748 series operator timedelta (#924)

* adding tests for #748

* updating __rmul__, rmul and mul

---------

Co-authored-by: Laurent Mutricy <[email protected]>

Author: mutricyl

pandas-stubs/core/series.pyi

@@ -1573,6 +1573,11 @@ class Series(IndexOpsMixin[S1], NDFrame):
     def __rdivmod__(self, other: num | _ListLike | Series[S1]) -> Series[S1]: ...  # type: ignore[override] # pyright: ignore[reportIncompatibleMethodOverride]
     def __rfloordiv__(self, other: num | _ListLike | Series[S1]) -> Series[S1]: ...
     def __rmod__(self, other: num | _ListLike | Series[S1]) -> Series[S1]: ...
+    @overload
+    def __rmul__(
+        self, other: timedelta | Timedelta | TimedeltaSeries | np.timedelta64
+    ) -> TimedeltaSeries: ...
+    @overload
     def __rmul__(self, other: num | _ListLike | Series) -> Series: ...
     def __rnatmul__(self, other: num | _ListLike | Series[S1]) -> Series[S1]: ...
     def __rpow__(self, other: num | _ListLike | Series[S1]) -> Series[S1]: ...
@@ -1794,13 +1799,22 @@ class Series(IndexOpsMixin[S1], NDFrame):
         fill_value: float | None = ...,
         axis: AxisIndex | None = ...,
     ) -> Series[S1]: ...
+    @overload
     def mul(
         self,
-        other: num | _ListLike | Series[S1],
+        other: timedelta | Timedelta | TimedeltaSeries | np.timedelta64,
         level: Level | None = ...,
         fill_value: float | None = ...,
         axis: AxisIndex | None = ...,
-    ) -> Series[S1]: ...
+    ) -> TimedeltaSeries: ...
+    @overload
+    def mul(
+        self,
+        other: num | _ListLike | Series,
+        level: Level | None = ...,
+        fill_value: float | None = ...,
+        axis: AxisIndex | None = ...,
+    ) -> Series: ...
     def multiply(
         self,
         other: num | _ListLike | Series[S1],
@@ -1869,13 +1883,22 @@ class Series(IndexOpsMixin[S1], NDFrame):
         fill_value: float | None = ...,
         axis: AxisIndex = ...,
     ) -> Series[S1]: ...
+    @overload
     def rmul(
         self,
-        other: Series[S1] | Scalar,
+        other: timedelta | Timedelta | TimedeltaSeries | np.timedelta64,
         level: Level | None = ...,
         fill_value: float | None = ...,
         axis: AxisIndex = ...,
-    ) -> Series[S1]: ...
+    ) -> TimedeltaSeries: ...
+    @overload
+    def rmul(
+        self,
+        other: num | _ListLike | Series,
+        level: Level | None = ...,
+        fill_value: float | None = ...,
+        axis: AxisIndex = ...,
+    ) -> Series: ...
     @overload
     def rolling(
         self,

tests/test_series.py

@@ -3214,3 +3214,28 @@ def test_diff_never3() -> None:
     if TYPE_CHECKING_INVALID_USAGE:
         # str -> TypeError: unsupported operand type(s) for -: 'str' and 'str'
         assert_never(pd.Series(["a", "b"]).diff())
+
+
+def test_operator_constistency() -> None:
+    # created for #748
+    s = pd.Series([1, 2, 3])
+    check(
+        assert_type(s * np.timedelta64(1, "s"), "TimedeltaSeries"),
+        pd.Series,
+        pd.Timedelta,
+    )
+    check(
+        assert_type(np.timedelta64(1, "s") * s, "TimedeltaSeries"),
+        pd.Series,
+        pd.Timedelta,
+    )
+    check(
+        assert_type(s.mul(np.timedelta64(1, "s")), "TimedeltaSeries"),
+        pd.Series,
+        pd.Timedelta,
+    )
+    check(
+        assert_type(s.rmul(np.timedelta64(1, "s")), "TimedeltaSeries"),
+        pd.Series,
+        pd.Timedelta,
+    )