有没有更快的方法来提取列表中的元素？

Question

suppose I have the list E = [1,2,1,4,5,4] , and I want to extract the 2nd, 3rd and 5th element in E , let A = [2,3,5] , is there a faster way I can get the elements? I tried E[A] but it doesn't work. Thanks!

Answer 1

Try this:

E = [1,2,1,4,5,4]
A = [2,3,5]

nE = [ E[a] for a in A ]

Answer 2

The itemgetter function from the operator module may do what you want:

from operator import itemgetter
E = [1,2,1,4,5,4]
A = [2,3,5]
print(itemgetter(*A)(E))

But you might need a different class altogether depending on the specifics of your speed needs.