title: How to display pandas DataFrame of floats using a format string for columns?
body: <p>I would like to display a pandas dataframe with a given format using <code>print()</code> and the IPython <code>display()</code>. For example:</p>
  
  <pre><code>df = pd.DataFrame([123.4567, 234.5678, 345.6789, 456.7890],
                    index=['foo','bar','baz','quux'],
                    columns=['cost'])
  print df
  
           cost
  foo   123.4567
  bar   234.5678
  baz   345.6789
  quux  456.7890
  </code></pre>
  
  <p>I would like to somehow coerce this into printing</p>
  
  <pre><code>         cost
  foo   $123.46
  bar   $234.57
  baz   $345.68
  quux  $456.79
  </code></pre>
  
  <p>without having to modify the data itself or create a copy, just change the way it is displayed.</p>
  
  <p>How can I do this?</p>