Real Estate Data Acquisition: Zillow Listings Crawling and Cleaning in Action

Why does Zillow Crawler have to use proxy IPs?

Brothers engaged in real estate data collection know that the Zillow platform is like a hedgehog - data fat but covered with thorns. Last week, I personally saw my colleague Zhang's server IP was blacked out, and more than 200 crawler threads were all down. The key point isZillow's Anti-Crawl Mechanism Is Tougher Than Subway SecurityThe general IP will be directly shut down for more than 20 consecutive visits.

That's when you have to rely on proxy IPs to play dress-up games. Take our ownipipgoFor dynamic residential IPs, each request is like a new vest, and the site can't tell if it's a live person or a machine. Especially when doing interstate listing comparisons, residential IPs in different regions can directly get hidden discounts on local prices, which is much more realistic than using data center IPs.

Choosing a proxy IP is deeper than you think.

Proxy IP on the market is a mixed bag, I have stepped in enough pits to write a textbook. Let's start with three hard indicators:

Special reminder: don't use shared IP pools for cheap, last time I used the shared IP of a certain family, the result was to climb to the house price data mixed with Canadian currency units, cleaning data almost to the collapse of the wash.Exclusive access to ipipgoIn this piece is really stable, each crawler task is assigned independent IP segments, the data contamination rate is directly reduced by seventy percent.

Hands-On Crawler System

Let's start with the real-world configuration scenario (Python example):

import requests
from itertools import cycle

ip_pool = ipipgo.get_proxy_pool(type='residential', region='auto')
proxies = cycle(ip_pool)

def fetch_listing(url).
    try.
        proxy = next(proxies)
        resp = requests.get(url, proxies={"http": proxy, "https")
                          proxies={"http": proxy, "https": proxy},
                          headers=generate_random_header(), timeout=8)
                          timeout=8)
        return resp.json()
    except Exception as e.
        ipipgo.report_failed(proxy) automatically rejects failed IPs
        return fetch_listing(url)

There are just three key tips:Randomized request header + automatic IP switching + timeout fusionThis detail can increase the success rate of the request by more than 40%. Remember to add "Referer": "https://www.zillow.com/" in the headers to disguise the source, this detail can make the success rate of the request more than 40%.

Data cleansing pits one deeper than the other

Crawling down the data is like an untreated rough house that has to be renovated. Common moths include:

• House price display "$1″ - in fact, JS dynamic loading failure
• Household information is hidden in the pictures
• Historical transaction history paged over 100 pages

It's time to use theOutlier Filtering + Multi-Source Verification. For example, for the floor space field, use a regular expression to match the number + sq ft format, and then compare the public records for COUNTY. Recommended to use ipipgo'sStatic Residential IPto do the checksum request and avoid triggering CAPTCHA.

Frequently Asked Questions QA

Q: What should I do if I always get my IP blocked?
A: Check three points: 1. whether the transparent proxy is used (must be highly anonymous) 2. whether the request frequency is >3 times/second 3. whether it is accessed with cookies. It is recommended to use ipipgo's automatic rotation mode and set a random delay of 5-7 seconds.

Q: I need to crawl historical transaction data how to get it?
A: Go Zillow's API reverse engineering, with residential IP to do distributed requests. Note to simulate the mouse movement trajectory, this is more stable with Selenium + ipipgo's browser integration solution.

Q: How do I break the CAPTCHA when I encounter it?
A: Immediately switch IP and reduce the frequency, recommended on the ipipgoCAPTCHA Retry MechanismIt automatically redirects the request that triggered the CAPTCHA to the manual coding channel, which saves more effort than the hard CAPTCHA recognition.

To be perfectly honest, in the business of real estate data collection.Residential agent for ipipgoIt is indeed my life preserver. The last time I helped a customer to capture the Los Angeles school district housing data, with a dynamic IP pool for 72 hours without turning over, the data integrity rate directly dry to 98.3%. This thing is the same as the fire of the fried dishes, mastered well can really come out of the hard dishes.