title: Problems getting JSON with urllib.URLopener
body: <p>I have problems getting JSON with <code>urllib.URLopener</code> even when I can see it in my navigator.</p>
  
  <p><strong>CODE:</strong></p>
  
  <pre><code>import urllib
  import json
  json_obj = urllib.URLopener()
  json_obj.retrieve(json_adress, self.home + "/.cache/program/file.json")
  </code></pre>
  
  <p><strong>ERROR:</strong></p>
  
  <pre><code>('http error', 404, 'Not Found', &lt;httplib.HTTPMessage instance at 0x7fa73d9b3a28&gt;)
  </code></pre>
  
  <p>5 minutes later I can get it, but another address fails. What is happening?</p>
  
  <p>For example, the URL of the JSON file is:</p>
  
  <pre><code>http://webservices.francetelevisions.fr/tools/getInfosOeuvre/v2/?idDiffusion=135842229&amp;catalogue=Pluzz&amp;callback=webserviceCallback_135842229
  </code></pre>