title: Python subtract list of strings from another list of strings
body: <p>I would like to subtract a list of strings where there are more than one element of the same (so set operations are not useful). </p>
  
  <p>Example:</p>
  
  <pre><code>C = ['A','B','B']
  D = ['B']
  </code></pre>
  
  <p>I would like a way to do so that:</p>
  
  <pre><code>C - D = ['A','B']
  </code></pre>
  
  <p>Example of what I got so far, but does not give the result I want</p>
  
  <pre><code>[item for item in C if item not in D]
  returns: ['A']
  </code></pre>
  
  <p><b>Here is a more elaborated example to show what I want:</b></p>
  
  <pre><code>C = ['A','B', 'A','A','B','B','B','X','B']
  
  D = ['A','B','B','Y']
  </code></pre>
  
  <p>This is what I want the result to be:</p>
  
  <pre><code>C - D = ['A', 'A', 'B', 'B','B','X']
  </code></pre>