curl in Python: Examples of PycURL Applications

What the heck is PyCURL?

In human terms, it's the "Swiss Army Knife" of Python, handling network requests like the curl command. It's based on the libcurl library, which is great for people who need toHigh-performance web requestsThe scenarios. When messing with proxy IP rotation, for example, it's not a fraction of a second faster than the requests library.

For example, it may take 5 seconds to access 10 websites with normal libraries, PyCURL may do it in 2 seconds. Especially with our ipipgoExclusive access to a high-speed proxy poolThe effect is pulled straight through!

Hands-on PyCURL Installation

Don't let the installation scare you, it's really just a two-step process:

 Install the system dependencies first (Ubuntu example)
sudo apt-get install libcurl4-openssl-dev

 Then install it with pip
pip install pycurl

If you get an error about missing headers, you probably don't have the openssl package installed. Remember toLoad dependencies before loading packagesDon't get the order wrong!

Proxy IP configuration practice teaching

Here's the kicker! Three-step configuration with ipipgo's proxy service:

import pycurl

c = pycurl.Curl()
c.setopt(pycurl.URL, 'http://检测网址.com')
c.setopt(pycurl.PROXY, 'gateway.ipipgo.com') proxy server address
c.setopt(pycurl.PROXYPORT, 9021) service port
c.setopt(pycurl.PROXYUSERPWD, 'user:password') account password
c.perform()

Watch out for potholes:

How do real business scenarios play out?

Suppose to do price monitoring, you have to access the e-commerce site with different IPs:

from io import BytesIO
import random

 List of proxies for ipipgo
proxies = [
    's1.ipipgo.com:9010',
    's2.ipipgo.com:9012',
    's3.ipipgo.com:9015'
]

buffer = BytesIO()
c = pycurl.Curl()
c.setopt(pycurl.WRITEDATA, buffer)
c.setopt(pycurl.URL, "https://某电商网站.com")
c.setopt(pycurl.PROXY, random.choice(proxies))
c.setopt(pycurl.SSL_VERIFYPEER, 0) skip SSL verification

try.
    c.perform()
    print(buffer.getvalue().decode('utf-8'))
except pycurl.error as e:: print(f "f")
    print(f "Crawl failed, error code: {e.args[0]}")

Use a random proxy to avoid being blocked, and remember to pair it with ipipgo'sAutomatic IP changefunction with a new IP for each request.

Guidelines on demining of common problems

Q: Why does it return garbled code?
A: add this line to set the encoding: c.setopt(pycurl.ENCODING, 'gzip,deflate')

Q: Proxy authentication always fails?
A: Check the account password format, must be user:passwd string, do not use Chinese symbols

Q: How can I increase my download speed?
A: Open in the ipipgo consolehigh speed channelwhile setting: c.setopt(pycurl.LOW_SPEED_LIMIT, 102400) Speed limit 100KB/s

Performance Optimization Tips

1. Reuse Curl objects: don't be silly and create new objects every time!
2. Enable connection pooling: c.setopt(pycurl.MAXCONNECTS, 5)
3. Enable DNS caching: c.setopt(pycurl.DNS_CACHE_TIMEOUT, 300)
4. with ipipgoLong-lasting static proxiesReduction in the number of certifications

Finally, to be honest, although PyCURL has great performance, the learning curve is a bit steep. If you mainly use proxy IP to do business, directly on the ipipgo SDK is more economical, their new intelligent routing function is really fragrant, automatically select the fastest node not to mention, but also can automatically retry failed requests.