numpy subarray

1>>> a
2array([[1, 2, 3],
3       [4, 5, 6],
4       [7, 8, 9]])
5>>> a[:2,:2]
6array([[1, 2],
7       [4, 5]])

1>>> a
2array([[1, 2, 3],
3       [4, 5, 6],
4       [7, 8, 9]])
5
6>>> a[:2,:2]
7array([[1, 2],
8       [4, 5]])
9