https://github.com/jmcnamara/polars_excel_writer

A Polars extension to serialize dataframes to Excel xlsx files
https://github.com/jmcnamara/polars_excel_writer

Last synced: 17 days ago
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A Polars extension to serialize dataframes to Excel xlsx files

• Host: GitHub
• URL: https://github.com/jmcnamara/polars_excel_writer
• Owner: jmcnamara
• License: apache-2.0
• Created: 2023-08-08T23:41:18.000Z (over 1 year ago)
• Default Branch: main
• Last Pushed: 2024-09-17T23:26:16.000Z (about 2 months ago)
• Last Synced: 2024-10-14T01:43:39.476Z (about 1 month ago)
• Language: Rust
• Size: 142 KB
• Stars: 14
• Watchers: 3
• Forks: 4
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE_Apache2.0

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README

        
# polars_excel_writer

The `polars_excel_writer` crate is a library for serializing Polars dataframes

to Excel Xlsx files.

It provides two interfaces for writing a dataframe to an Excel Xlsx file:

- [`ExcelWriter`] a simple Excel serializer that implements the Polars

  [`SerWriter`] trait to write a dataframe to an Excel Xlsx file.

- [`PolarsXlsxWriter`] a more configurable Excel serializer that more closely

  resembles the interface options provided by the Polars [`write_excel()`]

  dataframe method.

`ExcelWriter` uses `PolarsXlsxWriter` to do the Excel serialization which in

turn uses the [`rust_xlsxwriter`] crate.

[`ExcelWriter`]: https://docs.rs/polars_excel_writer/latest/polars_excel_writer/write/struct.ExcelWriter.html

[`PolarsXlsxWriter`]: https://docs.rs/polars_excel_writer/latest/polars_excel_writer/xlsx_writer/struct.PolarsXlsxWriter.html

[`SerWriter`]:

    https://docs.rs/polars/latest/polars/prelude/trait.SerWriter.html

[`CsvWriter`]:

    https://docs.rs/polars/latest/polars/prelude/struct.CsvWriter.html

[`rust_xlsxwriter`]: https://docs.rs/rust_xlsxwriter/latest/rust_xlsxwriter/

[`write_excel()`]:

   https://pola-rs.github.io/polars/py-polars/html/reference/api/polars.DataFrame.write_excel.html#polars.DataFrame.write_excel

## Example

An example of writing a Polar Rust dataframe to an Excel file using the

`ExcelWriter` interface.

```rust

use chrono::prelude::*;

use polars::prelude::*;

fn main() {

    // Create a sample dataframe for the example.

    let mut df: DataFrame = df!(

        "String" => &["North", "South", "East", "West"],

        "Integer" => &[1, 2, 3, 4],

        "Float" => &[4.0, 5.0, 6.0, 7.0],

        "Time" => &[

            NaiveTime::from_hms_milli_opt(2, 59, 3, 456).unwrap(),

            NaiveTime::from_hms_milli_opt(2, 59, 3, 456).unwrap(),

            NaiveTime::from_hms_milli_opt(2, 59, 3, 456).unwrap(),

            NaiveTime::from_hms_milli_opt(2, 59, 3, 456).unwrap(),

            ],

        "Date" => &[

            NaiveDate::from_ymd_opt(2022, 1, 1).unwrap(),

            NaiveDate::from_ymd_opt(2022, 1, 2).unwrap(),

            NaiveDate::from_ymd_opt(2022, 1, 3).unwrap(),

            NaiveDate::from_ymd_opt(2022, 1, 4).unwrap(),

            ],

        "Datetime" => &[

            NaiveDate::from_ymd_opt(2022, 1, 1).unwrap().and_hms_opt(1, 0, 0).unwrap(),

            NaiveDate::from_ymd_opt(2022, 1, 2).unwrap().and_hms_opt(2, 0, 0).unwrap(),

            NaiveDate::from_ymd_opt(2022, 1, 3).unwrap().and_hms_opt(3, 0, 0).unwrap(),

            NaiveDate::from_ymd_opt(2022, 1, 4).unwrap().and_hms_opt(4, 0, 0).unwrap(),

        ],

    )

    .unwrap();

    example1(&mut df).unwrap();

    example2(&df).unwrap();

}

// The ExcelWriter interface.

use polars_excel_writer::ExcelWriter;

fn example1(df: &mut DataFrame) -> PolarsResult<()> {

    let mut file = std::fs::File::create("dataframe.xlsx").unwrap();

    ExcelWriter::new(&mut file).finish(df)

}

// The PolarsXlsxWriter interface. For this simple case it is

// similar to the ExcelWriter interface but it has additional

// options to support more complex use cases.

use polars_excel_writer::PolarsXlsxWriter;

fn example2(df: &DataFrame) -> PolarsResult<()> {

    let mut xlsx_writer = PolarsXlsxWriter::new();

    xlsx_writer.write_dataframe(df)?;

    xlsx_writer.save("dataframe2.xlsx")?;

    Ok(())

}

```

Second output file (same as the first):



## See also

- [Changelog]: Recent additions and fixes.

- [Performance]: Performance comparison with Python based methods.

[Changelog]: https://github.com/jmcnamara/polars_excel_writer/blob/main/CHANGELOG.md

[Performance]: https://docs.rs/polars_excel_writer/latest/polars_excel_writer/#performance