AttributeError when using duckduckgo

[Ridhwanul Haque]

Select the search engine (0 for google / 1 for duckduckgo): 1
What do you want to search for ? >> fossasia
Traceback (most recent call last):
  File "rss-generator.py", line 149, in <module>
    main()
  File "rss-generator.py", line 144, in main
    urls = duckduckgo_search(query)
  File "rss-generator.py", line 104, in duckduckgo_search
    resp = requests.get(SEARCH_ENDPOINT, params = {'q' : query})
  File "/Library/Python/2.7/site-packages/requests/api.py", line 70, in get
    return request('get', url, params=params, **kwargs)
  File "/Library/Python/2.7/site-packages/requests/api.py", line 56, in request
    return session.request(method=method, url=url, **kwargs)
  File "/Library/Python/2.7/site-packages/requests/sessions.py", line 488, in request
    resp = self.send(prep, **send_kwargs)
  File "/Library/Python/2.7/site-packages/requests/sessions.py", line 609, in send
    r = adapter.send(request, **kwargs)
  File "/Library/Python/2.7/site-packages/requests/adapters.py", line 423, in send
    timeout=timeout
  File "/Library/Python/2.7/site-packages/requests/packages/urllib3/connectionpool.py", line 594, in urlopen
    chunked=chunked)
  File "/Library/Python/2.7/site-packages/requests/packages/urllib3/connectionpool.py", line 350, in _make_request
    self._validate_conn(conn)
  File "/Library/Python/2.7/site-packages/requests/packages/urllib3/connectionpool.py", line 835, in _validate_conn
    conn.connect()
  File "/Library/Python/2.7/site-packages/requests/packages/urllib3/connection.py", line 330, in connect
    cert = self.sock.getpeercert()
  File "/Library/Python/2.7/site-packages/requests/packages/urllib3/contrib/pyopenssl.py", line 324, in getpeercert
    'subjectAltName': get_subj_alt_name(x509)
  File "/Library/Python/2.7/site-packages/requests/packages/urllib3/contrib/pyopenssl.py", line 171, in get_subj_alt_name
    ext = cert.extensions.get_extension_for_class(
AttributeError: 'Extensions' object has no attribute 'get_extension_for_class'