Add example to contains

[jason-ivey]

Description

The contains documentation for contains, as well as many of the trait impls, is lacking at https://docs.rs/polars/latest/polars/prelude/trait.StringNameSpaceImpl.html#method.contains

Here is an example I made:

use polars::prelude::*;

fn main() {
    let mut df = DataFrame::new(
        vec![
            Column::new(
                "A".into(),
                ["foo", "bar", "foobar", "foo"],
            ),
            Column::new(
                "B".into(),
                ["bar", "foobar", "foo", "bar"],
            ),
        ]
    )
    .unwrap();

    let selected_and_filtered = df.filter(
        &df.column("A")
            .unwrap()
            .str()
            .unwrap()
            .contains(
                "foo",
                true
            )
            .unwrap()
    );

    println!("{:?}", selected_and_filtered);
}

Link

No response

[jason-ivey]

Is this the right channel to propose changes to the documentation?