python operator.itemgetter

import operator

a = [("b",2),("a",1),("c",0)]

b = sorted(a,key=operator.itemgetter(1)) # 使用元组的第二个元素进行排序
c = sorted(a,key=operator.itemgetter(1),reverse=True)

print (a)
print (b)
print (c)

结果：

[('b', 2), ('a', 1), ('c', 0)]
[('c', 0), ('a', 1), ('b', 2)]
[('b', 2), ('a', 1), ('c', 0)]