AttributeError: 'SelectQuery' object has no attribute 'is_active'
As the error suggests, user = User.select().where(User.email == resp.email) gives you back a SelectQuery, not an instance of User. You'll want to include an additional method call to actually fetch the record, something like .first(). first will return either an instance of User or None.
This would allow you to slightly adjust your code:
user = User.select().where(User.email == resp.email).first()if not user: # or if user is None: nickname = resp.nickname ...