Function arrow::compute::cast

pub fn cast(
    array: &dyn Array,
    to_type: &DataType
) -> Result<Arc<dyn Array + 'static>, ArrowError>

Expand description

Cast array to the provided data type and return a new Array with type to_type, if possible.

Behavior:

Boolean to Utf8: true => ‘1’, false => 0
Utf8 to boolean: true, yes, on, 1 => true, false, no, off, 0 => false, short variants are accepted, other strings return null or error
Utf8 to numeric: strings that can’t be parsed to numbers return null, float strings in integer casts return null
Numeric to boolean: 0 returns false, any other value returns true
List to List: the underlying data type is cast
Primitive to List: a list array with 1 value per slot is created
Date32 and Date64: precision lost when going to higher interval
Time32 and Time64: precision lost when going to higher interval
Timestamp and Date{32|64}: precision lost when going to higher interval
Temporal to/from backing primitive: zero-copy with data type change
Casting from float32/float64 to Decimal(precision, scale) rounds to the scale decimals (i.e. casting 6.4999 to Decimal(10, 1) becomes 6.5). This is the breaking change from 26.0.0. It used to truncate it instead of round (i.e. outputs 6.4 instead)

Unsupported Casts