def get_num_words(data_frame, tokens_col):
    """Get the maximum token found within a column.

    Args:
        data_frame: The frame from which the max value should be found.
        tokens_col: The string column name to be returned.
    Returns:
        Maximum token found within the given column.
    """
    return max(data_frame[tokens_col].apply(lambda x: max(x) if len(x) > 0 else 0))