本地运行 Scrapy 中的所有蜘蛛

Question

有没有办法在不使用 Scrapy 守护进程的情况下运行 Scrapy 项目中的所有蜘蛛？曾经有一种方法可以使用scrapy crawl 运行多个蜘蛛，但该语法已被删除，并且 Scrapy 的代码发生了很大变化。

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()

但是一旦一个蜘蛛注册到self.crawler.crawl()，我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'

有没有办法做到这一点？我宁愿不要为了像这样运行我所有的蜘蛛而开始子类化核心 Scrapy 组件。

Answer 1

Linux 脚本

#!/bin/bash
for spider in $(scrapy list)
do
scrapy crawl "$spider" -o "$spider".json
done

Answer 2

此代码适用于我的 scrapy 版本为 1.3.3（将其保存在 scrapy.cfg 的同一目录中）：

from scrapy.utils.project import get_project_settings
from scrapy.crawler import CrawlerProcess

setting = get_project_settings()
process = CrawlerProcess(setting)

for spider_name in process.spiders.list():
    print ("Running spider %s" % (spider_name))
    process.crawl(spider_name,query="dvh") #query dvh is custom argument used in your scrapy

process.start()

对于scrapy 1.5.x（所以你不会收到弃用警告）

from scrapy.utils.project import get_project_settings
from scrapy.crawler import CrawlerProcess

setting = get_project_settings()
process = CrawlerProcess(setting)

for spider_name in process.spider_loader.list():
    print ("Running spider %s" % (spider_name))
    process.crawl(spider_name,query="dvh") #query dvh is custom argument used in your scrapy

process.start()

Answer 3

@Steven Almeroth 的答案将在 Scrapy 1.0 中失败，您应该像这样编辑脚本：

from scrapy.commands import ScrapyCommand
from scrapy.utils.project import get_project_settings
from scrapy.crawler import CrawlerProcess

class Command(ScrapyCommand):

    requires_project = True
    excludes = ['spider1']

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

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

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

        for spider_name in crawler_process.spider_loader.list():
            if spider_name in self.excludes:
                continue
            spider_cls = crawler_process.spider_loader.load(spider_name) 
            crawler_process.crawl(spider_cls)
        crawler_process.start()

Answer 4

你为什么不直接使用类似的东西：

scrapy list|xargs -n 1 scrapy crawl

?

Answer 5

这是一个不在自定义命令中运行，而是手动运行 Reactor 并创建新的 Crawler for each spider 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()

您必须设计some signal system 以在所有蜘蛛完成后停止反应器。

编辑：这里是您如何在自定义命令中运行多个蜘蛛：

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()