django social auth get wrong access_token from google oauth2
all right. 
it turns out to be a problem of scope . 
the sample code set a default scope to mail.google.com while social-auth only have a default scope to read user information. 
the difference in length of token must be related to the scope
I am integrating google oauth2 to my website using django social auth. 
The problem is that with django social auth , I get an access_token like 

ya29.2QCqpS-uKGXMNOP8yZnN6Z-F5LfVnyd7jwa8TaLP43nTEp2NUPB_p7Hi

While with the code sample from google code
the access token is like :

ya29.2QCVXKc7XSNR3QxqRVAi0Z8Uz6mvolDGpezbZ9_r_oq7CXt01WvE9oUb90HXaynOLE4J8PjA5pzYDB

The first one does not work while the second one works fine 
does anyone have any idea on this ?