diff --git a/pandas/core/window/expanding.py b/pandas/core/window/expanding.py index c3ee53c1b4551..abe853a8aa259 100644 --- a/pandas/core/window/expanding.py +++ b/pandas/core/window/expanding.py @@ -51,6 +51,9 @@ class Expanding(RollingAndExpandingMixin): """ Provide expanding window calculations. + An expanding window yields the value of an aggregation statistic with all the data + available up to that point in time. + Parameters ---------- min_periods : int, default 1 @@ -69,6 +72,8 @@ class Expanding(RollingAndExpandingMixin): Returns ------- pandas.api.typing.Expanding + An instance of Expanding for further expanding window calculations, + e.g. using the ``sum`` method. See Also --------