Function arrow_select::take::take
source · pub fn take(
values: &dyn Array,
indices: &dyn Array,
options: Option<TakeOptions>,
) -> Result<ArrayRef, ArrowError>
Expand description
Take elements by index from Array, creating a new Array from those indexes.
┌─────────────────┐ ┌─────────┐ ┌─────────────────┐
│ A │ │ 0 │ │ A │
├─────────────────┤ ├─────────┤ ├─────────────────┤
│ D │ │ 2 │ │ B │
├─────────────────┤ ├─────────┤ take(values, indices) ├─────────────────┤
│ B │ │ 3 │ ─────────────────────────▶ │ C │
├─────────────────┤ ├─────────┤ ├─────────────────┤
│ C │ │ 1 │ │ D │
├─────────────────┤ └─────────┘ └─────────────────┘
│ E │
└─────────────────┘
values array indices array result
For selecting values by index from multiple arrays see crate::interleave
§Errors
This function errors whenever:
- An index cannot be casted to
usize
(typically 32 bit architectures) - An index is out of bounds and
options
is set to check bounds.
§Safety
When options
is not set to check bounds, taking indexes after len
will panic.
§Examples
let values = StringArray::from(vec!["zero", "one", "two"]);
// Take items at index 2, and 1:
let indices = UInt32Array::from(vec![2, 1]);
let taken = take(&values, &indices, None).unwrap();
let taken = taken.as_string::<i32>();
assert_eq!(*taken, StringArray::from(vec!["two", "one"]));