Struct polars_io::parquet::ParquetReader

source · [−]

pub struct ParquetReader<R: Read + Seek> { /* private fields */ }

Expand description

Read Apache parquet format into a DataFrame.

Implementations

source

impl<R: MmapBytesReader> ParquetReader<R>

source

pub fn finish_with_scan_ops(
 self,
 predicate: Option<Arc<dyn PhysicalIoExpr>>,
 aggregate: Option<&[ScanAggregation ]>,
 projection: Option<&[usize ]>
) -> Result<DataFrame>

source

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

Read the parquet file in parallel (default). The single threaded reader consumes less memory.

source

pub fn with_n_rows(self, num_rows: Option<usize>) -> Self

Stop parsing when n rows are parsed. By settings this parameter the csv will be parsed sequentially.

source

pub fn with_columns(self, columns: Option<Vec<String>>) -> Self

Columns to select/ project

source

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

Set the reader’s column projection. This counts from 0, meaning that vec![0, 4] would select the 1st and 5th column.

source

pub fn with_row_count(self, row_count: Option<RowCount>) -> Self

Add a row_count column.

source

pub fn schema(self) -> Result<Schema>

Trait Implementations

source

impl<R: MmapBytesReader> SerReader<R> for ParquetReader<R>

source

fn new(reader: R) -> Self

source

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

Rechunk to a single chunk after Reading file.

source

fn finish(self) -> Result<DataFrame>

Take the SerReader and return a parsed DataFrame.

Auto Trait Implementations

impl<R> RefUnwindSafe for ParquetReader<R> where
R: RefUnwindSafe,

impl<R> Send for ParquetReader<R> where
R: Send,

impl<R> Sync for ParquetReader<R> where
R: Sync,

impl<R> Unpin for ParquetReader<R> where
R: Unpin,

impl<R> UnwindSafe for ParquetReader<R> where
R: UnwindSafe,

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,

const: unstable · source

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more

source

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

const: unstable · source

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

Mutably borrows from an owned value. Read more

source

impl<T> From<T> for T

const: unstable · source

fn from(t: T) -> T

Returns the argument unchanged.

source

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

const: unstable · 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> Pointable for T

source

const ALIGN: usize

The alignment of pointer.

type Init = T

The type for initializers.

source

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

Initializes a with the given initializer. Read more

source

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

Dereferences the given pointer. Read more

source

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

Mutably dereferences the given pointer. Read more

source

unsafe fn drop(ptr: usize)

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

source

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

type Error = Infallible

The type returned in the event of a conversion error.

const: unstable · source

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

Performs the conversion.

source

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

type Error = >::Error

The type returned in the event of a conversion error.

const: unstable · source

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

Performs the conversion.

source

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

source

Struct polars_io::parquet::ParquetReader

Implementations

impl<R: MmapBytesReader> ParquetReader<R>

pub fn finish_with_scan_ops( self, predicate: Option<Arc<dyn PhysicalIoExpr>>, aggregate: Option<&[ScanAggregation]>, projection: Option<&[usize]>) -> Result<DataFrame>

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

pub fn with_n_rows(self, num_rows: Option<usize>) -> Self

pub fn with_columns(self, columns: Option<Vec<String>>) -> Self

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

pub fn with_row_count(self, row_count: Option<RowCount>) -> Self

pub fn schema(self) -> Result<Schema>

Trait Implementations

impl<R: MmapBytesReader> SerReader<R> for ParquetReader<R>

fn new(reader: R) -> Self

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

fn finish(self) -> Result<DataFrame>

Auto Trait Implementations

impl<R> RefUnwindSafe for ParquetReader<R> where R: RefUnwindSafe,

impl<R> Send for ParquetReader<R> where R: Send,

impl<R> Sync for ParquetReader<R> where R: Sync,

impl<R> Unpin for ParquetReader<R> where R: Unpin,

impl<R> UnwindSafe for ParquetReader<R> where R: UnwindSafe,

Blanket Implementations

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

fn type_id(&self) -> TypeId

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

fn borrow(&self) -> &T

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

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

impl<T> From<T> for T

fn from(t: T) -> T

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

fn into(self) -> U

impl<T> Pointable for T

const ALIGN: usize

type Init = T

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

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

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

unsafe fn drop(ptr: usize)

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

type Error = Infallible

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

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

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

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

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

fn vzip(self) -> V

pub fn finish_with_scan_ops(
self,
predicate: Option<Arc<dyn PhysicalIoExpr>>,
aggregate: Option<&[ScanAggregation ]>,
projection: Option<&[usize ]>
) -> Result<DataFrame>

impl<R> RefUnwindSafe for ParquetReader<R> where
R: RefUnwindSafe,

impl<R> Send for ParquetReader<R> where
R: Send,

impl<R> Sync for ParquetReader<R> where
R: Sync,

impl<R> Unpin for ParquetReader<R> where
R: Unpin,

impl<R> UnwindSafe for ParquetReader<R> where
R: UnwindSafe,

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

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

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

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

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

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

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