import http.client

conn = http.client.HTTPConnection("dlj.bz")

payload = "{\"long_url\": \"http://www.sina.com.cn\"}"

headers = {
    'content-type': "application/json"
    }

conn.request("POST", "/api/urlshortener", payload, headers)

res = conn.getresponse()
data = res.read()

print(data.decode("utf-8"))