python input()使用疑问

请大家帮忙看看，>_<

运行环境 虚拟机 ubuntu12.04 python3.5.1

用 input() python3 运行失败 用 raw_input()， python2 运行成功

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import os
import time

p = os.pipe()
childpid = os.fork()

if (childpid==0):
    os.close(p[1])
    while True:
        time.sleep(3)
        print('reading')
        msg = os.read(p[0],1024)
        print(msg)
        if msg == '':
            print('can not read anything')
            break
        if (msg == 'q'):
            os.close(p[0])#关闭管道
            break
else:
    os.close(p[0])
    while True:
        
        #python3.5 中运行出错
        str1 = input()
		#python2.7 中运行正确
        #str1 = raw_input('input anything:')
        os.write(p[1],str1)
        if(str1 == 'q'):
            os.close(p[1])#关闭管道
            os.wait()
            break

出错信息如图：

http://a3.topitme.com/b/09/bb/11773765731b5bb09bl.jpg