REF: share maybe_cast_slice_bound DTI/TDI/PI (#42897)

pandas/core/indexes/base.py

@@ -57,6 +57,7 @@
     deprecate_nonkeyword_arguments,
     doc,
 )
+from pandas.util._exceptions import find_stack_level
 
 from pandas.core.dtypes.cast import (
     can_hold_element,
@@ -6528,7 +6529,7 @@ def _deprecated_arg(self, value, name: str_t, methodname: str_t) -> None:
                 f"'{name}' argument in {methodname} is deprecated "
                 "and will be removed in a future version.  Do not pass it.",
                 FutureWarning,
-                stacklevel=3,
+                stacklevel=find_stack_level(),
             )
 
 

pandas/core/indexes/datetimelike.py

@@ -345,6 +345,43 @@ def _partial_date_slice(
             # try to find the dates
             return (lhs_mask & rhs_mask).nonzero()[0]
 
+    def _maybe_cast_slice_bound(self, label, side: str, kind=lib.no_default):
+        """
+        If label is a string, cast it to scalar type according to resolution.
+
+        Parameters
+        ----------
+        label : object
+        side : {'left', 'right'}
+        kind : {'loc', 'getitem'} or None
+
+        Returns
+        -------
+        label : object
+
+        Notes
+        -----
+        Value of `side` parameter should be validated in caller.
+        """
+        assert kind in ["loc", "getitem", None, lib.no_default]
+        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
+
+        if isinstance(label, str):
+            try:
+                parsed, reso = self._parse_with_reso(label)
+            except ValueError as err:
+                # DTI -> parsing.DateParseError
+                # TDI -> 'unit abbreviation w/o a number'
+                # PI -> string cannot be parsed as datetime-like
+                raise self._invalid_indexer("slice", label) from err
+
+            lower, upper = self._parsed_string_to_bounds(reso, parsed)
+            return lower if side == "left" else upper
+        elif not isinstance(label, self._data._recognized_scalars):
+            raise self._invalid_indexer("slice", label)
+
+        return label
+
     # --------------------------------------------------------------------
     # Arithmetic Methods
 

pandas/core/indexes/datetimes.py

@@ -25,7 +25,6 @@
 )
 from pandas._libs.tslibs import (
     Resolution,
-    parsing,
     timezones,
     to_offset,
 )
@@ -686,48 +685,10 @@ def _maybe_cast_for_get_loc(self, key) -> Timestamp:
             key = key.tz_convert(self.tz)
         return key
 
+    @doc(DatetimeTimedeltaMixin._maybe_cast_slice_bound)
     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.
-
-        Parameters
-        ----------
-        label : object
-        side : {'left', 'right'}
-        kind : {'loc', 'getitem'} or None
-
-        Returns
-        -------
-        label : object
-
-        Notes
-        -----
-        Value of `side` parameter should be validated in caller.
-        """
-        assert kind in ["loc", "getitem", None, lib.no_default]
-        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
-
-        if isinstance(label, str):
-            try:
-                parsed, reso = self._parse_with_reso(label)
-            except parsing.DateParseError as err:
-                raise self._invalid_indexer("slice", label) from err
-
-            lower, upper = self._parsed_string_to_bounds(reso, parsed)
-            # lower, upper form the half-open interval:
-            #   [parsed, parsed + 1 freq)
-            # because label may be passed to searchsorted
-            # the bounds need swapped if index is reverse sorted and has a
-            # length > 1 (is_monotonic_decreasing gives True for empty
-            # and length 1 index)
-            if self._is_strictly_monotonic_decreasing and len(self) > 1:
-                return upper if side == "left" else lower
-            return lower if side == "left" else upper
-        elif isinstance(label, self._data._recognized_scalars):
-            self._deprecate_mismatched_indexing(label)
-        else:
-            raise self._invalid_indexer("slice", label)
-
+        label = super()._maybe_cast_slice_bound(label, side, kind=kind)
+        self._deprecate_mismatched_indexing(label)
         return self._maybe_cast_for_get_loc(label)
 
     def slice_indexer(self, start=None, end=None, step=None, kind=lib.no_default):
@@ -804,7 +765,7 @@ def check_str_or_none(point):
             return indexer
 
     @doc(Index.get_slice_bound)
-    def get_slice_bound(self, label, side: str, kind=None) -> int:
+    def get_slice_bound(self, label, side: str, kind=lib.no_default) -> int:
         # GH#42855 handle date here instead of _maybe_cast_slice_bound
         if isinstance(label, date) and not isinstance(label, datetime):
             label = Timestamp(label).to_pydatetime()

pandas/core/indexes/period.py

@@ -464,44 +464,12 @@ def get_loc(self, key, method=None, tolerance=None):
         except KeyError as err:
             raise KeyError(orig_key) from err
 
+    @doc(DatetimeIndexOpsMixin._maybe_cast_slice_bound)
     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.
-
-        Parameters
-        ----------
-        label : object
-        side : {'left', 'right'}
-        kind : {'loc', 'getitem'}, or None
-
-        Returns
-        -------
-        bound : Period or object
-
-        Notes
-        -----
-        Value of `side` parameter should be validated in caller.
-
-        """
-        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)
-        elif isinstance(label, str):
-            try:
-                parsed, reso = self._parse_with_reso(label)
-            except ValueError as err:
-                # string cannot be parsed as datetime-like
-                raise self._invalid_indexer("slice", label) from err
-
-            lower, upper = self._parsed_string_to_bounds(reso, parsed)
-            return lower if side == "left" else upper
-        elif not isinstance(label, self._data._recognized_scalars):
-            raise self._invalid_indexer("slice", label)
+            label = Period(label, freq=self.freq)
 
-        return label
+        return super()._maybe_cast_slice_bound(label, side, kind=kind)
 
     def _parsed_string_to_bounds(self, reso: Resolution, parsed: datetime):
         grp = reso.freq_group

pandas/core/indexes/timedeltas.py

@@ -178,37 +178,6 @@ 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=lib.no_default):
-        """
-        If label is a string, cast it to timedelta according to resolution.
-
-        Parameters
-        ----------
-        label : object
-        side : {'left', 'right'}
-        kind : {'loc', 'getitem'} or None
-
-        Returns
-        -------
-        label : object
-        """
-        assert kind in ["loc", "getitem", None, lib.no_default]
-        self._deprecated_arg(kind, "kind", "_maybe_cast_slice_bound")
-
-        if isinstance(label, str):
-            try:
-                parsed, reso = self._parse_with_reso(label)
-            except ValueError as err:
-                # e.g. 'unit abbreviation w/o a number'
-                raise self._invalid_indexer("slice", label) from err
-
-            lower, upper = self._parsed_string_to_bounds(reso, parsed)
-            return lower if side == "left" else upper
-        elif not isinstance(label, self._data._recognized_scalars):
-            raise self._invalid_indexer("slice", label)
-
-        return label
-
     def _parse_with_reso(self, label: str):
         # the "with_reso" is a no-op for TimedeltaIndex
         parsed = Timedelta(label)