DEPR: unused kind arg in Index methods (pandas-dev#42857)

doc/source/whatsnew/v1.4.0.rst

@@ -160,6 +160,8 @@ Deprecations
 - Deprecated treating ``numpy.datetime64`` objects as UTC times when passed to the :class:`Timestamp` constructor along with a timezone. In a future version, these will be treated as wall-times. To retain the old behavior, use ``Timestamp(dt64).tz_localize("UTC").tz_convert(tz)`` (:issue:`24559`)
 - Deprecated ignoring missing labels when indexing with a sequence of labels on a level of a MultiIndex (:issue:`42351`)
 - Creating an empty Series without a dtype will now raise a more visible ``FutureWarning`` instead of a ``DeprecationWarning`` (:issue:`30017`)
+- Deprecated the 'kind' argument in :meth:`Index.get_slice_bound`, :meth:`Index.slice_indexer`, :meth:`Index.slice_locs`; in a future version passing 'kind' will raise (:issue:`42857`)
+-
 
 .. ---------------------------------------------------------------------------
 

pandas/core/indexes/base.py

@@ -5839,7 +5839,7 @@ def slice_indexer(
         start: Hashable | None = None,
         end: Hashable | None = None,
         step: int | None = None,
-        kind: str_t | None = None,
+        kind=no_default,
     ) -> slice:
         """
         Compute the slice indexer for input labels and step.
@@ -5855,6 +5855,8 @@ def slice_indexer(
         step : int, default None
         kind : str, default None
 
+            .. deprecated:: 1.4.0
+
         Returns
         -------
         indexer : slice
@@ -5880,6 +5882,8 @@ def slice_indexer(
         >>> idx.slice_indexer(start='b', end=('c', 'g'))
         slice(1, 3, None)
         """
+        self._deprecated_arg(kind, "kind", "slice_indexer")
+
         start_slice, end_slice = self.slice_locs(start, end, step=step)
 
         # return a slice
@@ -5928,6 +5932,8 @@ def _maybe_cast_slice_bound(self, label, side: str_t, kind=no_default):
         side : {'left', 'right'}
         kind : {'loc', 'getitem'} or None
 
+            .. deprecated:: 1.3.0
+
         Returns
         -------
         label : object
@@ -5962,7 +5968,7 @@ def _searchsorted_monotonic(self, label, side: str_t = "left"):
 
         raise ValueError("index must be monotonic increasing or decreasing")
 
-    def get_slice_bound(self, label, side: str_t, kind=None) -> int:
+    def get_slice_bound(self, label, side: str_t, kind=no_default) -> int:
         """
         Calculate slice bound that corresponds to given label.
 
@@ -5975,12 +5981,15 @@ def get_slice_bound(self, label, side: str_t, kind=None) -> int:
         side : {'left', 'right'}
         kind : {'loc', 'getitem'} or None
 
+            .. deprecated:: 1.4.0
+
         Returns
         -------
         int
             Index of label.
         """
-        assert kind in ["loc", "getitem", None]
+        assert kind in ["loc", "getitem", None, no_default]
+        self._deprecated_arg(kind, "kind", "get_slice_bound")
 
         if side not in ("left", "right"):
             raise ValueError(
@@ -6030,7 +6039,7 @@ def get_slice_bound(self, label, side: str_t, kind=None) -> int:
             else:
                 return slc
 
-    def slice_locs(self, start=None, end=None, step=None, kind=None):
+    def slice_locs(self, start=None, end=None, step=None, kind=no_default):
         """
         Compute slice locations for input labels.
 
@@ -6044,6 +6053,8 @@ def slice_locs(self, start=None, end=None, step=None, kind=None):
             If None, defaults to 1.
         kind : {'loc', 'getitem'} or None
 
+            .. deprecated:: 1.4.0
+
         Returns
         -------
         start, end : int
@@ -6062,6 +6073,7 @@ def slice_locs(self, start=None, end=None, step=None, kind=None):
         >>> idx.slice_locs(start='b', end='c')
         (1, 3)
         """
+        self._deprecated_arg(kind, "kind", "slice_locs")
         inc = step is None or step >= 0
 
         if not inc:

pandas/core/indexes/datetimes.py

@@ -729,7 +729,7 @@ def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
 
         return self._maybe_cast_for_get_loc(label)
 
-    def slice_indexer(self, start=None, end=None, step=None, kind=None):
+    def slice_indexer(self, start=None, end=None, step=None, kind=lib.no_default):
         """
         Return indexer for specified label slice.
         Index.slice_indexer, customized to handle time slicing.
@@ -743,6 +743,8 @@ def slice_indexer(self, start=None, end=None, step=None, kind=None):
           value-based selection in non-monotonic cases.
 
         """
+        self._deprecated_arg(kind, "kind", "slice_indexer")
+
         # For historical reasons DatetimeIndex supports slices between two
         # instances of datetime.time as if it were applying a slice mask to
         # an array of (self.hour, self.minute, self.seconds, self.microsecond).

pandas/core/indexes/multi.py

@@ -2586,7 +2586,7 @@ def _get_indexer_level_0(self, target) -> np.ndarray:
         return ci.get_indexer_for(target)
 
     def get_slice_bound(
-        self, label: Hashable | Sequence[Hashable], side: str, kind: str | None = None
+        self, label: Hashable | Sequence[Hashable], side: str, kind=lib.no_default
     ) -> int:
         """
         For an ordered MultiIndex, compute slice bound
@@ -2601,6 +2601,8 @@ def get_slice_bound(
         side : {'left', 'right'}
         kind : {'loc', 'getitem', None}
 
+            .. deprecated:: 1.4.0
+
         Returns
         -------
         int
@@ -2632,11 +2634,13 @@ def get_slice_bound(
         MultiIndex.get_locs : Get location for a label/slice/list/mask or a
                               sequence of such.
         """
+        self._deprecated_arg(kind, "kind", "get_slice_bound")
+
         if not isinstance(label, tuple):
             label = (label,)
         return self._partial_tup_index(label, side=side)
 
-    def slice_locs(self, start=None, end=None, step=None, kind=None):
+    def slice_locs(self, start=None, end=None, step=None, kind=lib.no_default):
         """
         For an ordered MultiIndex, compute the slice locations for input
         labels.
@@ -2655,6 +2659,8 @@ def slice_locs(self, start=None, end=None, step=None, kind=None):
             Slice step
         kind : string, optional, defaults None
 
+            .. deprecated:: 1.4.0
+
         Returns
         -------
         (start, end) : (int, int)
@@ -2688,6 +2694,7 @@ def slice_locs(self, start=None, end=None, step=None, kind=None):
         MultiIndex.get_locs : Get location for a label/slice/list/mask or a
                               sequence of such.
         """
+        self._deprecated_arg(kind, "kind", "slice_locs")
         # This function adds nothing to its parent implementation (the magic
         # happens in get_slice_bound method), but it adds meaningful doc.
         return super().slice_locs(start, end, step)

pandas/core/indexes/numeric.py

@@ -244,7 +244,7 @@ def _convert_slice_indexer(self, key: slice, kind: str):
 
             # We always treat __getitem__ slicing as label-based
             # translate to locations
-            return self.slice_indexer(key.start, key.stop, key.step, kind=kind)
+            return self.slice_indexer(key.start, key.stop, key.step)
 
         return super()._convert_slice_indexer(key, kind=kind)
 

pandas/tests/indexes/base_class/test_indexing.py

@@ -10,7 +10,8 @@ class TestGetSliceBounds:
     @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
     def test_get_slice_bounds_within(self, kind, side, expected):
         index = Index(list("abcdef"))
-        result = index.get_slice_bound("e", kind=kind, side=side)
+        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
+            result = index.get_slice_bound("e", kind=kind, side=side)
         assert result == expected
 
     @pytest.mark.parametrize("kind", ["getitem", "loc", None])
@@ -20,12 +21,13 @@ def test_get_slice_bounds_within(self, kind, side, expected):
     )
     def test_get_slice_bounds_outside(self, kind, side, expected, data, bound):
         index = Index(data)
-        result = index.get_slice_bound(bound, kind=kind, side=side)
+        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
+            result = index.get_slice_bound(bound, kind=kind, side=side)
         assert result == expected
 
     def test_get_slice_bounds_invalid_side(self):
         with pytest.raises(ValueError, match="Invalid value for side kwarg"):
-            Index([]).get_slice_bound("a", kind=None, side="middle")
+            Index([]).get_slice_bound("a", side="middle")
 
 
 class TestGetIndexerNonUnique:

pandas/tests/indexes/multi/test_indexing.py

@@ -820,7 +820,8 @@ def test_timestamp_multiindex_indexer():
 def test_get_slice_bound_with_missing_value(index_arr, expected, target, algo):
     # issue 19132
     idx = MultiIndex.from_arrays(index_arr)
-    result = idx.get_slice_bound(target, side=algo, kind="loc")
+    with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
+        result = idx.get_slice_bound(target, side=algo, kind="loc")
     assert result == expected
 
 

pandas/tests/indexes/numeric/test_indexing.py

@@ -545,13 +545,16 @@ class TestGetSliceBounds:
     @pytest.mark.parametrize("side, expected", [("left", 4), ("right", 5)])
     def test_get_slice_bounds_within(self, kind, side, expected):
         index = Index(range(6))
-        result = index.get_slice_bound(4, kind=kind, side=side)
+        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
+
+            result = index.get_slice_bound(4, kind=kind, side=side)
         assert result == expected
 
     @pytest.mark.parametrize("kind", ["getitem", "loc", None])
     @pytest.mark.parametrize("side", ["left", "right"])
     @pytest.mark.parametrize("bound, expected", [(-1, 0), (10, 6)])
     def test_get_slice_bounds_outside(self, kind, side, expected, bound):
         index = Index(range(6))
-        result = index.get_slice_bound(bound, kind=kind, side=side)
+        with tm.assert_produces_warning(FutureWarning, match="'kind' argument"):
+            result = index.get_slice_bound(bound, kind=kind, side=side)
         assert result == expected