oAuth 2.0 in Python for Google Analytics

I'm trying to access users Google Analytics data on a Python script. I have set up a landing page, and linked the HelloAnalytics.html page, now when the user clicks on that link it will be redirected to a google page where it is asked if he wants to share his Google Analytics Data with my App, so that looks great! If I'm right now my app has access to that user's data. Next in the "Google guide" I have: The OAuth 2.0 server authenticates the user and obtains consent from the user for your application to access the user's data. Next, Google's OAuth 2.0 server redirects the user back to your application along with a single-use authorization code. Your application exchanges this authorization code for an access token. Now my question is, how do I exchange this authorization code for an access token? Thanks