作用:实现深度爬取
爬取多个层级对应的页面数据
使用场景:爬取的数据没有在同一张页面
在手动请求的时候传递item:
yield scrapy.Request(url,callback,meta={‘item‘:item})
将meta这个字典传递给callback
callback中接收meta:
item = response.meta[‘item‘]
完整示例:
from moviePro.items import MovieproItem
class MovieSpider(scrapy.Spider):
name = ‘movie‘
# allowed_domains = [‘www.xxx.com‘]
start_urls = [‘https://www.4567tv.tv/index.php/vod/show/class/动作/id/1.html‘]
url = ‘https://www.4567tv.tv/index.php/vod/show/class/动作/id/1/page/%d.html‘
pageNum = 1
def parse(self, response):
li_list = response.xpath(‘/html/body/div[1]/div/div/div/div[2]/ul/li‘)
for li in li_list:
title = li.xpath(‘./div[1]/a/@title‘).extract_first()
detail_url = ‘https://www.4567tv.tv‘+li.xpath(‘./div[1]/a/@href‘).extract_first()
item = MovieproItem()
item[‘title‘] = title
#meta参数是一个字典,该字典就可以传递给callback指定的回调函数
yield scrapy.Request(detail_url,callback=self.parse_detail,meta={‘item‘:item})
if self.pageNum < 5:
self.pageNum += 1
new_url = format(self.url%self.pageNum)
yield scrapy.Request(new_url,callback=self.parse)
def parse_detail(self,response):
#接收meta:response.meta
item = response.meta[‘item‘]
desc = response.xpath(‘/html/body/div[1]/div/div/div/div[2]/p[5]/span[2]/text()‘).extract_first()
item[‘desc‘] = desc
yield item
原文:https://www.cnblogs.com/Hedger-Lee/p/13073958.html