occurences_in_radius_distance.py

class OccurencesInRadiusDistance(generics.ListAPIView):
    """API endpoint that returns all objects in a radius given a set of coordinates in url_params."""

    serializer_class = MyCustomSerializer
    permissions_classes = (permissions.IsAuthenticatedOrReadOnly, )

    def get_queryset(self):
        """This queryset returns all objects in a specified radius distance. We use PostGIS to create POINT objects and create the query.
            How to use postGIS on Django: https://docs.djangoproject.com/en/dev/ref/contrib/gis/install/postgis/
            
            Obs: The model must have a models.PointField field with point from its latitude and longitude
        """
        radius_distance = 5
        lon = self.request.query_params.get('lon', None)
        lat = self.request.query_params.get('lat', None)
        queryset = MyCustomModel.objects.all()

        if lon and lat:
            point = 'POINT({} {})'.format(lon, lat)
            pnt = GEOSGeometry(point)
            queryset = MyCustomModel.objects.filter(address_point__distance_lte=(pnt, D(km=radius_distance)))
            return queryset
        return queryset