only allow for Mapping names in set_names for MultiIndex

Author: MarcoGorelli

pandas-stubs/core/indexes/base.pyi

@@ -3,7 +3,6 @@ from collections.abc import (
     Callable,
     Hashable,
     Iterable,
-    Mapping,
     Sequence,
 )
 from datetime import (
@@ -82,6 +81,7 @@ from pandas._typing import (
     AnyArrayLikeInt,
     ArrayLike,
     AxesData,
+    Axis,
     CategoryDtypeArg,
     DropKeep,
     Dtype,
@@ -365,19 +365,18 @@ class Index(IndexOpsMixin[S1], ElementOpsMixin[S1]):
     def take(
         self,
         indices: TakeIndexer,
-        axis: int = 0,
+        axis: Axis = 0,
         allow_fill: bool = True,
         fill_value: Scalar | None = None,
         **kwargs: Any,
     ) -> Self: ...
     def repeat(
         self, repeats: int | AnyArrayLikeInt | Sequence[int], axis: None = None
-    ): ...
+    ) -> Self: ...
     def copy(self, name: Hashable = ..., deep: bool = False) -> Self: ...
     def format(
         self, name: bool = ..., formatter: Callable | None = ..., na_rep: _str = ...
     ) -> list[_str]: ...
-    def to_flat_index(self) -> Index: ...
     def to_series(
         self, index: Index | None = None, name: Hashable | None = None
     ) -> Series[S1]: ...
@@ -392,7 +391,7 @@ class Index(IndexOpsMixin[S1], ElementOpsMixin[S1]):
     def names(self, names: SequenceNotStr[Hashable | None]) -> None: ...
     def set_names(
         self,
-        names: Hashable | Sequence[Hashable] | Mapping[Any, Hashable],
+        names: Hashable | Sequence[Hashable],
         *,
         level: Level | Sequence[Level] | None = None,
         inplace: bool = False,

pandas-stubs/core/indexes/multi.pyi

@@ -2,9 +2,11 @@ from collections.abc import (
     Callable,
     Hashable,
     Iterable,
+    Mapping,
     Sequence,
 )
 from typing import (
+    Any,
     final,
     overload,
 )
@@ -115,7 +117,7 @@ class MultiIndex(Index):
         name: list[HashableT] = ...,
         allow_duplicates: bool = False,
     ) -> pd.DataFrame: ...
-    def to_flat_index(self): ...
+    def to_flat_index(self) -> Index: ...
     def remove_unused_levels(self): ...
     @property
     def nlevels(self) -> int: ...
@@ -163,3 +165,10 @@ class MultiIndex(Index):
     def insert(self, loc, item): ...
     def delete(self, loc): ...
     def isin(self, values, level=...) -> np_1darray_bool: ...
+    def set_names(
+        self,
+        names: Hashable | Sequence[Hashable] | Mapping[Any, Hashable],
+        *,
+        level: Level | Sequence[Level] | None = None,
+        inplace: bool = False,
+    ) -> Self: ...

tests/indexes/test_indexes.py

@@ -1529,6 +1529,7 @@ def test_index_set_names() -> None:
     """Test Index.where with multiple types of other GH1419."""
     idx = pd.Index([1, 2])
     check(assert_type(idx.set_names("chinchilla"), "pd.Index[int]"), pd.Index, np.int64)
+    check(assert_type(idx.set_names((0,)), "pd.Index[int]"), pd.Index, np.int64)
     check(
         assert_type(idx.set_names(["chinchilla"]), "pd.Index[int]"), pd.Index, np.int64
     )