Helper to define a delimited list of expressions - the delimiter
    defaults to ','. By default, the list elements and delimiters can
    have intervening whitespace, and comments, but this can be
    overridden by passing ``combine=True`` in the constructor. If
    ``combine`` is set to ``True``, the matching tokens are
    returned as a single token string, with the delimiters included;
    otherwise, the matching tokens are returned as a list of tokens,
    with the delimiters suppressed.

    Example::

        delimitedList(Word(alphas)).parseString("aa,bb,cc") # -> ['aa', 'bb', 'cc']
        delimitedList(Word(hexnums), delim=':', combine=True).parseString("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE']

def delimitedList( expr, delim=",", combine=False ):
    """Helper to define a delimited list of expressions - the delimiter
    defaults to ','. By default, the list elements and delimiters can
    have intervening whitespace, and comments, but this can be
    overridden by passing ``combine=True`` in the constructor. If
    ``combine`` is set to ``True``, the matching tokens are
    returned as a single token string, with the delimiters included;
    otherwise, the matching tokens are returned as a list of tokens,
    with the delimiters suppressed.

    Example::

        delimitedList(Word(alphas)).parseString("aa,bb,cc") # -> ['aa', 'bb', 'cc']
        delimitedList(Word(hexnums), delim=':', combine=True).parseString("AA:BB:CC:DD:EE") # -> ['AA:BB:CC:DD:EE']
    """
    dlName = _ustr(expr)+" ["+_ustr(delim)+" "+_ustr(expr)+"]..."
    if combine:
        return Combine( expr + ZeroOrMore( delim + expr ) ).setName(dlName)
    else:
        return ( expr + ZeroOrMore( Suppress( delim ) + expr ) ).setName(dlName)