在脚本文件功能中获取Scrapy爬虫的输出/结果

Question

我正在使用脚本文件在scrapy项目中运行Spider，Spider正在记录搜寻器的输出/结果。但是我想在某些功能的脚本文件中使用蜘蛛输出/结果。我不想将输出/结果保存在任何文件或数据库中。这是从https://doc.scrapy.org/en/latest/topics/practices.html#run-from-script获得的脚本代码

from twisted.internet import reactor
from scrapy.crawler import CrawlerRunner
from scrapy.utils.log import configure_logging
from scrapy.utils.project import get_project_settings

configure_logging({'LOG_FORMAT': '%(levelname)s: %(message)s'})
runner = CrawlerRunner(get_project_settings())


d = runner.crawl('my_spider')
d.addBoth(lambda _: reactor.stop())
reactor.run()

def spider_output(output):
#     do something to that output

我如何在“ spider_output”方法中获得蜘蛛输出。有可能获得输出/结果。

Answer 1

这是在列表中获取所有输出/结果的解决方案

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

from scrapy.signalmanager import dispatcher


def spider_results():
    results = []

    def crawler_results(signal, sender, item, response, spider):
        results.append(item)

    dispatcher.connect(crawler_results, signal=signals.item_passed)

    process = CrawlerProcess(get_project_settings())
    process.crawl(MySpider)
    process.start()  # the script will block here until the crawling is finished
    return results


if __name__ == '__main__':
    print(spider_results())

Answer 2

这是一个老问题，但供将来参考。如果您使用的是 python 3.6+，我建议您使用scrapyscript，它允许您运行 Spiders 并以超级简单的方式获得结果：

from scrapyscript import Job, Processor
from scrapy.spiders import Spider
from scrapy import Request
import json

# Define a Scrapy Spider, which can accept *args or **kwargs
# https://doc.scrapy.org/en/latest/topics/spiders.html#spider-arguments
class PythonSpider(Spider):
    name = 'myspider'

    def start_requests(self):
        yield Request(self.url)

    def parse(self, response):
        title = response.xpath('//title/text()').extract()
        return {'url': response.request.url, 'title': title}

# Create jobs for each instance. *args and **kwargs supplied here will
# be passed to the spider constructor at runtime
githubJob = Job(PythonSpider, url='http://www.github.com')
pythonJob = Job(PythonSpider, url='http://www.python.org')

# Create a Processor, optionally passing in a Scrapy Settings object.
processor = Processor(settings=None)

# Start the reactor, and block until all spiders complete.
data = processor.run([githubJob, pythonJob])

# Print the consolidated results
print(json.dumps(data, indent=4))

[
    {
        "title": [
            "Welcome to Python.org"
        ],
        "url": "https://www.python.org/"
    },
    {
        "title": [
            "The world's leading software development platform \u00b7 GitHub",
            "1clr-code-hosting"
        ],
        "url": "https://github.com/"
    }
]

Answer 3

AFAIK 没有办法做到这一点，因为crawl()：

返回爬行完成时触发的延迟。

除了将结果输出到记录器之外，爬虫不会将结果存储在任何地方。

然而，返回输出会与 scrapy 的整个异步性质和结构发生冲突，因此保存到文件然后读取它是这里的首选方法。
您可以简单地设计将项目保存到文件的管道，然后简单地读取spider_output. 您将收到结果，因为reactor.run()它会阻止您的脚本，直到输出文件完成为止。