polars_core::prelude

Struct ArrowField

pub struct ArrowField {
    pub name: PlSmallStr,
    pub dtype: ArrowDataType,
    pub is_nullable: bool,
    pub metadata: 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.

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§name: PlSmallStr

Its name

§dtype: ArrowDataType

Its logical ArrowDataType

§is_nullable: bool

Its nullability

§metadata: BTreeMap<PlSmallStr, PlSmallStr>

Additional custom (opaque) metadata.

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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.

Trait Implementations§

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impl Clone for Field

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fn clone(&self) -> Field

Returns a copy of the value. Read more
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fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source. Read more
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impl Debug for Field

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

Formats the value using the given formatter. Read more
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impl Default for Field

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fn default() -> Field

Returns the “default value” for a type. Read more
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impl From<&Field> for Field

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fn from(f: &ArrowField) -> Self

Converts to this type from the input type.
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impl Hash for Field

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

Feeds this value into the given Hasher. Read more
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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
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impl PartialEq for Field

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

Tests for self and other values to be equal, and is used by ==.
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fn ne(&self, other: &Rhs) -> bool

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

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impl StructuralPartialEq for Field

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impl Freeze for Field

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impl RefUnwindSafe for Field

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impl Send for Field

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impl Sync for Field

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impl Unpin for Field

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impl UnwindSafe for Field

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

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fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
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impl<T> Borrow<T> for T
where T: ?Sized,

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fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
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impl<T> BorrowMut<T> for T
where T: ?Sized,

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

Mutably borrows from an owned value. Read more
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impl<T> CloneToUninit for T
where T: Clone,

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

🔬This is a nightly-only experimental API. (clone_to_uninit)
Performs copy-assignment from self to dst. Read more
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impl<T> DynClone for T
where T: Clone,

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

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

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

Compare self to key and return true if they are equal.
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impl<T> From<T> for T

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fn from(t: T) -> T

Returns the argument unchanged.

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

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fn into(self) -> U

Calls U::from(self).

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

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impl<T> IntoEither for T

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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
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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
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impl<T> Pointable for T

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const ALIGN: usize = _

The alignment of pointer.
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type Init = T

The type for initializers.
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unsafe fn init(init: <T as Pointable>::Init) -> usize

Initializes a with the given initializer. Read more
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unsafe fn deref<'a>(ptr: usize) -> &'a T

Dereferences the given pointer. Read more
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unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

Mutably dereferences the given pointer. Read more
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unsafe fn drop(ptr: usize)

Drops the object pointed to by the given pointer. Read more
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impl<T> ToOwned for T
where T: Clone,

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type Owned = T

The resulting type after obtaining ownership.
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fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
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fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
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impl<T, U> TryFrom<U> for T
where U: Into<T>,

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type Error = Infallible

The type returned in the event of a conversion error.
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fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
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impl<T, U> TryInto<U> for T
where U: TryFrom<T>,

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

The type returned in the event of a conversion error.
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fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
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impl<V, T> VZip<V> for T
where V: MultiLane<T>,

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fn vzip(self) -> V