get_indexer

Author: MarcoGorelli

pandas-stubs/core/indexes/base.pyi

@@ -66,6 +66,7 @@ from pandas._typing import (
     S2_NSDT,
     T_COMPLEX,
     AnyAll,
+    AnyArrayLike,
     ArrayLike,
     AxesData,
     CategoryDtypeArg,
@@ -418,8 +419,12 @@ class Index(IndexOpsMixin[S1], ElementOpsMixin[S1]):
     ) -> Self: ...
     def get_loc(self, key: Label) -> int | slice | np_1darray[np.bool]: ...
     def get_indexer(
-        self, target, method: ReindexMethod | None = ..., limit=..., tolerance=...
-    ): ...
+        self,
+        target: Index,
+        method: ReindexMethod | None = None,
+        limit: int | None = None,
+        tolerance: Scalar | AnyArrayLike | Sequence[Scalar] | None = None,
+    ) -> np_1darray[np.intp]: ...
     def reindex(
         self,
         target,

pandas-stubs/core/indexes/range.pyi

@@ -62,7 +62,8 @@ class RangeIndex(_IndexSubclassBase[int, np.int64]):
     ) -> tuple[np_1darray[np.intp], RangeIndex]: ...
     @property
     def size(self) -> int: ...
-    def __floordiv__(
+    # Base class returns `Self`, but for `RangeIndex` that's not true.
+    def __floordiv__(  # type: ignore[override]
         self, other: float | Sequence[float] | Index[int] | Index[float]
     ) -> Index[int]: ...
     def all(self, *args: Any, **kwargs: Any) -> bool: ...

tests/indexes/test_rangeindex.py

@@ -1,12 +1,14 @@
 from __future__ import annotations
 
+import numpy as np
 import pandas as pd
 from typing_extensions import (
     assert_type,
 )
 
 from tests import (
     check,
+    np_1darray,
 )
 
 
@@ -39,8 +41,16 @@ def test_rangeindex_equals() -> None:
 
 
 def test_rangeindex_tolist() -> None:
-    ri = pd.RangeIndex(3)
+    ri = pd.RangeIndex.from_range(range(3))
     check(
         assert_type(ri.tolist(), list[int]),
         list[int],
     )
+
+
+def test_rangeindex_get_indexer() -> None:
+    ri = pd.RangeIndex.from_range(range(3))
+    check(
+        assert_type(ri.get_indexer(ri), np_1darray[np.intp]),
+        np_1darray[np.intp],
+    )