在 python 中索引多维数组

Question

I have an array like below and I want to keep only the 3rd element for each row.

Input

array(['a', 'b', 'c'], ['a1', 'b1', 'c1'],........['an', 'bn', 'cn'])

Expected output

array('c', 'c1', ...... 'cn')

I tried it using a for loop but it is taking too long. Is there a faster way to do this? Can someone please help?

Answer 1

Assuming that you mean a list when you mention an array .

This would be the code:

>>> my_list = [['a', 'b', 'c'], ['a1', 'b1', 'c1'], ['an', 'bn', 'cn']]
>>> [x[2] for x in my_list]
['c', 'c1', 'cn']
>>> 

Answer 2

The code

[x[2] for x in my_list]

pointed out by Gab is correct, however if you are making use of an numpy array, this will be probably more efficent:

x[:,2]