Question

我正在使用脚本文件在scrapy项目中运行蜘蛛，而蜘蛛正在记录爬虫输出/结果。但我想在某个函数中使用该脚本文件中的spider输出/结果。我不想将输出/结果保存在任何文件或数据库中。这是脚本代码来自https://doc.scrapy.org/en/latest/topics/practices.html#run-from-script

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

如何在蜘蛛网输出中获得蜘蛛输出？方法。可以获得输出/结果。

Answer 1

以下是将所有输出/结果列入列表的解决方案

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

AFAIK无法做到这一点，因为crawl()：

返回爬网结束时触发的延迟。

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，返回的输出会与scrapy的整个异步性质和结构发生冲突，因此保存到文件然后阅读它是一种优先的方法。
您可以简单地设计将项目保存到文件的管道，只需阅读spider_output中的文件即可。您将收到结果，因为reactor.run()阻止了您的脚本，直到输出文件仍然完整。

Answer 3

这是一个古老的问题，仅供以后参考。如果您使用的是Python 3.6+，我建议您使用scrapyscript，它可以让您以超级简单的方式运行Spider并获取结果：

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 4

我的建议是使用Python subprocess模块从脚本运行Spider，而不是使用scrapy docs中提供的方法从python脚本运行Spider。这样做的原因是，借助subprocess模块，您可以从蜘蛛内部捕获print的输出/日志，甚至语句。

在Python 3中，使用run方法执行蜘蛛程序。例如。

import subprocess
process = subprocess.run(command, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
if process.returncode == 0:
    result = process.stdout.decode('utf-8')
else:
    # code to check error using 'process.stderr'

将stdout / stderr设置为subprocess.PIPE将允许捕获输出，因此设置此标志非常重要。这里的command应该是一个序列或一个字符串（它是一个字符串，然后使用另外1个参数调用run方法：shell=True）。例如：

command = ['scrapy', 'crawl', 'website', '-a', 'customArg=blahblah']
# or
command = 'scrapy crawl website -a customArg=blahblah' # with shell=True
#or
import shlex
command = shlex.split('scrapy crawl website -a customArg=blahblah') # without shell=True

此外，process.stdout将包含脚本的输出，但类型为bytes。您需要使用str

将其转换为decode('utf-8')

Answer 5

它将返回列表中蜘蛛的所有结果。

from scrapyscript import Job, Processor
from scrapy.utils.project import get_project_settings


def get_spider_output(spider, **kwargs):
    job = Job(spider, **kwargs)
    processor = Processor(settings=get_project_settings())
    return processor.run([job])

在脚本文件函数

5 个答案: