Struct ParquetReader 

pub struct ParquetReader { /* private fields */ }

A Parquet file reader.

Uses a fluent builder pattern: construct with ParquetReader::new, chain optional configuration methods, then call ParquetReader::finish to load the data into a DataFrame.

Example

use plotlars_core::io::ParquetReader;

let df = ParquetReader::new("data/sales.parquet").finish().unwrap();

Implementations

impl ParquetReader

pub fn new(path: impl AsRef<Path>) -> Self

Create a new Parquet reader for the given file path.

pub fn columns(self, columns: Vec<&str>) -> Self

Select specific columns to load (projection pushdown).

pub fn n_rows(self, n_rows: usize) -> Self

Limit the number of rows to read.

pub fn finish(self) -> Result<DataFrame, PlotlarsError>

Execute the read and return a DataFrame.

Errors

Returns PlotlarsError::ParquetParse if the file cannot be read or parsed.

Trait Implementations

impl Clone for ParquetReader

fn clone(&self) -> ParquetReader

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.