def is_list_of_dec_nums(arg):
    """
    Determines if the argument is a list of decimal numbers

    :param arg: A string to be evaluate as a list of decimal numbers
    :type arg: str

    :return: A boolean indicator True or False
    :rtype:  bool

    :author: Milica Ng
    """
    if not isinstance(arg, list):
        return False
    elif not arg:
        return False
    else:
        for q in arg:
            if not isinstance(q, list):
                return False
    return True
