title: efficient way of removing None's from numpy array
body: <p>Is there an efficient way to remove Nones from numpy arrays and resize the array to its new size?</p>
  
  <p>For example, how would you remove the None from this frame without iterating through it in python.  I can easily iterate through it but was working on an api call that would be potentially called many times.  </p>
  
  <pre><code>a = np.array([1,45,23,23,1234,3432,-1232,-34,233,None])
  </code></pre>