Struct polars::frame::ser::csv::CsvReader

pub struct CsvReader<R> where
    R: Read + Seek,  { /* fields omitted */ }

Creates a DataFrame after reading a csv.

Implementations

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

pub fn with_schema(self, schema: Arc<Schema>) -> Self

Create a new DataFrame by reading a csv file.

Example

use polars::prelude::*;
use std::fs::File;

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

    CsvReader::new(file)
            .infer_schema(None)
            .has_header(true)
            .finish()
}

Set the CSV file's schema

pub fn has_header(self, has_header: bool) -> Self

Set whether the CSV file has headers

pub fn with_delimiter(self, delimiter: u8) -> Self

Set the CSV file's column delimiter as a byte character

pub fn infer_schema(self, max_records: Option<usize>) -> Self

Set the CSV reader to infer the schema of the file

pub fn with_batch_size(self, batch_size: usize) -> Self

Set the batch size (number of records to load at one time)

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

Set the reader's column projection

Trait Implementations

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

fn new(reader: R) -> Self

Create a new CsvReader from a file/ stream

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

Rechunk to one contiguous chunk of memory after all data is read

fn finish(self) -> Result<DataFrame>

Read the file and create the DataFrame.