对知乎内容使用爬虫爬取数据，为什么会遇到403问题？

#encoding=utf8
import urllib2
import json
import requests
from bs4 import BeautifulSoup

Default_Header = {'X-Requested-With': 'XMLHttpRequest',
                  'Referer': 'http://www.zhihu.com',
                  'User-Agent': 'Mozilla/5.0 (X11; Ubuntu; Linux x86_64; '
                                'rv:39.0) Gecko/20100101 Firefox/39.0',
                  'Host': 'www.zhihu.com'}
_session = requests.session()
_session.headers.update(Default_Header) 
resourceFile = open('/root/Desktop/UserId.text','r')
resourceLines = resourceFile.readlines()
resultFollowerFile = open('/root/Desktop/userIdFollowees.text','a+')
resultFolloweeFile = open('/root/Desktop/userIdFollowers.text','a+')

BASE_URL = 'https://www.zhihu.com/'
CAPTURE_URL = BASE_URL+'captcha.gif?r=1466595391805&type=login'
PHONE_LOGIN = BASE_URL + 'login/phone_num'

def login():
    '''登录知乎'''
    username = ''#用户名
    password = ''#密码，注意我这里用的是手机号登录，用邮箱登录需要改一下下面登录地址
    cap_content = urllib2.urlopen(CAPTURE_URL).read()
    cap_file = open('/root/Desktop/cap.gif','wb')
    cap_file.write(cap_content)
    cap_file.close()
    captcha = raw_input('capture:')
    data = {"phone_num":username,"password":password,"captcha":captcha}
    r = _session.post(PHONE_LOGIN, data)
    print (r.json())['msg']
    
def readFollowerNumbers(followerId,followType):
    '''读取每一位用户的关注者和追随者，根据type进行判断'''
    print followerId
    personUrl = 'https://www.zhihu.com/people/' + followerId.strip('\n')
    xsrf =getXsrf()
    hash_id = getHashId(personUrl)
    headers = dict(Default_Header)
    headers['Referer']= personUrl + '/follow'+followType
    followerUrl = 'https://www.zhihu.com/node/ProfileFollow'+followType+'ListV2'
    params = {"offset":0,"order_by":"created","hash_id":hash_id}
    params_encode = json.dumps(params)
    data = {"method":"next","params":params_encode,'_xsrf':xsrf}
    
    signIndex = 20
    offset = 0
    while signIndex == 20:
        params['offset'] = offset
        data['params'] = json.dumps(params)
        followerUrlJSON = _session.post(followerUrl,data=data,headers = headers)
        signIndex = len((followerUrlJSON.json())['msg'])
        offset = offset + signIndex
        followerHtml =  (followerUrlJSON.json())['msg']
        for everHtml in followerHtml:
            everHtmlSoup = BeautifulSoup(everHtml)
            personId =  everHtmlSoup.a['href']
            resultFollowerFile.write(personId+'\n')
            print personId
            
    
def getXsrf():
    '''获取用户的xsrf这个是当前用户的'''
    soup = BeautifulSoup(_session.get(BASE_URL).content)
    _xsrf = soup.find('input',attrs={'name':'_xsrf'})['value']
    return _xsrf
    
def getHashId(personUrl):
    '''这个是需要抓取的用户的hashid，不是当前登录用户的hashid'''
    soup = BeautifulSoup(_session.get(personUrl).content)
    hashIdText = soup.find('script', attrs={'data-name': 'current_people'})
    return json.loads(hashIdText.text)[3]

def main():
    login()
    followType = input('请配置抓取类别：0-抓取关注了谁 其它-被哪些人关注')
    followType = 'ees' if followType == 0 else 'ers'
    for followerId in resourceLines:
        try:
            readFollowerNumbers(followerId,followType)
            resultFollowerFile.flush()
        except:
            pass
   
if __name__=='__main__':
    main()

无非就是那些，　ｕｓｅｒａｇｅｎｔ，ｒｅｆｅｒｅｒ，ｔｏｋｅｎ，ｃｏｏｋｉｅ 觉得可能会是 2 个原因造成的:

1. 没带 cookies
2. _xsrf 或 hash_id 错误

这个问题我来回答下吧，知乎在“_xsrf”这个字段搞了个小动作，并不是首页页面取到的那个_xsrf 的值，而是在登录成功后通过cookie返回的那个“_xsrf ”的值，所以你需要获取正确的这个值，不然一直会报403错误（我是在Post提问时发现的，相信你遇到的问题类似，直接上代码）：

///

/// 知乎提问
///

/// 提问标题
/// 详细内容
/// 登录后获取的cookie
public void ZhiHuFaTie(string question_title,string question_detail,CookieContainer cookie)
{
question_title=“提问内容”;
question_detail=“问题详细描述”;

//遍历cookie，获取_xsrf 的值
var list = GetAllCookies(cookie);
foreach (var item in list)
{
if (item.Name == "_xsrf")
{
xsrf = item.Value;
break;
}
}
//发帖
var FaTiePostUrl = "http://www.zhihu.com/question/add";
var dd = topicStr.ToCharArray();
var FaTiePostStr = "question_title=" + HttpUtility.UrlEncode(question_title) + "&question_detail=" + HttpUtility.UrlEncode(question_detail) + "&anon=0&topic_ids=" + topicId + "&new_topics=&_xsrf="+xsrf;
var FaTieResult = nhp.PostResultHtml(FaTiePostUrl, cookie, "http://www.zhihu.com/", FaTiePostStr);
}


///

/// 遍历CookieContainer
///

///
///
public static List GetAllCookies(CookieContainer cc)
{
List lstCookies = new List();

Hashtable table = (Hashtable)cc.GetType().InvokeMember("m_domainTable",
System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.GetField |
System.Reflection.BindingFlags.Instance, null, cc, new object[] { });

foreach (object pathList in table.Values)
{
SortedList lstCookieCol = (SortedList)pathList.GetType().InvokeMember("m_list",
System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.GetField
| System.Reflection.BindingFlags.Instance, null, pathList, new object[] { });
foreach (CookieCollection colCookies in lstCookieCol.Values)
foreach (Cookie c in colCookies) lstCookies.Add(c);
}
return lstCookies;
} 修改header的X-Forwarded-For字段伪装ip 真的是很巧，昨天晚上刚刚遇到了这个问题。原因可能有有很多，我只说自己遇到的，仅供参考，提供一种思路。我爬取的是新浪微博，使用了代理。出现403是因为访问时网站拒绝，我在浏览器上操作也是一样，随便看里面几个网页就会出现403，不过刷新几次就好了。在代码中实现就是多请求几次。 看了楼上的答案，瞬间被镇住了。大牛真多，不过我建议题主去问问李开复好了~哈哈 话说接口是怎么抓到的...为何我用firebug抓不到接口..chrome的network也抓不到接口
话说直接请求followees也可以直接获取到,剩下的也就是正则了