models.py 文件源码

def get_current(self, request=None):
        """
        Returns the current Site based on the SITE_ID in the project's settings.
        If SITE_ID isn't defined, it returns the site with domain matching
        request.get_host(). The ``Site`` object is cached the first time it's
        retrieved from the database.
        """
        from django.conf import settings
        if getattr(settings, 'SITE_ID', ''):
            site_id = settings.SITE_ID
            return self._get_site_by_id(site_id)
        elif request:
            return self._get_site_by_request(request)

        raise ImproperlyConfigured(
            "You're using the Django \"sites framework\" without having "
            "set the SITE_ID setting. Create a site in your database and "
            "set the SITE_ID setting or pass a request to "
            "Site.objects.get_current() to fix this error."
        )