title: Individually labeled bars for bar graphs in matplotlib / Python
body: <p>I am trying to create bar graphs of letter frequency in Python. I thought the best way to accomplish this would be matplotlib, but I have been unable to decipher the documentation. Is it possible to label the bars of a matplotlib.pyplot.hist plot with one letter per bar, instead of a numerical axis? I think it must be, but I have not used matplotlib before.</p>
  
  <p>This is the sort of graph I'm after, rendered as text:</p>
  
  <pre><code>|
  |    *
  |    *  *
  | *  *  *
  +----------
    A  B  C
  </code></pre>