Struct JsonLineReader

pub struct JsonLineReader<'a, R>
where
    R: MmapBytesReader,
{ /* private fields */ }

Available on crate feature polars-io only.

Implementations

impl<'a, R> JsonLineReader<'a, R>

where R: 'a + MmapBytesReader,

pub fn with_n_rows(self, num_rows: Option<usize>) -> JsonLineReader<'a, R>

pub fn with_schema(self, schema: Arc<Schema<DataType>>) -> JsonLineReader<'a, R>

pub fn with_schema_overwrite( self, schema: &'a Schema<DataType>, ) -> JsonLineReader<'a, R>

pub fn with_rechunk(self, rechunk: bool) -> JsonLineReader<'a, R>

pub fn with_predicate( self, predicate: Option<Arc<dyn PhysicalIoExpr>>, ) -> JsonLineReader<'a, R>

pub fn with_projection( self, projection: Option<Arc<[PlSmallStr]>>, ) -> JsonLineReader<'a, R>

pub fn with_row_index( self, row_index: Option<&'a mut RowIndex>, ) -> JsonLineReader<'a, R>

pub fn infer_schema_len( self, infer_schema_len: Option<NonZero<usize>>, ) -> JsonLineReader<'a, R>

pub fn with_n_threads(self, n: Option<usize>) -> JsonLineReader<'a, R>

pub fn with_path<P>(self, path: Option<P>) -> JsonLineReader<'a, R>

where P: Into<PathBuf>,

pub fn with_chunk_size( self, chunk_size: Option<NonZero<usize>>, ) -> JsonLineReader<'a, R>

Sets the chunk size used by the parser. This influences performance

pub fn low_memory(self, toggle: bool) -> JsonLineReader<'a, R>

Reduce memory consumption at the expense of performance

pub fn with_ignore_errors(self, ignore_errors: bool) -> JsonLineReader<'a, R>

Set values as Null if parsing fails because of schema mismatches.

pub fn count(self) -> Result<usize, PolarsError>

impl JsonLineReader<'_, File>

pub fn from_path<P>(path: P) -> Result<JsonLineReader<'_, File>, PolarsError>

where P: Into<PathBuf>,

This is the recommended way to create a json reader as this allows for fastest parsing.

Trait Implementations

impl<R> SerReader<R> for JsonLineReader<'_, R>

where R: MmapBytesReader,

fn new(reader: R) -> JsonLineReader<'_, R>

Create a new JsonLineReader from a file/ stream

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

Take the SerReader and return a parsed DataFrame.

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

where Self: Sized,

Make sure that all columns are contiguous in memory by aggregating the chunks into a single array.