Free Web Crawler: Free Proxy Crawler Tool Usage

How many potholes have you stepped into with free proxy crawlers?

Recently, an e-commerce friend complained to me that he spent two days using a crawler to catch the price of competitors, and the result was that the IP was blocked just half an hour into the run. This scene is not particularly familiar? Many people think that using a free proxy can solve the problem, the result is that the free proxy pool of 10 IP 8 can not be connected, the remaining 2 speed than the snail is still slow.

I've tried an open source proxy pool program that grabs over 200 free IPs, only 3 of which actually work. What's more pitiful is that some proxies willModify the response contentFor example, inserting advertisements into web pages, or directly returning fake data. The best thing is that I've encountered a reverse phishing proxy that suddenly jumped to a spinach site while I was using it...

Hands-on Wheel Building

Write your own proxy crawler is not difficult, here to share a practical script framework. The core of the three steps: crawl → validation → into the library. If you use Python, 30 lines of code will be able to handle the basic functions:

import requests
from bs4 import BeautifulSoup


    sources = [
        'https://www.freeproxylists.net/', 'https://www.freeproxylists.net/', 'https://www.freeproxylists.net/'
        'https://proxyscrape.com/free-proxy-list'
    ]

    proxies = []
    for url in sources.
        try: resp = requests.get(url, timeout=10)
            resp = requests.get(url, timeout=10)
            soup = BeautifulSoup(resp.text, 'lxml')
             Here the parsing logic is written according to the structure of the site
             Example: Extracting IPs and ports
            rows = soup.select('table tr')
            for row in rows[1:]:: ip = row.select_one_port
                ip = row.select_one('td:nth-child(1)').text
                port = row.select_one('td:nth-child(2)').text
                proxies.append(f"{ip}:{port}")
        except Exception as e.
            print(f "Crawl failed: {url} - {str(e)}")
    return proxies

Focus on the validation link, which many newbies overlookProtocol type detectionSome proxies are clearly labeled as HTTPS available, but in reality they only support HTTP. Some proxies are clearly labeled as HTTPS available, but actually only support HTTP. it is recommended to verify with multiple target sites, such as testing access to Baidu (HTTP) and Zhihu (HTTPS) at the same time.

Free Lunch vs Professional Kitchen

To be honest, free proxies are good for temporary testing or low-frequency use. If you really want to engage in business-level crawling, you have to rely on professional services. Take ipipgo's dynamic residential proxies for example, they go to the local carrier IP pool, these three advantages are free proxies simply can not compare:

They have one.Intelligent RoutingThe function is especially practical, automatically matching the IP of the target website location. for example, if you want to climb Japan Rakuten, the system will automatically assign the residential IP of Tokyo or Osaka, you don't need to switch manually at all.

QA time: what you might want to ask

Q: Is it true that free proxies don't work at all?
A: Emergency can be, but do a good job of retrying the mechanism. It is recommended to set up 3 times automatic switching, and the timeout should not be more than 5 seconds

Q: How do I choose a package for ipipgo?
A: individual users choose dynamic standard version, 7.67 yuan / GB enough to climb hundreds of thousands of pages. Enterprise-level business directly on the customized program, they have an exclusive channel to avoid IP blocking!

Q: Does it support socks5 protocol?
A: All of their products support HTTP/HTTPS/Socks5, just check the protocol type directly in the client, no need to change the code.

A guide to avoiding pitfalls (highlights)

Finally, I'd like to share three bloody lessons:
1. Never write a dead proxy IP in the crawler code, must use the polling mechanism
2. Don't fight with CAPTCHA, switch IP immediately.
3. Prepare at least two sets of proxy providers for important projects, ipipgo + back-up program is most secure

Speaking of which, I have to mention ipipgo'sFailure compensation mechanismsIf an IP request fails, it will not only automatically replace the IP with a new one, but also return the traffic credit. This detail is particularly friendly to long-term crawler project, can save a lot of money.