doc: http://open.youku.com/docs/docs?id=87

def find_person_by_id(self, person_id):
        """doc: http://open.youku.com/docs/docs?id=87
        """
        url = 'https://openapi.youku.com/v2/persons/show.json'
        params = {
            'client_id': self.client_id,
            'person_id': person_id
        }
        r = requests.get(url, params=params)
        check_error(r)
        return r.json()