怎样在python中定义非闭包

class Averager():

    def __init__(self):

        self.series = []

    def __call__(self, new_value):

        self.series.append(new_value)

        total = sum(self.series)

        return total / len(self.series)

avg = Averager()

logging.info('avg(10) -> %s', avg(10))

logging.info('avg(20) -> %s', avg(20))

logging.info('avg(30) -> %s', avg(30))