Python Scrapy | 如何将响应从蜘蛛传递给主 function

Question

我曾尝试广泛搜索解决方案，但可能没有使用正确的关键字。 I am aware that I can use the shell to work with CSS and XPath selectors immediately, but I would like to know if this is possible to do in the IDE environment outside of the spider class, namely in another cell.

示例代码：

class ExampleSpider(scrapy.Spider):
    name = "exampleSpider"
    start_urls = ["https://www.example.com"]
    
    def parse(self, response):
        URL = "www.example.com/1/"
        yield response

然后我希望能够在另一个单元格中使用此响应和选择器：

table_rows = response.xpath("//div[@class='example']/table/tr") # produces error
print(table_rows.xpath("td[4]//text()")[0] .get()

它产生错误： NameError: name 'response' is not defined

任何帮助/指导将不胜感激。

Answer 1

如果我理解正确，您希望蜘蛛返回响应并在主脚本中解析它？

主要.py：

from scrapy.crawler import CrawlerProcess, CrawlerRunner
from scrapy.utils.project import get_project_settings
from scrapy.signalmanager import dispatcher
from scrapy import signals


def spider_output(spider):
    output = []

    def get_output(item):
        output.append(item)

    dispatcher.connect(get_output, signal=signals.item_scraped)

    settings = get_project_settings()
    settings['USER_AGENT'] = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36'
    process = CrawlerProcess(settings)
    process.crawl(spider)
    process.start()

    return output


if __name__ == "__main__":
    spider = "exampleSpider"
    response = spider_output(spider)
    response = response[0]['response']
    title = response.xpath('//h3//text()').get()
    price = response.xpath('//div[@class="card-body"]/h4/text()').get()

    print(f"Title: {title}")
    print(f"Price: {price}")

我们启动蜘蛛并将生成的项目附加到output 。 由于output只有一个值，我们不必循环，只需取第一个值response[0] 。 然后我们想从键response中获取值，所以response = response[0]['response'] 。

蜘蛛.py：

import scrapy


class ExampleSpider(scrapy.Spider):
    name = "exampleSpider"
    start_urls = ['https://scrapingclub.com/exercise/detail_basic/']

    def parse(self, response):
        yield {'response': response}

在这里，我们返回一个带有响应的项目。

步骤是：main->spider_output->spider->将响应项返回到spider_output->将项目附加到output列表->将output返回给main->从Z78E6221F6393D14CE6DZ中获取响应->解析响应。

Output：

Title: Long-sleeved Jersey Top
Price: $12.99