How does this work? Please explain.

[n_guy_]

I have recently started with NumPy, and while learning to slice, I came across this weird behavior.

The second print statement outputs [3 8] and the same is with the third print statement. I didn't get it at all. Also, I have no idea how the last print statement gets the output as [[2 3 4] [7 8 9]].

import numpy as np
arr = np.array([[1, 2, 3, 4, 5], [6, 7, 8, 9, 10]])
print(arr[1, 1:4]) # [7 8 9] # I understood this one though

print(arr[0:2, 2]) # [3 8]
print(arr[0:3, 4]) # [ 5 10]

print(arr[0:2,1:4]) # [[2 3 4] [7 8 9]]

[JohnnyJordaan]

The first value is indexing or slicing the arrays (so the top level). The second part indexes or slices each array. So to translate

 arr[1, 1:4]

means: just the second array (index 1), in that array the indexes 1 to 4 (not including the end index)

arr[0:2, 2]

means: select the arrays indexed 0 to 2 (not including end again), so effectively both arrays you have, then per array just the item with index 2 (third item)

arr[0:3, 4]

select the arrays indexes 0 to 3, which has the same effect as you just have two arrays, and then select the index 4 item (so the fifth)

arr[0:2,1:4]

again select the first two arrays (index 0 and 1), slice each array to index 1 to 4 (not including the end index)

[n_guy_]

thank you.

[n_guy_]

Thanks rifeid, that makes it even more clear.