python - Scrapy - 不会爬行

Question

我正在尝试运行递归爬行，由于我编写的爬行不能正常工作，因此我从网络上提取了一个示例并进行了尝试。我真的不知道问题出在哪里，但是爬行没有显示任何错误。谁能帮我解决这个问题。

另外，是否有任何逐步调试工具可以帮助理解蜘蛛的爬行流程。

非常感谢任何有关此问题的帮助。

MacBook:spiders hadoop$ scrapy crawl craigs -o items.csv -t csv
/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/zope/__init__.py:1: UserWarning: Module pkg_resources was already imported from /System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/pkg_resources.pyc, but /Library/Python/2.6/site-packages is being added to sys.path__import__('pkg_resources').declare_namespace(__name__)
/System/Library/Frameworks/Python.framework/Versions/2.6/Extras/lib/python/zope/__init__.py:1: UserWarning: Module site was already imported from /System/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site.pyc, but /Library/Python/2.6/site-packages is being added to sys.path__import__('pkg_resources').declare_namespace(__name__)
2013-02-08 20:35:55+0530 [scrapy] INFO: Scrapy 0.16.4 started (bot: myspider)
2013-02-08 20:35:55+0530 [scrapy] DEBUG: Enabled extensions: FeedExporter, LogStats, TelnetConsole, CloseSpider, WebService, CoreStats, SpiderState
2013-02-08 20:35:55+0530 [scrapy] DEBUG: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultHeadersMiddleware, RedirectMiddleware, CookiesMiddleware, HttpCompressionMiddleware, ChunkedTransferMiddleware, DownloaderStats
2013-02-08 20:35:55+0530 [scrapy] DEBUG: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
2013-02-08 20:35:55+0530 [scrapy] DEBUG: Enabled item pipelines: 
2013-02-08 20:35:55+0530 [craigs] INFO: Spider opened
2013-02-08 20:35:55+0530 [craigs] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 items (at 0 items/min)
2013-02-08 20:35:55+0530 [scrapy] DEBUG: Telnet console listening on 0.0.0.0:6023
2013-02-08 20:35:55+0530 [scrapy] DEBUG: Web service listening on 0.0.0.0:6080
2013-02-08 20:35:58+0530 [craigs] DEBUG: Crawled (200) <GET http://sfbay.craigslist.org/npo/> (referer: None)
2013-02-08 20:35:58+0530 [craigs] INFO: Closing spider (finished)
2013-02-08 20:35:58+0530 [craigs] INFO: Dumping Scrapy stats:
    {'downloader/request_bytes': 230,
     'downloader/request_count': 1,
 'downloader/request_method_count/GET': 1,
 'downloader/response_bytes': 7291,
 'downloader/response_count': 1,
 'downloader/response_status_count/200': 1,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2013, 2, 8, 15, 5, 58, 415553),
 'log_count/DEBUG': 7,
 'log_count/INFO': 4,
 'response_received_count': 1,
 'scheduler/dequeued': 1,
 'scheduler/dequeued/memory': 1,
 'scheduler/enqueued': 1,
 'scheduler/enqueued/memory': 1,
 'start_time': datetime.datetime(2013, 2, 8, 15, 5, 55, 343482)}
2013-02-08 20:35:58+0530 [craigs] INFO: Spider closed (finished)

我使用的代码如下，

from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import HtmlXPathSelector
#from craigslist_sample.items import CraigslistSampleItem

class MySpider(CrawlSpider):
    name = "craigs"
    allowed_domains = ["sfbay.craigslist.org"]
    start_urls = ["sfbay.craigslist.org/npo/"]

     rules = (Rule (SgmlLinkExtractor(allow=("d00\.html", ),restrict_xpaths=('//p[@id="nextpage"]',))
 , callback="parse_items", follow= True),
 )

    def parse_items(self, response):
        hxs = HtmlXPathSelector(response)
        titles = hxs.select("//p")
        items = []
        for titles in titles:
            item = CraigslistSampleItem()
            item ["title"] = titles.select("a/text()").extract()
            item ["link"] = titles.select("a/@href").extract()
            items.append(item)
        return(items)

Answer 1

1. 按照 payala 建议修改您的 SgmlLinkExtractor
2. 删除链接提取器的 restrict_xpaths 部分

这些更改将解决遇到的问题。我还会对用于选择标题的 xpath 提出以下建议，因为这将删除由于下一页链接也被选择而出现的空项目。

def parse_items(self, response):
    hxs = HtmlXPathSelector(response)
    titles = hxs.select("//p[@class='row']")