polars_io::parquet::write

Struct ParquetWriter

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pub struct ParquetWriter<W> { /* private fields */ }
Available on crate feature parquet only.
Expand description

Write a DataFrame to Parquet format.

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

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pub fn new(writer: W) -> Self
where W: Write,

Create a new writer

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pub fn with_compression(self, compression: ParquetCompression) -> Self

Set the compression used. Defaults to Zstd.

The default compression Zstd has very good performance, but may not yet been supported by older readers. If you want more compatibility guarantees, consider using Snappy.

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pub fn with_statistics(self, statistics: StatisticsOptions) -> Self

Compute and write statistic

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pub fn with_row_group_size(self, size: Option<usize>) -> Self

Set the row group size (in number of rows) during writing. This can reduce memory pressure and improve writing performance.

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pub fn with_data_page_size(self, limit: Option<usize>) -> Self

Sets the maximum bytes size of a data page. If None will be 1024^2 bytes.

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pub fn set_parallel(self, parallel: bool) -> Self

Serialize columns in parallel

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pub fn batched(self, schema: &Schema) -> PolarsResult<BatchedWriter<W>>

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pub fn finish(self, df: &mut DataFrame) -> PolarsResult<u64>

Write the given DataFrame in the writer W. Returns the total size of the file.

Auto Trait Implementations§

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impl<W> Freeze for ParquetWriter<W>
where W: Freeze,

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impl<W> RefUnwindSafe for ParquetWriter<W>
where W: RefUnwindSafe,

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impl<W> Send for ParquetWriter<W>
where W: Send,

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impl<W> Sync for ParquetWriter<W>
where W: Sync,

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impl<W> Unpin for ParquetWriter<W>
where W: Unpin,

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impl<W> UnwindSafe for ParquetWriter<W>
where W: UnwindSafe,

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where T: 'static + ?Sized,

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