在Scrapy中本地运行所有蜘蛛

Question

有没有一种方法可以在不使用Scrapy守护程序的情况下运行Scrapy项目中的所有蜘蛛程序？曾经有一种使用来运行多个Spider的方法scrapy crawl，但是该语法已删除，Scrapy的代码也进行了很多更改。

我尝试创建自己的命令：

from scrapy.command import ScrapyCommand
from scrapy.utils.misc import load_object
from scrapy.conf import settings

class Command(ScrapyCommand):
    requires_project = True

    def syntax(self):
        return '[options]'

    def short_desc(self):
        return 'Runs all of the spiders'

    def run(self, args, opts):
        spman_cls = load_object(settings['SPIDER_MANAGER_CLASS'])
        spiders = spman_cls.from_settings(settings)

        for spider_name in spiders.list():
            spider = self.crawler.spiders.create(spider_name)
            self.crawler.crawl(spider)

        self.crawler.start()

但是，一旦在上注册了蜘蛛self.crawler.crawl()，我就会得到所有其他蜘蛛的断言错误：

Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/scrapy/cmdline.py", line 138, in _run_command
    cmd.run(args, opts)
  File "/home/blender/Projects/scrapers/store_crawler/store_crawler/commands/crawlall.py", line 22, in run
    self.crawler.crawl(spider)
  File "/usr/lib/python2.7/site-packages/scrapy/crawler.py", line 47, in crawl
    return self.engine.open_spider(spider, requests)
  File "/usr/lib/python2.7/site-packages/twisted/internet/defer.py", line 1214, in unwindGenerator
    return _inlineCallbacks(None, gen, Deferred())
--- <exception caught here> ---
  File "/usr/lib/python2.7/site-packages/twisted/internet/defer.py", line 1071, in _inlineCallbacks
    result = g.send(result)
  File "/usr/lib/python2.7/site-packages/scrapy/core/engine.py", line 215, in open_spider
    spider.name
exceptions.AssertionError: No free spider slots when opening 'spidername'

有什么办法吗？我不想开始子类化核心Scrapy组件，而只是为了运行所有我的蜘蛛。

Answer 1

这是一个不在自定义命令中运行，而是手动运行Reactor并为每个蜘蛛创建新的Crawler的示例：

from twisted.internet import reactor
from scrapy.crawler import Crawler
# scrapy.conf.settings singlton was deprecated last year
from scrapy.utils.project import get_project_settings
from scrapy import log

def setup_crawler(spider_name):
    crawler = Crawler(settings)
    crawler.configure()
    spider = crawler.spiders.create(spider_name)
    crawler.crawl(spider)
    crawler.start()

log.start()
settings = get_project_settings()
crawler = Crawler(settings)
crawler.configure()

for spider_name in crawler.spiders.list():
    setup_crawler(spider_name)

reactor.run()

您将必须设计一些信号系统，以便在所有信号灯完成后停止反应堆。

编辑：这是您可以在自定义命令中运行多个蜘蛛的方法：

from scrapy.command import ScrapyCommand
from scrapy.utils.project import get_project_settings
from scrapy.crawler import Crawler

class Command(ScrapyCommand):

    requires_project = True

    def syntax(self):
        return '[options]'

    def short_desc(self):
        return 'Runs all of the spiders'

    def run(self, args, opts):
        settings = get_project_settings()

        for spider_name in self.crawler.spiders.list():
            crawler = Crawler(settings)
            crawler.configure()
            spider = crawler.spiders.create(spider_name)
            crawler.crawl(spider)
            crawler.start()

        self.crawler.start()