new_contents: from __future__ import unicode_literals
  
  from django.db import migrations
  
  
  def run_data_migration(apps, schema_editor):
      Attribute = apps.get_model('domain', 'Attribute')
      QuestionSet = apps.get_model('questions', 'QuestionSet')
  
      questionsets = QuestionSet.objects.filter(is_collection=True)
      for questionset in questionsets:
          if questionset.attribute.key != 'id':
              try:
                  questionset.attribute = Attribute.objects.get(parent=questionset.attribute, key='id')
                  questionset.save()
              except Attribute.DoesNotExist:
                  pass
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('questions', '0064_widget_type_choices'),
      ]
  
      operations = [
          migrations.RunPython(run_data_migration),
      ]
  
subject: Add data migration to update questionsets