title: Does urllib.request.urlopen(url) use cache?
body: <p>I have this long list of URL that I need to check response code of, where the links are repeated 2-3 times. I have written this script to check the response code of each URL. </p>
  
  <pre><code>connection =urllib.request.urlopen(url)
  return connection.getcode()
  </code></pre>
  
  <p>The URL comes in XML in this format </p>
  
  <pre><code> &lt; entry key="something" &gt; url&lt;/entry&gt;
   &lt; entry key="somethingelse" &gt; url&lt;/entry&gt; 
  </code></pre>
  
  <p>and I have to associate the response code with the attribute Key so I don't want to use a SET.</p>
  
  <p>Now I definitely don't want to make more than 1 request for the same URL so I was searching whether urlopen uses cache or not but didn't find a conclusive answer. If not what other technique can be used for this purpose.</p>