Struct deltalake::arrow::csv::reader::ReaderBuilder

pub struct ReaderBuilder { /* private fields */ }

CSV file reader builder

Implementations

impl ReaderBuilder

pub fn new(schema: Arc<Schema>) -> ReaderBuilder

Create a new builder for configuring CSV parsing options.

To convert a builder into a reader, call ReaderBuilder::build

Example

let mut file = File::open("test/data/uk_cities_with_headers.csv").unwrap();
// Infer the schema with the first 100 records
let (schema, _) = Format::default().infer_schema(&mut file, Some(100)).unwrap();
file.rewind().unwrap();

// create a builder
ReaderBuilder::new(Arc::new(schema)).build(file).unwrap();

pub fn with_header(self, has_header: bool) -> ReaderBuilder

Set whether the CSV file has a header

pub fn with_format(self, format: Format) -> ReaderBuilder

Overrides the Format of this `ReaderBuilder

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

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

pub fn with_escape(self, escape: u8) -> ReaderBuilder

pub fn with_quote(self, quote: u8) -> ReaderBuilder

pub fn with_terminator(self, terminator: u8) -> ReaderBuilder

pub fn with_null_regex(self, null_regex: Regex) -> ReaderBuilder

Provide a regex to match null values, defaults to ^$

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

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

pub fn with_bounds(self, start: usize, end: usize) -> ReaderBuilder

Set the bounds over which to scan the reader. start and end are line numbers.

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

Set the reader’s column projection

pub fn build<R>(self, reader: R) -> Result<BufReader<BufReader<R>>, ArrowError>

where R: Read,

Create a new Reader from a non-buffered reader

If R: BufRead consider using Self::build_buffered to avoid unnecessary additional buffering, as internally this method wraps reader in std::io::BufReader

pub fn build_buffered<R>(self, reader: R) -> Result<BufReader<R>, ArrowError>

where R: BufRead,

Create a new BufReader from a buffered reader

pub fn build_decoder(self) -> Decoder

Builds a decoder that can be used to decode CSV from an arbitrary byte stream

Trait Implementations

impl Debug for ReaderBuilder

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.