title: ImportError: No module named itertools
body: <p>I am trying to run this script:</p>
  
  <pre><code>    python schema2.py
  Traceback (most recent call last):
    File "schema2.py", line 1, in &lt;module&gt;
      import itertools
  ImportError: No module named itertools
  </code></pre>
  
  <p>and I am continuosly getting this error. my python version is 2.7.12...any idea why?</p>