如何在Scrapy Spider关闭后获得`item_scraped_count` - Python27

from scrapy import signals

class ItemCountExtension(object):
    def __init__(self):
        self.item_count = 0

    @classmethod
    def from_crawler(cls, crawler):
        ext = cls()
        crawler.signals.connect(ext.spider_closed, signal=signals.spider_closed)
        return ext

    def spider_closed(self, spider):
        self.item_count = spider.crawler.stats.get_value('item_scraped_count')
        self.process_item_count()

    def process_item_count(self):
        # 在这里可以对item_count进行进一步处理，如保存到数据库或输出到日志等
        print("Total items scraped:", self.item_count)

EXTENSIONS = {
    'your_project_name.item_count_extension.ItemCountExtension': 500,
}