Grab Zillow: A Guide to Capturing Home Price Trends

Why use a proxy IP to catch Zillow home prices?

Brothers who have engaged in data crawling know that the anti-climbing mechanism of real estate platforms such as Zillow is stricter than the cell gates. Ordinary users to check a few sets of listings is fine, but if you want to batch capture the trend of housing prices, minutes to your IP blacklist. This is the time to rely onProxy IP for guerrilla warfare--Change the IP address for each request to make the site think it's a different person checking the data.

To cite a real case: last year there was a friend who did overseas real estate analysis, used his own home broadband to catch 3 hours in a row, as a result, the next day found that the IP was permanently blocked, and even the normal look at the listings can not be. Later, he switched to a dynamic residential agent, and only then did he strip down half a year's worth of house price fluctuation data.

The Three Pitfalls of Choosing a Proxy IP

There are a plethora of proxy providers on the market, but none of the 90% are suitable for catching a hard case like Zillow:

Here's the kicker.Dynamic Residential AgentsThe addresses in this kind of IP pool are real home broadband and switch automatically with each request. Like the ipipgo service we use, there's aIntelligent Rotation ModelIt can automatically adjust the frequency of IP replacement according to the strength of website anti-climbing, and the success rate of catching Zillow can soar from 20% to more than 85%.

Hands-on configuration of proxy crawlers

Here's a demo in Python, remember to install the requests library first:

import requests
from itertools import cycle

 The format of the proxies provided by ipipgo
proxies_pool = [
    "http://用户:密码@gateway.ipipgo.com:20000",
    "http://用户:密码@gateway.ipipgo.com:20001", ...
    ... More Proxy Nodes
]
proxy_cycler = cycle(proxies_pool)

url = "https://www.zillow.com/homes/for_sale"

for page in range(1, 100): proxy = next(proxy_cycler)
    proxy = next(proxy_cycler)
    try: response = requests.get(url, proxies={"http")
        response = requests.get(url, proxies={"http": proxy}, timeout=10)
         Add parsing logic here...
    except Exception as e.
        print(f "Rollover with {proxy}, error message: {str(e)}")

Note two details:
1. Don't set the timeout too short, 8-15 seconds is recommended.
2. Mark the problem IP after each failure, ipipgo's background can automatically block the faulty node

Avoiding the tawdry maneuver of backcrawling

Zillow will now use these tactics to catch people:

• ▎ Mouse movement track detection (easy to hit with selenium)
• ▎ Page dwell time analysis (don't use a fixed delay, sleep randomly for 0.5-3 seconds)
• ▎ Request header characterization (remember to use ipipgo's request header camouflage feature)

Here's an evil trick: randomly insert it into the crawler.Common Search Terms for Real Estate AgentsFor example, keywords such as "3b2b" and "move-in ready", which are only used by real users, can effectively reduce the probability of being recognized.

The Data Cleaning Pit

The raw data captured is like a rough house, it has to be secondary processed:

 Handling house price unit conversions
def clean_price(text).
    if '10,000' in text: return float(text.replace('10,000',''))
        return float(text.replace('million','')) 10000
     Handling cases with dollar signs...

focus onHistorical Price CurveZillow will hide the price changes in a collapsed div, and it is recommended to use XPath with regular expressions to extract them.

Frequently Asked Questions QA

Q: Why is it still blocked after using a proxy?
A: 80% of the IP quality is not good, or the request frequency is too high. Change to ipipgoResidential Dynamic IP, set the request interval to 30 seconds or more.

Q: How many proxy IPs are needed to be enough?
A: According to our measured data, it takes about 50 IPs to rotate to catch 1000 listings. ipipgo's new user package has 100 IPs/day, which is completely enough for small to medium scale needs.

Q: How do I break the CAPTCHA when I encounter it?
A: Don't tough it out, stop the current IP request immediately. Turn on ipipgo backgroundAutomatic CAPTCHA Bypassfunction, the system will switch the high stash IP to try again.

Tell the truth.

Now a lot of tutorials teach people to use free proxies, that thing to catch the ordinary website is okay, Zillow is looking for abuse. Previously tested an open source proxy pool, 200 IP can be used in less than 5, low efficiency to doubt life. Then bite the bullet and go on the paid version of ipipgo, only to realize what is meant byLeave the professional work to the professional IPThe

Lastly, I would like to remind all of you that you need to be vigilant in capturing data, so don't crash other people's servers. Set a reasonable request frequency, with high-quality proxy, this is the way of sustainable data collection.