old_contents: import os
  
  from ckeditor.views import create_thumbnail, get_image_files, \
          get_thumb_filename
  from django.core.management.base import NoArgsCommand
  
  
  class Command(NoArgsCommand):
      """
      Creates thumbnail files for the CKEditor file image browser.
      Useful if starting to use django-ckeditor with existing images.
      """
      def handle_noargs(self, **options):
          for image in get_image_files():
              if not os.path.isfile(get_thumb_filename(image)):
                  self.stdout.write("Creating thumbnail for {0}".format(image))
                  try:
                      create_thumbnail(image)
                  except Exception as e:
                      self.stdout.write("Couldn't create thumbnail for {0}: {1}".format(image, e))
          self.stdout.write("Finished")
  
new_contents: import os
  
  from django.conf import settings
  from django.core.management.base import NoArgsCommand
  
  from ckeditor.views import get_image_files
  from ckeditor.utils import get_thumb_filename
  from ckeditor.image_processing import get_backend
  
  
  class Command(NoArgsCommand):
      """
      Creates thumbnail files for the CKEditor file image browser.
      Useful if starting to use django-ckeditor with existing images.
      """
      def handle_noargs(self, **options):
          if getattr(settings, 'CKEDITOR_IMAGE_BACKEND', None):
              backend = get_backend()
              for image in get_image_files():
                  if not os.path.isfile(get_thumb_filename(image)):
                      self.stdout.write("Creating thumbnail for {0}".format(image))
                      try:
                          backend.create_thumbnail(image)
                      except Exception as e:
                          self.stdout.write("Couldn't create thumbnail for {0}: {1}".format(image, e))
              self.stdout.write("Finished")
          else:
              self.stdout.write("No thumbnail backend is enabled")
  
subject: Use backends in management command.