Python Request Library: Advanced Usage of Requests

First, the proxy IP in the crawler in the actual combat tricks

When many brothers use Requests to do data collection, they often encounter theIP blockedof embarrassment. This is the time to proxy IP on the field! Here's a great trick to teach you:Dynamically switching agent poolsThe first is to change the skin to prevent being sniped. Just like playing the game to change the skin to prevent being sniped, we change a new IP every time we request. a real case: an e-commerce platform every 30 requests to seal IP, with ipipipgo's rotating agent, continuous collection of 3 hours did not trigger the seal.

The code is correct when written like this (note the proxy settings section):

import requests
from itertools import cycle

proxy_pool = cycle(ipipgo.get_proxies()) Here we call the ipipgo API to get the proxy pool.

for page in range(1,100): proxy = next(ipipgo.get_proxies())
    proxy = next(proxy_pool)
    try: response = requests.get()
        response = requests.get(
            'https://目标网站', proxies={"http": proxy, "https": proxy}, "https": proxy
            proxies={"http": proxy, "https": proxy},
            timeout=10
        )
        print(f "Page {page} captured successfully, using proxy: {proxy}")
    except.
        print("Current proxy failed, automatically switching to the next one")

Second, the golden combination of breakthrough anti-climbing validation

Nowadays, many websites not only block IPs, but also engage inhuman-computer verificationThis requires a proxy IP with request header masquerading. This is where proxy IPs are needed in conjunction with request header masquerading. Remember the three key points:

Special reminder: don't use transparent proxy! Some websites can detect the real IP. before helping customers to do recruitment data collection, with ipipgoDynamic Residential AgentsCombined with random UA, it perfectly bypasses the verification system of a certain hire.

Third, the correct posture of the API docking

Many newbies fall prey to proxy IPformat processingon. Using ipipgo's proxy as an example, their API returns the format ofip:port:username:password, remember to disassemble for use:

proxy_str = "192.168.1.1:8000:user123:pass456"
parts = proxy_str.split(':')
formatted_proxy = f "http://{parts[2]}:{parts[3]}@{parts[0]}:{parts[1]}"

Don't make cheap mistakes! I've seen people write their username and password directly into the code, and as a result, they have their hands full when changing proxies. It is recommended to put the authentication information in the environment variable, which is more secure and convenient.

IV. Exception Handling Book

Proxy with more will always encounter a variety of moths, these exceptions must be dealt with:

• ConnectionError: Proxy server not responding (possible IP failure)
• Timeout: It is more reasonable to set a timeout of 10 seconds
• ProxyError: Incorrect authentication information or mismatched proxy protocols

Recommendedretrying moduleImplement automatic retries:

from retrying import retry

@retry(stop_max_attempt_number=3)
def safe_request(url).
     Here's the code for the request with the proxy

V. QA Frequently Asked Questions

Q: What should I do if the proxy IP is invalid after using it?
A: It is recommended to use ipipgo's dynamic proxy service, their IP survival time is intelligently adjusted to automatically switch the failed node.

Q: What happened to the sudden slowdown of requests?
A: It may be that the current proxy line is congested, you can try:
1. Switching agents to other regions
2. Contact ipipgo technical support to adjust bandwidth
3. Check that the local network is working

Q: What should I do if I need to collect overseas websites?
A: ipipgo provides global 200+ countries and regions agents, remember to choose the export node of the corresponding region. But be careful to comply with the data collection policy of the target website.

VI. Optimization techniques for the press box

Finally, I'd like to share a couple of real-world experiences:
1. For high-frequency requestsSession objectmultiplex TCP connection
2. Establishment of reasonablemax_retriesparameters
3. Regularly clean the DNS cache (I've stepped in this pit)
4. Important items recommended for purchase by ipipgoExclusive Agent PackageStability upgrades of 60% or more

Remember, proxy IP is not a panacea, with a standardized crawler strategy. Last time a customer did not listen to advice, with ipipgo quality proxy but send 20 requests per second, the result is still blocked. Reasonable control of frequency is the king!