python 发送HTTP请求 post json 格式

import httplib 
import json
test_data = {'pictureName':''}

requrl = "http://10.1.24.88:8090/api/load_pic"
headerdata = {"Content-type": "application/json"}

conn = ("10.1.24.88",8090)

('POST',requrl,(test_data),headerdata) 

response = ()

res= ()

print res