Module polars_io::csv

This is supported on crate feature csv-file only.

(De)serializing CSV files

Maximal performance

Currently CsvReader::new has an extra copy. If you want optimal performance in CSV parsing/ reading, it is advised to use CsvReader::from_path.

Write a DataFrame to a csv file.

Example

use polars_core::prelude::*;
use polars_io::prelude::*;
use std::fs::File;

fn example(df: &mut DataFrame) -> Result<()> {
    let mut file = File::create("example.csv").expect("could not create file");

    CsvWriter::new(&mut file)
    .has_headers(true)
    .with_delimiter(b',')
    .finish(df)
}

Read a csv file to a DataFrame

Example

use polars_core::prelude::*;
use polars_io::prelude::*;
use std::io::Cursor;

let s = r#"
"sepal.length","sepal.width","petal.length","petal.width","variety"
5.1,3.5,1.4,.2,"Setosa"
4.9,3,1.4,.2,"Setosa"
4.7,3.2,1.3,.2,"Setosa"
4.6,3.1,1.5,.2,"Setosa"
5,3.6,1.4,.2,"Setosa"
5.4,3.9,1.7,.4,"Setosa"
4.6,3.4,1.4,.3,"Setosa"
"#;

let file = Cursor::new(s);
let df = CsvReader::new(file)
.infer_schema(Some(100))
.has_header(true)
.finish()
.unwrap();

assert_eq!("sepal.length", df.get_columns()[0].name());

Structs

CsvReader	Create a new DataFrame by reading a csv file.
CsvWriter	Write a DataFrame to csv.
WriterBuilder	A CSV writer builder

Enums

CsvEncoding