pandas.core.groupby.SeriesGroupBy.expanding — pandas 3.0.0.dev0+2098.g9c5b9ee823 documentation (original) (raw)

SeriesGroupBy.expanding(min_periods=1, method='single')[source]#

Return an expanding grouper, providing expanding functionality per group.

Parameters:

min_periodsint, default 1

Minimum number of observations in window required to have a value; otherwise, result is np.nan.

methodstr {‘single’, ‘table’}, default ‘single’

Execute the expanding operation per single column or row ('single') or over the entire object ('table').

This argument is only implemented when specifying engine='numba'in the method call.

Returns:

pandas.api.typing.ExpandingGroupby

An object that supports expanding transformations over each group.

See also

Series.expanding

Expanding transformations for Series.

DataFrame.expanding

Expanding transformations for DataFrames.

Series.groupby

Apply a function groupby to a Series.

DataFrame.groupby

Apply a function groupby.

Examples

df = pd.DataFrame( ... { ... "Class": ["A", "A", "A", "B", "B", "B"], ... "Value": [10, 20, 30, 40, 50, 60], ... } ... ) df Class Value 0 A 10 1 A 20 2 A 30 3 B 40 4 B 50 5 B 60

df.groupby("Class").expanding().mean() Value Class A 0 10.0 1 15.0 2 20.0 B 3 40.0 4 45.0 5 50.0