scrapy简书整站爬取

• 数据同步及异步存储到MySQL
• 对于ajax 加载的数据用selenium辅助加载解析
• 整站爬取提取url规则

jianshu.py 文件

import scrapy
from scrapy.linkextractors import LinkExtractor
from scrapy.spiders import CrawlSpider, Rule
from jianshu_spider.items import JianshuSpiderItem


class JianshuSpider(CrawlSpider):
    name = 'jianshu'
    allowed_domains = ['jianshu.com']
    start_urls = ['https://www.jianshu.com/']

    rules = (
        # 观察url发现，前缀都一样，后面是12个数字加小写字母的组合
        Rule(LinkExtractor(allow=r'.*/p/[0-9a-z]{12}.*'), callback='parse_detial', follow=True),
    )
    def parse_detial(self, response):
        title = response.xpath('//h1[@class="title"]/text()').extract_first('') # 提取标题
        avatar = response.xpath('//a[@class="avatar"]/img/@src').extract_first('') # 提取头像
        author = response.xpath('//span[@class="name"]/a/text()').extract_first('') # 提取作者
        publish_time = response.xpath('//span[@class="publish-time"]/text()').extract_first('') # 提取发布时间
        content = response.xpath('//div[@class="show-content"]').get() # 提取文章内容
        # 提取文章ip,也就是url上面的不一样的字符串
        process_url = response.url.split('?')[0] # 以问号分割取前一部分
        article_id = process_url.split('/')[-1] # 以 ‘/’ 分割获取最后一个字符串即为文章的id
        origin_url = response.url
        print(title)
        item = JianshuSpiderItem(title=title,avatar=avatar,author=author,publish_time=publish_time,
                             content=content,article_id=article_id,origin_url=origin_url)
        return item

item.py文件

import scrapy


class JianshuSpiderItem(scrapy.Item):
   # define the fields for your item here like:
   # name = scrapy.Field()
   title = scrapy.Field()
   avatar = scrapy.Field()
   author = scrapy.Field()
   publish_time = scrapy.Field()
   content = scrapy.Field()
   article_id = scrapy.Field()
   origin_url = scrapy.Field()

settings.py文件

ROBOTSTXT_OBEY = False
DOWNLOAD_DELAY = 1
DEFAULT_REQUEST_HEADERS = {
  'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8',
  'Accept-Language': 'en',
    'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36'
}
DOWNLOADER_MIDDLEWARES = {
   #'jianshu_spider.middlewares.JianshuSpiderDownloaderMiddleware': 543,
    'jianshu_spider.middlewares.SeleniumDownloadMiddleware': 543,

}
ITEM_PIPELINES = {
   'jianshu_spider.pipelines.JianshuSpiderPipeline': 300,
    #'jianshu_spider.pipelines.JianshuTwistedPipeline': 300,

}

pipelines.py文件

import pymysql
from twisted.enterprise import adbapi # 使用异步数据库处理连接池
from pymysql import cursors # 数据库游标类

class JianshuSpiderPipeline(object):
    def __init__(self):
        params = {
            'host':'127.0.0.1',
            'port':3306,
            'user':'root',
            'password':'1326628437',
            'database':'jianshu',
            'charset':'utf8'
        }
        self.conn = pymysql.connect(**params)
        self.sursor = self.conn.cursor()
        self._sql = None

    @property # 属性操作，可直接调用
    def sql(self):
        if not self._sql:
            self._sql = '''insert into article(title,author,avatar,publish_time,article_id,
            origin_url,content) value(%s,%s,%s,%s,%s,%s,%s)'''
            return self._sql
        return self._sql

    def process_item(self, item, spider):
        self.sursor.execute(self.sql,(item['title'],item['author'],item['avatar'],item['publish_time'],
                                      item['article_id'],item['origin_url'],item['content']))
        self.conn.commit()
        return item


# 异步实现插入数据库，插入操作是io操作，数据量大时，会出现堵塞，异步插入很有必要

class JianshuTwistedPipeline(object):
    def __init__(self):
        params = {
            'host':'127.0.0.1',
            'port':3306,
            'user':'root',
            'password':'1326628437',
            'database':'jianshu',
            'charset':'utf8',
            'cursorclass':cursors.DictCursor
        }
        # 调用异步连接池实现异步插入数据库
        self.dbpool = adbapi.ConnectionPool("pymysql",**params)
        self._sql = None

    @property
    def sql(self):
        if not self._sql:
            self._sql = '''insert into article(title,author,avatar,publish_time,article_id,
            origin_url,content) value(%s,%s,%s,%s,%s,%s,%s)'''
            return self._sql
        return self._sql

    def process_item(self,item,spider):
        # 异步插入数据
        defer = self.dbpool.runInteraction(self.insert_item,item)
        # 错误处理
        defer.addErrback(self.handle_error,item,spider)


    def insert_item(self,item,cursor):
        cursor.execute(self.sql,(item['title'],item['author'],item['avatar'],item['publish_time'],
                                      item['article_id'],item['origin_url'],item['content']))


    def handle_error(self,item,error,spider):
        print('+'*30 + 'error' + '+'*30)
        print(error)
        print('+'*30 + 'error' + '+'*30)

middleware.py文件

from selenium import webdriver
import time
from selenium.webdriver.common.by import By
from selenium.webdriver.support.wait import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from scrapy.http.response.html import HtmlResponse

# 用selenium重写请求过程，实现去爬取一些用ajax加载的页面
# 一些点赞数，评论数，喜欢数，推荐阅读的文章链接都是ajax加载的。
class SeleniumDownloadMiddleware(object):
    def __init__(self):
        self.browser = webdriver.Chrome() #
        self.wait = WebDriverWait(self.browser,10)

    def process_request(self,request,spider):
        self.browser.get(request.url)
        print('我正在用selenium自动化工具下载url')
        time.sleep(1)
        try:
            while True:
                # 这里因为有些文章下方有许多加载更多，在文章被一下专栏收录里，所以要重复点击
                showmore = self.browser.find_element_by_class_name('show-more')
                showmore.click()
                time.sleep(0.3)
                if not showmore:
                    break
        except:
            pass
        source = self.browser.page_source
        response = HtmlResponse(url=self.browser.current_url,request=request,body=source,encoding='utf-8')
        return response