How Python crawler uses proxy IP to crawl

Preface

Python crawler is a very powerful tool that can be used to crawl data from various websites. However, in some cases, we need to use proxy IP to complete data capture, such as bypassing IP restrictions or protecting private information. This article will introduce how to use proxy IP when using Python crawler to crawl data, and provide sample code and precautions.

1. What is a proxy IP?

A proxy IP is an IP address that acts as a middleman between the client and the server. The request sent by the client will first pass through the proxy IP server, and then forwarded by the proxy IP server to the target server. By using proxy IP, we can hide the real IP address and protect private information. At the same time, we can break through some IP restrictions and access websites that require circumventing the firewall.

2. Why you need to use proxy IP

In some cases, we need to crawl data from some websites, but the website may restrict the crawler, add verification codes, restrict IP addresses, etc., resulting in the inability to crawl normally. At this time, these restrictions can be bypassed by using the proxy IP and normal data capture can be achieved.

In addition, in some scenarios, we need to bypass the wall to access certain websites. In this case, using proxy IP is also a very convenient way.

3. Steps to use proxy IP for crawling

The steps for using proxy IP for crawling mainly include the following aspects:

1. Obtain the proxy IP address: You can obtain the proxy IP address through the free proxy IP list on the Internet, or by using the API of a third-party proxy IP service provider.
2. Set proxy IP: Set the obtained proxy IP address into the request header.
3. Send a request: Use the Python requests library to send a request and set the proxy IP in the request header.
4. Parse the response: Use the Python BeautifulSoup library to parse the request response.

Here is a Python example code for scraping using proxy IP:

import requests
from bs4 import BeautifulSoup

# 获取代理IP地址
proxy = 'http://218.60.8.99:3129'

# 设置请求头部信息
headers = {
    'User-Agent': 'Mozilla/5.0 (Windows NT 10.0;Win64;x64) AppleWebKit/537.36(KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'
}

# 设置代理IP
proxies = {
    'http': proxy,
    'https': proxy
}

# 发送GET请求
response = requests.get(url, headers=headers, proxies=proxies)

# 解析HTML
soup = BeautifulSoup(response.text, 'html.parser')

# 输出抓取到的数据
print(soup.text)

In this example, we first obtain a proxy IP address and set it into the request header. Then, we sent a GET request, set the proxy IP, and used the BeautifulSoup library to parse the HTML of the request response. Finally, we output the captured data.

4. Things to note when using proxy IP for crawling

In the process of using proxy IP for crawling, you need to pay attention to the following matters:

1. Availability of proxy IP: Different proxy IPs may have availability issues at different times. Therefore, we need to conduct usability testing before using the proxy IP.
2. Proxy IP request frequency limit: Some proxy IP providers have restrictions on request frequency. If the request frequency is too high, the IP may be banned. Therefore, we need to adjust according to the actual situation.
3. The legality of using proxy IP to crawl: Some websites have restrictions on crawling data. If crawled without authorization, legal issues may be involved. Therefore, we need to carefully read the relevant regulations of the target website when using proxy IP to crawl.

5. Summary

Using proxy IP for crawling can bypass some IP restrictions, making it easier for us to crawl websites that need to be accessed by circumventing the firewall. In actual use, we need to pay attention to issues such as the availability of proxy IPs and request frequency limits, and we need to comply with the relevant regulations of the target website to ensure the legality of using proxy IPs.