[BangPypers] GAE python oauth login

[VIMAL K]

I want to implement google oauth login service to my application. Can
anyone help me with it. I have written func, please help me to continue
with it.
The code i've written:

def google_login(self):
        flow = OAuth2WebServerFlow(
            client_id='client-code',
            client_secret='client secret',
            redirect_uri='--url--',
            scope='',
            user_agent='')
        authorize_url = flow.step1_get_authorize_url()
        self.redirect(authorize_url)
        credentials = flow.step2_exchange(self.request.params)
        storage = Storage('a_credentials_file')
        storage.put(credentials)
        http = httplib2.Http()
        https = credentials.authorize(http)
        service = build('calendar', 'v3', http=http)
        credentials = storage.get()