Add proxy credential to google-calendar connection - python-3.x

Question

Im trying to get event from google calendar by python, Im using google quickstart example, I get browser opening to confirm credential but on my pc I get following error:
Traceback (most recent call last):
File "C:\Programs\Python\Python35-32\lib\site-packages\httplib2\__init__.py", line 987, in _conn_request
conn.connect()
File "C:\Programs\Python\Python35-32\lib\http\client.py", line 1252, in connect
super().connect()
File "C:\Programs\Python\Python35-32\lib\http\client.py", line 849, in connect
(self.host,self.port), self.timeout, self.source_address)
File "C:\Programs\Python\Python35-32\lib\socket.py", line 693, in create_connection
for res in getaddrinfo(host, port, 0, SOCK_STREAM):
File "C:\Programs\Python\Python35-32\lib\socket.py", line 732, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno 11002] getaddrinfo failed
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\Users\myUser\Documents\Python_projects\quickstart.py", line 79, in <module>
main()
File "C:\Users\myUser\Documents\Python_projects\quickstart.py", line 60, in main
credentials = get_credentials()
File "C:\Users\myUser\Documents\Python_projects\quickstart.py", line 48, in get_credentials
credentials = tools.run_flow(flow, store, flags)
File "C:\Programs\Python\Python35-32\lib\site-packages\oauth2client\util.py", line 137, in positional_wrapper
return wrapped(*args, **kwargs)
File "C:\Programs\Python\Python35-32\lib\site-packages\oauth2client\tools.py", line 243, in run_flow
credential = flow.step2_exchange(code, http=http)
File "C:\Programs\Python\Python35-32\lib\site-packages\oauth2client\util.py", line 137, in positional_wrapper
return wrapped(*args, **kwargs)
File "C:\Programs\Python\Python35-32\lib\site-packages\oauth2client\client.py", line 2027, in step2_exchange
headers=headers)
File "C:\Programs\Python\Python35-32\lib\site-packages\httplib2\__init__.py", line 1314, in request
(response, content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey)
File "C:\Programs\Python\Python35-32\lib\site-packages\httplib2\__init__.py", line 1064, in _request
(response, content) = self._conn_request(conn, request_uri, method, body, headers)
File "C:\Programs\Python\Python35-32\lib\site-packages\httplib2\__init__.py", line 994, in _conn_request
raise ServerNotFoundError("Unable to find the server at %s" % conn.host)
httplib2.ServerNotFoundError: Unable to find the server at accounts.google.com
I suppose the problem is due to my proxy but where can I set proxy setting?
Thanks in advance