Struct polars::export::arrow::array::DictionaryArray

pub struct DictionaryArray<K> where
    K: DictionaryKey,  { /* private fields */ }

An Array whose values are encoded by keys. This Array is useful when the cardinality of values is low compared to the length of the Array.

Implementations

impl<'a, K> DictionaryArray<K> where
    K: DictionaryKey, 

pub fn iter(
    &'a self
) -> ZipValidity<'a, Box<dyn Scalar + 'static, Global>, DictionaryValuesIter<'a, K>>

Returns an iterator of Option<Box<dyn Array>>

pub fn values_iter(&'a self) -> DictionaryValuesIter<'a, K>

Returns an iterator of Box<dyn Array>

impl<K> DictionaryArray<K> where
    K: DictionaryKey, 

pub fn new_empty(data_type: DataType) -> DictionaryArray<K>

Returns a new empty DictionaryArray.

pub fn new_null(data_type: DataType, length: usize) -> DictionaryArray<K>

Returns an DictionaryArray whose all elements are null

pub fn from_data(
    keys: PrimitiveArray<K>,
    values: Arc<dyn Array + 'static>
) -> DictionaryArray<K>

The canonical method to create a new DictionaryArray.

pub fn slice(&self, offset: usize, length: usize) -> DictionaryArray<K>

Creates a new DictionaryArray by slicing the existing DictionaryArray.

Panics

iff offset + length > self.len().

pub unsafe fn slice_unchecked(
    &self,
    offset: usize,
    length: usize
) -> DictionaryArray<K>

Creates a new DictionaryArray by slicing the existing DictionaryArray.

Safety

Safe iff offset + length <= self.len().

pub fn with_validity(&self, validity: Option<Bitmap>) -> DictionaryArray<K>

Sets the validity bitmap on this Array.

Panic

This function panics iff validity.len() != self.len().

impl<K> DictionaryArray<K> where
    K: DictionaryKey, 

pub fn len(&self) -> usize

Returns the length of this array

pub fn validity(&self) -> Option<&Bitmap>

The optional validity. Equivalent to self.keys().validity().

pub fn keys(&self) -> &PrimitiveArray<K>

Returns the keys of the DictionaryArray. These keys can be used to fetch values from values.

pub fn values(&self) -> &Arc<dyn Array + 'static>

Returns the values of the DictionaryArray.

pub fn value(&self, index: usize) -> Box<dyn Scalar + 'static, Global>

Returns the value of the DictionaryArray at position i.

Trait Implementations

impl<K> Array for DictionaryArray<K> where
    K: DictionaryKey, 

fn as_any(&self) -> &(dyn Any + 'static)

Convert to trait object.

fn len(&self) -> usize

The length of the Array. Every array has a length corresponding to the number of elements (slots).

fn data_type(&self) -> &DataType

The DataType of the Array. In combination with Array::as_any, this can be used to downcast trait objects (dyn Array) to concrete arrays.

fn validity(&self) -> Option<&Bitmap>

The validity of the Array: every array has an optional Bitmap that, when available specifies whether the array slot is valid or not (null). When the validity is None, all slots are valid.

fn slice(
    &self,
    offset: usize,
    length: usize
) -> Box<dyn Array + 'static, Global>

Slices the Array, returning a new Box<dyn Array>.

unsafe fn slice_unchecked(
    &self,
    offset: usize,
    length: usize
) -> Box<dyn Array + 'static, Global>

Slices the Array, returning a new Box<dyn Array>.

fn with_validity(
    &self,
    validity: Option<Bitmap>
) -> Box<dyn Array + 'static, Global>

Sets the validity bitmap on this Array.

fn is_empty(&self) -> bool

whether the array is empty

fn null_count(&self) -> usize

The number of null slots on this Array.

fn is_null(&self, i: usize) -> bool

Returns whether slot i is null.

fn is_valid(&self, i: usize) -> bool

Returns whether slot i is valid.

impl<K> Clone for DictionaryArray<K> where
    K: Clone + DictionaryKey, 

fn clone(&self) -> DictionaryArray<K>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<K> Debug for DictionaryArray<K> where
    K: DictionaryKey, 

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

Formats the value using the given formatter.

impl<'_> From<&'_ CategoricalChunked> for DictionaryArray<u32>

fn from(ca: &CategoricalChunked) -> DictionaryArray<u32>

Performs the conversion.

impl<'_> From<&'_ CategoricalChunked> for DictionaryArray<i64>

fn from(ca: &CategoricalChunked) -> DictionaryArray<i64>

Performs the conversion.

impl<'a, T> From<GrowableDictionary<'a, T>> for DictionaryArray<T> where
    T: DictionaryKey, 

fn from(val: GrowableDictionary<'a, T>) -> DictionaryArray<T>

Performs the conversion.

impl<K, M> From<MutableDictionaryArray<K, M>> for DictionaryArray<K> where
    K: DictionaryKey,
    M: MutableArray, 

fn from(other: MutableDictionaryArray<K, M>) -> DictionaryArray<K>

Performs the conversion.

impl<'a, K> IntoIterator for &'a DictionaryArray<K> where
    K: DictionaryKey, 

type Item = Option<Box<dyn Scalar + 'static, Global>>

The type of the elements being iterated over.

type IntoIter = ZipValidity<'a, Box<dyn Scalar + 'static, Global>, DictionaryValuesIter<'a, K>>

Which kind of iterator are we turning this into?

fn into_iter(self) -> <&'a DictionaryArray<K> as IntoIterator>::IntoIter

Creates an iterator from a value.

impl<'_, K> PartialEq<&'_ (dyn Array + '_)> for DictionaryArray<K> where
    K: DictionaryKey, 

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl<K> PartialEq<DictionaryArray<K>> for DictionaryArray<K> where
    K: DictionaryKey, 

fn eq(&self, other: &DictionaryArray<K>) -> bool

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.