Web Crawler Definition: Web Crawler Techniques Explained Manual

What the hell is a web crawler?

To put it bluntly, a web crawler is like a 24-hour electronic scavenger. It will slip back and forth between various websites, and put all the content it sees into its own pocket. To give a grounded example, you brush a certain treasure every day to see the price comparison of goods, behind the reptile brother in the silent work.

However, nowadays, websites have learned to block IP addresses without moving. It's like when you go to the market to buy food, and the stallholder remembers your face and stops selling you. That's when you need toproxy IPIt serves as a "face mask" so that the crawler can continue to move bricks happily.

The real-world survival rules for proxy IPs

There are three main schools of proxy IPs on the market:
1. Dynamic residential IP: each visit to change a new vest, suitable for general data collection
2. Static residential IP: Fixed identity is good for operations that require login
3. Data center IPs: mass-produced in the server room, suitable for simple and rough jobs

This is a must.ipipgoThe proxy service of the family, they have a masterpiece called "IP rotation". For example, using their API to extract the IP, crawling data automatically switch identity, more skillful than the Monkey King's seventy-two changes:

import requests

proxy = "http://用户名:密码@gateway.ipipgo.com:端口"
url = "https://目标网站.com"

response = requests.get(url, proxies={"http": proxy, "https": proxy})
print(response.text)

Guide to avoiding pitfalls: five common mistakes made by novices

1. Don't be greedy, you'll suffer big losses.9 out of 10 free proxies are pits, if the data is not allowed, the account will be blocked.
2. Failure to look at the usage agreement: Some sites ban crawlers, don't wait for a lawsuit before you regret it!
3. IP switching too oftenOne second for 100 IPs is the same as holding up a sign that says, "I'm a robot."
4. Ignore request intervals: Suggests a randomized 3-8 second delay to mimic a real person's operation
5. Dead on one site: Don't Catch a Sheep, Diversify Risk with Multiple Targets

ipipgo's one-of-a-kind tips

There are four great tips for this agency's services:
- Real-life residential IPs in 200+ countries worldwide (not mass-produced in server rooms)
- Support HTTP/HTTPS/Socks5 three protocol modes
- Offers a foolproof client that works in two clicks
- Customizable and exclusive programs, pay-as-you-go with no waste

Practical QA triple question

Q: What should I do if my proxy IP is slow?
A: Priority is given to nodes that are geographically close. ipipgo's client comes with a delay test function, so it is recommended that you use this function to sift through a wave first.

Q: How do I know if the proxy is in effect?
A: Visit https://ip.ipipgo.com this inspection page to see the real export IP currently in use.

Q: What should I choose between dynamic and static proxies?
A: You need to log in to the website to choose static, simply collect data with dynamic. Can't decide can directly find ipipgo customer service, they support 1 to 1 program customization.

Finally, to do crawlers to pay attention to "theft has its own way". Don't stare at other people's websites to crawl to death, set a reasonable request frequency, not only is the respect for others, but also can make their own business to go a long way. After all, no one likes to be harassed by crawlers every day, right?