pandas.core.groupby.DataFrameGroupBy.cumsum — pandas 2.2.3 documentation (original) (raw)

DataFrameGroupBy.cumsum(axis=<no_default>, *args, **kwargs)[source]#

Cumulative sum for each group.

Returns:

Series or DataFrame

See also

Series.groupby

Apply a function groupby to a Series.

DataFrame.groupby

Apply a function groupby to each row or column of a DataFrame.

Examples

For SeriesGroupBy:

lst = ['a', 'a', 'b'] ser = pd.Series([6, 2, 0], index=lst) ser a 6 a 2 b 0 dtype: int64 ser.groupby(level=0).cumsum() a 6 a 8 b 0 dtype: int64

For DataFrameGroupBy:

data = [[1, 8, 2], [1, 2, 5], [2, 6, 9]] df = pd.DataFrame(data, columns=["a", "b", "c"], ... index=["fox", "gorilla", "lion"]) df a b c fox 1 8 2 gorilla 1 2 5 lion 2 6 9 df.groupby("a").groups {1: ['fox', 'gorilla'], 2: ['lion']} df.groupby("a").cumsum() b c fox 8 2 gorilla 10 7 lion 6 9