Web Crawling with Beautifulsoup4: Latest Library Tutorials

Hands on teaching you to use BS4 to catch data without blocking the number

What are you most afraid of when you are doing the crawler, IP being blocked is definitely in the top three! Today, let's talk about how to use Beautifulsoup4 (later referred to as BS4) to grab data with theipipgoIf you want to protect your IP with a proxy service from your home country, don't do all that nonsense, just get to the real stuff.

Don't step on potholes by preparing the environment

Install these essential libraries first:

pip install beautifulsoup4 requests fake-useragent

Be careful not to use too old requests version, it is recommended to use 2.28 or above. If you encounter installation errors, try adding the Tsinghua mirror source:

pip install -i https://pypi.tuna.tsinghua.edu.cn/simple package name

A crash course in basic BS4 usage

Give an example of catching e-commerce prices:

from bs4 import BeautifulSoup
import requests

headers = {'User-Agent': 'Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36'}
url = 'http://example.com/product'

response = requests.get(url, headers=headers)
soup = BeautifulSoup(response.text, 'lxml')
price = soup.select_one('.product-price').text.strip()

There are three key points here:

• User-Agent MasqueradeIt must be done. Straight to bare bones will be blocked.
• The parser is recommended to use lxml, which is three times faster than html.parser
• select_one is better than find and supports CSS selector syntax.

Proxy IP real-world access

Single IP hard dislike sooner or later finished, here to teach you how to take itipipgoof the agent pool:

proxies = {
    'http': 'http://用户名:密码@gateway.ipipgo.com:9020',
    'https': 'http://用户名:密码@gateway.ipipgo.com:9020'
}

try.
    response = requests.get(url, headers=headers, proxies=proxies, timeout=8)
except requests.exceptions.ProxyError: print("Proxy Exception", "Proxies", "Proxies", "Proxies")
    print("Proxy exception, automatically switching to new IP...")
     Here you can access the ipipgo API to change the IP automatically

Note when using ipipgo's exclusive proxy:

A Guide to Avoiding Pitfalls in Real Projects

I recently learned these lessons while helping a client catch a certain price comparison site:

1. Randomly sleep 1-3 seconds per request, don't use a fixed interval
2. Immediately switch to a new node in ipipgo when encountering a captcha
3. Important data with xpath to do a second check, to prevent the page structure changes

Frequently Asked Questions QA

Q: What should I do if the proxy IP is suddenly unavailable?
A：Check the error type in the "Connection Log" in the background of ipipgo, if the error is 407, it means that the authentication information is wrong, and if it is 403, it is recommended to switch the data center node.

Q: How can I optimize for slow crawling?
A: Put ipipgo's multiple proxy IPs into the queue and use asynchronous request libraries (such as aiohttp) to process them concurrently, which is measured to speed up 5-8 times.

Q: What should I do if I encounter Cloudflare protection?
A: This situation requires: 1. replace the high stash proxy 2. add the browser fingerprint header 3. go ipipgo's overseas residential IP pool. Three strokes can basically break.

Finally, a piece of advice: do not try to cheap with free agents, light loss of data, heavy anti-climbing mark. Although it costs money to use ipipgo's enterprise-level proxy, it is better than the other free proxies.High success rate of requests,IP pools are updated quickly, especially suitable for scenarios that require long-term stable data capture. New users remember to get 3G of experience traffic, enough for testing.