title: NumPy array element not getting updated
body: <p>I have a NumPy array as follows:</p>
  
  <pre><code>supp = np.array([['A', '5', '0'], ['B', '3', '0'], ['C', '4', '0'], ['D', '1', '0'], ['E', '2', '0']])
  </code></pre>
  
  <p>Now, I want to update the row[2] as row[1]/6.
  I'm using..</p>
  
  <p><code>for row in supp:
      row[2] = row[1].astype(int) / 6</code></p>
  
  <p>But row[2] seems to remain unaffected..</p>
  
  <pre><code>&gt;&gt;&gt; supp
  array([['A', '5', '0'],
     ['B', '3', '0'],
     ['C', '4', '0'],
     ['D', '1', '0'],
     ['E', '2', '0']],  
    dtype='&lt;U1')
  </code></pre>
  
  <p>I'm using Python 3.5.2 and NumPy 1.11.1.</p>
  
  <p>Any help is appreciated. Thanks in advance</p>