Struct polars::export::arrow::io::parquet::write::FileWriter

pub struct FileWriter<W> where
    W: Write,  { /* private fields */ }

This is supported on crate feature io_parquet only.

An interface to write a parquet to a Write

Implementations

impl<W> FileWriter<W> where
    W: Write, 

pub fn options(&self) -> &WriteOptions

The options assigned to the file

pub fn parquet_schema(&self) -> &SchemaDescriptor

The SchemaDescriptor assigned to this file

pub fn schema(&self) -> &Schema

The Schema assigned to this file

impl<W> FileWriter<W> where
    W: Write, 

pub fn try_new(
    writer: W,
    schema: Schema,
    options: WriteOptions
) -> Result<FileWriter<W>, ArrowError>

Returns a new FileWriter.

Error

If it is unable to derive a parquet schema from Schema.

pub fn start(&mut self) -> Result<(), ArrowError>

Writes the header of the file

pub fn write(
    &mut self,
    row_group: DynIter<'_, Result<DynStreamingIterator<'_, CompressedPage, ArrowError>, ArrowError>>,
    num_rows: usize
) -> Result<(), ArrowError>

Writes a row group to the file.

pub fn end(
    self,
    key_value_metadata: Option<Vec<KeyValue, Global>>
) -> Result<(u64, W), ArrowError>

Writes the footer of the parquet file. Returns the total size of the file.