def senderror(failure, options):
    recipient = [options.sender]
    sender = '"Internally Generated Message (%s)"<postmaster@%s>' % (sys.argv[0], smtp.DNSNAME)
    error = StringIO.StringIO()
    failure.printTraceback(file=error)
    body = StringIO.StringIO(error.getvalue() % ERROR_FMT)

    d = smtp.sendmail('localhost', sender, recipient, body)
    d.addBoth(lambda _: reactor.stop())
dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/mail/scripts/mailmail.py/senderror/swapped operands of `%`