无法索引此 numpy 数组 [Python]

Question

So the array is called lines and looks like this:

All I would like to do is index the 3rd column (all values in the rows). Which I thought would just be like this:

lines[:,2] which gives me this error:

IndexError: index 1 is out of bounds for axis 1 with size 1

So when I check the shape lines.shape I get:

(1, 4)

I'm not sure what the issue is?

Answer 1

You used nested list so If you want to get list

You can get first three row by

lines[:3]

If you want only the third row

lines[2][0]

Also, I created an array similar to yours.

x = np.array([[[1,2,3,4]],
             [[5,6,7,8]],
             [[5,6,7,8]],
             [[5,6,7,8]],
             [[5,6,7,8]]])

and

x.shape => (5, 1, 4)

You have something wrong with the shape.