What to parse with: Selenium, BeautifulSoup or Scrapy?

Web scraping or parsing is a mechanism for gathering information from the Internet. Companies use it to get data to analyze the market and competitors. They make strategic decisions based on the information obtained.

Parsing software developers use Selenium, BeautifulSoup, and Scrapy. First of all, they differ in the tasks they solve: 

• Selenium. Helps to automate the browser. That is, it allows you to control it: for example, to click buttons, fill out forms and get page content. This is useful for creating scripts that parse data or test applications.

• BeautifulSoup. It is a library for parsing HTML and XML documents. It allows you to easily and conveniently pull information from pages such as titles, text, links and other elements. 
• Scrapy. It is a framework for creating parsers. It provides powerful tools for automating the collection of data from the Internet. Scrapy allows you to create scripts that can go to websites, collect information and save it for later analysis or use.

As you can see, all of them are suitable for parsing. So how to make a choice? Let's try to highlight the advantages and disadvantages of each library.

Benefits of Selenium

• Selenium does a great job of handling sites that use AJAX or PJAX requests. This means that you can easily work with pages that are dynamically updated without reloading. 
• Selenium allows you to handle JavaScript on pages. This is important because many modern applications use JavaScript to create user interfaces. With Selenium you can execute JavaScript code on pages, interact with elements, run scripts and test the behavior of your application in various scenarios.

Disadvantages of Selenium

• Selenium manages browsers in headless mode, which means that the browser runs in the background without displaying a window on the screen. This can consume more computer resources, especially if many instances of the browser are launched at the same time. 
• Due to the fact that Selenium requires significant resources to manage browsers, the efficiency of the program may decrease. This is especially true when performing a large number of tasks or launching many browser sessions in parallel.

Benefits of BeautifulSoup

• BeautifulSoup is known for its ease of use. This means that even programming novices can easily learn it and start using it for parsing. It can be used to quickly extract data from HTML and XML documents without in-depth knowledge of data development or analysis.
• BeautifulSoup gathers around it an active community of users and developers who are willing to help with troubleshooting and answering questions. This means that if you have difficulties using the library, you can turn to the community for help. The large knowledge base and experienced users make the process of learning and using BeautifulSoup more convenient and efficient.

Disadvantages of BeautifulSoup

• BeautifulSoup can be somewhat slower compared to other parsing libraries, especially when processing large amounts of data. This can be a problem in projects that require fast processing of large amounts of data, such as web scraping of large websites or high load applications.
• For some complex projects that require sophisticated data processing and manipulation, BeautifulSoup's functionality may not be sufficient. In such cases, you may need to use more powerful tools or combine several libraries to achieve the desired results.

Benefits of Scrapy

• Scrapy has the ability to process queries asynchronously, allowing you to efficiently manage large amounts of data and queries. With this feature, you can perform multiple tasks simultaneously, reducing the time required to collect information from the Internet. This is especially useful when you need to collect data from multiple websites or process large amounts of information.
• Scrapy provides convenient tools to extend its functionality according to the project requirements. You can easily customize and extend the framework's functionality by adding new features or modifying existing ones. This makes Scrapy a flexible web scraper development tool that can be customized to meet the specific needs of your project.

Disadvantages of Scrapy

• Some users may find Scrapy a bit more difficult to use because of its features and abstract approach. 
• Scrapy requires a browser without a graphical interface, which is different from the usual use of conventional browsers. This can cause some difficulties when getting started, but is usually solved quite easily with detailed instructions or tutorials.

Comparison of Selenium, BeautifulSoup and Scrapy

The choice between Selenium, BeautifulSoup and Scrapy depends on the project you're working on. Let's drill down from the side of three important parameters: performance, extensibility, and ecosystem. They will help you make a choice:

Productivity

• Selenium can be a bit slower due to browser management, which requires more resources.
• BeautifulSoup and Scrapy are usually faster, especially when processing large amounts of data.

Extensibility

• Scrapy offers more flexible extension and customization options.
• BeautifulSoup is good for simple tasks, but functionality is limited compared to Scrapy and Selenium.
• Selenium is also extensible, but requires more work to customize.

Ecosystem

• Scrapy has a rich ecosystem with many additional tools and libraries.
• BeautifulSoup and Selenium are also popular, but their ecosystems are less extensive.

To summarize. When to choose what to choose:

• Choose Scrapy for large and complex projects with large amounts of data.
• BeautifulSoup is ideal for small tasks where simple HTML parsing is required.
• Selenium is suitable for sites that use JavaScript or when you need to interact with elements on the page.

Each tool has its own strengths and weaknesses, and the choice depends on the project requirements.