DEPR: kind kwarg in _maybe_cast_slice_bound (#41378)

doc/source/user_guide/scale.rst

@@ -345,6 +345,7 @@ we need to supply the divisions manually.
 Now we can do things like fast random access with ``.loc``.
 
 .. ipython:: python
+   :okwarning:
 
    ddf.loc["2002-01-01 12:01":"2002-01-01 12:05"].compute()
 

pandas/core/indexes/base.py

@@ -3680,7 +3680,7 @@ def is_int(v):
                 )
             indexer = key
         else:
-            indexer = self.slice_indexer(start, stop, step, kind=kind)
+            indexer = self.slice_indexer(start, stop, step)
 
         return indexer
 
@@ -5643,7 +5643,7 @@ def slice_indexer(
         >>> idx.slice_indexer(start='b', end=('c', 'g'))
         slice(1, 3, None)
         """
-        start_slice, end_slice = self.slice_locs(start, end, step=step, kind=kind)
+        start_slice, end_slice = self.slice_locs(start, end, step=step)
 
         # return a slice
         if not is_scalar(start_slice):
@@ -5673,7 +5673,7 @@ def _validate_indexer(self, form: str_t, key, kind: str_t):
         if key is not None and not is_integer(key):
             raise self._invalid_indexer(form, key)
 
-    def _maybe_cast_slice_bound(self, label, side: str_t, kind):
+    def _maybe_cast_slice_bound(self, label, side: str_t, kind=no_default):
         """
         This function should be overloaded in subclasses that allow non-trivial
         casting on label-slice bounds, e.g. datetime-like indices allowing
@@ -5693,7 +5693,8 @@ def _maybe_cast_slice_bound(self, label, side: str_t, kind):
         -----
         Value of `side` parameter should be validated in caller.
         """
-        assert kind in ["loc", "getitem", None]
+        assert kind in ["loc", "getitem", None, no_default]
+        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
 
         # We are a plain index here (sub-class override this method if they
         # wish to have special treatment for floats/ints, e.g. Float64Index and
@@ -5718,7 +5719,7 @@ 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) -> int:
+    def get_slice_bound(self, label, side: str_t, kind=None) -> int:
         """
         Calculate slice bound that corresponds to given label.
 
@@ -5748,7 +5749,7 @@ def get_slice_bound(self, label, side: str_t, kind) -> int:
 
         # For datetime indices label may be a string that has to be converted
         # to datetime boundary according to its resolution.
-        label = self._maybe_cast_slice_bound(label, side, kind)
+        label = self._maybe_cast_slice_bound(label, side)
 
         # we need to look up the label
         try:
@@ -5838,13 +5839,13 @@ def slice_locs(self, start=None, end=None, step=None, kind=None):
 
         start_slice = None
         if start is not None:
-            start_slice = self.get_slice_bound(start, "left", kind)
+            start_slice = self.get_slice_bound(start, "left")
         if start_slice is None:
             start_slice = 0
 
         end_slice = None
         if end is not None:
-            end_slice = self.get_slice_bound(end, "right", kind)
+            end_slice = self.get_slice_bound(end, "right")
         if end_slice is None:
             end_slice = len(self)
 
@@ -6176,6 +6177,18 @@ def shape(self) -> Shape:
         # See GH#27775, GH#27384 for history/reasoning in how this is defined.
         return (len(self),)
 
+    def _deprecated_arg(self, value, name: str_t, methodname: str_t) -> None:
+        """
+        Issue a FutureWarning if the arg/kwarg is not no_default.
+        """
+        if value is not no_default:
+            warnings.warn(
+                f"'{name}' argument in {methodname} is deprecated "
+                "and will be removed in a future version.  Do not pass it.",
+                FutureWarning,
+                stacklevel=3,
+            )
+
 
 def ensure_index_from_sequences(sequences, names=None):
     """

pandas/core/indexes/datetimes.py

@@ -724,7 +724,7 @@ def _maybe_cast_for_get_loc(self, key) -> Timestamp:
             key = key.tz_convert(self.tz)
         return key
 
-    def _maybe_cast_slice_bound(self, label, side: str, kind):
+    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
         """
         If label is a string, cast it to datetime according to resolution.
 
@@ -742,7 +742,8 @@ def _maybe_cast_slice_bound(self, label, side: str, kind):
         -----
         Value of `side` parameter should be validated in caller.
         """
-        assert kind in ["loc", "getitem", None]
+        assert kind in ["loc", "getitem", None, lib.no_default]
+        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
 
         if isinstance(label, str):
             freq = getattr(self, "freqstr", getattr(self, "inferred_freq", None))
@@ -823,12 +824,12 @@ def check_str_or_none(point):
         mask = np.array(True)
         deprecation_mask = np.array(True)
         if start is not None:
-            start_casted = self._maybe_cast_slice_bound(start, "left", kind)
+            start_casted = self._maybe_cast_slice_bound(start, "left")
             mask = start_casted <= self
             deprecation_mask = start_casted == self
 
         if end is not None:
-            end_casted = self._maybe_cast_slice_bound(end, "right", kind)
+            end_casted = self._maybe_cast_slice_bound(end, "right")
             mask = (self <= end_casted) & mask
             deprecation_mask = (end_casted == self) | deprecation_mask
 

pandas/core/indexes/interval.py

@@ -825,8 +825,9 @@ def _should_fallback_to_positional(self) -> bool:
         #  positional in this case
         return self.dtype.subtype.kind in ["m", "M"]
 
-    def _maybe_cast_slice_bound(self, label, side: str, kind):
-        return getattr(self, side)._maybe_cast_slice_bound(label, side, kind)
+    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
+        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
+        return getattr(self, side)._maybe_cast_slice_bound(label, side)
 
     @Appender(Index._convert_list_indexer.__doc__)
     def _convert_list_indexer(self, keyarr):

pandas/core/indexes/multi.py

@@ -2716,7 +2716,7 @@ def _get_indexer(
         return ensure_platform_int(indexer)
 
     def get_slice_bound(
-        self, label: Hashable | Sequence[Hashable], side: str, kind: str
+        self, label: Hashable | Sequence[Hashable], side: str, kind: str | None = None
     ) -> int:
         """
         For an ordered MultiIndex, compute slice bound
@@ -2729,7 +2729,7 @@ def get_slice_bound(
         ----------
         label : object or tuple of objects
         side : {'left', 'right'}
-        kind : {'loc', 'getitem'}
+        kind : {'loc', 'getitem', None}
 
         Returns
         -------
@@ -2747,13 +2747,13 @@ def get_slice_bound(
         Get the locations from the leftmost 'b' in the first level
         until the end of the multiindex:
 
-        >>> mi.get_slice_bound('b', side="left", kind="loc")
+        >>> mi.get_slice_bound('b', side="left")
         1
 
         Like above, but if you get the locations from the rightmost
         'b' in the first level and 'f' in the second level:
 
-        >>> mi.get_slice_bound(('b','f'), side="right", kind="loc")
+        >>> mi.get_slice_bound(('b','f'), side="right")
         3
 
         See Also
@@ -2820,7 +2820,7 @@ def slice_locs(self, start=None, end=None, step=None, kind=None):
         """
         # 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, kind=kind)
+        return super().slice_locs(start, end, step)
 
     def _partial_tup_index(self, tup, side="left"):
         if len(tup) > self._lexsort_depth:
@@ -3206,9 +3206,7 @@ def convert_indexer(start, stop, step, indexer=indexer, codes=level_codes):
 
                 # we have a partial slice (like looking up a partial date
                 # string)
-                start = stop = level_index.slice_indexer(
-                    key.start, key.stop, key.step, kind="loc"
-                )
+                start = stop = level_index.slice_indexer(key.start, key.stop, key.step)
                 step = start.step
 
             if isinstance(start, slice) or isinstance(stop, slice):

pandas/core/indexes/numeric.py

@@ -112,8 +112,9 @@ def _validate_dtype(cls, dtype: Dtype | None) -> None:
     # Indexing Methods
 
     @doc(Index._maybe_cast_slice_bound)
-    def _maybe_cast_slice_bound(self, label, side: str, kind):
-        assert kind in ["loc", "getitem", None]
+    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
+        assert kind in ["loc", "getitem", None, lib.no_default]
+        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
 
         # we will try to coerce to integers
         return self._maybe_cast_indexer(label)
@@ -346,7 +347,7 @@ 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)
 
     # ----------------------------------------------------------------
 

pandas/core/indexes/period.py

@@ -531,7 +531,7 @@ def get_loc(self, key, method=None, tolerance=None):
         except KeyError as err:
             raise KeyError(orig_key) from err
 
-    def _maybe_cast_slice_bound(self, label, side: str, kind: str):
+    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
         """
         If label is a string or a datetime, cast it to Period.ordinal according
         to resolution.
@@ -540,7 +540,7 @@ def _maybe_cast_slice_bound(self, label, side: str, kind: str):
         ----------
         label : object
         side : {'left', 'right'}
-        kind : {'loc', 'getitem'}
+        kind : {'loc', 'getitem'}, or None
 
         Returns
         -------
@@ -551,7 +551,8 @@ def _maybe_cast_slice_bound(self, label, side: str, kind: str):
         Value of `side` parameter should be validated in caller.
 
         """
-        assert kind in ["loc", "getitem"]
+        assert kind in ["loc", "getitem", None, lib.no_default]
+        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
 
         if isinstance(label, datetime):
             return Period(label, freq=self.freq)

pandas/core/indexes/timedeltas.py

@@ -192,7 +192,7 @@ def get_loc(self, key, method=None, tolerance=None):
 
         return Index.get_loc(self, key, method, tolerance)
 
-    def _maybe_cast_slice_bound(self, label, side: str, kind):
+    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
         """
         If label is a string, cast it to timedelta according to resolution.
 
@@ -206,7 +206,8 @@ def _maybe_cast_slice_bound(self, label, side: str, kind):
         -------
         label : object
         """
-        assert kind in ["loc", "getitem", None]
+        assert kind in ["loc", "getitem", None, lib.no_default]
+        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
 
         if isinstance(label, str):
             parsed = Timedelta(label)

pandas/core/indexing.py

@@ -1170,9 +1170,7 @@ def _get_slice_axis(self, slice_obj: slice, axis: int):
             return obj.copy(deep=False)
 
         labels = obj._get_axis(axis)
-        indexer = labels.slice_indexer(
-            slice_obj.start, slice_obj.stop, slice_obj.step, kind="loc"
-        )
+        indexer = labels.slice_indexer(slice_obj.start, slice_obj.stop, slice_obj.step)
 
         if isinstance(indexer, slice):
             return self.obj._slice(indexer, axis=axis)

pandas/tests/indexes/datetimes/test_indexing.py

@@ -679,18 +679,18 @@ def test_maybe_cast_slice_bounds_empty(self):
         # GH#14354
         empty_idx = date_range(freq="1H", periods=0, end="2015")
 
-        right = empty_idx._maybe_cast_slice_bound("2015-01-02", "right", "loc")
+        right = empty_idx._maybe_cast_slice_bound("2015-01-02", "right")
         exp = Timestamp("2015-01-02 23:59:59.999999999")
         assert right == exp
 
-        left = empty_idx._maybe_cast_slice_bound("2015-01-02", "left", "loc")
+        left = empty_idx._maybe_cast_slice_bound("2015-01-02", "left")
         exp = Timestamp("2015-01-02 00:00:00")
         assert left == exp
 
     def test_maybe_cast_slice_duplicate_monotonic(self):
         # https://github.com/pandas-dev/pandas/issues/16515
         idx = DatetimeIndex(["2017", "2017"])
-        result = idx._maybe_cast_slice_bound("2017-01-01", "left", "loc")
+        result = idx._maybe_cast_slice_bound("2017-01-01", "left")
         expected = Timestamp("2017-01-01")
         assert result == expected
 

pandas/tests/indexes/period/test_partial_slicing.py

@@ -110,9 +110,9 @@ def test_maybe_cast_slice_bound(self, make_range, frame_or_series):
 
         # Check the lower-level calls are raising where expected.
         with pytest.raises(TypeError, match=msg):
-            idx._maybe_cast_slice_bound("foo", "left", "loc")
+            idx._maybe_cast_slice_bound("foo", "left")
         with pytest.raises(TypeError, match=msg):
-            idx.get_slice_bound("foo", "left", "loc")
+            idx.get_slice_bound("foo", "left")
 
         with pytest.raises(TypeError, match=msg):
             obj["2013/09/30":"foo"]

pandas/tests/indexes/test_indexing.py

@@ -259,3 +259,16 @@ def test_getitem_deprecated_float(idx):
 
     expected = idx[1]
     assert result == expected
+
+
+def test_maybe_cast_slice_bound_kind_deprecated(index):
+    if not len(index):
+        return
+
+    with tm.assert_produces_warning(FutureWarning):
+        # passed as keyword
+        index._maybe_cast_slice_bound(index[0], "left", kind="loc")
+
+    with tm.assert_produces_warning(FutureWarning):
+        # pass as positional
+        index._maybe_cast_slice_bound(index[0], "left", "loc")