fix(series): #1372 cumprod

Author: cmp0xff

pandas-stubs/core/series.pyi

@@ -210,6 +210,10 @@ from pandas.plotting import PlotAccessor
 class _SupportsAdd(Protocol[_T_co]):
     def __add__(self, value: Self, /) -> _T_co: ...
 
+@type_check_only
+class _SupportsMul(Protocol[_T_co]):
+    def __mul__(self, value: Self, /) -> _T_co: ...
+
 class _iLocIndexerSeries(_iLocIndexer, Generic[S1]):
     # get item
     @overload
@@ -3503,17 +3507,8 @@ class Series(IndexOpsMixin[S1], NDFrame):
         *args: Any,
         **kwargs: Any,
     ) -> Series[S1]: ...
-    @overload
-    def cumprod(
-        self: Series[_str],
-        axis: AxisIndex = ...,
-        skipna: _bool = ...,
-        *args: Any,
-        **kwargs: Any,
-    ) -> Never: ...
-    @overload
     def cumprod(
-        self,
+        self: SupportsGetItem[Scalar, _SupportsMul[S1]],
         axis: AxisIndex = ...,
         skipna: _bool = ...,
         *args: Any,
@@ -3900,13 +3895,6 @@ class TimestampSeries(_SeriesSubclassBase[Timestamp, np.datetime64]):
         **kwargs: Any,
     ) -> Timedelta: ...
     def diff(self, periods: int = ...) -> TimedeltaSeries: ...  # type: ignore[override] # pyright: ignore[reportIncompatibleMethodOverride]
-    def cumprod(
-        self,
-        axis: AxisIndex = ...,
-        skipna: _bool = ...,
-        *args: Any,
-        **kwargs: Any,
-    ) -> Never: ...
 
 class TimedeltaSeries(_SeriesSubclassBase[Timedelta, np.timedelta64]):
     # ignores needed because of mypy
@@ -4012,39 +4000,18 @@ class TimedeltaSeries(_SeriesSubclassBase[Timedelta, np.timedelta64]):
         *args: Any,
         **kwargs: Any,
     ) -> TimedeltaSeries: ...
-    def cumprod(
-        self,
-        axis: AxisIndex = ...,
-        skipna: _bool = ...,
-        *args: Any,
-        **kwargs: Any,
-    ) -> Never: ...
 
 class PeriodSeries(_SeriesSubclassBase[Period, np.object_]):
     @property
     def dt(self) -> PeriodProperties: ...  # type: ignore[override] # pyright: ignore[reportIncompatibleMethodOverride]
     def __sub__(self, other: PeriodSeries) -> OffsetSeries: ...  # type: ignore[override] # pyright: ignore[reportIncompatibleMethodOverride]
     def diff(self, periods: int = ...) -> OffsetSeries: ...  # type: ignore[override] # pyright: ignore[reportIncompatibleMethodOverride]
-    def cumprod(
-        self,
-        axis: AxisIndex = ...,
-        skipna: _bool = ...,
-        *args: Any,
-        **kwargs: Any,
-    ) -> Never: ...
 
 class OffsetSeries(_SeriesSubclassBase[BaseOffset, np.object_]):
     @overload  # type: ignore[override]
     def __radd__(self, other: Period) -> PeriodSeries: ...
     @overload
     def __radd__(self, other: BaseOffset) -> OffsetSeries: ...
-    def cumprod(
-        self,
-        axis: AxisIndex = ...,
-        skipna: _bool = ...,
-        *args: Any,
-        **kwargs: Any,
-    ) -> Never: ...
 
 class IntervalSeries(
     _SeriesSubclassBase[Interval[_OrderableT], np.object_], Generic[_OrderableT]

pyproject.toml

@@ -36,13 +36,13 @@ types-pytz = ">= 2022.1.1"
 numpy = ">= 1.23.5"
 
 [tool.poetry.group.dev.dependencies]
-mypy = "1.17.1"
+mypy = "1.18.1"
 pandas = "2.3.2"
 pyarrow = ">=10.0.1"
 pytest = ">=7.1.2"
 pyright = ">=1.1.405"
 ty = ">=0.0.1a20"
-pyrefly = ">=0.32.0"
+pyrefly = ">=0.33.0"
 poethepoet = ">=0.16.5"
 loguru = ">=0.6.0"
 typing-extensions = ">=4.4.0"

tests/series/test_series.py

@@ -3948,24 +3948,18 @@ def test_timedelta_index_cumprod() -> None:
     offset_series = as_period_series - as_period_series
 
     if TYPE_CHECKING_INVALID_USAGE:
-        assert_type(pd.Series(["a", "b"]).cumprod(), Never)
+        offset_series.cumprod()  # type: ignore[misc] # pyright: ignore[reportAttributeAccessIssue]
 
     if TYPE_CHECKING_INVALID_USAGE:
-        assert_type(offset_series.cumprod(), Never)
+        pd.Series([pd.Timedelta(0), pd.Timedelta(1)]).cumprod()  # type: ignore[misc] # pyright: ignore[reportAttributeAccessIssue]
 
     if TYPE_CHECKING_INVALID_USAGE:
-        assert_type(pd.Series([pd.Timedelta(0), pd.Timedelta(1)]).cumprod(), Never)
+        pd.Series(  # type: ignore[misc]
+            [pd.Timestamp("2024-04-29"), pd.Timestamp("2034-08-28")]
+        ).cumprod()  # pyright: ignore[reportAttributeAccessIssue]
 
     if TYPE_CHECKING_INVALID_USAGE:
-        assert_type(
-            pd.Series(
-                [pd.Timestamp("2024-04-29"), pd.Timestamp("2034-08-28")]
-            ).cumprod(),
-            Never,
-        )
-
-    if TYPE_CHECKING_INVALID_USAGE:
-        assert_type(as_period_series.cumprod(), Never)
+        as_period_series.cumprod()  # type: ignore[misc] # pyright: ignore[reportAttributeAccessIssue]
 
 
 def test_series_str_methods() -> None:

tests/series/window/__init__.py

@@ -0,0 +1,11 @@
+import numpy as np
+import pandas as pd
+from typing_extensions import assert_type
+
+from tests import check
+
+series = pd.DataFrame({"A": [1.0, float("nan"), 2.0]})["A"]
+
+
+def test_window_any() -> None:
+    check(assert_type(series.cumprod(), pd.Series), pd.Series, np.floating)

tests/series/window/test_window_any.py

@@ -0,0 +1,15 @@
+import numpy as np
+import pandas as pd
+from typing_extensions import assert_type
+
+from tests import check
+
+series = pd.Series([3j, 3 + 4j, 2j])
+
+
+def test_window_complex() -> None:
+    check(
+        assert_type(series.cumprod(), "pd.Series[complex]"),
+        pd.Series,
+        np.complexfloating,
+    )

tests/series/window/test_window_complex.py

@@ -0,0 +1,11 @@
+import numpy as np
+import pandas as pd
+from typing_extensions import assert_type
+
+from tests import check
+
+series = pd.Series([3.0, float("nan"), 2.0])
+
+
+def test_window_float() -> None:
+    check(assert_type(series.cumprod(), "pd.Series[float]"), pd.Series, np.floating)

tests/series/window/test_window_float.py

@@ -0,0 +1,11 @@
+import numpy as np
+import pandas as pd
+from typing_extensions import assert_type
+
+from tests import check
+
+series = pd.Series([3, 1, 2])
+
+
+def test_window_int() -> None:
+    check(assert_type(series.cumprod(), "pd.Series[int]"), pd.Series, np.integer)

tests/series/window/test_window_int.py

@@ -0,0 +1,10 @@
+import pandas as pd
+
+from tests import TYPE_CHECKING_INVALID_USAGE
+
+series = pd.Series(["1", "a", "🐼"])
+
+
+def test_window_str() -> None:
+    if TYPE_CHECKING_INVALID_USAGE:
+        series.cumprod()  # type: ignore[misc] # pyright: ignore[reportAttributeAccessIssue]