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：

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

2

3 from spider import spiderhtml

4 from multiprocessing import pool

5 import sys,urllib,http,os,random,re,time

6 __author__ = 'waiting'

7 '''

8 使用了第三方的类库 beautifulsoup4，请自行安装

9 需要目录下的spider.py文件

10 运行环境：python3.4,windows7

11 '''

12

13 #收藏夹的地址

14 url = 'https://www.zhihu.com/collection/30822111' #page参数改为代码添加

15

16 #本地存放的路径,不存在会自动创建

17 store_path = 'e:\\zhihu\收藏夹\\会员才知道的世界'

18

19 class zhihucollectionspider(spiderhtml):

20 def __init__(self,pagestart, pageend, url):

21 self._url = url

22 self._pagestart = int(pagestart)

23 self._pageend = int(pageend)+1

24 self.downlimit = 0 #低于此赞同的答案不收录

25

26 def start(self):

27 for page in range(self._pagestart,self._pageend): #收藏夹的页数

28 url = self._url + '?page='+str(page)

29 content = self.geturl(url)

30 questionlist = content.find_all('div',class_='zm-item')

31 for question in questionlist: #收藏夹的每个问题

32 qtitle = question.find('h2',class_='zm-item-title')

33 if qtitle is none: #被和谐了

34 continue

35

36 questionstr = qtitle.a.string

37 qurl = 'https://www.zhihu.com'+qtitle.a['href'] #问题题目

38 qtitle = re.sub(r'[\\/:*?"<>]','#',qtitle.a.string) #windows文件/目录名不支持的特殊符号

39 try:

40 print('-----正在获取问题:'+qtitle+'-----') #获取到问题的链接和标题，进入抓取

41 except unicodeencodeerror:

42 print(r'---问题含有特殊字符无法显示---')

43 try:

44 qcontent = self.geturl(qurl)

45 except:

46 print('!!!!获取出错!!!!!')

47 pass

48 answerlist = qcontent.find_all('div',class_='zm-item-answer zm-item-expanded')

49 self._processanswer(answerlist,qtitle) #处理问题的答案

50 time.sleep(5)

51

52

53 def _processanswer(self,answerlist,qtitle):

54 j = 0

55 for answer in answerlist:

56 j = j + 1

57

58 upvoted = int(answer.find('span',class_='count').string.replace('k','000')) #获得此答案赞同数

59 if upvoted < self.downlimit:

60 continue

61 authorinfo = answer.find('div',class_='zm-item-answer-author-info') #获取作者信息

62 author = {'introduction':'','link':''}

63 try:

64 author['name'] = authorinfo.find('a',class_='author-link').string #获得作者的名字

65 author['introduction'] = str(authorinfo.find('span',class_='bio')['title']) #获得作者的简介

66 author['link'] = authorinfo.find('a',class_='author-link')['href']

67 except attributeerror:

68 author['name'] = '匿名用户'+str(j)

69 except typeerror: #简介为空的情况

70 pass #匿名用户没有链接

71

72 file_name = os.path.join(store_path,qtitle,'info',author['name']+'_info.txt')

73 if os.path.exists(file_name): #已经抓取过

74 continue

75

76 self.savetext(file_name,'{introduction}\r\n{link}'.format(**author)) #保存作者的信息

77 print('正在获取用户`{name}`的答案'.format(**author))

78 answercontent = answer.find('div',class_='zm-editable-content clearfix')

79 if answercontent is none: #被举报的用户没有答案内容

80 continue

81

82 imgs = answercontent.find_all('img')

83 if len(imgs) == 0: #答案没有上图

84 pass

85 else:

86 self._getimgfromanswer(imgs,qtitle,**author)

87

88 #收录图片

89 def _getimgfromanswer(self,imgs,qtitle,**author):

90 i = 0

91 for img in imgs:

92 if 'inline-image' in img['class']: #不抓取知乎的小图

93 continue

94 i = i + 1

95 imgurl = img['src']

96 extension = os.path.splitext(imgurl)[1]

97 path_name = os.path.join(store_path,qtitle,author['name']+'_'+str(i)+extension)

98 try:

99 self.saveimg(imgurl,path_name) #捕获各种图片异常，流程不中断

100 except:

101 pass

102

103 #收录文字

104 def _gettextfromanswer(self):

105 pass

106

107 #命令行下运行，例：zhihu.py 1 5 获取1到5页的数据

108 if __name__ == '__main__':

109 page, limit, paramsnum= 1, 0, len(sys.argv)

110 if paramsnum>=3:

111 page, pageend = sys.argv[1], sys.argv[2]

112 elif paramsnum == 2:

113 page = sys.argv[1]

114 pageend = page

115 else:

116 page,pageend = 1,1

117

118 spider = zhihucollectionspider(page,pageend,url)

119 spider.start()

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