方法和说明 |
extract()
它返回一个unicode字符串和选定的数据。
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re()
它返回一个unicode字符串列表,当正则表达式作为参数给出时提取。
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xpath()
它返回一个选择器列表,它表示由作为参数给出的 xpath 表达式选择的节点。
td> |
css()
它返回一个选择器列表,它表示由作为参数给出的 CSS 表达式选择的节点。
td> |
scrapy shell "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/"
[ ... Scrapy log here ... ] 2014-01-23 17:11:42-0400 [scrapy] DEBUG: Crawled (200) <GET http://www.dmoz.org/Computers/Programming/Languages/Python/Books/>(referer: None) [s] Available Scrapy objects: [s] crawler <scrapy.crawler.Crawler object at 0x3636b50> [s] item {} [s] request <GET http://www.dmoz.org/Computers/Programming/Languages/Python/Books/> [s] response <200 http://www.dmoz.org/Computers/Programming/Languages/Python/Books/> [s] settings <scrapy.settings.Settings object at 0x3fadc50> [s] spider <Spider 'default' at 0x3cebf50> [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]:
In [1]: response.xpath('//title') Out[1]: [<Selector xpath = '//title' data = u'<title>My Book-Scrapy'>] In [2]: response.xpath('//title').extract() Out[2]: [u'<title>My Book-Scrapy: Index: Chapters</title>'] In [3]: response.xpath('//title/text()') Out[3]: [<Selector xpath = '//title/text()' data = u'My Book-Scrapy: Index:'>] In [4]: response.xpath('//title/text()').extract() Out[4]: [u'My Book-Scrapy: Index: Chapters'] In [5]: response.xpath('//title/text()').re('(\w+):') Out[5]: [u'Scrapy', u'Index', u'Chapters']
response.xpath('//ul/li')
response.xpath('//ul/li/text()').extract()
response.xpath('//ul/li/a/text()').extract()
response.xpath('//ul/li/a/@href').extract()
import scrapy class MyprojectSpider(scrapy.Spider): name = "project" allowed_domains = ["dmoz.org"] start_urls = [ "http://www.dmoz.org/Computers/Programming/Languages/Python/Books/", "http://www.dmoz.org/Computers/Programming/Languages/Python/Resources/" ] def parse(self, response): for sel in response.xpath('//ul/li'): title = sel.xpath('a/text()').extract() link = sel.xpath('a/@href').extract() desc = sel.xpath('text()').extract() print title, link, desc