def handle(self, *args, **options):
        if not options["flag"] or not options["op"] or not options["email"]:
            print("Please specify an operation, a flag and an email")
            exit(1)

        op = options['op']
        flag = getattr(UserMessage.flags, options['flag'])
        all_until = options['all_until']
        email = options['email']

        user_profile = get_user_profile_by_email(email)

        if all_until:
            filt = models.Q(id__lte=all_until)
        else:
            filt = models.Q(message__id__in=[mid.strip() for mid in sys.stdin.read().split(',')])
        mids = [m.id for m in
                    UserMessage.objects.filter(filt, user_profile=user_profile).order_by('-id')]

        if options["for_real"]:
            sys.stdin.close()
            sys.stdout.close()
            sys.stderr.close()

        def do_update(batch):
            msgs = UserMessage.objects.filter(id__in=batch)
            if op == 'add':
                msgs.update(flags=models.F('flags').bitor(flag))
            elif op == 'remove':
                msgs.update(flags=models.F('flags').bitand(~flag))

        if not options["for_real"]:
            logging.info("Updating %s by %s %s" % (mids, op, flag))
            logging.info("Dry run completed. Run with --for-real to change message flags.")
            exit(1)

        utils.run_in_batches(mids, 400, do_update, sleep_time=3)
        exit(0)
dataset/ETHPy150Open zulip/zulip/zerver/management/commands/set_message_flags.py/Command.handle/original