title: Find the non-intersecting values of two arrays
body: <p>If I have two numpy arrays and want to find the the non-intersecting values, how do I do it?</p>
  
  <p>Here's a short example of what I can't figure out.</p>
  
  <pre><code>a = ['Brian', 'Steve', 'Andrew', 'Craig']
  b = ['Andrew','Steve']
  </code></pre>
  
  <p>I want to find the non-intersecting values.  In this case I want my output to be:</p>
  
  <pre><code>['Brian','Craig']
  </code></pre>
  
  <p>The opposite of what I want is done with this:</p>
  
  <pre><code>c=np.intersect1d(a,b)
  </code></pre>
  
  <p>which returns</p>
  
  <pre><code>['Andrew' 'Steve']
  </code></pre>