Costco Price Tracker: Costco Price Monitoring

First, Costco chopping party essential: price monitoring in the end what is the use?

Every time you go to Costco it's like opening a blind box for fear of missing out on sale items? Did you buy a nut box last year that's now down $30? That's when you need a price tracker.Keeping an eye on commodity prices 24 hours a dayThe system automatically compares prices. Especially when it comes to Black Friday, Christmas this kind of promotion, the system automatically compare prices can save a lot of money.

But here comes the problem - Costco official website is very strict in checking frequently visited IP addresses, and ordinary scripts will be blocked if they run for half an hour. Last week, my neighbor Lao Wang used a crawler to grab data, and as a result, his home broadband IP was blocked, and now he can't even open the official website...

Second, anti-blocking tips: proxy IP so play the price monitoring

This is the place to move out.Proxy IP ComboNow, simply put, it makes the server think that access requests are coming from different regions and different devices. With ipipgo's residential proxy service, which automatically switches IP addresses for each request, the official website can't tell if it's a real person or a robot.

import requests
from itertools import cycle

proxies = ipipgo.get_proxies(type='residential') get dynamic residential IP pools
proxy_pool = cycle(proxies)

def check_price(item_url).
    for attempt in range(5).
        try: proxy = next(proxy_pool)
            proxy = next(proxy_pool)
            response = requests.get(item_url,
                proxies={"http": proxy, "https": proxy}, timeout=10)
                timeout=10)
             The code to parse the price data...
            break
        except Exception as e.
            print(f "Failed request {attempt+1}, switching IPs and retrying.")

Third, the three big pits of the proxy IP: 90% people are planted here.

Don't look at the many online tutorials, but in practice it's all thunder:

Fourth, hand in hand teaching: build their own price comparison system

1. Go to the ipipgo website to register to receive500MB free trafficSelect North American Residential Agent Package
2. Install Python's requests-html library (works better than BeautifulSoup)
3. Configure the middleware for automatic IP switching, and it is recommended that the number of failed retries be set to more than five.
4. Capture the data and store it in the database, then use Matplotlib to generate price fluctuation graphs.

V. Practical QA: the trouble you may encounter

Q: What is the appropriate monitoring frequency?
A: Fresh produce 3 times a day, daily necessities 1 time a day is enough, don't check stocks like refreshing every minute!

Q: What should I do if I encounter dynamic loading prices?
A: change to Selenium + proxy plugin, remember to open in ipipgo backgroundBrowser Fingerprint Disguisefunctionality

Q: How do I receive timely alerts about price reductions?
A: Use IFTTT to bind the email notification, the price falls below the set threshold automatically triggered, much more trouble-free than manually watching!

Six, why recommend ipipgo, these three points do not really have other families

1. Exclusive supportCostco warehouse-level positioningThe price difference between different outlets can also be caught
2. When encountering CAPTCHA automatically call the coding service, the success rate soared from 47% to 89%.
3. Traffic overloaded constantly service, automatic speed reduction to 1 request / minute, to avoid sudden interruption of the loss of data

The last time I used a service provider that started with L, the monitoring was interrupted at 3am causing me to miss the TV drop and I was so angry that I just uninstalled it. I switched to ipipgo and set it up.Disconnect and reconnect automatically, and never dropped a chain again for six months.