How to get a Vec from polars Series or ChunkedArray?

You can collect the values into a Vec.

use polars::prelude::*;

fn main() -> Result<()> {
    let s = Series::new("a", 0..10i32);

    let as_vec: Vec<Option<i32>> = s.i32()?.into_iter().collect();

    // if we are certain we don't have missing values
    let as_vec: Vec<i32> = s.i32()?.into_no_null_iter().collect();
    Ok(())
}