我按照文檔了解如何在下面的 manytomanyfield 中刪除一個(gè)項(xiàng)目，但它似乎不起作用，我收到了一個(gè)屬性錯(cuò)誤。remove 方法在沒(méi)有中間模型的情況下工作得很好。models.py   class Song (models.Model):        author=models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, default=1)        timestamp= models.DateTimeField(auto_now_add=True, editable=False)        songname = models.CharField(max_length=500, null=False, blank=False)        tags = TaggableManager()        def __str__(self):            return self.songname    class Playlist (models.Model):        name = models.CharField(max_length=150, null=False, blank=False)        author = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, default=1)        song = models.ManyToManyField(Song, through='Playlist_Activity')    class Playlist_Activity(models.Model):        song= models.ForeignKey(Song, on_delete=models.CASCADE)        playlist= models.ForeignKey(Playlist, on_delete=models.CASCADE)        timestamp= models.DateTimeField(auto_now_add=True, editable=False)        class Meta:            ordering = ('timestamp',)Views.py@login_requireddef Playlist_Remove(request, id, P_id):    p = Playlist.objects.get(id=P_id)    s = p.song.get(id=id)        p.song.remove(s)    return redirect('account')