My JSON Encoder & Decoder

json.py

import json

def convert(obj):
	if isinstance(obj, dict):
		return dict((convert(key), convert(value)) for key, value in obj.iteritems())
	elif isinstance(obj, list):
		return [convert(element) for element in obj]
	elif isinstance(obj, unicode):
		return obj.encode('utf-8')
	else:
		return obj


class JSONEncoder(json.JSONEncoder):
	def default(self, obj):
		if isinstance(obj, datetime.datetime):
			return DateTimeConverter(None).to_url(obj)
		if isinstance(obj, datetime.timedelta):
			return str(obj)
		if isinstance(obj, long):
			return str(obj)
		if isinstance(obj, type):
			return repr(obj)
		if callable(getattr(obj, 'as_od', None)):
			return obj.as_od()
		if callable(getattr(obj, 'as_dict', None)):
			return obj.as_dict()

		return super(JSONEncoder, self).default(obj)


class JSONDecoder(json.JSONDecoder):
	def __init__(self, *args, **kwargs):
		args = list(args)
		if len(args) >= 2:
			if args[0] == None:
				args[0] == 'utf-8'
			if args[1] == None:
				args[1] = convert
		else:
			if 'encoding' not in kwargs:
				kwargs['encoding'] = 'utf-8'
			if 'object_hook' not in kwargs:
				kwargs['object_hook'] = convert
		super(JSONDecoder, self).__init__(*args, **kwargs)