Transpose coords by default (#3824)

* transpose coords by default

* whatsnew

* Update doc/whats-new.rst

Co-authored-by: crusaderky <crusaderky@gmail.com>

* Update whats-new.rst

Co-authored-by: crusaderky <crusaderky@gmail.com>

Author: max-sixty

doc/whats-new.rst

@@ -21,6 +21,12 @@ v0.16.0 (unreleased)
 
 Breaking changes
 ~~~~~~~~~~~~~~~~
+
+- ``groupby`` operations will restore coord dimension order. Pass ``restore_coord_dims=False``
+  to revert to previous behavior.
+- :meth:`DataArray.transpose` will now transpose coordinates by default.
+  Pass ``transpose_coords=False`` to revert to previous behaviour.
+  By `Maximilian Roos <https://github.com/max-sixty>`_
 - Alternate draw styles for :py:meth:`plot.step` must be passed using the
   ``drawstyle`` (or ``ds``) keyword argument, instead of the ``linestyle`` (or
   ``ls``) keyword argument, in line with the `upstream change in Matplotlib

xarray/core/dataarray.py

@@ -1,6 +1,5 @@
 import datetime
 import functools
-import warnings
 from numbers import Number
 from typing import (
     TYPE_CHECKING,
@@ -1915,15 +1914,15 @@ def to_unstacked_dataset(self, dim, level=0):
         # unstacked dataset
         return Dataset(data_dict)
 
-    def transpose(self, *dims: Hashable, transpose_coords: bool = None) -> "DataArray":
+    def transpose(self, *dims: Hashable, transpose_coords: bool = True) -> "DataArray":
         """Return a new DataArray object with transposed dimensions.
 
         Parameters
         ----------
         *dims : hashable, optional
             By default, reverse the dimensions. Otherwise, reorder the
             dimensions to this order.
-        transpose_coords : boolean, optional
+        transpose_coords : boolean, default True
             If True, also transpose the coordinates of this DataArray.
 
         Returns
@@ -1952,15 +1951,6 @@ def transpose(self, *dims: Hashable, transpose_coords: bool = None) -> "DataArra
                 coords[name] = coord.variable.transpose(*coord_dims)
             return self._replace(variable, coords)
         else:
-            if transpose_coords is None and any(self[c].ndim > 1 for c in self.coords):
-                warnings.warn(
-                    "This DataArray contains multi-dimensional "
-                    "coordinates. In the future, these coordinates "
-                    "will be transposed as well unless you specify "
-                    "transpose_coords=False.",
-                    FutureWarning,
-                    stacklevel=2,
-                )
             return self._replace(variable)
 
     @property

xarray/core/groupby.py

@@ -272,7 +272,7 @@ def __init__(
         squeeze=False,
         grouper=None,
         bins=None,
-        restore_coord_dims=None,
+        restore_coord_dims=True,
         cut_kwargs=None,
     ):
         """Create a GroupBy object
@@ -292,7 +292,7 @@ def __init__(
         bins : array-like, optional
             If `bins` is specified, the groups will be discretized into the
             specified bins by `pandas.cut`.
-        restore_coord_dims : bool, optional
+        restore_coord_dims : bool, default True
             If True, also restore the dimension order of multi-dimensional
             coordinates.
         cut_kwargs : dict, optional
@@ -389,21 +389,6 @@ def __init__(
                     "Failed to group data. Are you grouping by a variable that is all NaN?"
                 )
 
-        if (
-            isinstance(obj, DataArray)
-            and restore_coord_dims is None
-            and any(obj[c].ndim > 1 for c in obj.coords)
-        ):
-            warnings.warn(
-                "This DataArray contains multi-dimensional "
-                "coordinates. In the future, the dimension order "
-                "of these coordinates will be restored as well "
-                "unless you specify restore_coord_dims=False.",
-                FutureWarning,
-                stacklevel=2,
-            )
-            restore_coord_dims = False
-
         # specification for the groupby operation
         self._obj = obj
         self._group = group

xarray/tests/test_dataarray.py

@@ -2161,9 +2161,6 @@ def test_transpose(self):
         with pytest.raises(ValueError):
             da.transpose("x", "y")
 
-        with pytest.warns(FutureWarning):
-            da.transpose()
-
     def test_squeeze(self):
         assert_equal(self.dv.variable.squeeze(), self.dv.squeeze().variable)
 
@@ -2753,9 +2750,6 @@ def test_groupby_restore_coord_dims(self):
             )["c"]
             assert result.dims == expected_dims
 
-        with pytest.warns(FutureWarning):
-            array.groupby("x").map(lambda x: x.squeeze())
-
     def test_groupby_first_and_last(self):
         array = DataArray([1, 2, 3, 4, 5], dims="x")
         by = DataArray(["a"] * 2 + ["b"] * 3, dims="x", name="ab")