Question

我是一个蟒蛇新手，并尝试使用scrapy进行项目。 Scrapy 0.19安装在我的centos（linux 2.6.32）上，我按照scrapy文档页面上的说明进行操作，但发现，scrapy shell找不到'sel'对象，这是我的步骤：

[root@localhost rpm]# scrapy shell http://doc.scrapy.org/en/latest/_static/selectors-sample1.html
2014-03-02 06:33:23+0800 [scrapy] INFO: Scrapy 0.19.0 started (bot: scrapybot)
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Optional features available: ssl, http11, libxml2
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Overridden settings: {'LOGSTATS_INTERVAL': 0}
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Enabled extensions: TelnetConsole, CloseSpider, WebService, CoreStats, SpiderState
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Enabled downloader middlewares: HttpAuthMiddleware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultHeadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMiddleware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Enabled item pipelines: 
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Telnet console listening on 0.0.0.0:6023
2014-03-02 06:33:23+0800 [scrapy] DEBUG: Web service listening on 0.0.0.0:6080
2014-03-02 06:33:23+0800 [default] INFO: Spider opened
2014-03-02 06:33:24+0800 [default] DEBUG: Crawled (200) <GET 

http://doc.scrapy.org/en/latest/_static/selectors-sample1.html> (referer: None)
[s] Available Scrapy objects:
[s]   hxs        <HtmlXPathSelector xpath=None data=u'<html><head><base   href="http://example.c'>
[s]   item       {}
[s]   request    <GET http://doc.scrapy.org/en/latest/_static/selectors-sample1.html>
[s]   response   <200 http://doc.scrapy.org/en/latest/_static/selectors-sample1.html>
[s]   settings   <CrawlerSettings module=None>
[s]   spider     <BaseSpider 'default' at 0x3668ed0>
[s] Useful shortcuts:
[s]   shelp()           Shell help (print this help)
[s]   fetch(req_or_url) Fetch request (or URL) and update local objects
[s]   view(response)    View response in a browser

>>> sel.xpath('//title/text()')
Traceback (most recent call last):
File "<console>", line 1, in <module>
NameError: name 'sel' is not defined
>>>

谁能告诉我怎么解决？ thx提前

Answer 1

在sel版本中添加了0.20个对象。当您运行shell命令时，它会告诉您可以使用哪些对象，在您的情况下，hxs，它们具有类似的行为：

>>> hxs.select('//title/text()')

您应该先尝试阅读文档。在selectors部分中，非常清楚地说明了如何在当前版本中使用它们。

scrapy shell没有识别'sel'对象

1 个答案: