Scrapy框架的使用

• Scrapy框架的安装
• pip install pywin32
• 下载 Twisted 包       pip install Twisted包的路径
• pip insatll scrapy
• Scrapy的基本使用
• 切换到开始项目的目录 
• scrapy startproject my_first_spider 命令创建一个新项目
• scrapy genspider my_first_spider www.xxx.com 
•  目录结构如下
• 

• # -*- coding: utf-8 -*-
  import scrapy
  from my_first_spider.items import MyFirstSpiderItem
  
  
  class FirstSpider(scrapy.Spider):
      # 当前spider的名称
      name = 'first'
  
      # 允许的域名
      # allowed_domains = ['www.xxx.com']
  
      # 开始的第一个url
      start_urls = ['https://www.zhipin.com/c101010100/?query=python开发&page=1&ka=page-1']
  
      url = 'https://www.zhipin.com/c101010100/?query=python开发&page=%d&ka=page-1'
      page = 1
  
      # 用于解析的解析函数, 适用 xpath, 必传参数response
      def parse(self, response):
          div_list = response.xpath('//div[@class="job-list"]/ul/li')
          for div in div_list:
              job = div.xpath('./div/div[1]/h3/a/div[1]/text()').extract_first()
              salary = div.xpath('./div/div[1]/h3/a/span/text()').extract_first()
              company = div.xpath('./div/div[2]/div/h3/a/text()').extract_first()
  
              item = MyFirstSpiderItem()
  
              item['job'] = job
              item['salary'] = salary
              item['company'] = company
  
              yield item  # 将item对象返回给数据持久化管道(pipelines)
  
          # 分页爬取
          if self.page <= 7:
              print(f'第{self.page}页爬取完毕,开始爬取第{self.page+1}页')
              self.page += 1
              yield scrapy.Request(url=self.url%self.page, callback=self.parse)

• # -*- coding: utf-8 -*-
  
  # Define here the models for your scraped items
  #
  # See documentation in:
  # https://doc.scrapy.org/en/latest/topics/items.html
  
  import scrapy
  
  
  # 与管道交互,实例化item对象进行交互,将爬取到的数据封装在对象中,以对象的方式进行文件间数据传递
  class MyFirstSpiderItem(scrapy.Item):
      # define the fields for your item here like:
      # name = scrapy.Field()
      job = scrapy.Field()
      salary = scrapy.Field()
      company = scrapy.Field()

• # -*- coding: utf-8 -*-
  
  # Define your item pipelines here
  #
  # Don't forget to add your pipeline to the ITEM_PIPELINES setting
  # See: https://doc.scrapy.org/en/latest/topics/item-pipeline.html
  
  import redis
  
  # 写入boss.txt文件
  class MyFirstSpiderPipeline(object):
  
      fp = None
  
      def open_spider(self, spider):
          print('开始爬虫')
          self.fp = open('./boss.txt', 'w', encoding='utf8')
  
      def close_spider(self, spider):
          self.fp.close()
          print('爬虫结束')
  
      def process_item(self, item, spider):
  
          self.fp.write(item['job']+':'+item['salary']+':'+item['company']+'
  ')
  
          return item
  
  
  # MySQL 写入管道
  class MySqlPipeline(object):
      conn = None
      cursor = None
  
      # 爬虫开始后如若使用管道, 首先执行open_spider方法(打开mysql数据库连接)
      def open_spider(self, spider):
  
          import pymysql.cursors
  
          self.conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', password='root',
                                       db='scrapy', charset='utf8')
          # print('-----', self.conn)
          print('打开MySQL连接, 开始写入')
  
      # 第二步 执行process_item 函数, 在其中进行写入操作, 如若有在此管道之后还有管道 此方法要将item对象返回
      def process_item(self, item, spider):
  
          self.cursor = self.conn.cursor()
          try:
              self.cursor.execute(
                  'INSERT INTO boss (job_name, salary, company) VALUES ("%s", "%s", "%s")' % (item['job'], item['salary'], item['company']))
              self.conn.commit()
          except Exception as e:
              self.conn.rollback()
              print('出现错误, 事件回滚')
              print(e)
  
      # 第三部爬虫结束后执行close_spider方法(关闭MySQL连接)
      def close_spider(self, spider):
  
          self.conn.close()
          self.cursor.close()
          print('MySQl 写入完毕')
  
  
  # Redis 写入管道
  class RedisPipeline(object):
  
      conn = None
  
      def open_spider(self, spider):
          self.conn = redis.Redis(host='127.0.0.1', port=6379)
  
      #  第二步 执行process_item 函数, 在其中进行写入操作, 如若有在此管道之后还有管道 此方法要将item对象返回
      def process_item(self, item, spider):
          import json
          dic = {
              'job_name': item['job'],
              'salary': item['salary'],
              'company': item['company']
          }
          try:
              self.conn.lpush('boss', json.dumps(dic))
              print('redis 写入成功')
          except Exception as e:
  
              print('redis 写入失败', e)
          return item

• # Configure item pipelines
  # See https://doc.scrapy.org/en/latest/topics/item-pipeline.html
  ITEM_PIPELINES = {
     'my_first_spider.pipelines.MyFirstSpiderPipeline': 300,
     'my_first_spider.pipelines.RedisPipeline': 301,
     'my_first_spider.pipelines.MySqlPipeline': 302,
  }
  
  
  BOT_NAME = 'my_first_spider'
  
  SPIDER_MODULES = ['my_first_spider.spiders']
  NEWSPIDER_MODULE = 'my_first_spider.spiders'
  
  
  # Crawl responsibly by identifying yourself (and your website) on the user-agent
  USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36'
  
  # Obey robots.txt rules
  ROBOTSTXT_OBEY = False

• • 在命令行中输入 scrapy crawl first --nolog  --nolog不显示日志
  • 爬取成功
  • 
  •