daft.functions.list_flatten#

def list_flatten(list_expr: Expression) -> Expression:
    """Flattens one level of nesting in each list.

    Outer null rows are preserved as null. Null inner lists are skipped while flattening,
    and null leaf values are preserved in the output.

    Args:
        list_expr (List Expression): expression to flatten one level.

    Returns:
        Expression (List Expression): an expression with one fewer level of list nesting.
    """
    return Expression._call_builtin_scalar_fn("list_flatten", list_expr)