scrapy爬虫

爬虫scrapy入门

好久没有搞爬虫了，今天将最重要的一段代码贴上，以后学习。

# -*- coding: utf-8 -*-
import scrapy
from properties.items import PropertiesItem
from scrapy.loader import ItemLoader
from scrapy.http import Request
import urlparse

class BasicSpider(scrapy.Spider):
    name = "manual"
    allowed_domains = ["www"]
    start_urls = (
    'http://www.meizitu.com/a/list_1_2.html',
)

def parse_item(self, response):
    #item = PropertiesItem()
    #self.log("img_url %s" % response.xpath('//*[@id="picture"]/p/img/@src').extract())

    #item['img_url'] = response.xpath('//*[@id="picture"]/p/img/@src').extract()
    #return item
    l = ItemLoader(item = PropertiesItem(), response=response)
    l.add_xpath('img_url','//*[@id="picture"]/p/img/@src')

    return l.load_item()


def parse(self,response):
    # Get the next index URLs and yield Requests
    next_selector = response.xpath('//*[@id="wp_page_numbers"]/ul/li[18]/a/@href')

    for url in next_selector.extract():
        yield Request(urlparse.urljoin(response.url,url))

    # Get item URLs and yield Requests
    item_selector = response.xpath('//*[@id="maincontent"]/div[1]/ul/li/div/div/a/@href')
    for url in item_selector.extract():
        yield Request(url,callback=self.parse_item)