polars_io::parquet::read

Struct ParquetAsyncReader

Source
pub struct ParquetAsyncReader { /* private fields */ }
Available on crate features parquet and cloud only.
Expand description

A Parquet reader on top of the async object_store API. Only the batch reader is implemented since parquet files on cloud storage tend to be big and slow to access.

Implementations§

Source§

impl ParquetAsyncReader

Source

pub async fn from_uri( uri: &str, cloud_options: Option<&CloudOptions>, metadata: Option<FileMetadataRef>, ) -> PolarsResult<ParquetAsyncReader>

Source

pub async fn with_arrow_schema_projection( self, first_schema: &Arc<ArrowSchema>, projected_arrow_schema: Option<&ArrowSchema>, allow_missing_columns: bool, ) -> PolarsResult<Self>

Source

pub async fn schema(&mut self) -> PolarsResult<ArrowSchemaRef>

Source

pub async fn num_rows(&mut self) -> PolarsResult<usize>

Source

pub fn with_slice(self, slice: Option<(usize, usize)>) -> Self

Only positive offsets are supported for simplicity - the caller should translate negative offsets into the positive equivalent.

Source

pub fn with_row_index(self, row_index: Option<RowIndex>) -> Self

Source

pub fn set_rechunk(self, rechunk: bool) -> Self

Source

pub fn with_projection(self, projection: Option<Vec<usize>>) -> Self

Source

pub fn with_predicate(self, predicate: Option<Arc<dyn PhysicalIoExpr>>) -> Self

Source

pub fn use_statistics(self, toggle: bool) -> Self

Use statistics in the parquet to determine if pages can be skipped from reading.

Source

pub fn with_hive_partition_columns(self, columns: Option<Vec<Series>>) -> Self

Source

pub fn with_include_file_path( self, include_file_path: Option<(PlSmallStr, Arc<str>)>, ) -> Self

Source

pub fn read_parallel(self, parallel: ParallelStrategy) -> Self

Source

pub async fn batched( self, chunk_size: usize, ) -> PolarsResult<BatchedParquetReader>

Source

pub async fn get_metadata(&mut self) -> PolarsResult<&FileMetadataRef>

Source

pub async fn finish(self) -> PolarsResult<DataFrame>

Auto Trait Implementations§

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> From<T> for T

Source§

fn from(t: T) -> T

Returns the argument unchanged.

§

impl<T> Instrument for T

§

fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided [Span], returning an Instrumented wrapper. Read more
§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
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> Same for T

Source§

type Output = T

Should always be Self
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

§

impl<T> WithSubscriber for T

§

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>
where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a [WithDispatch] wrapper. Read more
§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a [WithDispatch] wrapper. Read more
§

impl<T> ErasedDestructor for T
where T: 'static,

§

impl<T> MaybeSendSync for T

§

impl<T> Ungil for T
where T: Send,