您还可以创建一个字典，将单词和单词的初始位置映射在一起，然后用它来替换单词和单词的各自位置。
>>> s = 'ASK NOT WHAT YOUR COUNTRY CAN DO FOR YOU ASK WHAT YOU CAN DO FOR YOUR COUNTRY'>>> >>> >>> l = s.split()>>> l['ASK', 'NOT', 'WHAT', 'YOUR', 'COUNTRY', 'CAN', 'DO', 'FOR', 'YOU', 'ASK', 'WHAT', 'YOU', 'CAN', 'DO', 'FOR', 'YOUR', 'COUNTRY']>>> >>> d = dict((s, l.index(s)+1) for s in set(l))>>> d{'DO': 7, 'COUNTRY': 5, 'CAN': 6, 'WHAT': 3, 'ASK': 1, 'YOUR': 4, 'NOT': 2, 'FOR': 8, 'YOU': 9}>>> list(map(lambda s: d[s], l))[1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 3, 9, 6, 7, 8, 4, 5]>>>
