Function arrow_cast::cast::cast_with_options

source ·
pub fn cast_with_options(
    array: &dyn Array,
    to_type: &DataType,
    cast_options: &CastOptions<'_>,
) -> Result<ArrayRef, ArrowError>
Expand description

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

Accepts CastOptions to specify cast behavior.

§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
  • List to FixedSizeList: the underlying data type is cast. If safe is true and a list element has the wrong length it will be replaced with NULL, otherwise an error will be returned
  • 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). Prior to version 26.0.0, casting would truncate instead (i.e. outputs 6.4 instead)

Unsupported Casts

  • To or from StructArray
  • List to primitive
  • Interval and duration