import string


def expanded_chars(ch, cset):
    """
    Add extra characters or ASCII punctuation marks to initial character set

    :param ch: initial character set
    :type ch: str
    :param cset: extra characters
    :type cset: list
    :return: final character set
    :rtype: str
    """
    if len(cset) > 0:
        # Add extra characters
        for i in cset:
            ch += i
    else:
        # Add ASCII punctuation marks
        ch += string.punctuation
    return ch