Function polars::export::arrow::compute::filter::filter

pub fn filter(
    array: &dyn Array, 
    filter: &BooleanArray
) -> Result<Box<dyn Array + 'static, Global>, ArrowError>

This is supported on crate feature compute_filter only.

Filters an Array, returning elements matching the filter (i.e. where the values are true).

Note that the nulls of filter are interpreted as false will lead to these elements being masked out.

Example

let array = PrimitiveArray::from_slice([5, 6, 7, 8, 9]);
let filter_array = BooleanArray::from_slice(&vec![true, false, false, true, false]);
let c = filter(&array, &filter_array)?;
let c = c.as_any().downcast_ref::<Int32Array>().unwrap();
assert_eq!(c, &PrimitiveArray::from_slice(vec![5, 8]));