title: Display a decimal in scientific notation
body: <p>How can I display <code>Decimal('40800000000.00000000000000')</code> as <code>'4.08E+10'</code>?</p>
  <p>I've tried this:</p>
  <pre><code>&gt;&gt;&gt; '%E' % Decimal('40800000000.00000000000000')
  '4.080000E+10'
  </code></pre>
  <p>But it has those extra 0's.</p>