我正在尝试接触 Scrapy，现在我尝试从词源网站提取信息:http://www.etymonline.com 现在，我只想得到这些词和它们的原始描述。这是 etymonline 中常见的 HTML 代码块的呈现方式:
<dt>
<a href="/index.php?term=address&allowed_in_frame=0">address (n.)</a>
<a href="http://dictionary.reference.com/search?q=address" class="dictionary" title="Look up address at Dictionary.com">
<img src="graphics/dictionary.gif" width="16" height="16" alt="Look up address at Dictionary.com" title="Look up address at Dictionary.com"/>
</a>
</dt>
<dd>
1530s, "dutiful or courteous approach," from <a href="/index.php?term=address&allowed_in_frame=0" class="crossreference">address</a> (v.) and from French <span class="foreign">adresse</span>. Sense of "formal speech" is from 1751. Sense of "superscription of a letter" is from 1712 and led to the meaning "place of residence" (1888).
</dd>
该词包含在 <dt> 中标记和下一个兄弟中的描述，<dd>标签。
获取页面上的单词列表，如 http://www.etymonline.com/index.php?l=a&p=9&allowed_in_frame=0 , 可以写成 word = sel.xpath('//dl/dt/a/text()').extract() .
然后我尝试遍历这个单词列表并使用这行代码提取相关信息 info = selInfo.xpath("//dl/dt[a='"+word[i]+"']/following-sibling::dd") .但这似乎不起作用。有什么想法吗？
最佳答案
前往 <dd>在<dt>之后, 您可以使用 following-sibling轴，你是对的。
following-sibling::dd全选 dd上下文节点之后的元素。因此，您需要使用位置谓词 [1] 将 XPath 限制为仅第一个。 .
对于每个 dt你得到的元素//dl/dt , 您选择 following-sibling::dd[1] .
这是一个使用 scrapy shell 的示例 session 对于术语“地址”:
$ scrapy shell "http://www.etymonline.com/index.php?allowed_in_frame=0&search=address&searchmode=none"
...
2014-11-26 10:34:53+0100 [default] DEBUG: Crawled (200) <GET http://www.etymonline.com/index.php?allowed_in_frame=0&search=address&searchmode=none> (referer: None)
[s] Available Scrapy objects:
[s] crawler <scrapy.crawler.Crawler object at 0x7f1396cc6950>
[s] item {}
[s] request <GET http://www.etymonline.com/index.php?allowed_in_frame=0&search=address&searchmode=none>
[s] response <200 http://www.etymonline.com/index.php?allowed_in_frame=0&search=address&searchmode=none>
[s] settings <scrapy.settings.Settings object at 0x7f1397399bd0>
[s] spider <Spider 'default' at 0x7f13966c05d0>
[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
In [1]: for dt in response.xpath('//dl/dt'):
print "Word:", dt.xpath('string(a)').extract()
print "Definition:", dt.xpath('string(following-sibling::dd[1])').extract()
print
...:
Word: [u'address (n.)']
Definition: [u'1530s, "dutiful or courteous approach," from address (v.) and from French adresse. Sense of "formal speech" is from 1751. Sense of "superscription of a letter" is from 1712 and led to the meaning "place of residence" (1888).']
Word: [u'addressee (n.)']
Definition: [u'1810; see address (v.) + -ee.']
Word: [u'address (v.)']
Definition: [u'early 14c., "to guide or direct," from Old French adrecier "go straight toward; straighten, set right; point, direct" (13c.), from Vulgar Latin *addirectiare "make straight," from Latin ad "to" (see ad-) + *directiare, from Latin directus "straight, direct" (see direct (v.)). Late 14c. as "to set in order, repair, correct." Meaning "to write as a destination on a written message" is from mid-15c. Meaning "to direct spoken words (to someone)" is from late 15c. Related: Addressed; addressing.']
Word: [u'salutatorian (n.)']
Definition: [u'1841, American English, from salutatory "of the nature of a salutation," here in the specific sense "designating the welcoming address given at a college commencement" (1702) + -ian. The address was originally usually in Latin and given by the second-ranking graduating student.']
...
Word: [u'reverend (adj.)']
Definition: [u'early 15c., "worthy of respect," from Middle French reverend, from Latin reverendus "(he who is) to be respected," gerundive of revereri (see reverence). As a form of address for clergymen, it is attested from late 15c.; earlier reverent (late 14c. in this sense). Abbreviation Rev. is attested from 1721, earlier Revd. (1690s). Very Reverend is used of deans, Right Reverend of bishops, Most Reverend of archbishops.']
Word: [u'nun (n.)']
Definition: [u'Old English nunne "nun, vestal, pagan priestess, woman devoted to religious life under vows," from Late Latin nonna "nun, tutor," originally (along with masc. nonnus) a term of address to elderly persons, perhaps from children\'s speech, reminiscent of nana (compare Sanskrit nona, Persian nana "mother," Greek nanna "aunt," Serbo-Croatian nena "mother," Italian nonna, Welsh nain "grandmother;" see nanny).']
In [2]:
关于python - Xpath 使用 Scrapy 获取下一个兄弟标签中的信息，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27139318/