Scrapy crawl from script always blocks script execution after scraping

Question

I am following this guide http://doc.scrapy.org/en/0.16/topics/practices.html#run-scrapy-from-a-script to run scrapy from my script. Here is part of my script:

Answer 1

In scrapy 0.19.x you should do this:

from twisted.internet import reactor
from scrapy.crawler import Crawler
from scrapy import log, signals
from testspiders.spiders.followall import FollowAllSpider
from scrapy.utils.project import get_project_settings

spider = FollowAllSpider(domain='scrapinghub.com')
settings = get_project_settings()
crawler = Crawler(settings)
crawler.signals.connect(reactor.stop, signal=signals.spider_closed)
crawler.configure()
crawler.crawl(spider)
crawler.start()
log.start()
reactor.run() # the script will block here until the spider_closed signal was sent

Note these lines

settings = get_project_settings()
crawler = Crawler(settings)

Without it your spider won't use your settings and will not save the items. Took me a while to figure out why the example in documentation wasn't saving my items. I sent a pull request to fix the doc example.

One more way to do it is just call command directly from you script

from scrapy import cmdline
cmdline.execute("scrapy crawl followall".split())  #followall is the spider's name

Answer 2

You will need to stop the reactor when the spider finishes. You can accomplish this by listening for the spider_closed signal:

from twisted.internet import reactor

from scrapy import log, signals
from scrapy.crawler import Crawler
from scrapy.settings import Settings
from scrapy.xlib.pydispatch import dispatcher

from testspiders.spiders.followall import FollowAllSpider

def stop_reactor():
    reactor.stop()

dispatcher.connect(stop_reactor, signal=signals.spider_closed)
spider = FollowAllSpider(domain='scrapinghub.com')
crawler = Crawler(Settings())
crawler.configure()
crawler.crawl(spider)
crawler.start()
log.start()
log.msg('Running reactor...')
reactor.run()  # the script will block here until the spider is closed
log.msg('Reactor stopped.')

And the command line log output might look something like:

stav@maia:/srv/scrapy/testspiders$ ./api
2013-02-10 14:49:38-0600 [scrapy] INFO: Running reactor...
2013-02-10 14:49:47-0600 [followall] INFO: Closing spider (finished)
2013-02-10 14:49:47-0600 [followall] INFO: Dumping Scrapy stats:
    {'downloader/request_bytes': 23934,...}
2013-02-10 14:49:47-0600 [followall] INFO: Spider closed (finished)
2013-02-10 14:49:47-0600 [scrapy] INFO: Reactor stopped.
stav@maia:/srv/scrapy/testspiders$