一个简单的python爬虫,爬取知乎

一个简单的python爬虫,爬取知乎

• 主要实现 爬取一个收藏夹 里 所有问题答案下的 图片

• 文字信息暂未收录，可自行实现，比图片更简单

• 具体代码里有详细注释，请自行阅读

项目源码：

 # -*- coding:utf-8 -*-

 from spider import SpiderHTML
 from multiprocessing import Pool
 import sys,urllib,http,os,random,re,time
 __author__ = 'waiting'
 '''
 使用了第三方的类库 BeautifulSoup4，请自行安装
 需要目录下的spider.py文件
 运行环境：python3.4,windows7
 '''

 #收藏夹的地址
 url = 'https://www.zhihu.com/collection/30822111'  #page参数改为代码添加

 #本地存放的路径,不存在会自动创建
 store_path = 'E:\\zhihu\收藏夹\\会员才知道的世界'

 class zhihuCollectionSpider(SpiderHTML):
   def __init__(self,pageStart, pageEnd, url):
     self._url = url
     self._pageStart = int(pageStart)
     self._pageEnd = int(pageEnd)+1
     self.downLimit = 0            #低于此赞同的答案不收录

   def start(self):
     for page in range(self._pageStart,self._pageEnd):    #收藏夹的页数
       url = self._url + '?page='+str(page)
       content = self.getUrl(url)
       questionList = content.find_all('div',class_='zm-item')
       for question in questionList:            #收藏夹的每个问题
         Qtitle = question.find('h2',class_='zm-item-title')
         if Qtitle is None:                #被和谐了
           continue

         questionStr = Qtitle.a.string
         Qurl = 'https://www.zhihu.com'+Qtitle.a['href']  #问题题目
         Qtitle = re.sub(r'[\\/:*?"<>]','#',Qtitle.a.string)      #windows文件/目录名不支持的特殊符号
         try:
           print('-----正在获取问题:'+Qtitle+'-----')    #获取到问题的链接和标题，进入抓取
         except UnicodeEncodeError:
           print(r'---问题含有特殊字符无法显示---')
         try:
           Qcontent = self.getUrl(Qurl)
         except:
           print('!!!!获取出错!!!!!')
           pass
         answerList = Qcontent.find_all('div',class_='zm-item-answer  zm-item-expanded')
         self._processAnswer(answerList,Qtitle)            #处理问题的答案
         time.sleep(5)

   def _processAnswer(self,answerList,Qtitle):
     j = 0
     for answer in answerList:
       j = j + 1

       upvoted = int(answer.find('span',class_='count').string.replace('K',''))   #获得此答案赞同数
       if upvoted < self.downLimit:
         continue
       authorInfo = answer.find('div',class_='zm-item-answer-author-info')        #获取作者信息
       author = {'introduction':'','link':''}
       try:
         author['name'] = authorInfo.find('a',class_='author-link').string       #获得作者的名字
         author['introduction'] = str(authorInfo.find('span',class_='bio')['title']) #获得作者的简介
         author['link'] = authorInfo.find('a',class_='author-link')['href']
       except AttributeError:
         author['name'] = '匿名用户'+str(j)
       except TypeError:                                  #简介为空的情况
         pass                                     #匿名用户没有链接

       file_name = os.path.join(store_path,Qtitle,'info',author['name']+'_info.txt')
       if os.path.exists(file_name):              #已经抓取过
         continue

       self.saveText(file_name,'{introduction}\r\n{link}'.format(**author))      #保存作者的信息
       print('正在获取用户`{name}`的答案'.format(**author))
       answerContent = answer.find('div',class_='zm-editable-content clearfix')
       if answerContent is None:                #被举报的用户没有答案内容
         continue

       imgs = answerContent.find_all('img')
       if len(imgs) == 0:                    #答案没有上图
         pass
       else:
         self._getImgFromAnswer(imgs,Qtitle,**author)

   #收录图片
   def _getImgFromAnswer(self,imgs,Qtitle,**author):
     i = 0
     for img in imgs:
       if 'inline-image' in img['class']:          #不抓取知乎的小图
         continue
       i = i + 1
       imgUrl = img['src']
       extension = os.path.splitext(imgUrl)[1]
       path_name = os.path.join(store_path,Qtitle,author['name']+'_'+str(i)+extension)
       try:
         self.saveImg(imgUrl,path_name)          #捕获各种图片异常，流程不中断
       except:
         pass

   #收录文字
   def _getTextFromAnswer(self):
     pass

 #命令行下运行，例：zhihu.py 1 5   获取1到5页的数据
 if __name__ == '__main__':
   page, limit, paramsNum= 1, 0, len(sys.argv)
   if paramsNum>=3:
     page, pageEnd = sys.argv[1], sys.argv[2]
   elif paramsNum == 2:
     page = sys.argv[1]
     pageEnd = page
   else:
     page,pageEnd = 1,1

   spider = zhihuCollectionSpider(page,pageEnd,url)
   spider.start()

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