old_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import migrations
  from django.db import transaction
  
  
  @transaction.atomic
  def create_topics(apps, schema_editor):
      Topic = apps.get_model("cfp", "Topic")
      Conference = apps.get_model("cfp", "Conference")
  
      for conf in Conference.objects.exclude(programming_language=''):
          topic = Topic.object.get_or_create(value=conf.programming_language)
          conf.topics.add(topic)
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('cfp', '0028_auto_20150228_0428'),
      ]
  
      operations = [
          migrations.RunPython(create_topics)
      ]
  
new_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import migrations
  from django.db import transaction
  
  
  @transaction.atomic
  def create_topics(apps, schema_editor):
      Topic = apps.get_model("cfp", "Topic")
      Conference = apps.get_model("cfp", "Conference")
  
      for conf in Conference.objects.exclude(programming_language=''):
          topic = Topic.objects.get_or_create(value=conf.programming_language)
          conf.topics.add(topic)
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('cfp', '0028_auto_20150228_0428'),
      ]
  
      operations = [
          migrations.RunPython(create_topics)
      ]
  
subject: Fix migration that never actually worked