如何在Python中对以下结构排序

Question

我有下面的Python列表。你知道吗

[[53.60495722746216, 'Percent Cats'],
 [45.298311033121294, 'Percent Dogs'],
 [1.0967317394165388, 'Percent Horses']]

现在我想要百分比最高的动物。在这种情况下，它将是Cats。你知道吗

如何对这个结构进行排序以获取值？你知道吗

Answer 1

a = [[53.60495722746216, 'Percent Cats'], [45.298311033121294, 'Percent Dogs'], [1.0967317394165388, 'Percent Horses']]
print sorted(a, key=lambda x:x[0], reverse=True)[0]

Answer 2

如果只需要得到一个值，则不需要对列表进行排序。使用内置的^{}函数和这样的自定义排序函数

In [3]: max(l, key=lambda x: x[0])[1] # compare first elements of inner lists
Out[3]: 'Percent Cats'

甚至

In [4]: max(l)[1] # compare lists directly
Out[4]: 'Percent Cats'

后面的代码也可以工作，因为sequence objects may be compared to other objects with the same sequence type：

The comparison uses lexicographical ordering: first the first two items are compared, and if they differ this determines the outcome of the comparison; if they are equal, the next two items are compared, and so on, until either sequence is exhausted. If all items of two sequences compare equal, the sequences are considered equal.