title: How do I iterate over a Python dictionary, ordered by values?
body: <p>I've got a dictionary like:</p>
  
  <pre><code>{ 'a': 6, 'b': 1, 'c': 2 }
  </code></pre>
  
  <p>I'd like to iterate over it <em>by value</em>, not by key. In other words:</p>
  
  <pre><code>(b, 1)
  (c, 2)
  (a, 6)
  </code></pre>
  
  <p>What's the most straightforward way?</p>