getjson.py

#!/usr/bin/env python
"""Retrieve json using t.w.c.getPage().

http://stackoverflow.com/questions/20460352/python-json-decoder-error
"""
import json
import sys
import urllib
from twisted.internet import reactor
from twisted.python.util import println
from twisted.web.client import getPage


path = 'ip' if len(sys.argv) < 2 else sys.argv[1]
d = getPage('http://httpbin.org/' + urllib.quote(path),
            timeout=20, headers={'Accept': 'application/json'})
d.addCallback(json.loads)           # parse response as json
d.addBoth(println)                  # print parsed data or an error
d.addBoth(lambda _: reactor.stop()) # exit
reactor.run()