python - 为什么__del__不执行呢？

Question

新手用python2.7写的一个scrapy爬虫，希望爬虫退出去的时候清理打开的firefox进程，发现不管用，请帮忙看下，为什么最下面的self.browser.quit不执行呢

    def __init__(self):
        self.browser = webdriver.Firefox()


    def __del__(self):
        self.browser.quit()

Answer 1

def spider_closed(self, spider):
    dosomething()

It seems that in scrapy you will be advised to do this scrapy: Call a function when a spider quits