extensions.py 文件源码

def from_crawler(cls, crawler):
        instance = cls(crawler.stats)
        crawler.signals.connect(instance.item_dropped, 
                                signal=signals.item_dropped)
        crawler.signals.connect(instance.item_scraped, 
                                signal=signals.item_scraped)
        crawler.signals.connect(instance.response_received, 
                                signal=signals.response_received)
        crawler.signals.connect(instance.response_downloaded, 
                                signal=signals.response_downloaded)
        crawler.signals.connect(instance.item_saved,
                                signal=mysignals.item_saved)
        crawler.signals.connect(instance.item_saved_failed,
                                signal=mysignals.item_saved_failed)
        crawler.signals.connect(instance.html_saved,
                                signal=mysignals.html_saved)
        crawler.signals.connect(instance.html_saved_failed,
                                signal=mysignals.html_saved_failed)
        crawler.signals.connect(instance.timeouterror,
                                signal=mysignals.timeouterror)
        crawler.signals.connect(instance.dnslookuperror,
                                signal=mysignals.dnslookuperror)
        return instance