Access Google Analytics data with rauth in Python

auth.py

import os
import json
from flask import Flask, request, redirect, jsonify
from rauth import OAuth2Service

GOOGLE_AUTH_URI = 'https://accounts.google.com/o/oauth2/auth'
GOOGLE_REVOKE_URI = 'https://accounts.google.com/o/oauth2/revoke'
GOOGLE_TOKEN_URI = 'https://accounts.google.com/o/oauth2/token'
GOOGLE_ANALYTICS_API_ENDPOINT = 'https://www.googleapis.com/analytics/v3/'

google = OAuth2Service(
    name='google',
    client_id=os.environ['GOOGLE_ANALYTICS_CLIENT_ID'],
    client_secret=os.environ['GOOGLE_ANALYTICS_CLIENT_SECRET'],
    access_token_url=GOOGLE_TOKEN_URI,
    authorize_url=GOOGLE_AUTH_URI,
    base_url=GOOGLE_ANALYTICS_API_ENDPOINT)

REDIRECT_URI = 'http://localhost:5000/auth/google/callback'

app = Flask(__name__)

@app.route('/auth/google')
def authorization():
    params = {
        'scope': 'https://www.googleapis.com/auth/analytics.readonly',
        'access_type': 'offline', 
        'response_type': 'code',
        'redirect_uri': REDIRECT_URI, 
    }
    authorize_url = google.get_authorize_url(**params)
    return redirect(authorize_url)

@app.route('/auth/google/callback')
def callback():
    credentials = google.get_access_token(data={
        'code': request.args['code'],
        'grant_type': 'authorization_code', 
        'redirect_uri': REDIRECT_URI
    }, decoder=json.loads)


    """
    # or instead, create a session right away
    session = google.get_auth_session(data={
        'code': request.args['code'],
        'grant_type': 'authorization_code', 
        'redirect_uri': REDIRECT_URI
    })

    print session.get('management/accountSummaries').json()
    """

    return jsonify(refresh_token=credentials)

app.run(debug=True)