Python Data Crawling: From Beginner to Hands-on

Hands-on with Python to crawl data without blocking numbers

Recently, some e-commerce friends came to me to complain, saying that using Python to catch the price of competitors is always blocked IP, and they are anxious to jump straight to their feet. I'm familiar with this. Last year, when I did the public opinion monitoring system, the server was directly blacklisted by the target website because I didn't handle the proxy IP well.

Let's nag this proxy IP doorway today. Let's start with a counterintuitive one:It's not that just any free agent will solve the problemI'm not sure if I'm going to be able to do that. Nine out of ten of those public free IPs are leftovers from other people's use, not to mention the slow speed, and may even carry viruses.

import requests
from random import choice

 Here's an example of a proxies pool using ipipgo
proxies_pool = [
    {"http": "http://user:pass@123.45.67.89:30001"}, {"http": "http://user:pass@123.45.67.89:30001"}, {"http": "http://user:pass@123.45.67.89:30001"}, }
    {"http": "http://user:pass@123.45.67.90:30001"}, ...
     ... More proxy nodes provided by ipipgo
]

def safe_request(url).
    try.
        proxy = choice(proxies_pool)
        response = requests.get(url, proxies=proxy, timeout=5)
        return response.text
    except Exception as e.
        print(f "Crawl failed to switch proxies automatically: {e}")
        return safe_request(url) recursive retry

Why doesn't your crawler survive three episodes?

Many newbies tend to fall into these potholes:

I have used ipipgo's residential proxy to do testing before, the same collection task, the survival rate of dynamic IP is higher than the data center IP 40% more than. Especially when collecting certain e-commerce platforms with strict wind control, the residential agent can simulate the behavior of real users, and it is not easy to trigger the protection mechanism.

Real-world case: rob Maotai script remodeling record

Last year, I helped a friend to change a robocall script, the original version directly with local IP, just run up to be blocked. Later used ipipgo's dynamic short-lived IP program to reduce the capture frequency from 3 times per second to 1.5 times per second with these modifications:

 Required configuration to disguise the browser
headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36",
    "Accept-Language": "zh-CN,zh;q=0.9"
}

 Intelligent time delay module
import random, time

def smart_delay():
    base = 1.2 base interval
    jitter = random.uniform(-0.3, 0.8) random jitter
    time.sleep(max(0.8, base + jitter)) no less than 0.8 seconds

The changed version ran steadily for three months and didn't roll over until the end of the event. Here's a tip:Don't use proxies for all requestsThe use of a mix of local IPs and proxy IPs can effectively reduce costs.

QA Session: Common Pitfalls for Newbies

Q: Can't I use the free agent?
A: Not to say that you can't use it at all, but it's like using public restroom paper towels, which can be used for temporary emergencies, but it's still safe to use it for long-term use or to buy it from your own house. Like ipipgo this professional service provider, IP purity is guaranteed, but also with automatic replacement.

Q: Should I choose a residential agent or an engine room agent?
A: Look at the usage scenario. The residential agent is used for snatching seconds, and the server room agent is used for data collection in large quantities. ipipgo provides both types, and can also be billed by the minute, which is suitable for developers like us who are short of cash.

Q: How do I check if the proxy is in effect?
A: Teach you a dirt method: write a script to visit https://httpbin.org/ip continuously to see if the return IP is changing. ipipgo background also has real-time dosage monitoring, you can see the IP replacement situation.

Say something from the heart.

Proxy IP this thing, used well is a godsend, not good is a money-burning machine. Select service providers have to look at three points:Enough IP inventory, flexible replacement mechanism, technical support and timeliness. Like ipipgo I've been using it for a little over half a year, and the best thing about it is their smart routing feature, which automatically selects the fastest line and saves me a lot of work compared to switching manually.

Finally, I would like to remind you all: do data collection to speak of virtue, do not have a website to the death grip. Control the frequency of requests, don't be lazy where the delay should be added, after all, we just engage in data, not DDoS attacks, right?