jsonify.py

from pylons import request, response
from simplejson import dumps

def jsonify(data):
    func = request.params.get('jsonp') or \
           request.params.get('callback') or \
           request.params.get('cb')
    body = dumps(data, indent=None if request.is_xhr else 2)
    response.charset = 'utf8'
    if func is not None:
        response.content_type = 'application/javascript'
        return "%s(%s);"%(func, body)
    else:
        response.content_type = 'application/json'
	return body

jsonify_usage.py

class FooController(BaseController):

    def index(self):
        # ...
  	return jsonify({'foo': 'bar'})