title: Remove elements from one array if present in another array, keep duplicates - NumPy / Python
body: <p>I have two arrays <code>A</code> (len of 3.8million)  and <code>B</code> (len of 20k).
  For the minimal example, lets take this case:</p>
  
  <pre><code>A = np.array([1,1,2,3,3,3,4,5,6,7,8,8])
  B = np.array([1,2,8])
  </code></pre>
  
  <p>Now I want the resulting array to be:</p>
  
  <pre><code>C = np.array([3,3,3,4,5,6,7])
  </code></pre>
  
  <p><strong>i.e. if any value in <code>B</code> is found in <code>A</code>, remove it from <code>A</code>, if not keep it.</strong> </p>
  
  <p>I would like to know if there is <strong>any way to do it without a <code>for</code> loop</strong> because it is a lengthy array and so it takes long time to loop. </p>