def filter_output_columns(output_columns, filter_columns):
    """
    Filters a list of columns and only keeps those present in a list of allowed columns.
    Returns original list of columns if no allowed columns specified.

    :param output_columns: a column list to filter
    :param filter_columns: a list of allowed columns
    :return: a filtered list of columns
    """
    if filter_columns:
        return [column for column in output_columns if column in filter_columns]

    return output_columns