docs/source/user-guide/io/csv.rst

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.. _io_csv:

CSV
===

Reading a csv is very straightforward with :py:func:`~datafusion.context.SessionContext.read_csv`

.. code-block:: python


    from datafusion import SessionContext

    ctx = SessionContext()
    df = ctx.read_csv("file.csv")

An alternative is to use :py:func:`~datafusion.context.SessionContext.register_csv`

.. code-block:: python

    ctx.register_csv("file", "file.csv")
    df = ctx.table("file")

If you require additional control over how to read the CSV file, you can use
:py:class:`~datafusion.options.CsvReadOptions` to set a variety of options.

.. code-block:: python

    from datafusion import CsvReadOptions
    options = (
        CsvReadOptions()
        .with_has_header(True) # File contains a header row
        .with_delimiter(";") # Use ; as the delimiter instead of ,
        .with_comment("#")  # Skip lines starting with #
        .with_escape("\\")  # Escape character
        .with_null_regex(r"^(null|NULL|N/A)$")  # Treat these as NULL
        .with_truncated_rows(True) # Allow rows to have incomplete columns
        .with_file_compression_type("gzip")  # Read gzipped CSV
        .with_file_extension(".gz") # File extension other than .csv
    )
    df = ctx.read_csv("data.csv.gz", options=options)

Details for all CSV reading options can be found on the
`DataFusion documentation site <https://datafusion.apache.org/library-user-guide/custom-table-providers.html>`_.