managers.py 文件源码

def filter_by_location(self, distance, lat, lon):
        min_lat, max_lat, min_lon, max_lon = self.bounding_coordinates(distance, lat, lon)
        artists_within_bounds = self.filter(
            lat__gte=min_lat,
            lat__lte=max_lat,
            lon__gte=min_lon,
            lon__lte=max_lon
        )

        nearby_artist_ids = []
        for artist in artists_within_bounds:
            if calc_distance((lat, lon,), (artist.lat, artist.lon,)).miles <= distance:
                nearby_artist_ids.append(artist.id)
        return self.filter(id__in=nearby_artist_ids)

    # TODO(lucas): Use annotations as much as possible to improve performance