Remove DataFrame.swapaxes (#57363)

* Remove swapaxes

* Remove swapaxes

Author: phofl

doc/redirects.csv

@@ -481,7 +481,6 @@ generated/pandas.DataFrame.style,../reference/api/pandas.DataFrame.style
 generated/pandas.DataFrame.sub,../reference/api/pandas.DataFrame.sub
 generated/pandas.DataFrame.subtract,../reference/api/pandas.DataFrame.subtract
 generated/pandas.DataFrame.sum,../reference/api/pandas.DataFrame.sum
-generated/pandas.DataFrame.swapaxes,../reference/api/pandas.DataFrame.swapaxes
 generated/pandas.DataFrame.swaplevel,../reference/api/pandas.DataFrame.swaplevel
 generated/pandas.DataFrame.tail,../reference/api/pandas.DataFrame.tail
 generated/pandas.DataFrame.take,../reference/api/pandas.DataFrame.take
@@ -1206,7 +1205,6 @@ generated/pandas.Series.str.zfill,../reference/api/pandas.Series.str.zfill
 generated/pandas.Series.sub,../reference/api/pandas.Series.sub
 generated/pandas.Series.subtract,../reference/api/pandas.Series.subtract
 generated/pandas.Series.sum,../reference/api/pandas.Series.sum
-generated/pandas.Series.swapaxes,../reference/api/pandas.Series.swapaxes
 generated/pandas.Series.swaplevel,../reference/api/pandas.Series.swaplevel
 generated/pandas.Series.tail,../reference/api/pandas.Series.tail
 generated/pandas.Series.take,../reference/api/pandas.Series.take

doc/source/reference/frame.rst

@@ -235,7 +235,6 @@ Reshaping, sorting, transposing
    DataFrame.swaplevel
    DataFrame.stack
    DataFrame.unstack
-   DataFrame.swapaxes
    DataFrame.melt
    DataFrame.explode
    DataFrame.squeeze

doc/source/whatsnew/v3.0.0.rst

@@ -109,6 +109,7 @@ Removal of prior version deprecations/changes
 - Removed :meth:`DataFrame.applymap`, :meth:`Styler.applymap` and :meth:`Styler.applymap_index` (:issue:`52364`)
 - Removed ``DataFrame.bool`` and ``Series.bool`` (:issue:`51756`)
 - Removed ``DataFrame.first`` and ``DataFrame.last`` (:issue:`53710`)
+- Removed ``DataFrame.swapaxes`` and ``Series.swapaxes`` (:issue:`51946`)
 - Removed ``DataFrameGroupBy.grouper`` and ``SeriesGroupBy.grouper`` (:issue:`56521`)
 - Removed ``DataFrameGroupby.fillna`` and ``SeriesGroupBy.fillna``` (:issue:`55719`)
 - Removed ``Index.format``, use :meth:`Index.astype` with ``str`` or :meth:`Index.map` with a ``formatter`` function instead (:issue:`55439`)

pandas/core/generic.py

@@ -161,7 +161,6 @@
     ensure_index,
 )
 from pandas.core.internals import BlockManager
-from pandas.core.internals.construction import ndarray_to_mgr
 from pandas.core.methods.describe import describe_ndframe
 from pandas.core.missing import (
     clean_fill_method,
@@ -755,66 +754,6 @@ def _set_axis(self, axis: AxisInt, labels: AnyArrayLike | list) -> None:
         labels = ensure_index(labels)
         self._mgr.set_axis(axis, labels)
 
-    @final
-    def swapaxes(self, axis1: Axis, axis2: Axis, copy: bool | None = None) -> Self:
-        """
-        Interchange axes and swap values axes appropriately.
-
-        .. deprecated:: 2.1.0
-            ``swapaxes`` is deprecated and will be removed.
-            Please use ``transpose`` instead.
-
-        Returns
-        -------
-        same as input
-
-        Examples
-        --------
-        Please see examples for :meth:`DataFrame.transpose`.
-        """
-        warnings.warn(
-            # GH#51946
-            f"'{type(self).__name__}.swapaxes' is deprecated and "
-            "will be removed in a future version. "
-            f"Please use '{type(self).__name__}.transpose' instead.",
-            FutureWarning,
-            stacklevel=find_stack_level(),
-        )
-
-        i = self._get_axis_number(axis1)
-        j = self._get_axis_number(axis2)
-
-        if i == j:
-            return self.copy(deep=False)
-
-        mapping = {i: j, j: i}
-
-        new_axes = [self._get_axis(mapping.get(k, k)) for k in range(self._AXIS_LEN)]
-        new_values = self._values.swapaxes(i, j)  # type: ignore[union-attr]
-        if self._mgr.is_single_block and isinstance(self._mgr, BlockManager):
-            # This should only get hit in case of having a single block, otherwise a
-            # copy is made, we don't have to set up references.
-            new_mgr = ndarray_to_mgr(
-                new_values,
-                new_axes[0],
-                new_axes[1],
-                dtype=None,
-                copy=False,
-            )
-            assert isinstance(new_mgr, BlockManager)
-            assert isinstance(self._mgr, BlockManager)
-            new_mgr.blocks[0].refs = self._mgr.blocks[0].refs
-            new_mgr.blocks[0].refs.add_reference(new_mgr.blocks[0])
-            out = self._constructor_from_mgr(new_mgr, axes=new_mgr.axes)
-            return out.__finalize__(self, method="swapaxes")
-
-        return self._constructor(
-            new_values,
-            *new_axes,
-            # The no-copy case for CoW is handled above
-            copy=False,
-        ).__finalize__(self, method="swapaxes")
-
     @final
     @doc(klass=_shared_doc_kwargs["klass"])
     def droplevel(self, level: IndexLabel, axis: Axis = 0) -> Self:

pandas/tests/copy_view/test_methods.py

@@ -86,7 +86,6 @@ def test_copy_shallow(using_copy_on_write):
         lambda df, copy: df.rename_axis(columns="test", copy=copy),
         lambda df, copy: df.astype({"b": "int64"}, copy=copy),
         # lambda df, copy: df.swaplevel(0, 0, copy=copy),
-        lambda df, copy: df.swapaxes(0, 0, copy=copy),
         lambda df, copy: df.truncate(0, 5, copy=copy),
         lambda df, copy: df.infer_objects(copy=copy),
         lambda df, copy: df.to_timestamp(copy=copy),
@@ -105,7 +104,6 @@ def test_copy_shallow(using_copy_on_write):
         "rename_axis1",
         "astype",
         # "swaplevel",  # only series
-        "swapaxes",
         "truncate",
         "infer_objects",
         "to_timestamp",
@@ -127,13 +125,7 @@ def test_methods_copy_keyword(request, method, copy, using_copy_on_write):
         index = date_range("2012-01-01", freq="D", periods=3, tz="Europe/Brussels")
 
     df = DataFrame({"a": [1, 2, 3], "b": [4, 5, 6], "c": [0.1, 0.2, 0.3]}, index=index)
-
-    if "swapaxes" in request.node.callspec.id:
-        msg = "'DataFrame.swapaxes' is deprecated"
-        with tm.assert_produces_warning(FutureWarning, match=msg):
-            df2 = method(df, copy=copy)
-    else:
-        df2 = method(df, copy=copy)
+    df2 = method(df, copy=copy)
 
     share_memory = using_copy_on_write or copy is False
 
@@ -161,7 +153,6 @@ def test_methods_copy_keyword(request, method, copy, using_copy_on_write):
         lambda ser, copy: ser.rename_axis(index="test", copy=copy),
         lambda ser, copy: ser.astype("int64", copy=copy),
         lambda ser, copy: ser.swaplevel(0, 1, copy=copy),
-        lambda ser, copy: ser.swapaxes(0, 0, copy=copy),
         lambda ser, copy: ser.truncate(0, 5, copy=copy),
         lambda ser, copy: ser.infer_objects(copy=copy),
         lambda ser, copy: ser.to_timestamp(copy=copy),
@@ -180,7 +171,6 @@ def test_methods_copy_keyword(request, method, copy, using_copy_on_write):
         "rename_axis0",
         "astype",
         "swaplevel",
-        "swapaxes",
         "truncate",
         "infer_objects",
         "to_timestamp",
@@ -204,13 +194,7 @@ def test_methods_series_copy_keyword(request, method, copy, using_copy_on_write)
         index = MultiIndex.from_arrays([[1, 2, 3], [4, 5, 6]])
 
     ser = Series([1, 2, 3], index=index)
-
-    if "swapaxes" in request.node.callspec.id:
-        msg = "'Series.swapaxes' is deprecated"
-        with tm.assert_produces_warning(FutureWarning, match=msg):
-            ser2 = method(ser, copy=copy)
-    else:
-        ser2 = method(ser, copy=copy)
+    ser2 = method(ser, copy=copy)
 
     share_memory = using_copy_on_write or copy is False
 
@@ -688,55 +672,6 @@ def test_to_frame(using_copy_on_write):
         tm.assert_frame_equal(df, expected)
 
 
-@pytest.mark.parametrize("ax", ["index", "columns"])
-def test_swapaxes_noop(using_copy_on_write, ax):
-    df = DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]})
-    df_orig = df.copy()
-    msg = "'DataFrame.swapaxes' is deprecated"
-    with tm.assert_produces_warning(FutureWarning, match=msg):
-        df2 = df.swapaxes(ax, ax)
-
-    if using_copy_on_write:
-        assert np.shares_memory(get_array(df2, "a"), get_array(df, "a"))
-    else:
-        assert not np.shares_memory(get_array(df2, "a"), get_array(df, "a"))
-
-    # mutating df2 triggers a copy-on-write for that column/block
-    df2.iloc[0, 0] = 0
-    if using_copy_on_write:
-        assert not np.shares_memory(get_array(df2, "a"), get_array(df, "a"))
-    tm.assert_frame_equal(df, df_orig)
-
-
-def test_swapaxes_single_block(using_copy_on_write):
-    df = DataFrame({"a": [1, 2, 3], "b": [4, 5, 6]}, index=["x", "y", "z"])
-    df_orig = df.copy()
-    msg = "'DataFrame.swapaxes' is deprecated"
-    with tm.assert_produces_warning(FutureWarning, match=msg):
-        df2 = df.swapaxes("index", "columns")
-
-    if using_copy_on_write:
-        assert np.shares_memory(get_array(df2, "x"), get_array(df, "a"))
-    else:
-        assert not np.shares_memory(get_array(df2, "x"), get_array(df, "a"))
-
-    # mutating df2 triggers a copy-on-write for that column/block
-    df2.iloc[0, 0] = 0
-    if using_copy_on_write:
-        assert not np.shares_memory(get_array(df2, "x"), get_array(df, "a"))
-    tm.assert_frame_equal(df, df_orig)
-
-
-def test_swapaxes_read_only_array():
-    df = DataFrame({"a": [1, 2], "b": 3})
-    msg = "'DataFrame.swapaxes' is deprecated"
-    with tm.assert_produces_warning(FutureWarning, match=msg):
-        df = df.swapaxes(axis1="index", axis2="columns")
-    df.iloc[0, 0] = 100
-    expected = DataFrame({0: [100, 3], 1: [2, 3]}, index=["a", "b"])
-    tm.assert_frame_equal(df, expected)
-
-
 @pytest.mark.parametrize(
     "method, idx",
     [

pandas/tests/frame/methods/test_swapaxes.py

@@ -232,11 +232,8 @@ def test_size_compat(self, frame_or_series):
     def test_split_compat(self, frame_or_series):
         # xref GH8846
         o = construct(frame_or_series, shape=10)
-        with tm.assert_produces_warning(
-            FutureWarning, match=".swapaxes' is deprecated", check_stacklevel=False
-        ):
-            assert len(np.array_split(o, 5)) == 5
-            assert len(np.array_split(o, 2)) == 2
+        assert len(np.array_split(o, 5)) == 5
+        assert len(np.array_split(o, 2)) == 2
 
     # See gh-12301
     def test_stat_unexpected_keyword(self, frame_or_series):