title: python scientific notation with forced leading zero
body: <p>I want to have Python2.7 print out floating point numbers in scientific notation, forced to start with 0. For instance, assume</p>
  
  <pre><code>a=1234567890e12
  print '{:22.16E}'.format(a)
  1.2345678900000000E+21
  </code></pre>
  
  <p>However, I want a print output that looks like:</p>
  
  <pre><code>0.1234567890000000E+22
  </code></pre>
  
  <p>Notice that the exponent is raised by one since the desired output is forced to a leading zero. How can I achieve this?
  Thanks.</p>