new_contents: from __future__ import print_function
  
  from django.core.management.base import BaseCommand
  
  from container.models import ContainerRun
  
  
  class Command(BaseCommand):
      help = "Set MD5 on any runs that still have a blank."
  
      def handle(self, **kwargs):
          batch_size = 100
          run_count = 0
          print('Starting.')
          while True:
              runs = ContainerRun.objects.filter(md5='')[:batch_size]
              batch_count = len(runs)
              if not batch_count:
                  break
              for run in runs:
                  run.set_md5()
                  run.save()
              run_count += batch_count
              print('Set MD5 on {} runs.'.format(run_count))
          print('Done.')
  
subject: Add script to set ContainerRun.md5 on existing runs, as part of #751.