爬虫练手：crawl模板用法小例

爬取目标：糗事百科全部文章的内容和网址。
直接上代码：

items.py

#糗事百科自动抓取
class QSBKAutoItem(scrapy.Item):
    # define the fields for your item here like:
    # name = scrapy.Field()
    content = scrapy.Field()
    link = scrapy.Field()

爬虫文件

# -*- coding: utf-8 -*-
import scrapy
from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule
from testscrapy01.items import QSBKAutoItem


class QsbkautoSpider(CrawlSpider):
    name = 'qsbkauto'
    allowed_domains = ['qiushibaike.com']
    start_urls = ['http://qiushibaike.com/']

    rules = (
        #指定链接提取的规律 r代表后面引号里面的字符均为非转义
        #follow:是指爬取了之后，是否还继续从该页面提取链接，然后继续爬下去
        Rule(LinkExtractor(allow=r'article'), callback='parse_item', follow=True),
    )

    def parse_item(self, response):
        item = QSBKAutoItem()
        #i['domain_id'] = response.xpath('//input[@id="sid"]/@value').extract()
        #i['name'] = response.xpath('//div[@id="name"]').extract()
        #i['description'] = response.xpath('//div[@id="description"]').extract()
        item["content"] = response.xpath("//div[@class='content']/text()").extract()[0]
        item["link"] = response.xpath("//link[@rel='canonical']/@href").extract()[0]
        print("内容：",item["content"])
        print("链接：",item["link"])
        print("*************************************************************")
        yield item

对以上代码的改进：

# coding=utf-8
from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule
from testscrapy01.items import QSBKAutoItem
import sys
reload(sys)
sys.setdefaultencoding('utf-8')

class QsbkautoSpider(CrawlSpider):
    name = 'qsbkauto1'
    allowed_domains = ['qiushibaike.com']
    start_urls = ['http://www.qiushibaike.com/']

    rules = (

        Rule(LinkExtractor(allow=r'page/\d*/?s=\d*'), follow=True),
        Rule(LinkExtractor(allow=(r'article/.*')), callback='parse_item',follow=True),
    )

    def parse_item(self, response):
        item = QSBKAutoItem()
        item["content"] = response.xpath("//div[@class='content']/text()").extract()[0]
        # item["link"] = response.xpath("//link[@rel='canonical']/@href").extract()[0]
        item["link"] = response.url
        content = "内容：" + item["content"]
        print(content.decode("utf-8"))
        link = "链接：" + item["link"]
        print(link.decode("utf-8"))
        print("*************************************************************")
        yield item