Steps and considerations for setting up a proxy for a crawler

Hey, guys! Hi everyone! Today we are going to talk about the steps and precautions for setting up a proxy for a crawler. I don't know if you have ever tried to crawl the web page data, suddenly the target website blocked the IP address, the whole crawler are "paralyzed"? Isn't it a super headache? Don't panic, like my experienced editor to tell you, the use of proxies can easily solve this problem! Hurry up with me to learn together!

I. Selecting a proxy server

First of all, we need to choose a reliable proxy server, as if we were looking for a reliable buddy, to ensure his stability and speed. There are a lot of free proxy servers out there, but they tend to be less practical because, ah, they can be slow and can often die. Ahem, by the way, other people's IP addresses you know, can not be used indiscriminately ah!

哈哈，不过别担心，我们可以使用一些收费的代理服务商，它们提供稳定快速的代理服务器，像是、ipipgo代理等等，有很多选择。这样一来，我们就能得到一个高质量的小伙伴啦！

II. Setting up the proxy

After selecting a proxy server, we need to set up the proxy. Here, I'll introduce you to two ways to set up a proxy by code.

The first way is to use the requests library, a very powerful web request library. We just need to specify the IP address and port number of the proxy server in the code, and then we can easily set up the proxy. It's like the following code:

ipipgothon
import requests

proxy = {
'http': 'http://127.0.0.1:8888',
'https': 'https://127.0.0.1:8888'
}

response = requests.get(url, proxies=proxy)

The second way is to use the urllib library, also a popular web request library. We need to use the ProxyHandler function of the urllib library to create a proxy handler, and then install it as a global proxy via the build_opener function and install_opener function. The specific code is as follows:

ipipgothon
from urllib import request

proxy = request.ProxyHandler({'http': 'http://127.0.0.1:8888', 'https': 'https://127.0.0.1:8888'})
opener = request.build_opener(proxy)
request.install_opener(opener)

response = request.urlopen(url)

You can choose the appropriate way to set up the proxy according to your actual situation.

III. Precautions

Of course, the use of agents also need to pay attention to some matters. Below I give you a list of a few points that need special attention, we must remember Oh!

1. Choose a stable proxy server: As mentioned earlier, stability is one of the important criteria for proxy servers. It is very important to choose a high quality, stable and fast proxy server to avoid frequent replacement of the proxy in the process of crawling, wasting time and resources.

2. Comply with proxy server usage rules: Different proxy servers may have different usage rules, including free proxies and paid proxies. Be sure to read and follow the proxy server's usage rules carefully to avoid being banned or charged at the wrong time.

3. Random switching proxy: In order to further improve the crawling effect, we can add random switching proxy logic in the code. This can effectively avoid frequent requests to the same proxy server to improve crawling speed and stability.

4. Regularly check the validity of the proxy: In the process of crawling for a long time, the validity of the proxy server will change, and some proxies may become invalid. Therefore, we need to regularly check the validity of the proxy, remove invalid proxies in a timely manner to ensure the smooth progress of crawling.

Hey guys, we will briefly explain here today! The use of proxies can help us to crawl the data smoothly, to avoid being blocked IP address. But le, I want to remind you, in the process of using the agent should also follow the law and morality Oh, do not maliciously crawl the site data, to protect the network environment of fairness and justice, we can long enjoy the fun of crawling! Hey, I send you a cheer words: everyone cheer, to become a crawler of the small hands it!