What is Web Crawling: An Explanation of the Principles of Data Acquisition Techniques

When you mess with data these days, if you can't capture it, you lose at the starting line

Folks have probably heard of web crawlers, which are, to put it bluntlyAutomatically pulling data from web pages with a program. For example, if you want to know the price fluctuation of the national milk tea store, you can't check it manually every day, right? This time to rely on crawling technology to automatically collect. But this thing has a hurdle - the site has anti-climbing mechanism, caught frequent visits to the IP will be directly blocked.

Proxy IPs are your cloak and dagger.

To give a real case: last year, there is a team to do e-commerce price comparison, with their own office network to capture data, the results of the next day the entire company network are the target site black. Later they used ipipgo'sDynamic residential agent pool, spreading the requests to real user IPs in different regions, the amount of data collection is directly quintupled.

import requests

 Use ipipgo's rotating proxy (remember to replace it with your own API)
proxy_api = "http://api.ipipgo.com/rotate?key=你的授权码"

def grab_data(url).
    proxies = {"http": proxy_api, "https": proxy_api}
    response = requests.get(url, proxies=proxies, timeout=10)
     This handles the parsing of the data...
    return response.text

The three main lifebloods of picking proxy IPs

1. Survival rate should be stableDon't use the ones that claim to be free and end up with 8 out of 10 IPs failing!
2. Level of anonymity: High-anonymity proxy to completely hide local features
3. Geographical coverage: It's the ones like ipipgo that can pinpoint municipal areas that are competitive

A practical guide to avoiding the pit

- Don't use a single IP to paint furiously, it's recommended2-3 seconds/repeattempo
- Don't be so tough when it comes to CAPTCHA, go on the coding platform.
- Focus on mobile page harvesting, anti-crawl mechanism is usually more lenient

I'm sure you want to ask these.

Q: Is it illegal to use a proxy IP?
A: Just like a kitchen knife can cut vegetables can also hurt people, the technology itself is legitimate, the key to see what data is collected. It is recommended to comply with the website's robots agreement.

Q: How to judge the proxy IP quality?
A: Write your own detection script, or just use ipipgo'sReal-time Availability Kanban, they are automatically filtering available nodes every minute in the background.

Q: What should I do if my IP is blocked?
A: Switch proxies immediately and check if the request frequency is over the limit. It is recommended to buy ipipgo directly if you use it for a long timeAutomatic package change, the system will intelligently rotate the IP pool.

Why recommend ipipgo

theirResidential Agency PoolIndeed there are two brushes, measured capture success rate can go to 98% or more. The hardest thing is that there's aRequesting the masquerade functionThe first thing you need to do is to use a proxy that can disguise your crawler requests as normal user browsing behavior. Previously, there is a real estate monitoring customers, with ordinary proxy was blocked 30 times a day, changed to ipipgo after a week of continuous operation did not trigger protection.

Finally, a nagging word: data capture is a protracted war, rather than tossing their own IP blocked, it is better to find a reliable proxy service provider. After allTime is money., spending energy on data analysis is the right thing to do.