Sort Tuple of chemical and coeff
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/3121979/how-to-sort-list-tuple-of-lists-tuples">How to sort (list/tuple) of lists/tuples?</a>  </p>
</blockquote>



<p>I have a list of tuples that i want to sort in numerical order by the second value in the tuple. A sample of the list im working with is:</p>

<pre><code>[('H2O', '6'), ('O2', '4')]
</code></pre>

<p>so what i would want in this case is:</p>

<pre><code>[('O2','4'),('H2O',6')]
</code></pre>

<p>I know this is really basic I just can seem to figure it out. </p>
