Python实现在线程里运行scrapy的方法
本文实例讲述了Python实现在线程里运行scrapy的方法。分享给大家供大家参考。具体如下:
如果你希望在一个写好的程序里调用scrapy,就可以通过下面的代码,让scrapy运行在一个线程里。
""" CodetorunScrapycrawlerinathread-worksonScrapy0.8 """ importthreading,Queue fromtwisted.internetimportreactor fromscrapy.xlib.pydispatchimportdispatcher fromscrapy.core.managerimportscrapymanager fromscrapy.core.engineimportscrapyengine fromscrapy.coreimportsignals classCrawlerThread(threading.Thread): def__init__(self): threading.Thread.__init__(self) self.running=False defrun(self): self.running=True scrapymanager.configure(control_reactor=False) scrapymanager.start() reactor.run(installSignalHandlers=False) defcrawl(self,*args): ifnotself.running: raiseRuntimeError("CrawlerThreadnotrunning") self._call_and_block_until_signal(signals.spider_closed,\ scrapymanager.crawl,*args) defstop(self): reactor.callFromThread(scrapyengine.stop) def_call_and_block_until_signal(self,signal,f,*a,**kw): q=Queue.Queue() defunblock(): q.put(None) dispatcher.connect(unblock,signal=signal) reactor.callFromThread(f,*a,**kw) q.get() #Usageexamplebelow: importos os.environ.setdefault('SCRAPY_SETTINGS_MODULE','myproject.settings') fromscrapy.xlib.pydispatchimportdispatcher fromscrapy.coreimportsignals fromscrapy.confimportsettings fromscrapy.crawlerimportCrawlerThread settings.overrides['LOG_ENABLED']=False#avoidlognoise defitem_passed(item): print"Justscrapeditem:",item dispatcher.connect(item_passed,signal=signals.item_passed) crawler=CrawlerThread() print"Startingcrawlerthread..." crawler.start() print"Crawlingsomedomain.com...." crawler.crawl('somedomain.com)#blockingcall print"Crawlinganotherdomain.com..." crawler.crawl('anotherdomain.com')#blockingcall print"Stoppingcrawlerthread..." crawler.stop()
希望本文所述对大家的Python程序设计有所帮助。