Python Web Crawl Scripts: Automated Capture Templates

A. Why is your crawler always blocked? Try this method

Friends who engage in website crawling understand that the biggest headache is the target site anti-climbing mechanism. A lot of new hands on the fierce dislike of requests library, the results did not catch a few pages of IP will be sealed to death. Here to teach you a trick:Use proxy IPs to rotate, it's like fighting a guerrilla war so that the server can't tell if you're a real person or a machine.

Second, the hand to teach you to install Python grab toolkit

Prepare these guys and gals first (remember to install the latest version):

pip install requests
pip install bs4
pip install fake-useragent

Focus on fake-useragent library, it can fake the browser logo, with proxy IP to use the best results. It's like going to a masquerade party, where you have to wear a mask and change your clothes so you won't be recognized.

Third, the proxy IP real code template (copy homework special)

Here's an example of ipipgo's service, their API is designed to be very user-friendly, and picking up an IP is as easy as buying a drink from a vending machine:

import requests
from fake_useragent import UserAgent

def get_ipipgo_proxy(): api_url =
    api_url = "https://api.ipipgo.com/get?format=json"
    resp = requests.get(api_url).json()
    return f "http://{resp['proxy']}"

headers = {'User-Agent': UserAgent().random}
proxies = {'http': get_ipipgo_proxy()}

try.
    response = requests.get('Target URL',
                          headers=headers,
                          proxies=proxies,
                          timeout=10)
    print(response.text)
except Exception as e.
    print(f "Crawl failed, change IP and fight again: {str(e)}")

Watch that timeout setting, give up if it's more than 10 seconds, don't hang on to a tree.

IV. Five guidelines for avoiding pitfalls (summary of lessons learned through blood and tears)

1. IP switching frequency:Don't be too diligent or too lazy, it is recommended to change the IP every 5-10 pages.
2. Request intervals:Add a random delay, using time.sleep(random.uniform(1,3))
3. Exception handling:Change IP immediately when encountering 4xx/5xx errors
4. Quality testing:Get the IP and test for availability before you start working.
5. Protocol matching:Don't confuse http and https, see what protocols are used on the right site!

V. Practical scenarios: e-commerce price monitoring cases

To give a real example, a friend who does price comparison used ipipgo's residential agent to successfully bypass the anti-climbing of an e-commerce platform. Key configuration parameters:

 Focused Parameter Setting
proxies = {
    'http': 'http://用户名:密码@gateway.ipipgo.com:端口',
    'https': 'http://用户名:密码@gateway.ipipgo.com:端口'
}

Their team now crawls 500,000 pieces of data stably every day, and the IP survival rate can keep more than 90%.

VI. Frequently Asked Questions QA

Q: What should I do if I use a proxy IP and still get blocked?
A: Check if the request header changes randomly, and also suggest upgrading to ipipgo's dynamic residential proxy package

Q: Do free proxies work?
A: Newbies can test the waters, but serious projects or recommended ipipgo paid services, the stability of the difference between the ten street!

Q: Do I need to maintain my own IP pool?
A: If you use ipipgo, you don't have to, their API will automatically filter invalid IPs, it's much more worry-free than maintaining it yourself.

Q: How do I break the CAPTCHA when I encounter it?
A: Appropriately reduce the crawl frequency, with ipipgo's high stash of proxies + request header randomization, can reduce 90% CAPTCHA

Why do you recommend ipipgo?

Having empirically compared seven or eight service providers on the market, ipipgo has three hardcore advantages:
1. Response speed ≤ 0.8 seconds (1.5 seconds + common elsewhere)
2. Support for pay-per-use, how much is used?
3. Exclusive failure retry compensation mechanism
Especially their intelligent routing function, can automatically select the fastest node, this is to improve the collection efficiency help thief.

Finally, do data collection is like a cat and mouse game, don't think of one method to eat everything. More testing of different strategies, the proxy IP, request header camouflage, frequency of access to the combination of these means, in order to long-term stable operation. What do not understand can go directly to the official website of ipipgo technical customer service, they are online 24 hours a day, more useful than watching tutorials.