Scrapy 框架
Scrapy是用纯Python实现一个为了爬取网站数据、提取结构性数据而编写的应用框架，用途非常广泛。
框架的力量，用户只需要定制开发几个模块就可以轻松的实现一个爬虫，用来抓取网页内容以及各种图片，非常之方便。
Scrapy 使用了 Twisted['twɪstɪd] 异步网络框架来处理网络通讯，可以加快我们的下载速度，不用自己去实现异步框架，并且包含了各种中间件接口，可以灵活的完成各种需求。
Scrapy架构图
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Windows 安装方式
Python 3
升级pip版本：
pip3 install --upgrade pip
通过pip 安装 Scrapy 框架
pip3 install Scrapy
Ubuntu 安装方式
通过pip3 安装 Scrapy 框架
sudo pip3 install scrapy
如果安装不成功再试着添加这些依赖库：
安装非Python的依赖
sudo apt-get install python3-dev python-pip libxml2-dev libxslt1-dev zlib1g-dev libffi-dev libssl-dev
安装后，只要在命令终端输入 scrapy，提示类似以下结果，代表已经安装成功
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创建语句
创建爬虫项目
scrapy startproject jobboleproject
新建爬虫文件
scrapy genspider jobbole jobbole.com
启动爬虫
scrapy crawl jobbole
item.py文件
import scrapy
class XiachufangspiderItem(scrapy.Item):
# define the fields for your item here like:
name = scrapy.Field()
img = scrapy.Field()
yongliao = scrapy.Field()
zuofa = scrapy.Field()
path = scrapy.Field()
pipelines.py文件
import json
import scrapy
from scrapy.pipelines.images import ImagesPipeline
from scrapy.utils.project import get_project_settings
import os
class XiachufangspiderPipeline(object):
def __init__(self):
self.f = open('xiachufang.json', 'a')
def process_item(self, item, spider):
self.f.write(json.dumps(dict(item), ensure_ascii=False)+'\n')
return item
def close_spider(self, spider):
self.f.close()
#把这个配置路径拿到
IMAGES_STORE = get_project_settings().get('IMAGES_STORE')
#下载图片
class XiachufangImgspiderPipeline(ImagesPipeline):
def get_media_requests(self, item, info):
#发起图片请求,把结果回调给item_completed
return scrapy.Request(url=item['img'])
def item_completed(self, results, item, info):
# for ok,x in results:
# if ok:
# x['path']
if imgs:
os.rename(IMAGES_STORE + imgs[0],
IMAGES_STORE + item['name'] + '.jpg')
item['path'] = os.getcwd() + '/' + IMAGES_STORE + item['name'] + '.jpg'
else:
item['path'] = ""
return item
xiachufang.py文件
# -*- coding: utf-8 -*-
import scrapy
from XiachufangSpider.items import XiachufangspiderItem
class XiachufangSpider(scrapy.Spider):
name = 'xiachufang'
allowed_domains = ['xiachufang.com']
start_urls = ['http://www.xiachufang.com/category/40076/']
def parse(self, response):
div_list = response.xpath('//div[@class="pure-u-3-4 category-recipe-list"]//div[@class="normal-recipe-list"]//li')
for div in div_list:
url = div.xpath('.//p[@class="name"]/a/@href').extract_first('')
print(url)
yield scrapy.Request(url='http://www.xiachufang.com' + url, callback=self.parseDetail)
def parseDetail(self, response):
item = XiachufangspiderItem()
name = response.xpath('//h1/text()').extract_first('').replace('\n', '').strip()
img = response.xpath('//div[@class="cover image expandable block-negative-margin"]/img/@src').extract_first('').replace('\n', '').strip()
yongliao = ''.join(response.xpath('//tr/td//text()').extract()).replace('\n', '').replace(' ', '')
zuofa = ''.join(response.xpath('//div[@class="steps"]//p/text()').extract())
item['name'] = name
item['img'] = img
item['yongliao'] = yongliao
item['zuofa'] = zuofa
print(item)
yield item
