title: Python: slicing a multi-dimensional array
body: <p>I'm new to Python and numpy. I've figured out how to slice 1 dimensional sequence: <code>arr[start:end]</code>, and access an element in the array: <code>el = arr[row][col]</code>.</p>
  
  <p>Trying something like <code>slice = arr[0:2][0:2]</code> (where <code>arr</code> is a numpy array) doesn't give me the first 2 rows and columns, but repeats the first 2 rows. What did I just do, and how do I slice along another dimension?</p>