title: Asterisk in function call
body: <p>I'm using itertools.chain to "flatten" a list of lists in this fashion:</p>
  
  <pre><code>uniqueCrossTabs = list(itertools.chain(*uniqueCrossTabs))
  </code></pre>
  
  <p>how is this different than saying:</p>
  
  <pre><code>uniqueCrossTabs = list(itertools.chain(uniqueCrossTabs))
  </code></pre>