Scrapy 简明教程
Scrapy - Using an Item
Description
Item 对象是 Python 的正规字典。我们可以使用以下语法来访问类的属性 −
>>> item = DmozItem()
>>> item['title'] = 'sample title'
>>> item['title']
'sample title'
将以上代码添加到以下示例 −
import scrapy
from tutorial.items import DmozItem
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'):
item = DmozItem()
item['title'] = sel.xpath('a/text()').extract()
item['link'] = sel.xpath('a/@href').extract()
item['desc'] = sel.xpath('text()').extract()
yield item
以上爬虫的输出将是 −
[scrapy] DEBUG: Scraped from <200
http://www.dmoz.org/Computers/Programming/Languages/Python/Books/>
{'desc': [u' - By David Mertz; Addison Wesley. Book in progress, full text,
ASCII format. Asks for feedback. [author website, Gnosis Software, Inc.\n],
'link': [u'http://gnosis.cx/TPiP/'],
'title': [u'Text Processing in Python']}
[scrapy] DEBUG: Scraped from <200
http://www.dmoz.org/Computers/Programming/Languages/Python/Books/>
{'desc': [u' - By Sean McGrath; Prentice Hall PTR, 2000, ISBN 0130211192,
has CD-ROM. Methods to build XML applications fast, Python tutorial, DOM and
SAX, new Pyxie open source XML processing library. [Prentice Hall PTR]\n'],
'link': [u'http://www.informit.com/store/product.aspx?isbn=0130211192'],
'title': [u'XML Processing with Python']}