Make groupby/resample args keyword-only, start groupby_bins deprecation

doc/whats-new.rst

@@ -55,6 +55,10 @@ New Features
 
 Breaking Changes
 ~~~~~~~~~~~~~~~~
+- Passing keyword-only arguments of :py:meth:`Dataset.groupby`,
+  :py:meth:`DataArray.groupby`, :py:meth:`Dataset.resample` and
+  :py:meth:`DataArray.resample` positionally, deprecated since v2024.07.0, now
+  raises a ``TypeError`` (:issue:`11721`, :pull:`11744`).
 - The ``DataArray.dt.weekofyear`` and ``DataArray.dt.week`` accessors,
   deprecated since v0.16.2, have been removed. Use
   ``DataArray.dt.isocalendar().week`` instead (:issue:`11721`, :pull:`11742`).
@@ -120,6 +124,11 @@ Breaking Changes
 
 Deprecations
 ~~~~~~~~~~~~
+- Passing any argument after ``bins`` positionally to
+  :py:meth:`Dataset.groupby_bins` and :py:meth:`DataArray.groupby_bins` is
+  deprecated. It was meant to be deprecated in v2024.07.0, but the warning never
+  fired (:issue:`11721`, :pull:`11744`).
+  By `Mohansree Vijayakumar <https://github.com/mohansree14>`_.
 - ``reset_encoding`` of :py:class:`Dataset`, :py:class:`DataArray` and
   :py:class:`Variable` now emits a ``FutureWarning`` instead of a ``UserWarning``,
   like the other deprecations, and gives the right version (2023.10).

xarray/core/dataarray.py

@@ -7140,7 +7140,6 @@ def interp_calendar(
         """
         return interp_calendar(self, target, dim=dim)
 
-    @_deprecate_positional_args("v2024.07.0")
     def groupby(
         self,
         group: GroupInput = None,
@@ -7284,11 +7283,12 @@ def groupby(
         )
         return DataArrayGroupBy(self, rgroupers, restore_coord_dims=restore_coord_dims)
 
-    @_deprecate_positional_args("v2024.07.0")
+    @_deprecate_positional_args("v2026.10.0")
     def groupby_bins(
         self,
         group: Hashable | DataArray | IndexVariable,
         bins: Bins,
+        *,
         right: bool = True,
         labels: ArrayLike | Literal[False] | None = None,
         precision: int = 3,
@@ -7712,7 +7712,6 @@ def coarsen(
             coord_func=coord_func,
         )
 
-    @_deprecate_positional_args("v2024.07.0")
     def resample(
         self,
         indexer: Mapping[Hashable, ResampleCompatible | Resampler] | None = None,

xarray/core/dataset.py

@@ -10318,7 +10318,6 @@ def interp_calendar(
         """
         return interp_calendar(self, target, dim=dim)
 
-    @_deprecate_positional_args("v2024.07.0")
     def groupby(
         self,
         group: GroupInput = None,
@@ -10431,11 +10430,12 @@ def groupby(
 
         return DatasetGroupBy(self, rgroupers, restore_coord_dims=restore_coord_dims)
 
-    @_deprecate_positional_args("v2024.07.0")
+    @_deprecate_positional_args("v2026.10.0")
     def groupby_bins(
         self,
         group: Hashable | DataArray | IndexVariable,
         bins: Bins,
+        *,
         right: bool = True,
         labels: ArrayLike | None = None,
         precision: int = 3,
@@ -10704,7 +10704,6 @@ def coarsen(
             coord_func=coord_func,
         )
 
-    @_deprecate_positional_args("v2024.07.0")
     def resample(
         self,
         indexer: Mapping[Any, ResampleCompatible | Resampler] | None = None,

xarray/tests/test_groupby.py

@@ -3069,17 +3069,37 @@ def test_multiple_groupers_string(as_dataset) -> None:
     actual = obj.groupby(("labels1", "labels2")).mean()
     assert_identical(expected, actual)
 
-    # Passes `"labels2"` to squeeze; will raise an error around kwargs rather than the
-    # warning & type error in the future
-    with pytest.warns(FutureWarning):
-        with pytest.raises(TypeError):
-            obj.groupby("labels1", "labels2")  # type: ignore[arg-type, call-arg]
+    with pytest.raises(TypeError, match=r"positional argument"):
+        obj.groupby("labels1", "labels2")  # type: ignore[arg-type, call-arg]
     with pytest.raises(ValueError):
         obj.groupby("labels1", foo="bar")  # type: ignore[arg-type]
     with pytest.raises(ValueError):
         obj.groupby("labels1", foo=UniqueGrouper())
 
 
+@pytest.mark.parametrize("as_dataset", [True, False])
+def test_keyword_only_args(as_dataset: bool) -> None:
+    obj: DataArray | Dataset = DataArray(
+        [1, 2, 3],
+        dims="time",
+        coords={"time": pd.date_range("2000-01-01", periods=3)},
+        name="foo",
+    )
+    if as_dataset:
+        obj = obj.to_dataset()
+
+    with pytest.raises(TypeError, match=r"positional argument"):
+        obj.groupby("time", False)  # type: ignore[call-arg]
+    with pytest.raises(TypeError, match=r"positional argument"):
+        obj.resample({"time": "D"}, True)  # type: ignore[call-arg]
+
+    obj = obj.assign_coords(x=("time", [1, 2, 3]))
+    expected = obj.groupby_bins("x", [0, 2, 4], right=False).sum()
+    with pytest.warns(FutureWarning, match=r"Passing 'right' as positional"):
+        actual = obj.groupby_bins("x", [0, 2, 4], False).sum()  # type: ignore[call-arg]
+    assert_identical(expected, actual)
+
+
 @pytest.mark.parametrize("shuffle", [True, False])
 @pytest.mark.parametrize("use_flox", [True, False])
 def test_multiple_groupers(use_flox: bool, shuffle: bool) -> None: