Sunsetting Python 2
Really difficult to track are issues caused by things like the map function now returning an iterator object. I.e. the content of the iterator is empty on second use.<p><pre><code>  Python 3.4.3 (default, Oct 14 2015, 20:28:29) 
  [GCC 4.8.4] on linux
  Type "help", "copyright", "credits" or "license" for more information.
  >>> x = map(lambda v: v + 1, [1, 2, 3])
  >>> list(x)
  [2, 3, 4]
  >>> list(x)
  []</code></pre>