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>>> a
{‘a‘: 5, ‘c‘: 3, ‘b‘: 4, ‘e‘: 1, ‘d‘: 2}
>>> sorted(a.items())
[(‘a‘, 5), (‘b‘, 4), (‘c‘, 3), (‘d‘, 2), (‘e‘, 1)]
>>> sorted(aa.items(),key = lambda d:d[1])
[(‘e‘, 1), (‘d‘, 2), (‘c‘, 3), (‘b‘, 4), (‘a‘, 5)]
>>> sorted(aa.items(),key = lambda d:d[1],reverse=True)
[(‘a‘, 5), (‘b‘, 4), (‘c‘, 3), (‘d‘, 2), (‘e‘, 1)]
原文：http://my.oschina.net/jk409/blog/352413