I am using OAuthlib for conducting OAuth flow of Google. It was working well for 4 to 5 months. Suddenly I started getting below error:
File "/home/whitesnow-2/Gaurav/Axonator/AxVirtualEnv/local/lib/python2.7/site-packages/oauthlib/oauth2/rfc6749/parameters.py", 
line 409, in validate_token_parameters raise w Warning: Scope has changed from 
"https://www.googleapis.com/auth/calendar 
https://www.googleapis.com/auth/docs 
https://www.googleapis.com/auth/spreadsheets 
https://www.googleapis.com/auth/drive.file
https://www.googleapis.com/auth/userinfo.email 
https://www.googleapis.com/auth/userinfo.profile" to 
"https://www.googleapis.com/auth/calendar 
https://www.googleapis.com/auth/docs 
https://www.googleapis.com/auth/spreadsheets 
https://www.googleapis.com/auth/drive.file 
https://www.googleapis.com/auth/userinfo.email 
https://www.googleapis.com/auth/userinfo.profile".
Below is the code for generating OAuth authorization URL:
flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
    settings.GOOGLE_OAUTH2_CLIENT_SECRETS_JSON,
    scopes=['https://www.googleapis.com/auth/calendar https://www.googleapis.com/auth/docs https://www.googleapis.com/auth/spreadsheets https://www.googleapis.com/auth/drive.file https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile'],
    redirect_uri=REDIRECT_URI
)
authorization_url, state = flow.authorization_url(
    access_type='offline',
    include_granted_scopes='true',
    prompt='consent'
)
Below is the code for Google OAuth callback:
auth_code = request.GET.get("code")
objectid = request.GET.get("state")
error = request.GET.get("error")
if error == "access_denied":
    return "Access Denied"
else:
    flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
        settings.GOOGLE_OAUTH2_CLIENT_SECRETS_JSON,
        scopes=['https://www.googleapis.com/auth/calendar https://www.googleapis.com/auth/docs https://www.googleapis.com/auth/spreadsheets https://www.googleapis.com/auth/drive.file https://www.googleapis.com/auth/userinfo.email https://www.googleapis.com/auth/userinfo.profile'],
        redirect_uri=REDIRECT_URI
    )
    flow.fetch_token(code=auth_code)
 
     
     
     
     
     
     
     
     
    