Autor:Codenga10.07.2024

What is Web Scraping?

Web Scraping is a technique for automatically collecting data from the internet. Sometimes it is referred to as Data Scraping, which means roughly the same thing.

In practice, it involves using special programs that search the content of websites and extract the data we are interested in. This data is then automatically saved to a database or spreadsheet.

What is web scraping used for?

This technique is used to analyze data collected from various sources. Here are some example applications:

• Online stores use scraping to monitor product prices at competitors.
• Companies developing AI mechanisms often collect large amounts of data needed to train models.
• Content aggregation portals automatically gather content from various websites.
• Companies frequently use scraping to gather profiles of potential job candidates.
• Companies involved in building a brand image use scraping to monitor any mentions or opinions about a given brand.

When used ethically and legally, web scraping can be a powerful tool for gathering information.

Is web scraping legal?

The legality of this practice is complex and varies by country.

It's important to pay attention to the following aspects:

• Most websites have their terms of service, which often explicitly prohibit automatic data collection. Violating this ban can have legal consequences.
• Content protected by copyright usually requires the owner's permission.
• Collecting personal data may violate privacy regulations, such as GDPR in the European Union.

As you can see, the topic is complex. Fully legal scraping requires considering these factors.

How does web scraping work - basic steps

The web scraping technique can be described in a few simple steps:

1. Choose the website from which you want to collect data.
2. Use an appropriate tool to send a request to the site and retrieve its HTML code.
3. Analyze the HTML code and find the data that interests you (e.g., product prices or user profiles).
4. Use an appropriate tool to extract this data from the code.
5. Save the data to a database.

In practice, you need certain tools, which we will discuss shortly.

Tools for web scraping

Web scraping is a programming technique - you usually need to write a simple program that extracts data from a website. The table below shows solutions for several popular languages.

These are just selected examples - many popular languages have dedicated libraries for scraping.

How to defend against scraping?

On one hand, sometimes we want to retrieve data from other websites. On the other hand, we often want to protect our own site from automatic content retrieval. Here, a conflict of interest arises.

If you want to take steps to limit the possibility of scraping, consider the following solutions:

• CAPTCHA - a tool that protects forms against bots and other automatic tools.
• Blocking IP addresses that send too many requests to your site.
• Restricting access to content, so only logged-in users can access it.
• Clearly stating the rules in the site's terms of service. Explicitly prohibit scraping and be able to take legal action against those who break this rule.
• Monitoring site traffic and using tools that block suspicious behavior.

In practice, such protections are a combination of legal and technical elements. Completely blocking scraping can be very difficult - it is worth considering whether it is worth the additional effort and cost.

Summary

Web scraping is a technique for automatically collecting data from the internet using special programs. The legality of scraping is complex and depends on legal regulations and the terms of use of websites. To protect your site from scraping, you can apply various technical and legal safeguards, although completely eliminating scraping can be difficult and costly.