polars.Series.cum_sum#

Series.cum_sum(*, reverse: bool = False) → Series[source]#

Get an array with the cumulative sum computed at every element.

Parameters:

Notes

Dtypes in {Int8, UInt8, Int16, UInt16} are cast to Int64 before summing to prevent overflow issues.

Examples

>>> s = pl.Series("a", [1, 2, 3])
>>> s.cum_sum()
shape: (3,)
Series: 'a' [i64]
[
    1
    3
    6
]