title: Python: understanding (None for g in g if (yield from g) and False)
body: <p>James Powell, in his short description for an upcoming presentation, says he is the proud inventor of one of the gnarliest Python one-liners:</p>
  
  <pre><code>(None for g in g if (yield from g) and False)
  </code></pre>
  
  <p>I am trying to figure out this generator, and since I live with Python 2.7.x, I'm also tripping over the <code>(yield from g)</code> expression.</p>
  
  <p>How do I read this, and what would be the python 2.7.x analog?</p>
  
  <hr>
  
  <p>What a great discussion below! I want to check if I have this correct in the main.</p>
  
  <pre><code>&gt;&gt;&gt; l = [10, 11, iter(xrange(5)), 12, 13]
  &gt;&gt;&gt; g = iter(l)
  &gt;&gt;&gt; flat_g = (None for g in g if (yield from g) and False)
  &gt;&gt;&gt; list(flat_g)
  [10, 11, 0, 1, 2, 3, 4, 12, 13]
  </code></pre>
  
  <p>Is that about right?</p>