def __get_author_last_name(author):
        """
        Take a string of author(s), get the first author name, then get the first authors last name only.

        :param str author: Author(s)
        :return str _author: First author's last name
        """
        _author = ""
        if isinstance(author, str):
            try:
                # example:   'Ahmed, Moinuddin and Anchukaitis, Kevin J and ...'
                # If this is a list of authors, try to split it and just get the first author.
                if " and " in author:
                    _author = author.split(" and ")[0]
                # 'Ahmed, Moinuddin; Anchukaitis, Kevin J;  ...'
                elif ";" in author:
                    _author = author.split(";")[0]
            except Exception:
                _author = ""
            try:
                # example :  'Ahmed Moinuddin,  Anchukaitis Kevin J,  ...'
                _author = author.replace(" ", "")
                if "," in author:
                    _author = author.split(",")[0]
            except Exception:
                _author = ""
        elif isinstance(author, list):
            try:
                # example:  [{'name': 'Ahmed, Moinuddin'}, {'name': 'Anchukaitis, Kevin J.'}, ..]
                # just get the last name of the first author. this could get too long.
                _author = author[0]["name"].split(",")[0]
            except Exception as e:
                _author = ""

        return _author
Take a string of author(s), get the first author name, then get the first authors last name only.

        :param str author: Author(s)
        :return str _author: First author's last name