Avoiding being blocked while scraping websites like Zillow is critical since it involves navigating around measures that are put in place to protect the website's data and ensure fair use of its services. It is important to note that web scraping can be against the terms of service of some websites, and in some jurisdictions, it may have legal implications. Always read and comply with the website's terms of service and legal requirements before scraping its contents.
Here are some strategies to minimize the risk of being blocked when scraping Zillow or similar websites:
1. Respect robots.txt
Check Zillow's robots.txt file (usually found at http://www.zillow.com/robots.txt) to see which paths are disallowed for web crawlers. Respect these rules to avoid legal issues and potential blocking.
2. Use Headers
Make your requests look like they are coming from a browser by adding headers, particularly the User-Agent.
import requests
headers = {
'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.3'
}
response = requests.get('https://www.zillow.com/', headers=headers)
3. Limit Request Rate
Send requests at a human-like interval. Do not bombard the server with a large number of requests in a short period.
import time
# Make a request approximately every 10 seconds
while True:
response = requests.get('https://www.zillow.com/', headers=headers)
# Process the response here
time.sleep(10)
4. Use Proxies
Rotate through different IP addresses using proxy services to avoid IP bans.
import requests
proxies = {
'http': 'http://10.10.1.10:3128',
'https': 'http://10.10.1.10:1080',
}
response = requests.get('https://www.zillow.com/', headers=headers, proxies=proxies)
5. Use Session Objects
Maintain a session to reuse TCP connections and cookies, which can make your scraper look more like a regular user.
session = requests.Session()
session.headers.update(headers)
response = session.get('https://www.zillow.com/')
6. Handle Exceptions and Status Codes
Detect blocks and handle them appropriately, such as backing off for a while or changing IP addresses.
response = requests.get('https://www.zillow.com/', headers=headers)
if response.status_code == 429:
# Handle rate limiting
time.sleep(60)
elif response.status_code == 403:
# Handle block
# Possibly change IP or stop scraping
pass
7. Use CAPTCHA Solving Services
If CAPTCHAs are encountered, you can use CAPTCHA solving services, though it can be ethically and legally contentious.
8. Use a Headless Browser
Sometimes scraping with a headless browser like Selenium can help bypass certain JavaScript-based protections.
from selenium import webdriver
options = webdriver.ChromeOptions()
options.add_argument('--user-agent=Your User Agent Here')
driver = webdriver.Chrome(chrome_options=options)
driver.get('https://www.zillow.com/')
9. Be Ethical
- Do not scrape personal data without consent.
- Do not disrupt Zillow's services or scrape at a scale that negatively impacts the website.
Legal and Ethical Considerations
Remember that scraping websites like Zillow may violate their terms of service. Zillow, in particular, is known for taking legal action against unauthorized scraping of their data. Always seek legal advice before engaging in web scraping and strive to maintain ethical standards in your data collection practices.
Lastly, consider reaching out to Zillow for official access to their data. They might have an API or other data solutions that could meet your needs while staying within the bounds of their terms of service.
