python框架Scrapy中crawlSpider的使用——爬取内容写进MySQL

一、先在MySQL中创建test数据库，和相应的site数据表

二、创建Scrapy工程

#scrapy startproject 工程名
scrapy startproject demo4

三、进入工程目录，根据爬虫模板生成爬虫文件

#scrapy genspider -l # 查看可用模板
#scrapy genspider -t 模板名 爬虫文件名 允许的域名
scrapy genspider -t crawl test sohu.com

四、设置IP池或用户代理（middlewares.py文件）

 # -*- coding: utf-8 -*-
 # 导入随机模块
 import random
 # 导入有关IP池有关的模块
 from scrapy.downloadermiddlewares.httpproxy import HttpProxyMiddleware
 # 导入有关用户代理有关的模块
 from scrapy.downloadermiddlewares.useragent import UserAgentMiddleware

 # IP池
 class HTTPPROXY(HttpProxyMiddleware):
     # 初始化 注意一定是 ip=''
     def __init__(self, ip=''):
         self.ip = ip

     def process_request(self, request, spider):
         item = random.choice(IPPOOL)
         try:
             print("当前的IP是："+item["ipaddr"])
             request.meta["proxy"] = "http://"+item["ipaddr"]
         except Exception as e:
             print(e)
             pass

 # 设置IP池
 IPPOOL = [
     {"ipaddr": "182.117.102.10:8118"},
     {"ipaddr": "121.31.102.215:8123"},
     {"ipaddr": "1222.94.128.49:8118"}
 ]

 # 用户代理
 class USERAGENT(UserAgentMiddleware):
     #初始化 注意一定是 user_agent=''
     def __init__(self, user_agent=''):
         self.user_agent = user_agent

     def process_request(self, request, spider):
         item = random.choice(UPPOOL)
         try:
             print("当前的User-Agent是："+item)
             request.headers.setdefault('User-Agent', item)
         except Exception as e:
             print(e)
             pass

 # 设置用户代理池
 UPPOOL = [
     "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Firefox/52.0", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3071.115 Safari/537.36", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.79 Safari/537.36 Edge/14.14393"
 ]

五、settngs.py配置

 COOKIES_ENABLED = False

 DOWNLOADER_MIDDLEWARES = {
     # 'scrapy.downloadermiddlewares.httpproxy.HttpProxyMiddleware':123,
     # 'demo4.middlewares.HTTPPROXY' : 125,
     'scrapy.downloadermiddlewares.useragent.UserAgentMiddleware': 2,
     'demo4.middlewares.USERAGENT': 1
 }

 ITEM_PIPELINES = {
     'demo4.pipelines.Demo4Pipeline': 300,
 }

六、定义爬取关注的数据（items.py文件）

 # -*- coding: utf-8 -*-
 import scrapy
 # Define here the models for your scraped items
 #
 # See documentation in:
 # http://doc.scrapy.org/en/latest/topics/items.html

 class Demo4Item(scrapy.Item):
     name = scrapy.Field()
     link = scrapy.Field()

七、爬虫文件编写（test.py）

 # -*- coding: utf-8 -*-
 import scrapy
 from scrapy.linkextractors import LinkExtractor
 from scrapy.spiders import CrawlSpider, Rule
 from demo4.items import Demo4Item

 class TestSpider(CrawlSpider):
     name = 'test'
     allowed_domains = ['sohu.com']
     start_urls = ['http://www.sohu.com/']

     rules = (
         Rule(LinkExtractor(allow=('http://news.sohu.com'), allow_domains=('sohu.com')), callback='parse_item',
              follow=False),
         # Rule(LinkExtractor(allow=('.*?/n.*?shtml'),allow_domains=('sohu.com')), callback='parse_item', follow=False),
     )

     def parse_item(self, response):
         i = Demo4Item()
         i['name'] = response.xpath('//div[@class="news"]/h1/a/text()').extract()
         i['link'] = response.xpath('//div[@class="news"]/h1/a/@href').extract()
         #i['description'] = response.xpath('//div[@id="description"]').extract()
         return i

八、管道文件编写（pipelines.py）

 # -*- coding: utf-8 -*-
 import pymysql
 import json
 # Define your item pipelines here
 #
 # Don't forget to add your pipeline to the ITEM_PIPELINES setting
 # See: http://doc.scrapy.org/en/latest/topics/item-pipeline.html

 class Demo4Pipeline(object):
     def __init__(self):
         # 数据库连接
         self.conn = pymysql.connect(host='localhost', user='root', password='', database='chapter17', charset='utf8')
         self.cur = self.conn.cursor()

     def process_item(self, item, spider):
         # 排除空值
         for j in range(0, len(item["name"])):
             nam = item["name"][j]
             lin = item["link"][j]
             print(type(nam))
             print(type(lin))
             # 注意参数化编写
             sql = "insert into site(name,link) values(%s,%s)"
             self.cur.execute(sql,(nam,lin))
             self.conn.commit()
         return item
     def close_spider(self, spider):
         self.cur.close()
         self.conn.close()

九、总结

1.注意在测试完数据库正常运行时，再开始写入数据，当然，在sql参数化处理的过程中，注意格式，千万不要弄错了