title: How does Python generate this result due to circular reference?
body: <p>I'm reading on Python variables, objects and references, and stumbled on the notion of circular reference. The book presents an example:</p>
  <pre><code>L = [1,2]
  L.append(L)
  L
  </code></pre>
  <p>I tried on Python, the result is:</p>
  <pre><code>[1,2, [...]]
  </code></pre>
  <p>I kind of understand circular reference but not sure how Python generates this result, I mean, where it starts, where it goes on and how it ends up with this list. Very much appreciate if any one could help explain this.</p>