title: Cannot connect to proxy error on requests.get() or requests.post() in python
body: <p>I have two URLs to fetch data from. Using my code, the first URL is working, whereas the second URL is giving <code>ProxyError</code>.</p>
  
  <p>I am using <code>requests</code> library in Python 3 and tried searching the problem in Google and here, but with no success.</p>
  
  <p>My code snippet is:</p>
  
  <pre><code>    import requests
  
      proxies = {
        'http': 'http://user:pass@xxx.xxx.xxx.xxx:xxxx',
        'https': 'http://user:pass@xxx.xxx.xxx.xxx:xxxx',
      }
  
      url1 = 'https://en.oxforddictionaries.com/definition/act'
      url2 = 'https://dictionary.cambridge.org/dictionary/english/act'
  
      r1 = requests.get(url1, proxies=proxies)
      r2 = requests.get(url2, proxies=proxies)
  </code></pre>
  
  <p><code>url1</code> works fine, but <code>url2</code> gives following error:</p>
  
  <pre><code>    ProxyError: HTTPSConnectionPool(host='dictionary.cambridge.org', port=443): Max retries exceeded with url: /dictionary/english/act (Caused by ProxyError('Cannot connect to proxy.', RemoteDisconnected('Remote end closed connection without response',)))
  </code></pre>
  
  <p>Same happens on using <code>request.post()</code></p>
  
  <ol>
  <li><p>Please explain me why this is happening, and is there any difference between the handshaking of both the URLs?</p></li>
  <li><p><code>urllib.request.urlopen</code> is working fine, so I am explicity looking for answers using <code>requests</code></p></li>
  </ol>