unifying python api response

gistfile1.py

import json

class API :
	ERROR = -1
	OK = 0

class APIResponse(API) :
	def __init__(self, code, data) :
		self.code = code
		self.data = data

	def __str__(self) :
		response = {}
		response['code'] = self.code
		response['data'] = str(self.data)
		return json.dumps(response)

res = APIResponse(API.ERROR, "foo")
print res