Trait polars_core::chunked_array::ops::ChunkApply

pub trait ChunkApply<'a, A, B> {
    fn apply_cast_numeric<F, S>(&'a self, f: F) -> ChunkedArray<S>
    where
        F: Fn(A) -> S::Native + Copy,
        S: PolarsNumericType;
    fn branch_apply_cast_numeric_no_null<F, S>(
        &'a self, 
        f: F
    ) -> ChunkedArray<S>
    where
        F: Fn(Option<A>) -> S::Native + Copy,
        S: PolarsNumericType;
    fn apply<F>(&'a self, f: F) -> Self
    where
        F: Fn(A) -> B + Copy;
    fn apply_with_idx<F>(&'a self, f: F) -> Self
    where
        F: Fn((usize, A)) -> B + Copy;
    fn apply_with_idx_on_opt<F>(&'a self, f: F) -> Self
    where
        F: Fn((usize, Option<A>)) -> Option<B> + Copy;
}

Fastest way to do elementwise operations on a ChunkedArray when the operation is cheaper than branching due to null checking

Required methods

fn apply_cast_numeric<F, S>(&'a self, f: F) -> ChunkedArray<S> where
    F: Fn(A) -> S::Native + Copy,
    S: PolarsNumericType, 

Apply a closure elementwise and cast to a Numeric ChunkedArray. This is fastest when the null check branching is more expensive than the closure application.

Null values remain null.

fn branch_apply_cast_numeric_no_null<F, S>(&'a self, f: F) -> ChunkedArray<S> where
    F: Fn(Option<A>) -> S::Native + Copy,
    S: PolarsNumericType, 

Apply a closure on optional values and cast to Numeric ChunkedArray without null values.

fn apply<F>(&'a self, f: F) -> Self where
    F: Fn(A) -> B + Copy, 

Apply a closure elementwise. This is fastest when the null check branching is more expensive than the closure application. Often it is.

Null values remain null.

Example

use polars_core::prelude::*;
fn double(ca: &UInt32Chunked) -> UInt32Chunked {
    ca.apply(|v| v * 2)
}

fn apply_with_idx<F>(&'a self, f: F) -> Self where
    F: Fn((usize, A)) -> B + Copy, 

Apply a closure elementwise. The closure gets the index of the element as first argument.

fn apply_with_idx_on_opt<F>(&'a self, f: F) -> Self where
    F: Fn((usize, Option<A>)) -> Option<B> + Copy, 

Apply a closure elementwise. The closure gets the index of the element as first argument.

Implementors

impl<'a> ChunkApply<'a, &'a str, Cow<'a, str>> for Utf8Chunked

fn apply_cast_numeric<F, S>(&'a self, f: F) -> ChunkedArray<S> where
    F: Fn(&'a str) -> S::Native + Copy,
    S: PolarsNumericType, 

fn branch_apply_cast_numeric_no_null<F, S>(&'a self, f: F) -> ChunkedArray<S> where
    F: Fn(Option<&'a str>) -> S::Native + Copy,
    S: PolarsNumericType, 

fn apply<F>(&'a self, f: F) -> Self where
    F: Fn(&'a str) -> Cow<'a, str> + Copy, 

fn apply_with_idx<F>(&'a self, f: F) -> Self where
    F: Fn((usize, &'a str)) -> Cow<'a, str> + Copy, 

fn apply_with_idx_on_opt<F>(&'a self, f: F) -> Self where
    F: Fn((usize, Option<&'a str>)) -> Option<Cow<'a, str>> + Copy, 

impl<'a> ChunkApply<'a, bool, bool> for BooleanChunked

fn apply_cast_numeric<F, S>(&self, f: F) -> ChunkedArray<S> where
    F: Fn(bool) -> S::Native + Copy,
    S: PolarsNumericType, 

fn branch_apply_cast_numeric_no_null<F, S>(&self, f: F) -> ChunkedArray<S> where
    F: Fn(Option<bool>) -> S::Native + Copy,
    S: PolarsNumericType, 

fn apply<F>(&self, f: F) -> Self where
    F: Fn(bool) -> bool + Copy, 

fn apply_with_idx<F>(&'a self, f: F) -> Self where
    F: Fn((usize, bool)) -> bool + Copy, 

fn apply_with_idx_on_opt<F>(&'a self, f: F) -> Self where
    F: Fn((usize, Option<bool>)) -> Option<bool> + Copy, 

impl<'a> ChunkApply<'a, Series, Series> for ListChunked

fn apply<F>(&'a self, f: F) -> Self where
    F: Fn(Series) -> Series + Copy, 

Apply a closure F elementwise.

fn apply_with_idx<F>(&'a self, f: F) -> Self where
    F: Fn((usize, Series)) -> Series + Copy, 

Apply a closure elementwise. The closure gets the index of the element as first argument.

fn apply_with_idx_on_opt<F>(&'a self, f: F) -> Self where
    F: Fn((usize, Option<Series>)) -> Option<Series> + Copy, 

Apply a closure elementwise. The closure gets the index of the element as first argument.

fn apply_cast_numeric<F, S>(&self, f: F) -> ChunkedArray<S> where
    F: Fn(Series) -> S::Native + Copy,
    S: PolarsNumericType, 

fn branch_apply_cast_numeric_no_null<F, S>(&self, f: F) -> ChunkedArray<S> where
    F: Fn(Option<Series>) -> S::Native + Copy,
    S: PolarsNumericType, 

impl<'a, T> ChunkApply<'a, <T as ArrowPrimitiveType>::Native, <T as ArrowPrimitiveType>::Native> for ChunkedArray<T> where
    T: PolarsNumericType, 

fn apply_cast_numeric<F, S>(&self, f: F) -> ChunkedArray<S> where
    F: Fn(T::Native) -> S::Native + Copy,
    S: PolarsNumericType, 

fn branch_apply_cast_numeric_no_null<F, S>(&self, f: F) -> ChunkedArray<S> where
    F: Fn(Option<T::Native>) -> S::Native + Copy,
    S: PolarsNumericType, 

fn apply<F>(&'a self, f: F) -> Self where
    F: Fn(T::Native) -> T::Native + Copy, 

fn apply_with_idx<F>(&'a self, f: F) -> Self where
    F: Fn((usize, T::Native)) -> T::Native + Copy, 

fn apply_with_idx_on_opt<F>(&'a self, f: F) -> Self where
    F: Fn((usize, Option<T::Native>)) -> Option<T::Native> + Copy,