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This article mainly introduces "what are Python reptiles and anti-reptiles". In daily operation, I believe many people have doubts about what Python reptiles and anti-reptiles are. The editor consulted all kinds of materials and sorted out simple and easy-to-use methods of operation. I hope it will be helpful for you to answer the questions of "what are Python reptiles and anti-reptiles?" Next, please follow the editor to study!

What is a reptile?

In today's society, the network is full of a large number of useful data, we only need to observe patiently, coupled with some technical means, we can obtain a large number of valuable data. The "technical means" here refer to web crawlers.

Crawlers are programs that automatically access web content, such as search engines, Google,Baidu, etc., which run a huge crawler system every day to crawl data from websites all over the world for users to use when searching.

Malicious crawlers will not only occupy a lot of website traffic, resulting in real needs of users can not enter the site, but also may cause the leakage of key information of the site, affecting the normal operation of the website or app.

Therefore, for websites with high data value, website developers will give some technical means for web crawlers.

For those of you who want to implement a simple crawler case on your own, you can read my previous article:

The five steps will take you to explore the truth behind the crawler crawling the video barrage, and attach the crawler to realize the source code.

Common anti-reptile measures

Generally speaking, we will subdivide the means of anti-crawler in terms of characteristics, which can be divided into information verification anti-crawler, dynamic rendering anti-crawler, text confusion anti-crawler, behavior verification anti-crawler and so on.

Its Chinese text confusion class anti-crawler is the most interesting, while behavior verification anti-crawler is the most difficult one.

Text confusion anti-crawler

To put it simply, text obfuscation is how to effectively prevent crawlers from obtaining important text data in Web applications. The premise of anti-crawler is that it can not affect the normal browsing of web pages and reading text content, and it is easy to see the direct confusion of text, so developers usually use the mapping relationship between fonts to achieve confusion.

For example: the text mapping of the car House forum.

Here, through the font mapping of some special text, when the web crawler can not directly obtain the complete data, and does not affect the normal reading of normal users.

Dynamic rendering of anti-crawler

With the continuous iteration of the technology of the times, more and more websites have changed from traditional static data loading to dynamic data loading, and the dynamic loading process is accompanied by more and more data encryption.

The simple understanding of dynamic data loading is to let the browser load the general framework of the website first, and then issue an asynchronous request to complete the data filling. In the process of sending the request, by encrypting the request parameters, to shield out very low-level crawler scripts.

For example: red point dataset-js parameter encryption

Here, by verifying the key parameters when sending asynchronous requests, directly intercepting some of the most basic crawler requests, we must simulate the process of parameter encryption in order to get the data normally.

Behavior verification anti-crawler

Behavioral CAPTCHA is a popular CAPTCHA. Literally, it is through the user's actions to complete the verification, without having to understand the distorted picture text. There are two common types: drag type and touch type.

At this point, the study on "what is Python crawler and anti-crawler" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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