numpy array slicing unxpected results

Question

I don\'t understand the behavior below. numpy arrays can generally be accessed through indexing, so [:,1] should be equivalent to [:][1], or so I thought. Could someone explain

Answer 1

[:] creates a copy of your list ...

so that is essentially the same as

array[1] == array[:][1]

which correctly returns in this case [4,5,6]

while array[:,1] says return the first column which is indeed [2,5]

eg

a = [
      [1,2,3],
      [4,5,6]
    ]

so as you can see column 0 (a[:,0] )would be [1,4] and column 2(a[:,2]) would be [3,6]

meanwhilea[1] refers to the row 1 (or [4,5,6]) and a[0] would be the 0 row (or [1,2,3])