title: Delete columns from numpy array depending on a condition on a single cell
body: <p>Above all, sorry for my bad English.</p>
  
  <p>I have this array <code>t</code>: </p>
  
  <pre><code>array([[ 0,  1,  2,  0,  4,  5,  6,  7,  8,  9],
         [ 0, 11,  0, 13,  0, 15,  0, 17, 18,  0]])
  </code></pre>
  
  <p>I would like to delete the columns where the value of second line is null. Here, I would like to delete the columns 0, 2, 4, 6 and 9, to obtain this array:  </p>
  
  <pre><code>array([[  1,   0,   5,   7,  8 ],
         [ 11,  13,  15,  17, 18 ]])
  </code></pre>
  
  <p>I tried with <code>np.sum()</code> but didn't succeed.</p>