To cache, or not to cache? This is a question many programmers, data scientists, and web scrapers need to answer. In this chapter, we will show you how to use caching for your web crawlers; but should you use caching?

If you need to perform a large crawl, which may be interrupted due to an error or exception, caching can help by not forcing you to recrawl all the pages you might have already covered. Caching can also help you by allowing you to access those pages while offline (for your own data analysis or development purposes).

However, if having the most up-to-date and current information from the site is your highest priority, then caching might not make sense. In addition, if you don't plan large or repeated crawls, you might just want to scrape the page each time.

You may want to outline how often the pages you are scraping change or how often you should scrape new pages and clear the cache before implementing it; but first, let's learn how to use caching!