AttributeError:不能对指定中间模型的ManyToManyField使用remove()。改为使用songs.Playlist_Activity的管理器

# 导入相关模块和类
from django.db import models

# 定义中间模型
class Playlist_Activity(models.Model):
    playlist = models.ForeignKey(Playlist, on_delete=models.CASCADE)
    activity = models.ForeignKey(Activity, on_delete=models.CASCADE)
    extra_field = models.CharField(max_length=100)

# 定义Playlist模型
class Playlist(models.Model):
    name = models.CharField(max_length=100)
    activities = models.ManyToManyField(Activity, through=Playlist_Activity)

# 定义Activity模型
class Activity(models.Model):
    name = models.CharField(max_length=100)

# 使用管理器进行操作
playlist = Playlist.objects.get(id=1)
activity = Activity.objects.get(id=1)

# 添加关联对象
playlist.activities.add(activity, through_defaults={'extra_field': 'some value'})

# 删除关联对象
playlist.activities.remove(activity, through_defaults={'extra_field': 'some value'})