title: Convert elements of a list into binary
body: <p>Suppose I have a list:</p>
  
  <pre><code>lst = [0, 1, 0, 0]
  </code></pre>
  
  <p>How can I make python interpret this list as a binary number 0100 so that <code>2*(0100)</code>  gives me <code>01000</code>?</p>
  
  <p>The only way that I can think of is to first make a function that converts the "binary" elements to corresponding integers(to base 10) and then use bin() function..</p>
  
  <p>Is there a better way?</p>