Object of type 'Decimal' is not JSON serializable

def empall(self): 
        all = []
        try:
            conn = getConnection()
            cursor = conn.cursor()
            try:
                cursor.execute("select * from emp01")
                rows = cursor.fetchall()

                objects_list = []
                for row in rows:
                    d = collections.OrderedDict()
                    d['empno'] = row[0]
                    d['ename'] = row[1]
                    d['sal'] = row[2]
                    objects_list.append(d)
                all = json.dumps(objects_list)
            except Exception as e:
                print(e)
        except Exception as e:
            print(e)
        finally:
            cursor.close()
            conn.close()
        return all

Object of type 'Decimal' is not JSON serializable