python newbie. I can't understand the following about numpy arrays: x = np.array([[0, 1],[2,3],[4,5],[6,7]]) x array([[0, 1], [2, 3], [4, 5], [6, 7]]) x.shape (4, 2) y = x[:,0] y array([0, 2, 4, 6]) y.shape (4,) Why is the shape for y reported as (4,) ? I expected it to be a (4,1) array. thanks in advance