使用scrapy从网站提取链接时出错_Scrapy

使用scrapy从网站提取链接时出错

scrapy

使用scrapy从网站提取链接时出错,scrapy,Scrapy,当我执行以下代码时，我只能提取一个链接，而不是网站特定页面中的所有链接 from scrapy import Spider from scrapy.http import Request class BooksSpider(Spider): name = 'books' allowed_domains = ['books.toscrape.com/'] start_urls= ["http://books.toscrape.com"] def parse(

当我执行以下代码时，我只能提取一个链接，而不是网站特定页面中的所有链接

from scrapy import Spider
from scrapy.http import Request


class BooksSpider(Spider):
    name = 'books'
    allowed_domains = ['books.toscrape.com/']
    start_urls= ["http://books.toscrape.com"]


    def parse(self, response):
        books = response.xpath("//h3/a/@href").extract()

        for book in books:
            absolute_url = response.urljoin(book)
            yield Request(absolute_url), callback=self.parse_page)

    def parse_page(self, response):
        pass

这是只提取网站“books.toscrape.com”的第一个链接的输出。谁能帮我理解这里的错误是什么，或者这是由于一些系统错误造成的。这太令人沮丧了，因为所有的循环和其他一切都很好。我想收益率存在一些问题，我如何处理这个错误：

2020-05-26 12:09:23 [scrapy.utils.log] INFO: Scrapy 2.1.0 started (bot: scrap_book)
2020-05-26 12:09:23 [scrapy.utils.log] INFO: Versions: lxml 4.5.1.0, libxml2 2.9.5, cssselect 1.1.0, parsel 1.6.0, w3lib 1.22.0, Twisted 20.3.0, Python 3.8.2 (tags/v3.8.2:7b3ab59, Feb 25 2020, 22:45:29) [MSC v.1916 32 bit (Intel)], pyOpenSSL 19.1.0 (OpenSSL 1.1.1g  21 Apr 2020), cryptography 2.9.2, Platform Windows-10-10.0.18362-SP0
2020-05-26 12:09:23 [scrapy.utils.log] DEBUG: Using reactor: twisted.internet.selectreactor.SelectReactor
2020-05-26 12:09:23 [scrapy.crawler] INFO: Overridden settings:
{'BOT_NAME': 'scrap_book',
 'NEWSPIDER_MODULE': 'scrap_book.spiders',
 'ROBOTSTXT_OBEY': True,
 'SPIDER_MODULES': ['scrap_book.spiders']}
2020-05-26 12:09:23 [scrapy.extensions.telnet] INFO: Telnet Password: 7b1edefe67af4658
2020-05-26 12:09:23 [scrapy.middleware] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats',
 'scrapy.extensions.telnet.TelnetConsole',
 'scrapy.extensions.logstats.LogStats']
2020-05-26 12:09:25 [scrapy.middleware] INFO: Enabled downloader middlewares:
['scrapy.downloadermiddlewares.robotstxt.RobotsTxtMiddleware',
 'scrapy.downloadermiddlewares.httpauth.HttpAuthMiddleware',
 'scrapy.downloadermiddlewares.downloadtimeout.DownloadTimeoutMiddleware',
 'scrapy.downloadermiddlewares.defaultheaders.DefaultHeadersMiddleware',
 'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware',
 'scrapy.downloadermiddlewares.retry.RetryMiddleware',
 'scrapy.downloadermiddlewares.redirect.MetaRefreshMiddleware',
 'scrapy.downloadermiddlewares.httpcompression.HttpCompressionMiddleware',
 'scrapy.downloadermiddlewares.redirect.RedirectMiddleware',
 'scrapy.downloadermiddlewares.cookies.CookiesMiddleware',
 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware',
 'scrapy.downloadermiddlewares.stats.DownloaderStats']
2020-05-26 12:09:25 [scrapy.middleware] INFO: Enabled spider middlewares:
['scrapy.spidermiddlewares.httperror.HttpErrorMiddleware',
 'scrapy.spidermiddlewares.offsite.OffsiteMiddleware',
 'scrapy.spidermiddlewares.referer.RefererMiddleware',
 'scrapy.spidermiddlewares.urllength.UrlLengthMiddleware',
 'scrapy.spidermiddlewares.depth.DepthMiddleware']
2020-05-26 12:09:26 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2020-05-26 12:09:26 [scrapy.core.engine] INFO: Spider opened
2020-05-26 12:09:26 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2020-05-26 12:09:26 [scrapy.extensions.telnet] INFO: Telnet console listening on 127.0.0.1:6024
2020-05-26 12:09:26 [scrapy.core.engine] DEBUG: Crawled (404) <GET http://books.toscrape.com/robots.txt> (referer: None)
2020-05-26 12:09:26 [scrapy.core.engine] DEBUG: Crawled (200) <GET http://books.toscrape.com> (referer: None)
2020-05-26 12:09:27 [scrapy.spidermiddlewares.offsite] DEBUG: Filtered offsite request to 'books.toscrape.com': <GET http://books.toscrape.com/catalogue/a-light-in-the-attic_1000/ind 'response_received_count': 2,
 'robotstxt/request_count': 1,
 'robotstxt/response_count': 1,
 'robotstxt/response_status_count/404': 1,
 'scheduler/dequeued': 1,
 'scheduler/dequeued/memory': 1,
 'scheduler/enqueued': 1,
 'scheduler/enqueued/memory': 1,
 'start_time': datetime.datetime(2020, 5, 26, 6, 24, 26, 117907)}
2020-05-26 12:09:28 [scrapy.core.engine] INFO: Spider closed (finished)

2020-05-26 12:09:23[scrapy.utils.log]信息：scrapy 2.1.0已启动（bot:scrape\u book）
2020-05-26 12:09:23[scrapy.utils.log]信息：版本：lxml 4.5.1.0，libxml2.9.5，cssselect 1.1.0，parsel 1.6.0，w3lib 1.22.0，Twisted 20.3.0，Python 3.8.2（tags/v3.8.2:7b3ab59，2020年2月25日，22:45:29）[MSC v.1916 32位（英特尔）]，pyOpenSSL 19.1.1.0（OpenSSL.1.1g，2020年4月21日），加密2.9.2，平台Windows-10-SP0.1830
2020-05-26 12:09:23[scrapy.utils.log]调试：使用reactor:twisted.internet.selectreactor.selectreactor
2020-05-26 12:09:23[抓取程序]信息：覆盖设置：
{'BOT_NAME'：'scrape_book'，
“NEWSPIDER_模块”：“废书.蜘蛛”，
“机器人服从”：没错，
“SPIDER_模块”：['scrapt_book.SPIDER']}
2020-05-26 12:09:23[scrapy.extensions.telnet]信息：telnet密码：7b1edefe67af4658
2020-05-26 12:09:23[scrapy.middleware]信息：启用的扩展：
['scrapy.extensions.corestats.corestats'，
'scrapy.extensions.telnet.TelnetConsole'，
'scrapy.extensions.logstats.logstats']
2020-05-26 12:09:25[scrapy.middleware]信息：启用的下载程序中间件：
['scrapy.downloaderMiddleware.robotstxt.RobotsTxtMiddleware'，
'scrapy.downloaderMiddleware.httpauth.HttpAuthMiddleware'，
'scrapy.downloadermiddleware.downloadtimeout.DownloadTimeoutMiddleware'，
'scrapy.downloaderMiddleware.defaultheaders.DefaultHeadersMiddleware'，
'scrapy.DownloaderMiddleware.useragent.UserAgentMiddleware'，
'scrapy.DownloaderMiddleware.retry.RetryMiddleware'，
'scrapy.DownloaderMiddleware.redirect.MetaRefreshMiddleware'，
'scrapy.DownloaderMiddleware.httpcompression.HttpCompressionMiddleware'，
'scrapy.DownloaderMiddleware.redirect.RedirectMiddleware'，
“scrapy.DownloaderMiddleware.cookies.CookiesMiddleware”，
'scrapy.downloadermiddleware.httpproxy.HttpProxyMiddleware'，
'scrapy.downloadermiddleware.stats.DownloaderStats']
2020-05-26 12:09:25[scrapy.middleware]信息：启用的蜘蛛中间件：
['scrapy.spidermiddleware.httperror.httperror中间件'，
'刮皮.SpiderMiddleware.场外.场外Iddleware'，
“scrapy.Spidermiddleware.referer.RefererMiddleware”，
'scrapy.spiderMiddleware.urllength.UrlLengthMiddleware'，
'scrapy.spidermiddleware.depth.DepthMiddleware']
2020-05-26 12:09:26[scrapy.middleware]信息：启用的项目管道：
[]
2020-05-26 12:09:26[刮屑.堆芯.发动机]信息：十字轴已打开
2020-05-26 12:09:26[scrapy.extensions.logstats]信息：爬网0页（0页/分钟），爬网0项（0项/分钟）
2020-05-26 12:09:26[scrapy.extensions.telnet]信息：telnet控制台监听127.0.0.1:6024
2020-05-26 12:09:26[scrapy.core.engine]调试：爬网（404）（参考：无）
2020-05-26 12:09:26[scrapy.core.engine]调试：爬网（200）（参考：无）
2020-05-26 12:09:27[scrapy.spidermiddleware.offsite]调试：过滤到'books.toscrape.com'的非现场请求：正如scrapy所说，由于您允许的_域，链接被过滤：

DEBUG:对“books.toscrape.com”的已筛选异地请求

将您的代码更改为allowed_domains=['books.toscrape.com']
，它应该可以正常工作
此外，在您发布的代码中，由于在绝对url
后面有一个括号太多，因此收益率有一个错误。应该是：yield Request（绝对url，callback=self.parse\u page）
非常感谢。我只是个初学者，你的帮助对我来说意义重大。