title: Extract common element from 2 tuples python
body: <p>I have 2 tuples A &amp; B. How can I extract the common elements of A &amp; B to form a new tuple?
  For example:</p>
  
  <pre><code>    A -&gt; (1,'a',(2,'b'),3,'c',4)
      B -&gt; (1,(2,'b'),4,8)
      new_tuple -&gt; (1,(2,'b'),4)
  </code></pre>
  
  <p>Thanks.</p>