Python __json__

json.py

# -*- coding: utf-8 -*-

import datetime
import simplejson

#json.dumps
__dumps = simplejson.dumps


def dumpsOverloaded(*args, **kwargs):
	return __dumps(default=json_unknown, *args, **kwargs)


def json_unknown(o):
	if isinstance(o, datetime.datetime):
		s = o.isoformat()
	else:
		try:
			s = o.__json__()
		except KeyError:
			raise TypeError(repr(o) + " is not JSON serializable")
	return s

simplejson.dumps = dumpsOverloaded

json = simplejson

answer for http://stackoverflow.com/q/3768895/1115187

KeyError? Did you mean AttributeError?