title: serializing result of a queryset with json raises error:
body: <p>I was trying to serialize a Python list but got errors that it's not serializable.  Is there a limitation on serializing a list of Long integers?</p>
  
  <pre><code>&gt;&gt;&gt; ids=p.values_list('id',flat=True)
  &gt;&gt;&gt; ids
  [335L, 468L, 481L, 542L, 559L, 567L, 609L]
  &gt;&gt;&gt; import simplejson as json
  &gt;&gt;&gt; str=json.dumps(ids)
  
  Traceback (most recent call last):
     File "&lt;console&gt;", line 1, in &lt;module&gt;
    File "C:\Program Files\Google\google_appengine\lib\simplejson\simplejson\__ini
  t__.py", line 265, in dumps
      return _default_encoder.encode(obj)
    File "C:\Program Files\Google\google_appengine\lib\simplejson\simplejson\encod
  er.py", line 216, in encode
      chunks = list(chunks)
    File "C:\Program Files\Google\google_appengine\lib\simplejson\simplejson\encod
  er.py", line 495, in _iterencode
      o = _default(o)
    File "C:\Program Files\Google\google_appengine\lib\simplejson\simplejson\encod
  er.py", line 190, in default
      raise TypeError(repr(o) + " is not JSON serializable")
  TypeError: [335L, 468L, 481L, 542L, 559L, 567L, 609L] is not JSON serializable
  &gt;&gt;&gt;
  </code></pre>