Function polars::prelude::reduce_exprs

source · 
pub fn reduce_exprs<F, E>(f: F, exprs: E) -> Expr
where
    F: 'static + Fn(Series, Series) -> Result<Option<Series>, PolarsError> + Send + Sync + Clone,
    E: AsRef<[Expr]>,
Available on crate feature lazy only.
Expand description

Analogous to Iterator::reduce.

An accumulator is initialized to the series given by the first expression in exprs, and then each subsequent value of the accumulator is computed from f(acc, next_expr_series). If exprs is empty, an error is returned when collect is called.