def _process_df_index_names(data):
    """Create a list containing the index names of a pandas.DataFrame

    If the index does not have names, assign them as index0, index1, etc.

    Args:
        data (pandas.DataFrame): The data set to process index names for

    Returns:
        list: A list of index names for the in put data set
    """
    index_names = list(data.index.names)
    if index_names[0]:
        return index_names
    else:
        num_cols = len(index_names)
        return ['index' + str(i) for i in range(num_cols)]