        # change coord and dim
+        renamed_both = da.rename({"dim": "dim_new", "coord": "coord_new"})
+        assert renamed_both.dims == ("dim_new",)
+        assert "coord_new" in renamed_both.coords
+        expected_both = xr.DataArray(
+            [1, 2, 3],
+            dims="dim_new",
+            name="name",
+            coords={"coord_new": ("dim_new", [5, 6, 7])},
+        )
+        assert_identical(renamed_both, expected_both)
+
+        # change coord and dim with kwargs
+        renamed_bothkw = da.rename(dim="dim_new", coord="coord_new")
+        assert renamed_bothkw.dims == ("dim_new",)
+        assert "coord_new" in renamed_bothkw.coords
+        assert_identical(renamed_bothkw, expected_both)
+
+        # change all
+        renamed_all = da.rename("name_new", dim="dim_new", coord="coord_new")
+        assert renamed_all.name == "name_new"
+        assert renamed_all.dims == ("dim_new",)
+        assert "coord_new" in renamed_all.coords
+        expected_all = xr.DataArray(
+            [1, 2, 3],
+            dims="dim_new",
+            name="name_new",
+            coords={"coord_new": ("dim_new", [5, 6, 7])},
+        )
+        assert_identical(renamed_all, expected_all)
 
     def test_init_value(self) -> None:
         expected = DataArray(