# 如何按值对 Python 字典进行排序# (== get a representation sorted by value)>>> xs = {'a': 4, 'b': 3, 'c': 2, 'd': 1}>>> sorted(xs.items(), key=lambda x: x[1])[('d', 1), ('c', 2), ('b', 3), ('a', 4)]# Or:>>> import operator>>> sorted(xs.items(), key=operator.itemgetter(1))[('d', 1), ('c', 2), ('b', 3), ('a', 4)]