如何在 Python 脚本中运行 Scrapy

我是 Scrapy 的新手，我正在寻找一种从 Python 脚本运行 Scrapy 的方法。我找到了两个解释这一点的资料来源:

Http://tryolabs.com/blog/2011/09/27/calling-scrapy-python-script/

Http://snipplr.com/view/67006/using-scrapy-from-a-script/

我不知道应该把 Spider 代码放在哪里，也不知道如何从 main 函数调用它。请帮帮我。这是示例代码:

# This snippet can be used to run scrapy spiders independent of scrapyd or the scrapy command line tool and use it from a script.
#
# The multiprocessing library is used in order to work around a bug in Twisted, in which you cannot restart an already running reactor or in this case a scrapy instance.
#
# [Here](http://groups.google.com/group/scrapy-users/browse_thread/thread/f332fc5b749d401a) is the mailing-list discussion for this snippet.


#!/usr/bin/python
import os
os.environ.setdefault('SCRAPY_SETTINGS_MODULE', 'project.settings') #Must be at the top before other imports


from scrapy import log, signals, project
from scrapy.xlib.pydispatch import dispatcher
from scrapy.conf import settings
from scrapy.crawler import CrawlerProcess
from multiprocessing import Process, Queue


class CrawlerScript():


def __init__(self):
self.crawler = CrawlerProcess(settings)
if not hasattr(project, 'crawler'):
self.crawler.install()
self.crawler.configure()
self.items = []
dispatcher.connect(self._item_passed, signals.item_passed)


def _item_passed(self, item):
self.items.append(item)


def _crawl(self, queue, spider_name):
spider = self.crawler.spiders.create(spider_name)
if spider:
self.crawler.queue.append_spider(spider)
self.crawler.start()
self.crawler.stop()
queue.put(self.items)


def crawl(self, spider):
queue = Queue()
p = Process(target=self._crawl, args=(queue, spider,))
p.start()
p.join()
return queue.get(True)


# Usage
if __name__ == "__main__":
log.start()


"""
This example runs spider1 and then spider2 three times.
"""
items = list()
crawler = CrawlerScript()
items.append(crawler.crawl('spider1'))
for i in range(3):
items.append(crawler.crawl('spider2'))
print items


# Snippet imported from snippets.scrapy.org (which no longer works)
# author: joehillen
# date  : Oct 24, 2010

谢谢你。

81922 次浏览
小开

Though I haven't tried it I think the answer can be found within the scrapy documentation. To quote directly from it:

from twisted.internet import reactor
from scrapy.crawler import Crawler
from scrapy.settings import Settings
from scrapy import log
from testspiders.spiders.followall import FollowAllSpider


spider = FollowAllSpider(domain='scrapinghub.com')
crawler = Crawler(Settings())
crawler.configure()
crawler.crawl(spider)
crawler.start()
log.start()
reactor.run() # the script will block here

From what I gather this is a new development in the library which renders some of the earlier approaches online (such as that in the question) obsolete.

小开

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 to do so is just call command directly from you script

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

Copied this answer from my first answer in here: https://stackoverflow.com/a/19060485/1402286

小开

When there are multiple crawlers need to be run inside one python script, the reactor stop needs to be handled with caution as the reactor can only be stopped once and cannot be restarted.

However, I found while doing my project that using 

os.system("scrapy crawl yourspider")

is the easiest. This will save me from handling all sorts of signals especially when I have multiple spiders.

If Performance is a concern, you can use multiprocessing to run your spiders in parallel, something like:

def _crawl(spider_name=None):
if spider_name:
os.system('scrapy crawl %s' % spider_name)
return None


def run_crawler():


spider_names = ['spider1', 'spider2', 'spider2']


pool = Pool(processes=len(spider_names))
pool.map(_crawl, spider_names)
小开

All other answers reference Scrapy v0.x. According to the updated docs, Scrapy 1.0 demands:

import scrapy
from scrapy.crawler import CrawlerProcess


class MySpider(scrapy.Spider):
# Your spider definition
...


process = CrawlerProcess({
'USER_AGENT': 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)'
})


process.crawl(MySpider)
process.start() # the script will block here until the crawling is finished
小开 
# -*- coding: utf-8 -*-
import sys
from scrapy.cmdline import execute




def gen_argv(s):
sys.argv = s.split()




if __name__ == '__main__':
gen_argv('scrapy crawl abc_spider')
execute()

Put this code to the path you can run scrapy crawl abc_spider from command line. (Tested with Scrapy==0.24.6)

小开

If you want to run a simple crawling, It's easy by just running command:

scrapy crawl . There is another options to export your results to store in some formats like: Json, xml, csv.

scrapy crawl -o result.csv or result.json or result.xml.

you may want to try it

小开

Simply we can use

from scrapy.crawler import CrawlerProcess
from project.spiders.test_spider import SpiderName


process = CrawlerProcess()
process.crawl(SpiderName, arg1=val1,arg2=val2)
process.start()

Use these arguments inside spider __init__ function with the global scope.

小开

it is an improvement of Scrapy throws an error when run using crawlerprocess

and https://github.com/scrapy/scrapy/issues/1904#issuecomment-205331087

First create your usual spider for successful command line running. it is very very important that it should run and export data or image or file

Once it is over, do just like pasted in my program above spider class definition and below __name __ to invoke settings.

it will get necessary settings which "from scrapy.utils.project import get_project_settings" failed to do which is recommended by many

both above and below portions should be there together. only one don't run. Spider will run in scrapy.cfg folder not any other folder

tree diagram may be displayed by the moderators for reference

#Tree
[enter image description here][1]


#spider.py
import sys
sys.path.append(r'D:\ivana\flow') #folder where scrapy.cfg is located


from scrapy.crawler import CrawlerProcess
from scrapy.settings import Settings
from flow import settings as my_settings


#----------------Typical Spider Program starts here-----------------------------


spider class definition here


#----------------Typical Spider Program ends here-------------------------------


if __name__ == "__main__":


crawler_settings = Settings()
crawler_settings.setmodule(my_settings)


process = CrawlerProcess(settings=crawler_settings)
process.crawl(FlowSpider) # it is for class FlowSpider(scrapy.Spider):
process.start(stop_after_crawl=True)

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