>>> print raw_input('input something: ')
input something: HA!
HA!
>>>

import subprocess as sp
import time
from threading import Thread

class Tcmd(Thread):
    def __init__ (self):
        Thread.__init__(self)
        self.evt=threading.Event()
    def run(self):
        self.c=sp.Popen(["cmd"],stdin=sp.PIPE,stdout=sp.PIPE)
        self.evt.set()
        while 1:
            a=self.c.stdout.readline()
            if not a:
                break
            print("send:"+a)
    def put(self,cmd):
        self.c.stdin.write(cmd)

obj=Tcmd()
obj.start()
obj.evt.wait()
obj.put("dir\n")
time.sleep(2)
obj.put("echo\n")
time.sleep(2)
obj.put("exit\n")
obj.join()