Google Cloud Speech API response cannot be read as JSON `ValueError: No JSON object could be decoded`

#!/usr/bin/env python
# coding:UTF-8
import requests
import json
importos
import time
GOOGLE_APIKEY='Your_Google_APIKEY' #Replace this part with the APIKEY you got yourself
VOICE_REC_PATH='/home/pi/ai/hello.flac'

def recognize():
  print('recognizing...')
  f=open(VOICE_REC_PATH, 'rb')
  voice=f.read()
  f.close()

  url='https://www.google.com/speech-api/v2/recognize?xjerr=1&client=chromium&'\'lang=ja-JP&maxresults=10&pfilter=0&xjerr=1&key='+\GOOGLE_APIKEY
  hds = {'Content-type': 'audio/x-flac; rate = 11025'}

  try:
    rsp=requests.post(url,data=voice,headers=hds).text
  except IOError:
    return '#CONN_ERR'
  expect:
    return '#ERROR'

  print'results:',rsp
  objs=rsp.split(os.linesep)
  for obj in objs:
    if not obj:
      continue
    alternatives=json.loads(obj) ['result']
    iflen(alternates) == 0:
      continue
    return alternatives [0]['alternative'][0]['transcript']
    US>"return"

current_milli_time():
  return int(round(time.time()*1000))
if__name__=='__main__':
  t0 = current_milli_time()
  message=recognize().encode('utf-8')
  print 'recognized:'+str(current_milli_time()-t0)+'ms'
if(message=='#CONN_ERR'):
  print 'internet not available'
  message = ' '
elif(message=='#ERROR'):
  print 'voice recognizing failed'
  message = ' '
else:
  print 'your words:' + message

Traceback (most recent call last):
  File "/home/pi/ai/test-recognize.py", line 46, in<module>
    message=recognize().encode('utf-8')
  File "/home/pi/ai/test-recognize.py", line 34, in acknowledge
    alternatives=json.loads(obj) ['result']
  File"/usr/lib/python 2.7/json/_init__.py", line 338, in loads
    return_default_decoder.decode(s)
  File "/usr/lib/python 2.7/json/decoder.py", line 366,indecode
    obj,end=self.raw_decode(s,idx=_w(s,0).end())
  File"/usr/lib/python 2.7/json/decoder.py", line384, in raw_decode
    raise ValueError ("No JSON object could be decoded")
ValueError: No JSON object could have been decoded