def authenticate(self, **credentials):
        qs = EmailAddress.objects.filter(Q(primary=True) | Q(verified=True))
        try:
            email_address = qs.get(email__iexact=credentials["username"])
        except (EmailAddress.DoesNotExist, KeyError):
            return None
        else:
            user = email_address.user
            try:
                if user.check_password(credentials["password"]):
                    return user
            except __HOLE__:
                return None
dataset/ETHPy150Open pinax/django-user-accounts/account/auth_backends.py/EmailAuthenticationBackend.authenticate