How to use the vaping.io.subprocess.PIPE function in vaping

def probe(self):
        codec = munge.get_codec('yaml')()
        msg = {}
        msg['data'] = []
        msg['ts'] = (datetime.datetime.utcnow() - datetime.datetime(1970, 1, 1)).total_seconds()

        # FIXME use poll
        for host in self.hosts:
            args = shlex.split(self.command.format(host=host))
            proc = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)

            # TODO poll, timeout, maybe from parent process for better control?
            with proc.stdout:
                #msg['data'].append(proc.stdout.read())
                msg['data'].append(codec.load(proc.stdout))

        return msg

port = 33434

        # -f first_ttl
        # -m max_ttl
        args = [
            command,
            '-n',
            # -w wait time seconds
            '-w1',
            # -q number of queries
            '-q1',
            self.mtr_host,
        ]

        # get both stdout and stderr
        proc = self.popen(args, stdout=subprocess.PIPE,
                          stderr=subprocess.STDOUT)

        with proc.stdout:
            hosts = self.parse_traceroute(iter(proc.stdout.readline, b''))
        return hosts

def _run_proc(self):
        args = [
            self.config['command'],
            '-u',
            '-C%d' % self.count,
            '-p%d' % self.period,
            '-e'
        ]
        args.extend(self.hosts_args())
        data = list()

        # get both stdout and stderr
        proc = self.popen(args, stdout=subprocess.PIPE,
                          stderr=subprocess.STDOUT)

        # TODO poll, timeout, maybe from parent process for better control?
        with proc.stdout:
            for line in iter(proc.stdout.readline, b''):
                data.append(self.parse_verbose(line.decode("utf-8")))

        return data

def popen(self, *args):
        """ make cmd command and popen it """
        cmd = ['sflowtool',]
        cmd.extend(args)
#        cmd.extend(self.hosts)
        self.log.debug(' '.join(cmd))

        # get both stdout and stderr
        return subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)

def poll_process(self, cmd, stdout, stderr):
        proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        while True:
            try:
                fds = [proc.stdout.fileno(), proc.stderr.fileno()]
                ret = select.select(fds, [], [])

                for fd in ret[0]:
                    if fd == proc.stdout.fileno():
                        read = proc.stdout.readline()
                        #stdout.append(read)
                    if fd == proc.stderr.fileno():
                        read = proc.stderr.readline()
                        self.log.error("stderr" + read)

                if proc.poll() != None:
                    self.log.warning("poll break")
                    break