前言

D:\pythonwork>scrapy shell www.baidu.com

# -*- coding: utf-8 -*-
import scrapy
from wallpaper.items import WallpaperItem


class WallspiderSpider(scrapy.Spider):
    name = 'wallspider'
    allowed_domains = ['wall.alphacoders.com']
    start_urls = ['https://wall.alphacoders.com/']


    def parse(self, response):
        picx_list = response.xpath("//div[@class='center']//div[@class='boxgrid']/a/@href").getall()

        for picx in picx_list:
            url = 'https://wall.alphacoders.com/'+str(picx)
            #回调给下一层处理函数
            yield scrapy.Request(url,callback=self.detail_parse)


    def detail_parse(self, response):
        pic_url = response.xpath("//*[@id='page_container']/div[4]/a/@href").get()
        pic_size = response.xpath("//*[@id='wallpaper_info_table']/tbody//span/span[2]/a/text()").get()
        pic_name = response.xpath("//*[@id='page_container']/div/a[4]/span/text()").get()
        wall_item = WallpaperItem()
        wall_item['pic_url'] = pic_url
        wall_item['pic_size'] = pic_size.split()[0]
        wall_item['pic_name'] = pic_name
        print(wall_item)
        return wall_item

yield scrapy.Request(item['url'], meta={'item': item}, callback=self.detail_parse)

# -*- coding: utf-8 -*-
import scrapy
from Tencent.items import TencentItem
 
 
class TencentSpider(scrapy.Spider):
    # 爬虫名称
    name = 'tencent'
    # 允许爬取的域名
    allowed_domains = ['www.xxx.com']
    # 爬虫基础地址 用于爬虫域名的拼接
    base_url = 'https://www.xxx.com/'
    # 爬虫入口爬取地址
    start_urls = ['https://www.xxx.com/position.php']
    # 爬虫爬取页数控制初始值
    count = 1
    # 爬虫爬取页数 10为只爬取一页
    page_end = 1
 
    def parse(self, response):
 
 
        nodeList = response.xpath("//table[@class='tablelist']/tr[@class='odd'] | //table[@class='tablelist']/tr[@class='even']")
        for node in nodeList:
            item = TencentItem()
 
            item['title'] = node.xpath("./td[1]/a/text()").extract()[0]
            if len(node.xpath("./td[2]/text()")):
                item['position'] = node.xpath("./td[2]/text()").extract()[0]
            else:
                item['position'] = ''
            item['num'] = node.xpath("./td[3]/text()").extract()[0]
            item['address'] = node.xpath("./td[4]/text()").extract()[0]
            item['time'] = node.xpath("./td[5]/text()").extract()[0]
            item['url'] = self.base_url + node.xpath("./td[1]/a/@href").extract()[0]
            # 根据内页地址爬取
            yield scrapy.Request(item['url'], meta={'item': item}, callback=self.detail_parse)
 
            # 有下级页面爬取 注释掉数据返回
            # yield item
 
        # 循环爬取翻页
        nextPage = response.xpath("//a[@id='next']/@href").extract()[0]
        # 爬取页数控制及末页控制
        if self.count < self.page_end and nextPage != 'javascript:;':
            if nextPage is not None:
                # 爬取页数控制值自增
                self.count = self.count + 1
                # 翻页请求
                yield scrapy.Request(self.base_url + nextPage, callback=self.parse)
        else:
            # 爬虫结束
            return None
 
    def detail_parse(self, response):
        # 接收上级已爬取的数据
        item = response.meta['item']   
 
        #一级内页数据提取 
        item['zhize'] = response.xpath("//*[@id='position_detail']/div/table/tr[3]/td/ul[1]").xpath('string(.)').extract()[0]
        item['yaoqiu'] = response.xpath("//*[@id='position_detail']/div/table/tr[4]/td/ul[1]").xpath('string(.)').extract()[0]
 
        # 二级内页地址爬取
        yield scrapy.Request(item['url'] + "&123", meta={'item': item}, callback=self.detail_parse2)
 
        # 有下级页面爬取 注释掉数据返回
        # return item
 
    def detail_parse2(self, response):
        # 接收上级已爬取的数据
        item = response.meta['item']
 
        # 二级内页数据提取 
        item['test'] = "111111111111111111"
 
        # 最终返回数据给爬虫引擎
        return item