bigframes.pandas.api.typing.DataFrameGroupBy.expanding

DataFrameGroupBy.expanding(min_periods: int = 1) → Window

Provides expanding functionality.

Examples:

>>> import bigframes.pandas as bpd
>>> lst = ['a', 'a', 'c', 'c', 'e']
>>> ser = bpd.Series([1, 0, -2, -1, 2], index=lst)
>>> ser.groupby(level=0).expanding().min()
index  index
a      a         1
       a         0
c      c        -2
       c        -2
e      e         2
dtype: Int64

Returns:

An expanding grouper, providing expanding functionality per group.

Return type:

bigframes.pandas.DataFrame or bigframes.pandas.Series