对知乎内容使用爬虫爬取数据，为什么会遇到403问题？

我想抓取知乎上用户的关注信息，如查看A关注了哪些人，通过www.zhihu.com/people/XXX/followees这个页面来获得followee的列表，但是在抓取中遇到了403问题。
1.爬虫仅仅是为了搜集用户关注信息，用于学术研究，绝非商业或其他目的
2.使用PHP，利用curl构造请求，使用simple_html_dom来解析文档
3.在用户的关注者（Followees）列表，应该是使用Ajax进行动态加载更多的followees，于是我想直接爬接口的数据，通过firebug查看到，加载更多的关注者似乎是通过http://www.zhihu.com/node/ProfileFolloweesListV2 进行的，并且post的数据有_xsrf,method,parmas，于是我在模拟保持登录的情况下，对这个链接提交请求，并带有post过去的所需要的参数，但是返回的是403。
4.但是我同样模拟登录的情况下，可以解析到如赞同数、感谢数这些不需要Ajax的数据
5.我使用curl_setopt($ch, CURLOPT_HTTPHEADER, $header );来设置请求头，使其与我在浏览器中提交的请求的请求头一致，但是这样任然导致403错误
6.我尝试打印出curl的请求头与浏览器发出的请求头进行比较，但是没有找到正确的方式（百度出的curl_getinfo()似乎打印出的相应报文）
7.有许多人曾因为没有设置User-Agent或者X-Requested-With遭遇403，但是我在5中描述设置请求头时都设置了
8.如果叙述不详需要贴出代码，我可以贴出代码
9.这个爬虫是我毕设的一部分，需要获取数据来进行接下来的工作，如1所说，爬取数据纯粹是为了学术研究

回复内容：

如果带有防火墙功能的服务器，连续抓取可能被干掉，除非你有很多代理服务器。或者最简单用adsl不断重新拨号更换ip 你先找个浏览器，研究一下request的HTTP Header再来抓 这两天刚好做了一个抓取用户的关注着和追随者的的爬虫在抓数据，使用的是Python。这里给你一段python的代码，你可以对着代码看一下你的代码问题。
403应该就是请求的时候一些数据发错了，下面的代码中涉及到一个打开的文本，文本中的内容是用户的id，文本里面的内容样式我截了图放在最后面。

<code class="language-python3"><span class="c">#encoding=utf8</span>
<span class="kn">import</span> <span class="nn">urllib2</span>
<span class="kn">import</span> <span class="nn">json</span>
<span class="kn">import</span> <span class="nn">requests</span>
<span class="kn">from</span> <span class="nn">bs4</span> <span class="k">import</span> <span class="n">BeautifulSoup</span>

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

<span class="n">BASE_URL</span> <span class="o">=</span> <span class="s">'https://www.zhihu.com/'</span>
<span class="n">CAPTURE_URL</span> <span class="o">=</span> <span class="n">BASE_URL</span><span class="o">+</span><span class="s">'captcha.gif?r=1466595391805&type=login'</span>
<span class="n">PHONE_LOGIN</span> <span class="o">=</span> <span class="n">BASE_URL</span> <span class="o">+</span> <span class="s">'login/phone_num'</span>

<span class="k">def</span> <span class="nf">login</span><span class="p">():</span>
    <span class="sd">'''登录知乎'''</span>
    <span class="n">username</span> <span class="o">=</span> <span class="s">''</span><span class="c">#用户名</span>
    <span class="n">password</span> <span class="o">=</span> <span class="s">''</span><span class="c">#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</span>
    <span class="n">cap_content</span> <span class="o">=</span> <span class="n">urllib2</span><span class="o">.</span><span class="n">urlopen</span><span class="p">(</span><span class="n">CAPTURE_URL</span><span class="p">)</span><span class="o">.</span><span class="n">read</span><span class="p">()</span>
    <span class="n">cap_file</span> <span class="o">=</span> <span class="nb">open</span><span class="p">(</span><span class="s">'/root/Desktop/cap.gif'</span><span class="p">,</span><span class="s">'wb'</span><span class="p">)</span>
    <span class="n">cap_file</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">cap_content</span><span class="p">)</span>
    <span class="n">cap_file</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
    <span class="n">captcha</span> <span class="o">=</span> <span class="n">raw_input</span><span class="p">(</span><span class="s">'capture:'</span><span class="p">)</span>
    <span class="n">data</span> <span class="o">=</span> <span class="p">{</span><span class="s">"phone_num"</span><span class="p">:</span><span class="n">username</span><span class="p">,</span><span class="s">"password"</span><span class="p">:</span><span class="n">password</span><span class="p">,</span><span class="s">"captcha"</span><span class="p">:</span><span class="n">captcha</span><span class="p">}</span>
    <span class="n">r</span> <span class="o">=</span> <span class="n">_session</span><span class="o">.</span><span class="n">post</span><span class="p">(</span><span class="n">PHONE_LOGIN</span><span class="p">,</span> <span class="n">data</span><span class="p">)</span>
    <span class="nb">print</span> <span class="p">(</span><span class="n">r</span><span class="o">.</span><span class="n">json</span><span class="p">())[</span><span class="s">'msg'</span><span class="p">]</span>
    
<span class="k">def</span> <span class="nf">readFollowerNumbers</span><span class="p">(</span><span class="n">followerId</span><span class="p">,</span><span class="n">followType</span><span class="p">):</span>
    <span class="sd">'''读取每一位用户的关注者和追随者，根据type进行判断'''</span>
    <span class="nb">print</span> <span class="n">followerId</span>
    <span class="n">personUrl</span> <span class="o">=</span> <span class="s">'https://www.zhihu.com/people/'</span> <span class="o">+</span> <span class="n">followerId</span><span class="o">.</span><span class="n">strip</span><span class="p">(</span><span class="s">'</span><span class="se">\n</span><span class="s">'</span><span class="p">)</span>
    <span class="n">xsrf</span> <span class="o">=</span><span class="n">getXsrf</span><span class="p">()</span>
    <span class="n">hash_id</span> <span class="o">=</span> <span class="n">getHashId</span><span class="p">(</span><span class="n">personUrl</span><span class="p">)</span>
    <span class="n">headers</span> <span class="o">=</span> <span class="nb">dict</span><span class="p">(</span><span class="n">Default_Header</span><span class="p">)</span>
    <span class="n">headers</span><span class="p">[</span><span class="s">'Referer'</span><span class="p">]</span><span class="o">=</span> <span class="n">personUrl</span> <span class="o">+</span> <span class="s">'/follow'</span><span class="o">+</span><span class="n">followType</span>
    <span class="n">followerUrl</span> <span class="o">=</span> <span class="s">'https://www.zhihu.com/node/ProfileFollow'</span><span class="o">+</span><span class="n">followType</span><span class="o">+</span><span class="s">'ListV2'</span>
    <span class="n">params</span> <span class="o">=</span> <span class="p">{</span><span class="s">"offset"</span><span class="p">:</span><span class="mi">0</span><span class="p">,</span><span class="s">"order_by"</span><span class="p">:</span><span class="s">"created"</span><span class="p">,</span><span class="s">"hash_id"</span><span class="p">:</span><span class="n">hash_id</span><span class="p">}</span>
    <span class="n">params_encode</span> <span class="o">=</span> <span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="n">params</span><span class="p">)</span>
    <span class="n">data</span> <span class="o">=</span> <span class="p">{</span><span class="s">"method"</span><span class="p">:</span><span class="s">"next"</span><span class="p">,</span><span class="s">"params"</span><span class="p">:</span><span class="n">params_encode</span><span class="p">,</span><span class="s">'_xsrf'</span><span class="p">:</span><span class="n">xsrf</span><span class="p">}</span>
    
    <span class="n">signIndex</span> <span class="o">=</span> <span class="mi">20</span>
    <span class="n">offset</span> <span class="o">=</span> <span class="mi">0</span>
    <span class="k">while</span> <span class="n">signIndex</span> <span class="o">==</span> <span class="mi">20</span><span class="p">:</span>
        <span class="n">params</span><span class="p">[</span><span class="s">'offset'</span><span class="p">]</span> <span class="o">=</span> <span class="n">offset</span>
        <span class="n">data</span><span class="p">[</span><span class="s">'params'</span><span class="p">]</span> <span class="o">=</span> <span class="n">json</span><span class="o">.</span><span class="n">dumps</span><span class="p">(</span><span class="n">params</span><span class="p">)</span>
        <span class="n">followerUrlJSON</span> <span class="o">=</span> <span class="n">_session</span><span class="o">.</span><span class="n">post</span><span class="p">(</span><span class="n">followerUrl</span><span class="p">,</span><span class="n">data</span><span class="o">=</span><span class="n">data</span><span class="p">,</span><span class="n">headers</span> <span class="o">=</span> <span class="n">headers</span><span class="p">)</span>
        <span class="n">signIndex</span> <span class="o">=</span> <span class="nb">len</span><span class="p">((</span><span class="n">followerUrlJSON</span><span class="o">.</span><span class="n">json</span><span class="p">())[</span><span class="s">'msg'</span><span class="p">])</span>
        <span class="n">offset</span> <span class="o">=</span> <span class="n">offset</span> <span class="o">+</span> <span class="n">signIndex</span>
        <span class="n">followerHtml</span> <span class="o">=</span>  <span class="p">(</span><span class="n">followerUrlJSON</span><span class="o">.</span><span class="n">json</span><span class="p">())[</span><span class="s">'msg'</span><span class="p">]</span>
        <span class="k">for</span> <span class="n">everHtml</span> <span class="ow">in</span> <span class="n">followerHtml</span><span class="p">:</span>
            <span class="n">everHtmlSoup</span> <span class="o">=</span> <span class="n">BeautifulSoup</span><span class="p">(</span><span class="n">everHtml</span><span class="p">)</span>
            <span class="n">personId</span> <span class="o">=</span>  <span class="n">everHtmlSoup</span><span class="o">.</span><span class="n">a</span><span class="p">[</span><span class="s">'href'</span><span class="p">]</span>
            <span class="n">resultFollowerFile</span><span class="o">.</span><span class="n">write</span><span class="p">(</span><span class="n">personId</span><span class="o">+</span><span class="s">'</span><span class="se">\n</span><span class="s">'</span><span class="p">)</span>
            <span class="nb">print</span> <span class="n">personId</span>
            
    
<span class="k">def</span> <span class="nf">getXsrf</span><span class="p">():</span>
    <span class="sd">'''获取用户的xsrf这个是当前用户的'''</span>
    <span class="n">soup</span> <span class="o">=</span> <span class="n">BeautifulSoup</span><span class="p">(</span><span class="n">_session</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="n">BASE_URL</span><span class="p">)</span><span class="o">.</span><span class="n">content</span><span class="p">)</span>
    <span class="n">_xsrf</span> <span class="o">=</span> <span class="n">soup</span><span class="o">.</span><span class="n">find</span><span class="p">(</span><span class="s">'input'</span><span class="p">,</span><span class="n">attrs</span><span class="o">=</span><span class="p">{</span><span class="s">'name'</span><span class="p">:</span><span class="s">'_xsrf'</span><span class="p">})[</span><span class="s">'value'</span><span class="p">]</span>
    <span class="k">return</span> <span class="n">_xsrf</span>
    
<span class="k">def</span> <span class="nf">getHashId</span><span class="p">(</span><span class="n">personUrl</span><span class="p">):</span>
    <span class="sd">'''这个是需要抓取的用户的hashid，不是当前登录用户的hashid'''</span>
    <span class="n">soup</span> <span class="o">=</span> <span class="n">BeautifulSoup</span><span class="p">(</span><span class="n">_session</span><span class="o">.</span><span class="n">get</span><span class="p">(</span><span class="n">personUrl</span><span class="p">)</span><span class="o">.</span><span class="n">content</span><span class="p">)</span>
    <span class="n">hashIdText</span> <span class="o">=</span> <span class="n">soup</span><span class="o">.</span><span class="n">find</span><span class="p">(</span><span class="s">'script'</span><span class="p">,</span> <span class="n">attrs</span><span class="o">=</span><span class="p">{</span><span class="s">'data-name'</span><span class="p">:</span> <span class="s">'current_people'</span><span class="p">})</span>
    <span class="k">return</span> <span class="n">json</span><span class="o">.</span><span class="n">loads</span><span class="p">(</span><span class="n">hashIdText</span><span class="o">.</span><span class="n">text</span><span class="p">)[</span><span class="mi">3</span><span class="p">]</span>

<span class="k">def</span> <span class="nf">main</span><span class="p">():</span>
    <span class="n">login</span><span class="p">()</span>
    <span class="n">followType</span> <span class="o">=</span> <span class="nb">input</span><span class="p">(</span><span class="s">'请配置抓取类别：0-抓取关注了谁 其它-被哪些人关注'</span><span class="p">)</span>
    <span class="n">followType</span> <span class="o">=</span> <span class="s">'ees'</span> <span class="k">if</span> <span class="n">followType</span> <span class="o">==</span> <span class="mi">0</span> <span class="k">else</span> <span class="s">'ers'</span>
    <span class="k">for</span> <span class="n">followerId</span> <span class="ow">in</span> <span class="n">resourceLines</span><span class="p">:</span>
        <span class="k">try</span><span class="p">:</span>
            <span class="n">readFollowerNumbers</span><span class="p">(</span><span class="n">followerId</span><span class="p">,</span><span class="n">followType</span><span class="p">)</span>
            <span class="n">resultFollowerFile</span><span class="o">.</span><span class="n">flush</span><span class="p">()</span>
        <span class="k">except</span><span class="p">:</span>
            <span class="k">pass</span>
   
<span class="k">if</span> <span class="n">__name__</span><span class="o">==</span><span class="s">'__main__'</span><span class="p">:</span>
    <span class="n">main</span><span class="p">()</span>
</code>

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