use polars_core::error::PolarsResult; use polars_core::prelude::Series; use pyo3_polars_derive::polars_expr; #[polars_expr(output_type=Int32)] fn horizontal_product(series: &[Series], _kwargs: Option<&str>) -> PolarsResult { let mut acc = series[0].clone(); for s in &series[1..] { acc = &acc * s } Ok(acc) } fn main() {}