Why do you encounter 403 problems when using a crawler to crawl data on Zhihu content?

I want to capture the follow information of users on Zhihu, such as checking who A follows, and get the list of followees through the page www.zhihu.com/people/XXX/followees, but I encountered a 403 problem during the capture.
1. The crawler is only for collecting user attention information, for academic research, and is not for commercial or other purposes.
2. Use PHP, use curl to construct requests, and use simple_html_dom to parse documents. 3. In the user's followers (Followees) The list should use Ajax to dynamically load more followees, so I want to directly crawl the interface data. I can see through firebug that loading more followers seems to be done through
http://www.zhihu.com/ node/ProfileFolloweesListV2, and the post data includes _xsrf, method, parmas, so I submitted a request to this link while simulating that I stayed logged in, with the parameters required for the post. , but 403 is returned. 4. But when I also simulate login, I can parse data that does not require Ajax, such as the number of likes and thanks.
5. I use curl_setopt($ch, CURLOPT_HTTPHEADER, $header); to set the request header so that The request headers are consistent with the request headers I submitted in the browser, but this still resulted in a 403 error
6. I tried to print out the curl request headers and compare them with the request headers sent by the browser, but did not find the correct way (Baidu The curl_getinfo() seems to print out the corresponding message)
7. Many people have encountered 403 because User-Agent or X-Requested-With was not set, but I set it when setting the request header as described in 5
8 .If the description is unclear and you need to post the code, I can post the code
9. This crawler is part of my graduation project and I need to obtain data for the next work. As 1 said, crawling data is purely for academic research
Reply content:

If the server has a firewall function, continuous crawling may be killed unless you have many proxy servers. Or the easiest way is to use adsl to constantly redial and change the IP address. You first find a browser and study the HTTP Header of the request and then capture it. In the past two days, I just made a crawler to capture users' followings and followers, using Python. Here is a piece of python code for you. You can look at the code to see your code problem.

403 should be that some data was sent incorrectly during the request. The following code involves an open text. The content in the text is the user's ID. I took a screenshot of the content style in the text and put it at the end.

<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>

It’s nothing more than those, useragent, referrer, token, cookie I think it may be caused by 2 reasons:

1. No cookies
2. _xsrf or hash_id error

Let me answer this question. Zhihu has made a small move in the "_xsrf" field. It is not the _xsrf value obtained from the home page, but the "_xsrf" value returned through the cookie after successful login. , so you need to get the correct value, otherwise a 403 error will always be reported (I found this out when Post asked a question, I believe you will encounter similar problems, so go directly to the code):

///

/ // Zhihu question
///

/// Question title
/// Details Content
/// Cookie obtained after logging in
public void ZhiHuFaTie(string question_title,string question_detail,CookieContainer cookie)
{
question_title="Question Content";
question_detail="Question Detailed Description";

//Traverse cookies and get the value of _xsrf
var list = GetAllCookies(cookie);
foreach (var item in list)
{
if (item.Name = = "_xsrf")
{
xsrf = item.Value;
break;
}
}
//Post
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);
}


///

// / Traverse CookieContainer
///

///
///
public static List {
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;
} Modify the X-Forwarded-For field of the header to disguise the IP address What a coincidence, I just encountered this problem last night. There may be many reasons, I will only tell you what I encountered, for reference only and to provide an idea. I crawled Sina Weibo and used a proxy. The 403 appears because the website is rejected when accessing. I do the same thing on the browser. If I just look at a few web pages, 403 will appear, but it will be fine if I refresh it a few times. The implementation in the code is to request multiple times. After reading the answer above, I was instantly stunned. There are so many great people, but I suggest you ask Kai-Fu Lee ~ Haha Let’s talk about how the interface is caught... Why can’t I catch the interface with firebug? Chrome’s network can’t catch the interface either
Speaking of which, you can get it directly by directly requesting followees. The rest is regular.