lakehouse_csv_read

Public callable

Read a CSV file from a Fabric lakehouse Files path.

This reads from the lakehouse Files/ area using the ABFSS root stored in a Housepath. In the Source step, use it for raw file ingestion before standardisation or conversion to Delta tables.

Parameters:

Name	Type	Description	Default
lh	Housepath	Lakehouse path object returned by get_path.	required
relative_path	str	Path to the CSV file or folder under the lakehouse root, for example "Files/raw/orders.csv" or "Files/raw/orders/".	required
spark_session	object	Spark session to use. If omitted, the helper uses the notebook global spark.	None
header	bool	Whether the first row of the CSV file contains column names.	True

Returns:

Type	Description
DataFrame	Spark DataFrame loaded from the CSV path.

Raises:

Type	Description
ValueError	If lh.root or relative_path is missing.
RuntimeError	If no Spark session is available.

Examples:

>>> lh_source = get_path("Sandbox", "Source", config=CONFIG)
>>> df = lakehouse_csv_read(lh_source, "Files/raw/orders.csv")

Source code in src/fabricops_kit/fabric_io.py

def lakehouse_csv_read(lh, relative_path, spark_session=None, header=True):
    """Read a CSV file from a Fabric lakehouse Files path.

    This reads from the lakehouse `Files/` area using the ABFSS root stored in
    a `Housepath`. In the Source step, use it for raw file ingestion before
    standardisation or conversion to Delta tables.

    Parameters
    ----------
    lh : Housepath
        Lakehouse path object returned by `get_path`.
    relative_path : str
        Path to the CSV file or folder under the lakehouse root, for example
        `"Files/raw/orders.csv"` or `"Files/raw/orders/"`.
    spark_session : object, optional
        Spark session to use. If omitted, the helper uses the notebook global
        `spark`.
    header : bool, default True
        Whether the first row of the CSV file contains column names.

    Returns
    -------
    pyspark.sql.DataFrame
        Spark DataFrame loaded from the CSV path.

    Raises
    ------
    ValueError
        If `lh.root` or `relative_path` is missing.
    RuntimeError
        If no Spark session is available.

    Examples
    --------
    >>> lh_source = get_path("Sandbox", "Source", config=CONFIG)
    >>> df = lakehouse_csv_read(lh_source, "Files/raw/orders.csv")
    """
    if not getattr(lh, "root", None):
        raise ValueError("lh.root is required.")
    if not relative_path:
        raise ValueError("relative_path is required.")

    spark_obj = _get_spark(spark_session)
    path = f"{lh.root.rstrip('/')}/{relative_path.lstrip('/')}"
    return spark_obj.read.option("header", header).csv(path)