来自json的脚本输出的scrapy

Question

I am running scrapy in a python script

def setup_crawler(domain):
    dispatcher.connect(stop_reactor, signal=signals.spider_closed)
    spider = ArgosSpider(domain=domain)
    settings = get_project_settings()
    crawler = Crawler(settings)
    crawler.configure()
    crawler.crawl(spider)
    crawler.start()
    reactor.run()

it runs successfully and stops but where is the result ? I want the result in json format, how can I do that?

result = responseInJSON

like we do using command

scrapy crawl argos -o result.json -t json

Answer 1

You need to set FEED_FORMAT and FEED_URI settings manually:

settings.overrides['FEED_FORMAT'] = 'json'
settings.overrides['FEED_URI'] = 'result.json'

If you want to get the results into a variable you can define a Pipeline class that would collect items into the list. Use the spider_closed signal handler to see the results:

import json

from twisted.internet import reactor
from scrapy.crawler import Crawler
from scrapy import log, signals
from scrapy.utils.project import get_project_settings


class MyPipeline(object):
    def process_item(self, item, spider):
        results.append(dict(item))

results = []
def spider_closed(spider):
    print results

# set up spider    
spider = TestSpider(domain='mydomain.org')

# set up settings
settings = get_project_settings()
settings.overrides['ITEM_PIPELINES'] = {'__main__.MyPipeline': 1}

# set up crawler
crawler = Crawler(settings)
crawler.signals.connect(spider_closed, signal=signals.spider_closed)
crawler.configure()
crawler.crawl(spider)

# start crawling
crawler.start()
log.start()
reactor.run() 

FYI, look at how Scrapy parses command-line arguments .

Also see: Capturing stdout within the same process in Python .

Answer 2

I managed to make it work simply by adding the FEED_FORMAT and FEED_URI to the CrawlerProcess constructor, using the basic Scrapy API tutorial code as follows:

process = CrawlerProcess({
'USER_AGENT': 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1)',
'FEED_FORMAT': 'json',
'FEED_URI': 'result.json'
})

Answer 3

Easy!

from scrapy import cmdline

cmdline.execute("scrapy crawl argos -o result.json -t json".split())

Put that script where you put scrapy.cfg