爬取评论运行成功但是文件无内容

极客星

要爬取某产品的评论，但是运行后生成了保存文件，但是文件却无内容。

scrawl的代码如下：

import scrapy
from tutorial.items import CommentItem

class CommentSpider(scrapy.Spider):
        name = "comment"
        #allowed_domains = ['dmoztools.net'] #要爬取的网页最开始的网址，注释掉也可以？
        start_urls = ['https://www.xiaomiyoupin.com/detail?gid=105472']
       
        def parse(self, response):
                sel = scrapy.selector.Selector(response)
                sites = sel.xpath('//*[@id="root"]/div/div[3]/div/div[1]/div[2]/div[1]/div[2]/div/div[2]/div[1]')   
                items = []
                for site in sites:
                        item = CommentItem()
                        #item['title'] = site.xpath('a/div/text()').extract()
                        #item['link'] = site.xpath('a/@href').extract()
                        item['desc'] = site.xpath('div[1]/div[2]/text()').extract()
                        items.append(item)
                       
                return items
               


输入：scrapy crawl comment -o items.csv -t csv
结果如下：
2019-05-18 23:00:34 [scrapy.utils.log] INFO: Scrapy 1.6.0 started (bot: tutorial)
2019-05-18 23:00:34 [scrapy.utils.log] INFO: Versions: lxml 4.3.3.0, libxml2 2.9.5, cssselect 1.0.3, parsel 1.5.1, w3lib 1.20.0, Twisted 19.2.0, Python 3.6.6 (v3.6.6:4cf1f54eb7, Jun 27 2018, 03:37:03) [MSC v.1900 64 bit (AMD64)], pyOpenSSL 19.0.0 (OpenSSL 1.1.1b  26 Feb 2019), cryptography 2.6.1, Platform Windows-10-10.0.16299-SP0
2019-05-18 23:00:34 [scrapy.crawler] INFO: Overridden settings: {'BOT_NAME': 'tutorial', 'FEED_FORMAT': 'csv', 'FEED_URI': 'items.csv', 'NEWSPIDER_MODULE': 'tutorial.spiders', 'ROBOTSTXT_OBEY': True, 'SPIDER_MODULES': ['tutorial.spiders']}
2019-05-18 23:00:34 [scrapy.extensions.telnet] INFO: Telnet Password: f2c681ad1dfdf14f
2019-05-18 23:00:34 [scrapy.middleware] INFO: Enabled extensions:
['scrapy.extensions.corestats.CoreStats',
'scrapy.extensions.telnet.TelnetConsole',
'scrapy.extensions.feedexport.FeedExporter',
'scrapy.extensions.logstats.LogStats']
2019-05-18 23:00:34 [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']
2019-05-18 23:00:34 [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']
2019-05-18 23:00:34 [scrapy.middleware] INFO: Enabled item pipelines:
[]
2019-05-18 23:00:34 [scrapy.core.engine] INFO: Spider opened
2019-05-18 23:00:34 [scrapy.extensions.logstats] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2019-05-18 23:00:35 [scrapy.extensions.telnet] INFO: Telnet console listening on 127.0.0.1:6023
2019-05-18 23:00:35 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.xiaomiyoupin.com/robots.txt> (referer: None)
2019-05-18 23:00:35 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.xiaomiyoupin.com/detail?gid=105472> (referer: None)
2019-05-18 23:00:35 [scrapy.core.engine] INFO: Closing spider (finished)
2019-05-18 23:00:35 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 465,
'downloader/request_count': 2,
'downloader/request_method_count/GET': 2,
'downloader/response_bytes': 4094,
'downloader/response_count': 2,
'downloader/response_status_count/200': 2,
'finish_reason': 'finished',
'finish_time': datetime.datetime(2019, 5, 18, 15, 0, 35, 417569),
'log_count/DEBUG': 2,
'log_count/INFO': 9,
'response_received_count': 2,
'robotstxt/request_count': 1,
'robotstxt/response_count': 1,
'robotstxt/response_status_count/200': 1,
'scheduler/dequeued': 1,
'scheduler/dequeued/memory': 1,
'scheduler/enqueued': 1,
'scheduler/enqueued/memory': 1,
'start_time': datetime.datetime(2019, 5, 18, 15, 0, 34, 998829)}
2019-05-18 23:00:35 [scrapy.core.engine] INFO: Spider closed (finished)

生成了文件，但是里面无内容，就大神指点。

_谪仙

yield item,去掉return

极客星

_谪仙 发表于 2019-5-19 00:36
yield item,去掉return

大神，我把最后的returnitems 换成 yield items，还是没用，输出的还是空文档

_谪仙

1. for site in sites:
   
2.                         item = CommentItem()
   
3.                         #item['title'] = site.xpath('a/div/text()').extract()
   
4.                         #item['link'] = site.xpath('a/@href').extract()
   
5.                         item['desc'] = site.xpath('div[1]/div[2]/text()').extract()
   
6.                         //items.append(item)
   
7.                         yield item
   
8.                 //return items
   
9.                

复制代码

_谪仙

极客星 发表于 2019-5-19 12:20
大神，我把最后的returnitems 换成 yield items，还是没用，输出的还是空文档

是CommentItem()的对象，不是items

极客星

_谪仙 发表于 2019-5-19 12:21

双//打进去报错啊，这样的话运行后还是没有结果

        def parse(self, response):
                sel = scrapy.selector.Selector(response)
                sites = sel.xpath('//*[@id="root"]/div/div[3]/div/div[1]/div[2]/div[1]/div[2]/div/div[2]/div[1]')   
                items = []
                for site in sites:
                        item = CommentItem()
                        #item['title'] = site.xpath('a/div/text()').extract()
                        #item['link'] = site.xpath('a/@href').extract()
                        item['desc'] = site.xpath('div[1]/div[2]/text()').extract()
                        items.append(item)
                       
               
                        yield items
                return items
               

_谪仙

极客星 发表于 2019-5-19 12:53
双//打进去报错啊，这样的话运行后还是没有结果

        def parse(self, response):

注释写错了，那个是C的，把//改成#