Web Scraping as the name implies is a technology that extracts data from websites. It is an automated process in which an application processes the HTML of a web page to extract data for processing, eg. It converts a web page to another format and then copies it to a local database or spreadsheet for later retrieval or analysis.
Many people know Selenium to be used for automation testing. However, Selenium has other use cases. An important use of Selenium is in web scraping. In this article, we will discuss whether you should be using Selenium for Web Scraping or other tools such as Beautiful Soup. Let’s begin by understanding the benefits and drawbacks of using Selenium for web scraping.
Benefits of Using Selenium for Web Scraping
However, web scraping is considered to be the most reliable and efficient data acquisition method among all these methods. Web scraping, also known as the extraction of web data, is an automated process of scraping big data from websites.
Drawbacks of using Selenium for Web Scraping
As much as there are advantages to using selenium for web scraping, there must be some drawbacks. Let’s see a few of these drawbacks below.
- A large network traffic generated: Web browsers download many supplementary files that are of no value to you (such as CSS, JS, and image files). If you only request resources you really need (with different HTTP requirements) this can generate a lot of traffic.
- Time and Resources Consumption: When you use WebDriver to scrape web pages you load the entire web browser into the system memory. Not only does this take time and consume system resources, but it can also cause your security subsystem to overreact (and even not allow your program to run).
- Slow Scraping Process: Since a browser waits for the entire web page to load, and only then allows you to access its elements, the scraping process can take longer than making a simple HTTP request to the webserver.
Types of Web Scraping with Selenium
There are two types of webscraping with Selenium:
- Static web scraping
- Dynamic web scraping
There is a difference between static websites and dynamic websites. In static pages, the content remains the same unless someone changes them manually. On the other hand, content can move from multiple visitors to dynamic websites. For example, it can be changed according to the user profile. This increases its time complexity as a dynamic website on the client side can process a static page on the server-side while on the client side.
The content of the static website is downloaded locally, and the corresponding scripts are used to collect the data. In contrast, dynamic website content is generated only for any number of requests during the initial load request. In order to delete the data on the website, Selenium provides some standard locators which help in locating the content of the test page. Locators are nothing more than keywords associated with HTML pages. For further details on why you should use or how to use selenium for web scraping, you can do yourself some good by getting certification on an online selenium training course to widen your horizon.
I hope this article is useful for making the right decision in your bid to use selenium as a web scraping tool.