Pythoncurl Requests: A Guide to Using the PycURL Library

I. What the heck is PycURL?

There are a lot of python libraries for network requests, why do you have to use pycurl, which is actually a python binding for the curl command, and it's not half as fast as the requests library. Especially if you need to handle large file transfers or high concurrency scenarios, using it can save a lot of server resources.

We do data collection brothers understand that the use of proxy ip is just needed. For example, with ipipgo's proxy service, with pycurl this magic weapon, can easily bypass the anti-climbing mechanism. The following code is the most basic use:

import pycurl
from io import BytesIO

buffer = BytesIO()
c = pycurl.Curl()
c.setopt(c.URL, 'http://example.com')
c.setopt(c.WRITEDATA, buffer)
c.perform()
c.close()

Secondly, you have to avoid those pits in the installation library

Installing pycurl is notpip installIt's done. A lot of newbies get stuck in this step, and the error messages can be confusing. Here's a tip: install the libcurl development library first, then install pycurl. different systems have different commands, so I'll organize a table for you:

Install the dependency and run it againpip install pycurl, remember to add compilation parameters:PYCURL_SSL_LIBRARY=openssl pip install pycurl, which avoids the pitfalls of SSL certificate validation.

Third, the correct way to open the proxy IP

Here's the kicker! Using ipipgo's proxy service, setting up a proxy in pycurl is actually extraordinarily simple. The key is to understand these parameters:

c = pycurl.Curl()
c.setopt(pycurl.PROXY, 'proxy.ipipgo.com:9021') here fill in the address provided by ipipgo
c.setopt(pycurl.PROXYUSERPWD, 'username:password') account authentication information
c.setopt(pycurl.PROXYTYPE, pycurl.PROXYTYPE_HTTP) Adjust according to proxy type

There's an easy place to roll over--timeout setting. It is recommended to match it this way:

• Connection timeout:c.setopt(pycurl.CONNECTTIMEOUT, 30)
• Request timeout:c.setopt(pycurl.TIMEOUT, 120)

Fourth, the actual combat case: automatic IP acquisition

Combined with ipipgo's API for automatic proxy switching, this is the real deal. For example, to cycle through 10 pages to collect:

import json
from ipipgo_client import get_proxy Assume this is the SDK for ipipgo_.

for page in range(10): proxy = get_proxy(type='http')
    proxy = get_proxy(type='http') Get a new proxy every time.
    c = pycurl.Curl()
    c.setopt(pycurl.PROXY, f"{proxy['ip']}:{proxy['port']}")
     Other request configurations...
    try.
        c.perform()
    except pycurl.error as e.
        print(f "The {page}th request rolled over: {e}")

V. Three axes of performance optimization

1. connection reuse: Don't be a fool and create a new connection every time, use thec.setopt(pycurl.FORBID_REUSE, False)Enabling Connection Pooling

2. DNS caching: plusc.setopt(pycurl.DNS_CACHE_TIMEOUT, 300)It saves a lot of searching time

3. compressed transmission: Settingsc.setopt(pycurl.ACCEPT_ENCODING, 'gzip')Reduced traffic consumption