Proxy IP, also known as proxy server, is a network protocol service server that acts as a middleman between the client and the server.

In Python programming, proxy IP plays a very important role. It can not only hide our real IP address and prevent being blocked by the target website, but also improve the efficiency and stability of network requests. This article will explore the application of proxy IP in Python programming from basic to advanced.

1. Basic knowledge of proxy IP

There are two main types of proxy IPs: transparent proxy and anonymous proxy. Transparent proxies expose the original IP address, while anonymous proxies do not. In addition, proxy IP has two protocol types: HTTP and HTTPS. The former is used for ordinary web browsing, and the latter is used for encrypted HTTPS websites.

In Python, we can use various libraries and tools to set up and use proxy IPs. One of the most commonly used libraries is requests, which allows us to set a proxy when sending HTTP requests.

2. Basic application: Use the requests library to set up the proxy

In the requests library, we can use the proxy IP by setting the proxies parameter. Here's a simple example:

import requests

proxies = {

   "http": "http://10.10.1.10:3128",

   "https": "http://10.10.1.10:1080",

}

requests.get("http://example.org", proxies=proxies)

In the above code, we first define a proxy dictionary, which contains the proxy IP and port for HTTP and HTTPS. Then, when calling the requests.get() method, we pass in the proxy dictionary as the proxies parameter to set the proxy IP.

3. Advanced application: automatically obtain and rotate proxy IP

Although manually setting proxy IPs can meet some basic needs, in actual use, we often need a large number of proxy IPs, and hope that these proxy IPs can be automatically rotated to improve the stability and efficiency of the crawler. At this time, we can use some third-party libraries or tools to automatically obtain and rotate proxy IPs.

Use third-party libraries

proxybroker is a popular Python library that automatically obtains and tests proxy IPs from a list of public proxy servers. Here is an example using proxybroker:

from proxybroker import Broker

# Create a Broker instance

broker = Broker(

     types=['http', 'https'],

     limit=100,

     threads=50

)

# Get proxy IP

proxies = broker.find()

# Use proxy IP

for proxy in proxies:

     print(proxy)

     # Use the requests library to set the proxy IP and send the request

     response = requests.get("http://example.org", proxies={"http": proxy.host, "https": proxy.host})

print(response.text)

In the above code, we first create a Broker instance and specify the proxy type (HTTP and HTTPS) to obtain, the maximum number of brokers, and the number of concurrent threads. Then, by calling the broker.find() method, we can obtain a set of proxy IPs. Finally, we iterate through these proxy IPs and use the requests library to set the proxy IP and send the request.

Use proxy IP pool

In addition to using third-party libraries, we can also build a proxy IP pool to manage and rotate proxy IPs. The proxy IP pool can be a simple database or in-memory list used to store and update proxy IPs. In actual use, we can obtain proxy IPs from various sources and add them to the proxy IP pool.

Then, when sending a network request, a proxy IP is randomly selected from the proxy IP pool to use. This not only enables automatic rotation of proxy IPs, but also improves the stability and efficiency of the crawler.

4. Precautions and best practices

There are a few things to note when using a proxy IP:

The quality and stability of the proxy IP are very important. If a poor-quality proxy IP is used, it may cause problems such as request failure, slow speed, or being banned.

Pay attention to the anonymity of the proxy IP. If the anonymity of the proxy IP is poor, it may be identified as a crawler by the target website and corresponding anti-crawler measures may be taken.

Use proxy IPs appropriately. Do not overuse or abuse proxy IPs to avoid putting excessive pressure on the proxy server or being banned.

Best practices include:

Use a reliable proxy IP service or tool to obtain a proxy IP.

The proxy IPs in the proxy IP pool are regularly updated and tested to ensure their quality and stability.

When sending network requests, properly set parameters such as request headers and request intervals to reduce the risk of being blocked by the target website.

5. Summary and Outlook

Proxy IP plays an important role in Python programming. It can not only hide our real IP address and prevent being blocked by the target website, but also improve the efficiency and stability of network requests.

By learning and mastering the basic knowledge, usage and best practices of proxy IP, we can better use proxy IP to improve the stability and efficiency of the crawler.