Trait polars::prelude::ChunkSet

source · [−]
pub trait ChunkSet<'a, A, B> {
    fn set_at_idx<I>(
        &'a self,
        idx: I,
        opt_value: Option<A>
    ) -> Result<Self, PolarsError>
    where
        I: IntoIterator<Item = usize>;
    fn set_at_idx_with<I, F>(&'a self, idx: I, f: F) -> Result<Self, PolarsError>
    where
        I: IntoIterator<Item = usize>,
        F: Fn(Option<A>) -> Option<B>;
    fn set(
        &'a self,
        mask: &ChunkedArray<BooleanType>,
        opt_value: Option<A>
    ) -> Result<Self, PolarsError>;
}
Expand description

Create a ChunkedArray with new values by index or by boolean mask. Note that these operations clone data. This is however the only way we can modify at mask or index level as the underlying Arrow arrays are immutable.

Required Methods

Set the values at indexes idx to some optional value Option<T>.

Example
let ca = UInt32Chunked::new("a", &[1, 2, 3]);
let new = ca.set_at_idx(vec![0, 1], Some(10)).unwrap();

assert_eq!(Vec::from(&new), &[Some(10), Some(10), Some(3)]);

Set the values at indexes idx by applying a closure to these values.

Example
let ca = Int32Chunked::new("a", &[1, 2, 3]);
let new = ca.set_at_idx_with(vec![0, 1], |opt_v| opt_v.map(|v| v - 5)).unwrap();

assert_eq!(Vec::from(&new), &[Some(-4), Some(-3), Some(3)]);

Set the values where the mask evaluates to true to some optional value Option<T>.

Example
let ca = Int32Chunked::new("a", &[1, 2, 3]);
let mask = BooleanChunked::new("mask", &[false, true, false]);
let new = ca.set(&mask, Some(5)).unwrap();
assert_eq!(Vec::from(&new), &[Some(1), Some(5), Some(3)]);

Implementors