title: Get common characters from strings
body: <p>I'm looking for the way of comparing two strings and being able to get back, as separate strings:</p>
  
  <ul>
  <li>All the common characters,</li>
  <li>The uncommon characters, (all characters but without the common ones)</li>
  <li>Characters that are unique to one string.</li>
  </ul>
  
  <p>Example:</p>
  
  <pre><code>A = "123 ABC"
  B = "135 AZ"
  
  thingamajigger(A, B)  # would give all these:
  
  intersect = "13 A"  # (includes space)
  exclusion = "2BCZ5"
  a_minus_b = "2BC"
  b_minus_a = "5Z"
  </code></pre>
  
  <p><code>a_minus_b</code> is quite simple... but if there's one of those fancy one-liner ways to pull it off, then I'm open.</p>
  
  <pre><code>for i in B:
      A = A.replace(i, "")
  </code></pre>
  
  <p>It's a bit like boolean operations on strings.</p>