# Polars

??? abstract "TLDR"

    ```{ .python .no-check }

    import edsnlp

    stream = edsnlp.data.from_polars(df, converter="omop")

    stream = stream.map_pipeline(nlp)

    res = stream.to_polars(converter="omop")

    # or equivalently

    edsnlp.data.to_polars(stream, converter="omop")

    ```

We provide methods to read and write documents (raw or annotated) from and to Polars DataFrames.

As an example, imagine that we have the following OMOP dataframe (we'll name it `note_df`)

| note_id | note_text                                     | note_datetime |

|--------:|:----------------------------------------------|:--------------|

|       0 | Le patient est admis pour une pneumopathie... | 2021-10-23    |

## Reading from a Polars Dataframe {: #edsnlp.data.polars.from_polars }

::: edsnlp.data.polars.from_polars

    options:

        heading_level: 3

        show_source: false

        show_toc: false

        show_bases: false

## Writing to a Polars DataFrame {: #edsnlp.data.polars.to_polars }

::: edsnlp.data.polars.to_polars

    options:

        heading_level: 3

        show_source: false

        show_toc: false

        show_bases: false