Thank you. I've tried setting debug to false but it causes a problem with the template. Do you know how I set it to false without affecting the design? I've tried a couple of ways as suggested on SO but all seem to return a server error.
For the case when the user isn't willing to give access to his/her twitter account.
The error returned is KeyError, since you are trying to access :
user = User.objects.get(username = authorized_tokens['screen_name'])
I see that you have put a try, except blocks. But you are not catching the KeyError exception. You are only making an exception when the user doesn't exist.
you should add a block : except KeyError. And figure out the logic for this particular case. (probably just redirecting the user to the home page)