如何用 Python 爬取社交网络

Posted 2023-05-05

参考技术A #!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Author: Administrator
# @Date: 2015-10-31 15:45:27
# @Last Modified by: Administrator
# @Last Modified time: 2015-11-23 16:57:31
import requests
import sys
import json
import re
reload(sys)
sys.setdefaultencoding('utf-8')

#获取到匹配字符的字符串
def find(pattern,test):
finder = re.search(pattern, test)
start = finder.start()
end = finder.end()
return test[start:end-1]

cookies =
'_ga':'GA1.2.10sdfsdfsdf', '_za':'8d570b05-b0b1-4c96-a441-faddff34',
'q_c1':'23ddd234234',
'_xsrf':'234id':'"ZTE3NWY2ZTsdfsdfsdfWM2YzYxZmE=|1446435757|15fef3b84e044c122ee0fe8959e606827d333134"',
'z_c0':'"QUFBQXhWNGZsdfsdRvWGxaeVRDMDRRVDJmSzJFN1JLVUJUT1VYaEtZYS13PT0=|14464e234767|57db366f67cc107a05f1dc8237af24b865573cbe5"',
'__utmt':'1', '__utma':'51854390.109883802f8.1417518721.1447917637.144c7922009.4',
'__utmb':'518542340.4.10.1447922009', '__utmc':'51123390', '__utmz':'5185435454sdf06.1.1.utmcsr=zhihu.com|utmcgcn=(referral)|utmcmd=referral|utmcct=/',
'__utmv':'51854340.1d200-1|2=registration_date=2028=1^3=entry_date=201330318=1'

headers = 'user-agent':
'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (Khtml, like Gecko) Chrome/38.0.2125.111 Safari/537.36',
'referer':'http://www.zhihu.com/question/following',
'host':'www.zhihu.com','Origin':'http://www.zhihu.com',
'Content-Type':'application/x-www-form-urlencoded; charset=UTF-8',
'Connection':'keep-alive','X-Requested-With':'XMLHttpRequest','Content-Length':'81',
'Accept-Encoding':'gzip,deflate','Accept-Language':'zh-CN,zh;q=0.8','Connection':'keep-alive'


#多次访问之后，其实一加载时加载20个问题，具体参数传输就是offset，以20递增

dicc = "offset":60
n=20
b=0

# 与爬取图片相同的是，往下拉的时候也会发送http请求返回json数据，但是不同的是，像模拟登录首页不同的是除了
# 发送form表单的那些东西后，知乎是拒绝了我的请求了，刚开始以为是headers上的拦截，往headers添加浏览器
# 访问是的headers那些信息添加上，发现还是拒绝访问。

#想了一下，应该是cookie原因。这个加载的请求和模拟登录首页不同
#所以补上其他的cookies信息，再次请求，请求成功。
for x in xrange(20,460,20):
n = n+20
b = b+20
dicc['offset'] = x
formdata = 'method':'next','params':'"offset":20','_xsrf':'20770d88051f0f45e941570645f5e2e6'

#传输需要json串，和python的字典是有区别的，需要转换
formdata['params'] = json.dumps(dicc)
# print json.dumps(dicc)
# print dicc

circle = requests.post("http://www.zhihu.com/node/ProfileFollowedQuestionsV2",
cookies=cookies,data=formdata,headers=headers)

#response内容 其实爬过一次之后就大同小异了。 都是
#问题返回的json串格式
# "r":0,
# "msg": ["<div class=\"zm-profile-section-item zg-clear\">\n
# <span class=\"zm-profile-vote-count\">\n<div class=\"zm-profile-vote-num\">205K<\/div>\n
# <div class=\"zm-profile-vote-type\">\u6d4f\u89c8<\/div>\n
# <\/span>\n<div class=\"zm-profile-section-main\">\n
# <h2 class=\"zm-profile-question\">\n
# <a class=\"question_link\" target=\"_blank\" href=\"\/question\/21719532\">
# \u4ec0\u4e48\u4fc3\u4f7f\u4f60\u8d70\u4e0a\u72ec\u7acb\u5f00\u53d1\u8005\u4e4b\u8def\uff1f<\/a>\n
# <\/h2>\n<div class=\"meta zg-gray\">\n<a data-follow=\"q:link\" class=\"follow-link zg-unfollow meta-item\"
# href=\"javascript:;\" id=\"sfb-868760\">
# <i class=\"z-icon-follow\"><\/i>\u53d6\u6d88\u5173\u6ce8<\/a>\n<span class=\"zg-bull\">•<\/span>\n63 \u4e2a\u56de\u7b54\n<span class=\"zg-bull\">•<\/span>\n3589 \u4eba\u5173\u6ce8\n<\/div>\n<\/div>\n<\/div>",
# "<div class=\"zm-profile-section-item zg-clear\">\n
# <span class=\"zm-profile-vote-count\">\n
# <div class=\"zm-profile-vote-num\">157K<\/div>\n
# <div class=\"zm-profile-vote-type\">\u6d4f\u89c8<\/div>\n
# <\/span>\n<div class=\"zm-profile-section-main\">\n
# <h2 class=\"zm-profile-question\">\n
# <a class=\"question_link\" target=\"_blank\" href=\"\/question\/31764065\">
# \u672c\u79d1\u6e23\u6821\u7684\u5b66\u751f\u5982\u4f55\u8fdb\u5165\u7f8e\u5e1d\u725b\u6821\u8bfbPhD\uff1f<\/a>\n
# <\/h2>\n<div class=\"meta zg-gray\">\n
# <a data-follow=\"q:link\" class=\"follow-link zg-unfollow meta-item\" href=\"javascript:;\" id=\"sfb-4904877\">
# <i class=\"z-icon-follow\"><\/i>\u53d6\u6d88\u5173\u6ce8<\/a>\n<span class=\"zg-bull\">•
# <\/span>\n112 \u4e2a\u56de\u7b54\n<span class=\"zg-bull\">•<\/span>\n1582 \u4eba\u5173\u6ce8\n
# <\/div>\n<\/div>\n<\/div>"]
# print circle.content

#同样json串需要自己 转换成字典后使用
jsondict = json.loads(circle.text)
msgstr = jsondict['msg']
# print len(msgstr)

#根据自己所需要的提取信息规则写出正则表达式
pattern = 'question\/.*?/a>'
try:
for y in xrange(0,20):
wholequestion = find(pattern, msgstr[y])
pattern2 = '>.*?<'
finalquestion = find(pattern2, wholequestion).replace('>','')
print str(b+y)+" "+finalquestion

#当问题已经访问完后再传参数 抛出异常 此时退出循环
except Exception, e:
print "全部%s个问题" %(b+y)
break

如何用python 爬虫在社交媒体上抓取评论

参考技术A 这个和用不用python没啥关系，是数据来源的问题。

调用淘宝API，使用 api相关接口获得你想要的内容，我 记得api中有相关的接口，你可以看一下接口的说明。
用python做爬虫来进行页面数据的获取。
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希望能帮到你。