TYP: @Final for more Index methods (#39333)

Author: jbrockmendel

pandas/core/indexes/base.py

@@ -822,6 +822,7 @@ def take(self, indices, axis=0, allow_fill=True, fill_value=None, **kwargs):
         )
         return self._shallow_copy(taken)
 
+    @final
     def _maybe_disallow_fill(self, allow_fill: bool, fill_value, indices) -> bool:
         """
         We only use pandas-style take when allow_fill is True _and_
@@ -960,6 +961,7 @@ def __deepcopy__(self, memo=None):
     # --------------------------------------------------------------------
     # Rendering Methods
 
+    @final
     def __repr__(self) -> str_t:
         """
         Return a string representation for this object.
@@ -1710,6 +1712,7 @@ def droplevel(self, level=0):
 
         return self._drop_level_numbers(levnums)
 
+    @final
     def _drop_level_numbers(self, levnums: List[int]):
         """
         Drop MultiIndex levels by level _number_, not name.
@@ -1827,6 +1830,7 @@ def is_monotonic_decreasing(self) -> bool:
         """
         return self._engine.is_monotonic_decreasing
 
+    @final
     @property
     def _is_strictly_monotonic_increasing(self) -> bool:
         """
@@ -1844,6 +1848,7 @@ def _is_strictly_monotonic_increasing(self) -> bool:
         """
         return self.is_unique and self.is_monotonic_increasing
 
+    @final
     @property
     def _is_strictly_monotonic_decreasing(self) -> bool:
         """
@@ -1868,6 +1873,7 @@ def is_unique(self) -> bool:
         """
         return self._engine.is_unique
 
+    @final
     @property
     def has_duplicates(self) -> bool:
         """
@@ -2239,6 +2245,7 @@ def _is_all_dates(self) -> bool:
         return is_datetime_array(ensure_object(self._values))
 
     @cache_readonly
+    @final
     def is_all_dates(self):
         """
         Whether or not the index values only consist of dates.
@@ -3269,6 +3276,7 @@ def get_loc(self, key, method=None, tolerance=None):
         """
 
     @Appender(_index_shared_docs["get_indexer"] % _index_doc_kwargs)
+    @final
     def get_indexer(
         self, target, method=None, limit=None, tolerance=None
     ) -> np.ndarray:
@@ -3328,6 +3336,7 @@ def _get_indexer(
 
         return ensure_platform_int(indexer)
 
+    @final
     def _check_indexing_method(self, method):
         """
         Raise if we have a get_indexer `method` that is not supported or valid.
@@ -4542,7 +4551,7 @@ def putmask(self, mask, value):
         np.putmask(values, mask, converted)
         return self._shallow_copy(values)
 
-    def equals(self, other: object) -> bool:
+    def equals(self, other: Any) -> bool:
         """
         Determine if two Index object are equal.
 
@@ -5104,6 +5113,7 @@ def get_indexer_for(self, target, **kwargs):
         indexer, _ = self.get_indexer_non_unique(target)
         return indexer
 
+    @final
     def _get_indexer_non_comparable(self, target: Index, method, unique: bool = True):
         """
         Called from get_indexer or get_indexer_non_unique when the target
@@ -5142,7 +5152,7 @@ def _get_indexer_non_comparable(self, target: Index, method, unique: bool = True
             return no_matches, missing
 
     @property
-    def _index_as_unique(self):
+    def _index_as_unique(self) -> bool:
         """
         Whether we should treat this as unique for the sake of
         get_indexer vs get_indexer_non_unique.
@@ -5178,6 +5188,7 @@ def _maybe_promote(self, other: Index):
 
         return self, other
 
+    @final
     def _should_compare(self, other: Index) -> bool:
         """
         Check if `self == other` can ever have non-False entries.
@@ -5786,10 +5797,6 @@ def _cmp_method(self, other, op):
             with np.errstate(all="ignore"):
                 result = ops.comp_method_OBJECT_ARRAY(op, self._values, other)
 
-        elif is_interval_dtype(self.dtype):
-            with np.errstate(all="ignore"):
-                result = op(self._values, np.asarray(other))
-
         else:
             with np.errstate(all="ignore"):
                 result = ops.comparison_op(self._values, other, op)
@@ -5808,6 +5815,7 @@ def _arith_method(self, other, op):
             return (Index(result[0]), Index(result[1]))
         return Index(result)
 
+    @final
     def _unary_method(self, op):
         result = op(self._values)
         return Index(result, name=self.name)

pandas/core/indexes/datetimelike.py

@@ -162,7 +162,7 @@ def __array_wrap__(self, result, context=None):
 
     # ------------------------------------------------------------------------
 
-    def equals(self, other: object) -> bool:
+    def equals(self, other: Any) -> bool:
         """
         Determines if two Index objects contain the same elements.
         """
@@ -508,7 +508,7 @@ def _partial_date_slice(
     __truediv__ = make_wrapped_arith_op("__truediv__")
     __rtruediv__ = make_wrapped_arith_op("__rtruediv__")
 
-    def shift(self, periods=1, freq=None):
+    def shift(self: _T, periods: int = 1, freq=None) -> _T:
         """
         Shift index by desired number of time frequency increments.
 
@@ -567,7 +567,7 @@ def _get_delete_freq(self, loc: int):
                         freq = self.freq
         return freq
 
-    def _get_insert_freq(self, loc, item):
+    def _get_insert_freq(self, loc: int, item):
         """
         Find the `freq` for self.insert(loc, item).
         """
@@ -593,7 +593,7 @@ def _get_insert_freq(self, loc, item):
         return freq
 
     @doc(NDArrayBackedExtensionIndex.delete)
-    def delete(self, loc):
+    def delete(self: _T, loc) -> _T:
         result = super().delete(loc)
         result._data._freq = self._get_delete_freq(loc)
         return result
@@ -710,6 +710,7 @@ def _intersection(self, other: Index, sort=False) -> Index:
         return self._wrap_setop_result(other, result)
 
     def _can_fast_intersect(self: _T, other: _T) -> bool:
+        # Note: we only get here with len(self) > 0 and len(other) > 0
         if self.freq is None:
             return False
 
@@ -725,9 +726,6 @@ def _can_fast_intersect(self: _T, other: _T) -> bool:
             #  so intersection will preserve freq
             return True
 
-        elif not len(self) or not len(other):
-            return False
-
         elif isinstance(self.freq, Tick):
             # We "line up" if and only if the difference between two of our points
             #  is a multiple of our freq
@@ -741,9 +739,6 @@ def _can_fast_union(self: _T, other: _T) -> bool:
         # Assumes that type(self) == type(other), as per the annotation
         # The ability to fast_union also implies that `freq` should be
         #  retained on union.
-        if not isinstance(other, type(self)):
-            return False
-
         freq = self.freq
 
         if freq is None or freq != other.freq:
@@ -769,7 +764,7 @@ def _can_fast_union(self: _T, other: _T) -> bool:
         # Only need to "adjoin", not overlap
         return (right_start == left_end + freq) or right_start in left
 
-    def _fast_union(self, other, sort=None):
+    def _fast_union(self: _T, other: _T, sort=None) -> _T:
         if len(other) == 0:
             return self.view(type(self))
 

pandas/core/indexes/interval.py

@@ -729,7 +729,7 @@ def _get_indexer_pointwise(self, target: Index) -> Tuple[np.ndarray, np.ndarray]
         return ensure_platform_int(indexer), ensure_platform_int(missing)
 
     @property
-    def _index_as_unique(self):
+    def _index_as_unique(self) -> bool:
         return not self.is_overlapping
 
     _requires_unique_msg = (

pandas/core/indexes/range.py

@@ -337,10 +337,6 @@ def is_monotonic_increasing(self) -> bool:
     def is_monotonic_decreasing(self) -> bool:
         return self._range.step < 0 or len(self) <= 1
 
-    @property
-    def has_duplicates(self) -> bool:
-        return False
-
     def __contains__(self, key: Any) -> bool:
         hash(key)
         try: