When making requests to sites protected by Cloudflare, you may encounter errors related to Cloudflare blocking automated requests. A common error message is "Cloudflare Ray ID:... Your IP may be blocked by Cloudflare...". This happens because Cloudflare tries to prevent DDoS attacks and abusive bots by detecting non-browser requests.
The good news is that we can solve this by explicitly enabling cookies in the Python Requests library. Here's what's happening and how to fix it.
Understanding Cloudflare Bot Protection
Cloudflare sits in front of many major sites and acts like a protective shield. One of its defenses is looking for visitors that don't act like real browsers.
Bots and scrapers typically don't handle cookies like a normal browser would. So Cloudflare sees the lack of cookies as a red flag. When Requests doesn't manage cookies by default, Cloudflare assumes it's an abusive bot and blocks it.
Enabling Cookies in Requests
Here is a simple snippet that enables cookie handling in Requests:
import requests
session = requests.Session()
session.cookies.set_policy(requests.cookies.DefaultCookiePolicy(strict_ns_domain=False))We create a Requests Session, which allows cookie persistence across requests.
Then we set the cookie policy to be more permissive on domain names by setting
With this Session, Requests will now send cookies, helping avoid Cloudflare errors.
Making Requests Through Cloudflare
We can now make requests through Cloudflare protected sites:
response = session.get("https://example.com")
print(response.text)The key points are:
This will populate and send cookies like a real browser, bypassing Cloudflare bot protections.
Debugging Other Cloudflare Issues
If you still get blocked by Cloudflare, here are some other things to try:
Cloudflare is constantly tweaking their bot detection rules, so you may need a combination of cookie handling, headers, delays, proxies and more.
Test iteratively until you find a set of evasion techniques that work. The key is mimicking a real browser enough to fly under Cloudflare's radar.
Caveats of Cloudflare Anti-Bot Bypasses
While it's possible to bypass Cloudflare protections, there are some downsides to consider:
Make sure you comply with site terms and scrape ethically. Build delays, proxies and other limits into your requests.
And realize that playing "cat and mouse" with Cloudflare's rules is prone to breakage down the road. There are no perfect, evergreen solutions when dealing with adaptive bot detection.
Key Takeaways for Handling Cloudflare Errors
To recap, here are the key points on solving Cloudflare errors with Python Requests:
With some cookie tweaking, your scraper may just have enough browser fingerprints to start working again! But it requires ongoing attention as Cloudflare evolves.
Hopefully this gives you a roadmap for dealing with frustrating Cloudflare blocks in Python scraping projects.