Anyone who has played with python crawlers knows that in the process of writing crawler programs, you may encounter the anti-crawling strategy of the target website, and you need to constantly fight against the website technically, and you need to constantly update the anti-crawling strategy. These policies prevent excessive crawling by programs from impacting server load. Here are some experience tips that I have summarized for you to check out.
When we write a crawler IP program in Python, we can adopt the following strategies to deal with the anti-crawling strategy of the target website:
1. Use crawler IP
By using crawler IP, you can hide your real IP address and avoid being blocked by the target website. You can buy a crawler IP or use a free crawler IP, but be aware that free crawler IPs may be unstable and may have been blocked by the target website.
2. Set request headers
Many websites will check the User-Agent field in the request header and reject the request if it is found to be a crawler. You can set request headers to simulate a browser sending a request.
3. Limit crawling speed
If your crawler crawls too fast, it may be detected by the target website. You can set delays to limit crawl speed.
4. Use Cookies
Some websites require you to log in before you can access them. You can use cookies in your crawler program to simulate the login state.
5. Use verification code identification service
Some websites use verification codes to block crawlers. You can use a verification code recognition service, such as 2Captcha, to automatically identify and enter verification codes.
6. Dynamic page crawling
Some websites use JavaScript to dynamically load data. You can use libraries such as Selenium and Pyppeteer to simulate browser behavior and crawl dynamic pages.
7. Use machine learning
Some websites will use more complex anti-crawling strategies, such as behavioral analysis, etc. You can use machine learning algorithms to make your crawler more like human users.
Please note that the above strategies may involve legal issues. When using them, please make sure to comply with relevant laws and regulations, respect the website's terms of use, and do not engage in illegal crawling activities.
To write a crawler IP program in Python, you can follow the following steps:
1. Install the necessary libraries
First, you need to install some necessary libraries, such as requests and beautifulsoup4. You can use pip to install these libraries:
pip install requests beautifulsoup4
2. Get the crawler IP
You can get a crawler IP from a free crawler IP website, or buy a crawler IP. The obtained crawler IP is usually a string containing the IP address and port number, such as "192.168.1.1:8080".
3. Set the crawler IP
When using the requests library to send a request, you can set the proxies parameter to use the crawler ip. For example:
proxies = {
"http": "http://192.168.1.1:8080",
"https": "http://192.168.1.1:8080",
}
response = requests.get("http://www.example.com", proxies=proxies)
4. Parse web pages
You can usebeautifulsoup4 the library to parse the obtained web page content. For example:
from bs4 import BeautifulSoup
soup = BeautifulSoup(response.text, 'html.parser')
# 然后你可以使用soup对象来查找、提取网页中的信息。
# 获取爬虫IP：http://jshk.com.cn/mb/reg.asp?kefu=xjy
5. Deal with anti-crawling strategies
As mentioned earlier, you may need to deal with the anti-crawling strategy of the target website, such as setting request headers, limiting crawling speed, using cookies, etc.
6. Save data
Finally, you can save the crawled data to a file or database.
This is just a basic tutorial, the exact code may vary depending on your needs and the structure of your target website. When writing crawler programs, please make sure to comply with relevant laws and regulations, respect the website's terms of use, and do not engage in illegal crawling activities.
The above are some strategies and detailed steps. How to anti-crawl, you must deal with the anti-crawling strategy of the target website, such as setting request headers, limiting crawling speed, using cookies, etc. If there are more problems, crawlers basically have to solve these problems. Everything was smooth sailing. If you have better suggestions, you can leave a message for discussion.