Webスクレイピングとは

Price comparison tools and news aggregators pull their data through web scraping. Let’s see what it is, why it’s used, and how to do it responsibly.

Web scraping is automating data extraction from websites. Instead of copy-pasting by hand, a program gathers public info and saves it for analysis.

Scraping is four steps: request a page, receive its HTML, parse out the data you want, then store it in a structured format. We’ll go deep on each.

People scrape for real work: price comparison, market and competitor research, news aggregation, and lead generation. The use cases are everywhere.

Don’t mix these up: crawling discovers pages by following links; scraping extracts specific data from pages you already know. Find vs. read.

Public data isn’t a free-for-all. Scraping is powerful, so weigh the ethical and legal side before you write a single line.

Respect the sites you hit: check robots.txt for allowed paths, and read the Terms of Service — many forbid scraping outright.

Fire too many fast requests and you can overload a server. Be polite: add rate limiting — a delay between requests — so you don’t cause harm.

Scraping law is complex and regional. Watch copyright, data ownership, and privacy rules — especially with personal info. Stay compliant.

Let's test your understanding of web scraping fundamentals!

Nice start! You’ve got what scraping is, the request-parse-store flow, scraping vs. crawling, and why ethics and legality come first. Next up: HTTP.