add overloads for multiindex.isin

Author: MarcoGorelli

pandas-stubs/core/indexes/multi.pyi

@@ -165,7 +165,12 @@ class MultiIndex(Index):
     def equal_levels(self, other): ...
     def insert(self, loc, item): ...
     def delete(self, loc): ...
-    def isin(self, values, level=...) -> np_1darray_bool: ...
+    @overload  # type: ignore[override]
+    def isin(self, values: Iterable[Any], level: Level) -> np_1darray_bool: ...
+    @overload
+    def isin(
+        self, values: Iterable[Iterable[Any]], level: None = None
+    ) -> np_1darray_bool: ...  # pyright: ignore[reportIncompatibleMethodOverride]
     def set_names(
         self,
         names: Hashable | Sequence[Hashable] | Mapping[Any, Hashable],

tests/indexes/test_indexes.py

@@ -62,6 +62,11 @@ def test_index_isin() -> None:
     check(assert_type(ind.isin(pd.Index([2, 4])), np_1darray_bool), np_1darray_bool)
     check(assert_type(ind.isin(iter([2, "4"])), np_1darray_bool), np_1darray_bool)
 
+    mi = pd.MultiIndex.from_arrays([[1, 2, 3]])
+    check(assert_type(mi.isin([[3]]), np_1darray_bool), np_1darray_bool)
+    if TYPE_CHECKING_INVALID_USAGE:
+        mi.isin({3})  # type: ignore[arg-type]  # pyright: ignore[reportArgumentType]
+
 
 def test_index_astype() -> None:
     indi = pd.Index([1, 2, 3])