title: Python: how to find common values in three lists
body: <p>I try to find common list of values for three different lists:</p>
  
  <pre><code>a = [1,2,3,4]
  b = [2,3,4,5]
  c = [3,4,5,6]
  </code></pre>
  
  <p>of course naturally I try to use the <code>and</code> operator however that way I just get the value of last <code>list</code> in expression:</p>
  
  <pre><code>&gt;&gt; a and b and c
  out: [3,4,5,6]
  </code></pre>
  
  <p>Is any short way to find the common values list:</p>
  
  <pre><code>[3,4]
  </code></pre>
  
  <p>Br</p>