title: How to remove specific elements in a numpy array
body: <p>How can I remove some specific elements from a numpy array? Say I have</p>
  
  <pre><code>import numpy as np
  
  a = np.array([1,2,3,4,5,6,7,8,9])
  </code></pre>
  
  <p>I then want to remove <code>3,4,7</code> from <code>a</code>. All I know is the index of the values (<code>index=[2,3,6]</code>).</p>