polars.cum_sum

polars.cum_sum(
    *names: str,
) → Expr

Cumulatively sum all values.

Syntactic sugar for col(names).cum_sum().

Parameters:

*names

Name(s) of the columns to use in the aggregation.

See also

cumsum_horizontal

Examples

>>> df = pl.DataFrame(
...     {
...         "a": [1, 2, 3],
...         "b": [4, 5, 6],
...     }
... )
>>> df.select(pl.cum_sum("a"))
shape: (3, 1)
┌─────┐
│ a   │
│ --- │
│ i64 │
╞═════╡
│ 1   │
│ 3   │
│ 6   │
└─────┘