Struct polars::prelude::IpcReader

pub struct IpcReader<R> { /* private fields */ }

Read Arrows IPC format into a DataFrame

Example

use polars_core::prelude::*;
use std::fs::File;
use polars_io::ipc::IpcReader;
use polars_io::SerReader;

fn example() -> Result<DataFrame> {
    let file = File::open("file.ipc").expect("file not found");

    IpcReader::new(file)
        .finish()
}

Implementations

impl<R> IpcReader<R> where
    R: Read + Seek, 

pub fn schema(&mut self) -> Result<Schema, PolarsError>

Get schema of the Ipc File

pub fn arrow_schema(&mut self) -> Result<Schema, PolarsError>

Get arrow schema of the Ipc File, this is faster than creating a polars schema.

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

Stop reading when n rows are read.

pub fn with_columns(self, columns: Option<Vec<String, Global>>) -> IpcReader<R>

Columns to select/ project

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

Add a row_count column.

pub fn with_projection(
    self,
    projection: Option<Vec<usize, Global>>
) -> IpcReader<R>

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

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

Trait Implementations

impl<R> SerReader<R> for IpcReader<R> where
    R: Read + Seek, 

fn new(reader: R) -> IpcReader<R>

fn set_rechunk(self, rechunk: bool) -> IpcReader<R>

Rechunk to a single chunk after Reading file.

fn finish(self) -> Result<DataFrame, PolarsError>

Take the SerReader and return a parsed DataFrame.