title: Plotting histograms against classes in pandas / matplotlib
body: <p>Is there a idiomatic way to plot the histogram of a feature for two classes?
  In pandas, I basically want</p>
  
  <pre><code>df.feature[df.class == 0].hist()
  df.feature[df.class == 1].hist()
  </code></pre>
  
  <p>To be in the same plot. I could do</p>
  
  <pre><code>df.feature.hist(by=df.class)
  </code></pre>
  
  <p>but that gives me two separate plots.</p>
  
  <p>This seems to be a common task so I would imagine there to be an idiomatic way to do this. Of course I could manipulate the histograms manually to fit next to each other but usually pandas does that quite nicely.</p>
  
  <p>Basically I want this matplotlib example in one line of pandas: <a href="http://matplotlib.org/examples/pylab_examples/barchart_demo.html">http://matplotlib.org/examples/pylab_examples/barchart_demo.html</a></p>
  
  <p>I thought I was missing something, but maybe it is not possible (yet).</p>