fix for DataFrameGroupBy.value_counts (#1257)

Author: Dr-Irv

pandas-stubs/core/groupby/generic.pyi

@@ -272,7 +272,7 @@ class DataFrameGroupBy(GroupBy[DataFrame], Generic[ByT, _TT]):
     @overload
     def __getitem__(  # pyright: ignore[reportIncompatibleMethodOverride]
         self, key: Iterable[Hashable]
-    ) -> DataFrameGroupBy[ByT, bool]: ...
+    ) -> DataFrameGroupBy[ByT, _TT]: ...
     def nunique(self, dropna: bool = ...) -> DataFrame: ...
     def idxmax(
         self,

tests/test_groupby.py

@@ -1093,3 +1093,12 @@ def test_series_value_counts() -> None:
         Series,
         np.float64,
     )
+
+
+def test_dataframe_value_counts() -> None:
+    df = DataFrame({"a": [1, 1, 2], "b": [4, 5, 6], "c": [5, 5, 2]})
+    check(
+        assert_type(df.groupby("a")[["b", "c"]].value_counts(), "Series[int]"),
+        Series,
+        np.int64,
+    )