new_contents: # -*- coding: utf-8 -*-
  # Generated by Django 1.11.17 on 2020-12-24 10:20
  from __future__ import unicode_literals
  
  from django.db import migrations
  
  
  def fix_wallpost_ctype(apps, schema_editor):
      ContentType = apps.get_model('contenttypes', 'ContentType')
      Assignment = apps.get_model('assignments', 'Assignment')
      Event = apps.get_model('events', 'Event')
  
      Activity = apps.get_model('activities', 'Activity')
      Wallpost = apps.get_model('wallposts', 'Wallpost')
  
      assigment_ctype = ContentType.objects.get_for_model(Assignment)
      event_ctype = ContentType.objects.get_for_model(Event)
      posts = Wallpost.objects.filter(content_type__in=[event_ctype, assigment_ctype])
      for post in posts:
          act = Activity.objects.get(pk=post.object_id)
          post.content_type = act.polymorphic_ctype
          post.save()
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('time_based', '0043_auto_20201217_0743'),
      ]
  
      operations = [
          migrations.RunPython(fix_wallpost_ctype, migrations.RunPython.noop)
      ]
  
subject: Migrate wallposts to right ctype