old_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import migrations
  from django.contrib.auth.models import Group
  import logging
  
  logger = logging.getLogger(__file__)
  
  
  def add_groups(*args):
      group, created = Group.objects.get_or_create(name='nodes_and_users')
      if created:
          logger.info('nodes_and_users group created')
  
      try:
          group = Group.objects.get(name='prereg_group')
          group.name = 'prereg'
          group.save()
          logger.info('prereg_group renamed to prereg')
      except Group.DoesNotExist:
          group, created = Group.objects.get_or_create(name='prereg')
          if created:
              logger.info('prereg group created')
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('base', '0001_groups'),
      ]
  
      operations = [
          migrations.RunPython(add_groups),
      ]
  
new_contents: # -*- coding: utf-8 -*-
  from __future__ import unicode_literals
  
  from django.db import migrations
  from django.contrib.auth.models import Group
  import logging
  
  logger = logging.getLogger(__file__)
  
  
  def add_groups(*args):
      group, created = Group.objects.get_or_create(name='nodes_and_users')
      if created:
          logger.info('nodes_and_users group created')
  
      try:
          group = Group.objects.get(name='prereg_group')
          group.name = 'prereg'
          group.save()
          logger.info('prereg_group renamed to prereg')
      except Group.DoesNotExist:
          group, created = Group.objects.get_or_create(name='prereg')
          if created:
              logger.info('prereg group created')
  
  
  def remove_groups(*args):
      Group.objects.filter(name='nodes_and_users').delete()
  
      group = Group.objects.get(name='prereg')
      group.name = 'prereg_group'
      group.save()
  
  
  class Migration(migrations.Migration):
  
      dependencies = [
          ('base', '0001_groups'),
      ]
  
      operations = [
          migrations.RunPython(add_groups, remove_groups),
      ]
  
subject: Add reverse migration for new groups