text: import datetime
  
  from django.utils import timezone
  from django.core.management.base import BaseCommand
  
  from ...models import SentNotification
  
  
  def valid_date(s):
      return datetime.datetime.strptime(s, "%Y-%m-%d")
  
  
  class Command(BaseCommand):
      help = 'Deletes notifications between the date ranges specified.'
  
      def add_arguments(self, parser):
          parser.add_argument('--start', help="includes this date, format YYYY-MM-DD", type=valid_date)
          parser.add_argument('--end', help="up to this date, format YYYY-MM-DD", type=valid_date)
  
      def handle(self, *args, **options):
          today = timezone.now().replace(hour=0, minute=0, second=0, microsecond=0)
          start_date = options['start'] if options['start'] else today
          end_date = options['end'] if options['end'] else today + datetime.timedelta(days=1)
          qs = SentNotification.objects.filter(date_sent__range=[start_date, end_date])
          present_notifications = qs.count()
          deleted_notifications = qs.delete()
          deleted_num = deleted_notifications[0] if deleted_notifications is not None else present_notifications
          self.stdout.write('Successfully deleted {num} notification(s)'.format(num=deleted_num))
  