5-Essential-Skills-For-Web-Crawling

Here are 5 essential skills when it comes to Web crawling that any programmer needs:

1. Knowledge of web crawling frameworks like Scrapy, Puppeteer, or Goutte

Coding from scratch on your own can only take you so far. You will find that the frameworks can abstract out the complexities of building a spider, making concurrent connections, using selectors for scraping, working with files, infinite pages, etc. quite easily.

2. Understanding of the basics of CSS selectors or XPath

Heavy JQuery users will graduate right away into CSS selectors. XPath, if you are really serious about finding whatever data you want to be able to scrape.

3. Understand how to speed up crawling by run multiple spiders by setting the appropriate concurrency and also running daemons like Scrapyd

Coding a stable scrape that can get you the data is just the first step. You want to make sure the footprint of the amount of time taken in crawling for data is reduced to as small a footprint as possible for the rest of the system to do its thing. So once the code is working, the process of multiplying its speed begins.

4. Learn how to pretend to be a human when writing a bot

This article explains all the nuances you need to know to stop showing some obvious ‘tells’ that web servers are picking up from your scraper.

5. Overcome IP blocks by working with Rotating Proxies like Proxies API.

The hard reality of web crawling is no matter what measures you take, and you always run the risk of an IP block because you can only toggle so many IPs and so many servers. A carefully selected rotating proxy service is super essential in any web crawling machinery.

The author is the founder of Proxies API, a proxy rotation API service.