Struct polars_io::parquet::ParquetReader

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

This is supported on crate feature feature only.

Read Apache parquet format into a DataFrame.

Implementations

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

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

This is supported on crate feature lazy only.

pub fn with_stop_after_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.

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

Trait Implementations

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

fn new(reader: R) -> Self

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

Rechunk to a single chunk after Reading file.

fn finish(self) -> Result<DataFrame>

Take the SerReader and return a parsed DataFrame.