polars_core::prelude

Struct ArrowField

pub struct ArrowField {
    pub name: PlSmallStr,
    pub dtype: ArrowDataType,
    pub is_nullable: bool,
    pub metadata: Option<Arc<BTreeMap<PlSmallStr, PlSmallStr>>>,
}
Expand description

Represents Arrow’s metadata of a “column”.

A Field is the closest representation of the traditional “column”: a logical type (ArrowDataType) with a name and nullability. A Field has optional [Metadata] that can be used to annotate the field with custom metadata.

Almost all IO in this crate uses Field to represent logical information about the data to be serialized.

Fields§

§name: PlSmallStr

Its name

§dtype: ArrowDataType

Its logical ArrowDataType

§is_nullable: bool

Its nullability

§metadata: Option<Arc<BTreeMap<PlSmallStr, PlSmallStr>>>

Additional custom (opaque) metadata.

Implementations§

§

impl Field

pub fn new(name: PlSmallStr, dtype: ArrowDataType, is_nullable: bool) -> Field

Creates a new Field.

pub fn with_metadata(self, metadata: BTreeMap<PlSmallStr, PlSmallStr>) -> Field

Creates a new Field with metadata.

pub fn dtype(&self) -> &ArrowDataType

Returns the Field’s ArrowDataType.

pub fn is_enum(&self) -> bool

pub fn is_categorical(&self) -> bool

Trait Implementations§

§

impl Clone for Field

§

fn clone(&self) -> Field

Returns a copy of the value. Read more
1.0.0 · Source§

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
§

impl Debug for Field

§

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter. Read more
§

impl Default for Field

§

fn default() -> Field

Returns the “default value” for a type. Read more
Source§

impl From<&Field> for Field

Source§

fn from(f: &ArrowField) -> Self

Converts to this type from the input type.
§

impl Hash for Field

§

fn hash<__H>(&self, state: &mut __H)
where __H: Hasher,

Feeds this value into the given Hasher. Read more
1.3.0 · Source§

fn hash_slice<H>(data: &[Self], state: &mut H)
where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher. Read more
§

impl PartialEq for Field

§

fn eq(&self, other: &Field) -> bool

Tests for self and other values to be equal, and is used by ==.
1.0.0 · Source§

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
§

impl Eq for Field

§

impl StructuralPartialEq for Field

Auto Trait Implementations§

§

impl Freeze for Field

§

impl RefUnwindSafe for Field

§

impl Send for Field

§

impl Sync for Field

§

impl Unpin for Field

§

impl UnwindSafe for Field

Blanket Implementations§

Source§

impl<T> Any for T
where T: 'static + ?Sized,

Source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
Source§

impl<T> Borrow<T> for T
where T: ?Sized,

Source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
Source§

impl<T> BorrowMut<T> for T
where T: ?Sized,

Source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
Source§

impl<T> CloneToUninit for T
where T: Clone,

Source§

unsafe fn clone_to_uninit(&self, dst: *mut u8)

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
Source§

impl<T> DynClone for T
where T: Clone,

Source§

fn __clone_box(&self, _: Private) -> *mut ()

§

impl<Q, K> Equivalent<K> for Q
where Q: Eq + ?Sized, K: Borrow<Q> + ?Sized,

§

fn equivalent(&self, key: &K) -> bool

Compare self to key and return true if they are equal.
Source§

impl<T> From<T> for T

Source§

fn from(t: T) -> T

Returns the argument unchanged.

Source§

impl<T, U> Into<U> for T
where U: From<T>,

Source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

Source§

impl<T> IntoEither for T

Source§

fn into_either(self, into_left: bool) -> Either<Self, Self>

Converts self into a Left variant of Either<Self, Self> if into_left is true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
Source§

fn into_either_with<F>(self, into_left: F) -> Either<Self, Self>
where F: FnOnce(&Self) -> bool,

Converts self into a Left variant of Either<Self, Self> if into_left(&self) returns true. Converts self into a Right variant of Either<Self, Self> otherwise. Read more
§

impl<T> Pointable for T

§

const ALIGN: usize = _

The alignment of pointer.
§

type Init = T

The type for initializers.
§

unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
§

unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
§

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
§

unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
Source§

impl<T> ToOwned for T
where T: Clone,

Source§

type Owned = T

The resulting type after obtaining ownership.
Source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
Source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
Source§

impl<T, U> TryFrom<U> for T
where U: Into<T>,

Source§

type Error = Infallible

The type returned in the event of a conversion error.
Source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
Source§

impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

Source§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
Source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
§

impl<V, T> VZip<V> for T
where V: MultiLane<T>,

§

fn vzip(self) -> V